For biologic agents, few biomarkers of exposure or dose have been identified, and their validity for exposure assessment in the indoor environment is often unknown. Testing to determine the presence of immunoglobulin E (IgE) to specific fungi might be a useful component of a complete clinical evaluation in the diagnosis of illnesses (e.g., rhinitis and asthma) that can be caused by immediate hypersensitivity (17,24). Testing is usually done by in vitro tests for serum specific IgE, or by skin prick or puncture tests. Detection of immunoglobulin G (IgG) to specific fungi has been used as a marker of exposure to agents that might cause illnesses such as hypersensitivity pneumonitis (17,24). However, the ubiquitous nature of many fungi and the lack of specificity of fungal antigens limit the usefulness of these types of tests in evaluating possible building-related illness and fungal exposure (17,24). Specific serologic tests (e.g., tests for cryptococcal antigen, coccidioidal antibody, and Histoplasma antigen) are useful in the diagnosis of some fungal infections, but these are the exception. The routine clinical use of immunoassays as a primary means of assessing environmental fungal exposure or health effects related to fungal exposure is not recommended. Health-care providers whose patients express concern about the relation between symptoms and possible exposure to fungi are advised to use immunoassay results with care and only in combination with other clinical information, including history, physical findings, and other laboratory results (24).
In recent years, increased concern has arisen about exposure to specific molds that produce substances called mycotoxins. Health effects related to mycotoxins are generally related to ingestion of large quantities of fungal-contaminated material (17). No conclusive evidence exists of a link between indoor exposure to airborne mycotoxin and human illness (6,25). Many molds can potentially produce toxins given the right conditions (6,11,17). Some molds that produce mycotoxins are commonly found in moisture-damaged buildings; research related to the importance of these findings is ongoing. Although the potential for health problems is an important reason to prevent or minimize indoor mold growth and to remediate any indoor mold contamination, evidence is inadequate to support recommendations for greater urgency of remediation in cases where mycotoxin-producing fungi have been isolated.
The interpretation of environmental sampling data generally requires professional judgment, and medical conclusions cannot be made based solely on the results of analysis of environmental sampling. In the context of mold growth following a major hurricane or flood, mold growth itself and the extent of growth based on a thorough visual inspection is sufficient to categorize a building as moldy or not moldy. This should provide sufficient information for action and no additional characterization is needed.
Clean-up and Prevention
The most effective way to eliminate mold growth is to remove it from materials that can be cleaned and to discard materials that cannot be cleaned or are physically damaged beyond use (9,18,19,26--30). Persons with respiratory conditions, allergies, asthma, or weakened immune systems should avoid mold cleanup if possible or seek the advice of their doctor and determine what type of personal protective equipment is appropriate. Appropriate PPE (e.g., tight-fitting NIOSH-approved N-95 respirator, gloves to limit contact of mold and cleaning solutions with skin, and goggles) (13,26--30) should be used when performing clean-up or other activities in mold-contaminated homes or buildings after a flood.
Removing mold problems requires a series of actions (6,9,16). The order of these actions is sometimes important (6), but might vary on a case-by-case basis. Typically, the following actions are taken regardless of whether a problem is small and simple or large and complex:
Take emergency action to stop water intrusion, if needed.
Determine the extent of water damage and mold contamination.
Plan and implement remediation activities.
--- If needed, establish containment and protection for workers and occupants.
--- Eliminate or limit water or moisture sources.
--- Decontaminate or remove damaged materials, as appropriate.
--- Dry any wet materials, if possible.
--- Evaluate whether space has been successfully remediated.
--- Reassemble the space to prevent or limit possibility of recurrence by controlling sources of moisture.
For small, simple problems, the entire list of tasks can be done by one person. Large, complex problems might require many persons from different professions and trades. For circumstances that fall between those extremes, some combination of occupant action and professional intervention will be appropriate. In general, no single discipline brings together all the required knowledge for successful assessment and remediation.
Returning to Mold-Contaminated Homes or Buildings After a Flood
When persons return to homes or buildings after a flood, they should take the following steps (6,9,16,26--30):
Clean up and dry out the building quickly. Open doors and windows and use fans or dehumidifiers to dry out the building.
Remove all porous items that have been wet for >48 hours and that cannot be thoroughly cleaned and dried. These items can remain a source of mold growth and should be removed from the home or building. Porous, noncleanable items include carpeting and carpet padding, upholstery, wallpaper, drywall, ceiling tiles, insulation material, some clothing, leather, paper, some wood and wood products, and food. Removal and cleaning are important because even dead mold can cause allergic reactions.
Clean wet items and surfaces with detergent and water to prevent mold growth.
Temporarily store damaged or discarded items outside the home or building until insurance claims can be processed.
Removing and Cleaning Up Mold in a Building
For cleaning mold covering <10 square feet in an area flooded by clean water, detergent and water might be adequate (9,16). However after hurricanes and major floods, flood water is likely to be contaminated and, in this setting, mold can be removed with a bleach solution of 1 cup chlorine bleach per 1 gallon of water (26--30). Never mix bleach or bleach-containing products with ammonia or ammonia-containing products. If water damage is substantial or mold growth covers >10 square feet, consult the EPA guide, Mold Remediation in Schools and Commercial Buildings (15).
Some companies specialize in water damage restoration and can assess the issues involved in cleaning up homes after a flood. Two professional trade groups that might be able to help locate such an expert are the Association of Specialists in Cleaning and Restoration (http://www.ascr.org/) and the Institute of Inspection, Cleaning, and Restoration Certification (http://www.iicrc.org/).
Contractors used for remediation should have experience in cleaning mold. Check references and ask the contractor to follow the recommendations in the guidelines of the American Conference of Governmental Industrial Hygienists (ACGIH) or other guidelines from professional organizations or state agencies. Contact your state health department's website for information about state licensing requirements for contractors in your state. Examples of websites from states that have recently dealt with natural disasters include http://www.tdh.state.tx.us/beh/mold (Texas) and http://www.lslbc.louisiana.gov/ (Louisiana).
Cleaning Clothes, Textiles, or Stuffed Animals
Ensure that laundry is washed in safe water. Use only water that is properly disinfected or that the authorities have stated is safe. Take the appropriate steps to make sure that use of gas or electric appliances is safe.
Before using a washing machine that was in a flooded building, run the machine through one full cycle before washing clothes. Use hot water and a disinfectant or sanitizer. Take clothes and linens outdoors and shake off any dried mud or dirt before washing them. Hose off muddy items to remove all dirt before putting them in the washer.
If the items are only wet, they can be laundered normally. Check the labels on clothes and linens and wash them in detergent and warm water if possible, or take them to a professional cleaner. Adding chlorine bleach to the wash cycle will remove most mildew and will sanitize the clothing. However, bleach might fade some fabrics and damage other fabrics. If the label reads "dry clean only," shake out loose dirt and take the item to a professional cleaner.
Consult a remediation professional for advice on whether heavily mold-contaminated items made of leather, suede, or a similar material are salvageable or should be discarded. Do not burn or bury textiles that cannot be cleaned. Put them into properly sealed plastic bags and dispose of them as you would normal household garbage in your area.
Salvaging Household Items
When assessing or remediating mold contamination to a house, homeowners or clean-up personnel might decide to repair or clean household items (e.g., housewares or kitchen items) damaged or contaminated by flood waters. As with clothing and other textiles, make sure the water being used is safe. Use only water that is properly disinfected or that the authorities have stated is safe.
Nonporous items (e.g., dishes, pots, glass items, and hard plastic items) can be salvaged. However, because floodwaters are contaminated, nonporous items should be washed by hand in a disinfectant and then air-dried. Do not use a dish towel. Porous items (e.g., cloth, some wood and wood products, and soft plastic) must be discarded because they probably absorbed whatever contaminants were in the floodwaters.
Before using the dishwasher, clean and disinfect it. Then use a hot setting to wash your pots, pans, dishes, and utensils. Do not use the energy-saving setting. Throw away canned foods that are bulging, opened, or damaged. Food containers with screw-caps, snap-lids, crimped caps (soda pop bottles), twist caps, flip tops, snap-open, and home-canned foods should be discarded if they have come into contact with floodwater because they cannot be disinfected. If intact cans have come in contact with floodwater or storm water, remove the labels, wash the cans, and dip them in a solution of 1 cup of bleach in 5 gallons of water. Relabel the cans with a marker.
Cleaning a Heating, Ventilating, and Air Conditioning System
All surfaces of an HVAC system and all its components that were submerged during a flood are potential reservoirs for dirt, debris, and microorganisms, including bacteria and mold. In addition, moisture can collect in areas of HVAC system components that were not submerged (e.g., air supply ducts above the water line), and this also can lead to the growth of microorganisms. Therefore, all flood water-contaminated and moisture-laden components of the HVAC system should be thoroughly inspected, cleaned of dirt and debris, and disinfected by a qualified professional. CDC has prepared recommendations for professionals to help ensure that floodwater-contaminated HVAC system components are properly cleaned and remediated (21). If HVAC systems are not properly cleaned and disinfected to prevent the dissemination of mold and other debris throughout a building, bioaerosols of mold and other microorganisms might exists and can cause a variety of adverse health effects to the building's occupants. Ensure that the HVAC system is shut down before any remedial activities.
Prevention After the Flood
Limited scientific information exists on the efficacy and impact of prevention strategies. In addition, little of the practical knowledge acquired and applied by design, construction, and maintenance professionals has been subject to thorough validation (6). No generally accepted health-based standards exist for remediation (6).
If property owners decide to make extensive repairs or completely rebuild after a flood, they might consider designing and building in a way that will limit the potential for future mold growth (6,30). The key to prevention of mold is to eliminate or limit the conditions that foster microbial growth by limiting water intrusion and the nutrients that allow mold to grow (6,9,16,30). The two basic approaches are to keep moisture-sensitive materials dry and to use materials that are not easily biodegradable or which offer a poor substrate for mold growth.
Personal Protective Equipment
Workers and their employers might be required to wear or provide protection to minimize exposure to mold. Workers and employers should refer to pertinent OSHA standards and NIOSH guidelines. Information also is provided for the public.
Minimizing exposure to mold involves using PPE and administrative and engineering controls (6,17,18,31,32). Administrative controls include identifying mold-contaminated areas promptly, restricting access to these areas, and minimizing aerosol generating activities (e.g., by suppressing dust) (3,6,18,27,29,32). Engineering controls include ventilating mold-contaminated areas adequately and using heavy equipment with sealed positive pressure, air-conditioned cabs that contain filtered air recirculation units to protect the workers (6,17,18,31,32). Misting contaminated materials with water is a control measure used to reduce dust levels during debris removal.
Workers should wear PPE regardless of the engineering controls used, especially for skin and eye protection (1,9,17,18,32). Primary functions of PPE in a mold-contaminated environment are prevention of the inhalation and ingestion of mold and mold spores and prevention of mold contact with skin or eyes (1,32). PPE requirements for workers are likely to differ from the PPE recommendations for homeowners or other building occupants who are less likely to disturb and aerosolize contaminated materials. In addition, PPE recommendations for persons with underlying illness or compromised immune systems will differ from PPE recommendations for healthy persons. Proper training or instruction in the use of protective equipment is essential for effective use. Guidelines for protection of and training recommendation for workers have been published (33).
Types of Personal Protective Equipment
Skin and Eye Protection
Gloves keep the hands clean and free from contact with mold (9,29). Gloves also protect hands from potentially irritating cleaning solutions (29,32,33). Long gloves that extend to the middle of the forearm are recommended. The glove material should be selected on the basis of the type of substance or chemical being handled. When using a biocide (e.g., chlorine bleach) or a strong cleaning solution, gloves made from natural rubber, neoprene, nitrile, polyurethane, or PVC are needed. When using a mild detergent or plain water, ordinary household rubber gloves can be used. Latex or nonlatex medical examination gloves should be used if hands are likely to be in contact with infectious materials. Persons with natural rubber latex allergy should not use natural rubber latex gloves and should consult the NIOSH Alert on latex gloves for further information (34).
To protect eyes, properly fitted goggles or a full face-piece respirator are needed. Goggles must be designed to prevent the entry of dust and small particles. Safety glasses or goggles with open vent holes are not appropriate in mold remediation. CDC has published guidelines on this topic (35).
When conducting building inspections and remediation work, workers or homeowners might encounter hazardous biologic agents and chemical and physical hazards. Consequently, appropriate personal protective clothing, either reusable or disposable, is recommended to minimize cross-contamination between work areas and clean areas, to prevent the transfer and spread of mold and other contaminants to street clothing, and to eliminate skin contact with mold or chemicals (9,32). In hot environments, precautions to prevent dehydration and heat stress when wearing protective clothing (e.g., drink plenty of water) are needed.
Disposable PPE should be discarded after it is used. Such equipment should be placed into impermeable bags and usually can be discarded as ordinary construction waste. Protective equipment for biocide applicators (e.g., goggles or face shield, aprons or other protective clothing, gloves, and respiratory protection) must be selected on the basis of the product manufacturer's warnings and recommendations. In addition, the manufacturer's recommended precautions should be followed. Reusable protective clothing, including respiratory equipment (36,37), should be cleaned according to manufacturers' recommendations for PPE exposed to mold and other potentially hazardous chemicals (e.g., bleach and biocides).
Inhalation is the primary exposure route of concern related to mold for workers, homeowners, and building occupants (6,9,17,18). When administrative and engineering controls are not adequate to eliminate airborne exposure to mold (or dust containing mold), respirators provide additional protection from inhalation of airborne mold, contaminated dust, and other particulates that are released during dust-generating processes (e.g., remediation work or debris removal) (6,9,17).
Respirators provide varying levels of protection. Selecting a respirator to minimize exposure to molds should be based on a qualitative assessment because quantitative data on mold-contaminated environments are not informative (38--41). All decisions about respirator selection should be made with knowledge of the relative protective capabilities and the advantages and disadvantages of different respirators. Further discussion of respirator selection is available (38--41).
Standard surgical or dust masks are intended for use only as barriers against large particles and do not provide protection against many airborne particles (38). Respirators used to protect persons from airborne contaminants (including mold and mold spores) must be certified by CDC's NIOSH. In addition, as specified by the OSHA respiratory protection standard (37), workers whose employers require them to use respirators must be properly trained, have medical clearance, and be properly fit-tested before they use the respirator. If a worker must use respirators, the worker's employer must develop and implement a written respiratory protection program with worksite-specific procedures and elements. Additional information on respiratory protection is available from OSHA (37,42,43).
PPE Guidelines for Workers in Mold-Contaminated Areas
Exposure to some level of airborne mold is inevitable because molds are found indoors and outdoors (6,17). However, demolishing or cleaning heavily mold-contaminated materials outdoors can lead to excessive exposure to mold. The level of exposure to mold outdoors is primarily based on the amount of mold-contaminated material, the amount of mold in the material, and the type of work being performed. The need for PPE (including respiratory, skin, and eye protection) for outdoor workers requires ongoing professional assessment that considers the potential for exposure to mold and the potential for exposure to other hazardous substances that might be in the outdoor work area.
Guidelines summarized below are based on guidelines from OSHA (37,42,43), EPA (13), and the New York City Department of Health and Mental Hygiene (18). These guidelines recommend particular respirators on the basis of the size of the area of mold contamination. However, the size criteria are based on general professional judgment and practicality because data are limited related to the extent of contamination to the frequency or severity of health effects.
When determining the potential for airborne exposure to mold and the need for PPE, the size of the area is not the only criterion to be considered. The activities being performed in relation to the mold-contaminated materials are at least as important. Therefore, ongoing professional judgment always must play a part in decisions concerning PPE. For example, any remediation or other work that disturbs mold and causes mold spores to become airborne increases the degree of respiratory exposure. Actions that tend to disperse mold include breaking apart moldy porous materials such as wallboard; destructive invasive procedures to examine or remediate mold growth in a wall cavity; removal of contaminated wallpaper by stripping or peeling; and using fans to dry items or ventilate areas. In addition, health status and other characteristics of the persons potentially exposed to mold also might need to be considered (Table 1).
Category I Protection
Respiratory protection (e.g., N-95 disposable respirator). Respirators must be used in accordance with the OSHA respiratory protection standard (9,37).
Gloves and eye protection.
For use while cleaning the following:
Small isolated areas (<10 square feet) of heating, ventilation, and HVAC systems (includes pipes, ducts, and vents).
Isolated areas (<100 square feet) of building materials (e.g., ceiling tiles, small areas on walls, and individual or multiple wallboard panels).
Category II Protection
Respiratory protection with full face-piece respirators, with N100, R100, P100 (or for powered air purifying respirators, HEPA) particulate filters. Respirators must be used in accordance with the OSHA respiratory protection standard (13).
Disposable protective clothing covering entire body including both head and shoes.
For use while cleaning the following:
Large contaminated areas (>10 square feet) of HVAC systems.
Extensively contaminated (>100 contiguous square feet) building materials.
Any size area where substantial dust is generated during cleaning or debris removal (e.g., when abrasives must be used to clean contaminated surfaces or plaster walls are being demolished).
Areas where the visible concentration of mold is heavy (blanket coverage rather than patchy).
These guidelines should be followed according to professional judgment. For example, more protective respirators might be required if toxic contaminants such as asbestos or lead are encountered during cleanup. All workers dealing with large areas of contamination should be properly trained to handle hazardous materials.
PPE Guidelines for the Public (Nonworkers) in Residences and Nonoccupational Settings
Clean-up, Debris Removal, or Similar Activities
The activities (and possible exposure to mold) of persons re-entering their homes or working outside might be similar to those of workers. Preventing the creation of dust and limiting exposure to dust are the best ways to minimize exposure to mold (1,9,18). For example, using wet mops or vacuums with HEPA filters instead of dry sweeping dust and debris will decrease the amount of dust in the air (1,9,18).
If building occupants, residents, or anyone must be around mold-contaminated dust, respirators will offer some protection. Particulate respirators (such as NIOSH-certified N-95 respirators) can be purchased in safety supply stores and in most home improvement stores. Several factors are required for respirators to provide protection from inhalation hazards (15,38,41,43):
The respirator must fit well and be worn correctly. The manufacturer's instructions on the package should be followed. Because respirators are meant to be used by healthy workers who have had training, medical evaluations, and a proper fitting, the amount of protection provided by a respirator to the general public might be much less.
No U.S. agency tests and certifies respirators for public use. However, NIOSH tests and certifies respirators for use by workers to protect against workplace hazards. Respirators certified by NIOSH will be labeled "NIOSH Approved" and will have an approval label that identifies the hazard it will protect against. The N-95 respirator is approved only for particulates including dust in the air from sweeping, sawing, mold removal, and other activities that cause dust. The N-95 respirator is not designed to protect against exposure to vapors or gases (e.g., carbon monoxide) and will not provide protection from them.
A properly worn disposable respirator requires that:
Metal nose piece, if present, is on the top to adjust the fit to the wearer's nose.
NIOSH label is on the bottom outside of the respirator.
Both respirator retaining straps are in place, and they are securing the respirator to the face (some respirators have only one strap).
For the Public Not Involved in Clean-up, Debris Removal, or Similar Activities
Persons not involved in activities that disturb mold-contaminated materials have a lower risk for inhalation exposure relative to persons performing those types of activities. Persons collecting belongings, visually inspecting homes or buildings, or doing basic clean-up for short periods in a previously flooded home or building will not usually need to use a respirator.
The effect of exposure to mold varies widely. Persons who might be affected to a greater extent than the majority of healthy adults include (5,6,9):
persons with respiratory conditions (e.g., asthma) or allergies, and
persons with weakened immune systems (e.g., patients receiving chemotherapy, organ or bone marrow transplant recipients, or persons with human immunodeficiency virus infection or autoimmune diseases).
Persons with special health concerns should consult their health-care provider if they are concerned about mold exposure. Symptoms that might seem related to mold exposure might have other causes, such as bacterial or viral infections or other allergies. The level of risk associated with exposure activities and the potential benefit of recommended PPE are unknown for pregnant women, persons aged >65 years, and children aged <12 years; exposure-reducing behavior and respiratory protection might be difficult for children aged <12 years.
Using respirators or other PPE might increase health risks for persons with underlying health conditions. Persons who have trouble breathing while using a respirator should stop working and contact a doctor or other medical provider (1).
For persons at potentially increased health risks from exposure to mold, persons of unknown or uncertain risk, or persons unable to use respirators, caution is recommended when entering heavily mold contaminated environments, particularly when mold clean-up is occurring. Persons in these categories should avoid such situations if possible.
Potential Health Effects of Fungal Contamination
In recent years, the health effects of exposure to mold in built environments have been a subject of intense public concern. These concerns and how they are approached will have important implications for the reconstruction and rehabilitation of cities in states affected by major hurricanes or floods.
Many clinical conditions could be caused by the fungal contamination associated with flooding after major hurricanes or floods. Predicting what might occur is speculative. However, many of these conditions are uncommon and will be recognized only if there is a high clinical index of suspicion (Table 2). Anticipating what medical problems could be associated with post-flood fungal contamination might help in preventing them by identifying susceptible populations and making recommendations for reducing potentially harmful exposures.
Although this report focuses on potential health effects of fungal contamination, other exposures are also of concern. For example, dampness favors proliferation of dust mites and microorganisms such as bacteria (44,45) and nontuberculous mycobacteria (46). Endotoxins (components of the cell walls of Gram-negative bacteria) have strong inflammatory properties (6,44,45,47--49). Moisture also can release chemical constituents from building materials (6). Standing water supports rodent and cockroach infestations (15,44,45) and proliferation of mosquitoes (30). Fecal contamination of the environment raises concerns about protozoal and helminthic parasites (50). Fungi are not the sole potential cause of many conditions discussed in this report, and these conditions are only a subset of the conditions of concern to clinicians and public health professionals dealing with the aftermath of major hurricanes or floods (51).
Overview of Fungal-Induced Diseases
Fungi can cause a variety of infectious (52--58) and noninfectious conditions (6,44,45,47,59,60). Several basic mechanisms can underlie these conditions, including immunologic (e.g., IgE-mediated allergic), infectious, and toxic (6). Several of these mechanisms contribute to pathogenesis of a fungal-induced disease. The types and severity of symptoms and diseases related to mold exposure depend in part on the extent of the mold present, the extent of the person's exposure, and the susceptibility of the person (e.g., persons who have allergic conditions or who are immunosuppressed are more susceptible than those without such conditions). Molds produce a variety of volatile organic compounds (6,7,60), the most common being ethanol (61), which are responsible for the musty odors associated with fungal growth. Exposure to moldy indoor environments is also associated with a variety of upper and lower respiratory tract symptoms (6).
Institute of Medicine Report on Damp Indoor Spaces and Health
In recent years, the issue of how damp indoor spaces and mold contamination affect human health has been highly controversial. In response, CDC commissioned the Institute of Medicine (IOM) to perform a comprehensive review of the scientific literature in this area. The resulting report (6) was published in 2004 and remains the most current and authoritative source of information on this subject. The IOM categorized its findings into four categories:
sufficient evidence of a causal relation,
sufficient evidence of an association,
limited or suggestive evidence of an association, and
inadequate or insufficient evidence to determine whether an association exists.
"Inadequate or insufficient evidence to determine whether an association exists" does not rule out the possibility of an association. Rather, it indicates that no studies examined the relation or that published study results were of insufficient quality, consistency, or statistical power to permit a conclusion about an association. No conditions exists for which the IOM found sufficient evidence of a causal relation with mold or with damp indoor spaces. Several of the conditions are of particular interest to those engaged in the response to major hurricanes or floods (Table 3). Sufficient evidence links upper respiratory tract symptoms (e.g., nasal congestion, sneezing, runny or itchy nose, and throat irritation) to damp indoor environments and mold (with exposure to mold often determined by self-report). Similarly, sufficient evidence exists for a link with the lower respiratory tract symptoms of cough and wheeze. Sufficient evidence also was found for a link between damp indoor environments, mold, and asthma symptoms in sensitized persons with asthma. Evidence also is sufficient for an association between mold exposure and hypersensitivity pneumonitis in a small proportion of susceptible persons, invasive respiratory and other fungal infections in severely immunocompromised persons, and fungal colonization of the respiratory tract or infection in persons with chronic pulmonary disorders.
IgE-Mediated Diseases Caused by Fungi
IgE-mediated, or allergic, responses underlie the most common types of diseases associated with exposure to fungi (6,45,47,48,49). Atopy, or the genetic predisposition to form IgE responses to aeroallergens, is an important risk factor (45,47,48,49). Clinical conditions associated with allergies include allergic rhinitis and asthma (6,45,47,48,49). Allergic rhinitis is often associated with allergic conjunctivitis and sinusitis (45,47,49).
Symptoms of allergic rhinitis include sneezing; itching of the nose, eyes, mouth, or throat; nasal stuffiness; clear rhinorrhea; and, if associated with allergic conjunctivitis, red, itchy eyes. If associated with sinusitis, persons also might complain of sinus fullness or postnasal drip, often purulent (47--49). Signs on physical examination include pale, boggy nasal mucosa; nasal obstruction; and conjunctival redness. Examination of nasal scrapings or secretions indicates eosinophilic inflammation (47--49). If appropriate allergy prick skin testing reagents or in vitro tests for serum specific IgE are conducted, they demonstrate specific IgE-sensitization to causative allergens (45,47--49). Skin testing reagents and blood tests documenting IgE-sensitization to molds are, with few exceptions, poorly standardized and of unclear sensitivity and specificity (45). The conventional hierarchy of treatment is avoidance of exposure to inciting agents; pharmacotherapy with antihistamines, decongestants, or anti-inflammatory agents (e.g., nasal steroid sprays); or, as a last resort, allergen immunotherapy (47--49). Immunotherapy with fungal allergenic extracts is, with a few exceptions, of unknown efficacy (47).
Asthma is a disease characterized by episodic, reversible airways obstruction and eosinophilic airways inflammation (45,47--49,62,63). Over time, chronic asthma can lead to airways remodeling and irreversible airways obstruction (45,47--49,62,63). Persons with asthma often have symptoms such as chest tightness, wheezing, dyspnea, or cough (45,47--49,62,63). Physical examination during active asthma might indicate wheezing, but results of examinations between attacks are most often normal (62,63). If performed during an active asthma attack, spirometry most often indicates obstruction that reverses with inhalation of a bronchodilator (62,63). Persons with asthma generally exhibit bronchial hyperreactivity to methacholine challenge (45,47--49,62). However, a small proportion of persons without asthma and a substantial proportion of persons with airway disorders, including chronic obstructive pulmonary disease (COPD), also might exhibit hyperreactivity to inhaled methacholine (49); therefore, test results must be considered together with other clinical information (47--49,62,63). Approaches to demonstrating specific IgE sensitization to molds and limitations of available methods are as described for allergic rhinitis (45,47--49). Asthma is associated with airways inflammation that can be demonstrated by examining induced sputum for eosinophils or measuring exhaled nitric oxide (47), but these tests are often not performed in clinical settings.
Comprehensive guidelines for the staging and treatment of asthma are provided by the National Institutes of Health (62,63). Identifying and avoiding triggers, including occupational triggers, is a critical element of treatment. It is important to identify persons with asthma triggered by materials in flood-damaged areas so avoidance measures can be taken. Drug treatment of asthma consists of symptom controllers such as bronchodilators and anti-inflammatory agents (e.g., corticosteroids or leukotriene antagonists) (47--49,62,63). The role of allergen immunotherapy with most fungal agents in treatment of asthma is unclear (48). Therapy with monoclonal anti-IgE is a recently developed treatment option that can be used in carefully selected patients when other, less expensive modalities fail to reduce dependence on systemic corticosteroids (63). The exacerbation of symptoms of asthma is consistently associated with damp buildings (6). If persons with asthma must engage in activities within damp or mold contaminated buildings, their asthma should be well controlled before entering these buildings, and those around them should be aware of the signs of asthma symptoms. The onset of symptoms while in damp moldy environments, especially while wearing PPE, should be an indication to leave the area and to seek appropriate medical care.
Allergic Diseases Associated With Airways Colonization
Allergic bronchopulmonary aspergillosis (ABPA) is a disease that can occur when the airways of persons with obstructive pulmonary diseases (e.g., asthma or cystic fibrosis) become colonized with Aspergillus fumigatus or other Aspergillus species (6,17,45,47--49). Inflammatory responses lead to additional airways damage. Marked worsening of existing asthma is a typical presentation of ABPA. Symptoms include recurrent episodes of bronchial obstruction, fever, malaise, expectoration of brownish plugs, peripheral blood eosinophilia, hemoptysis, and sometimes asymptomatic pulmonary consolidation. Other features include immediate skin test reactivity to Aspergillus spp. antigens, precipitating serum antibodies to A. fumigatus, markedly elevated serum total IgE, fleeting lung infiltrates, and central bronchiectasis (45,47--49). Criteria for diagnosis have been published (45,47--49). Airways colonization with other fungal species can result in a similar clinical picture. Although no known relation exists between levels of exposure to Aspergillus spp. and development of ABPA, clinicians should suspect and evaluate for the condition when appropriate.
Allergic fungal sinusitis (AFS) is typically noninvasive and occurs in allergic, immunocompetent patients (6,45,47--49): most have asthma, and 85% have nasal polyps (47). Invasive fungal sinusitis can occur in patients who are immunocompromised with illnesses such as diabetes, hematologic malignancies or immunosuppressive treatments or chronic steroid therapy (6,47). Fungal colonization is associated with a characteristic allergic mucin containing high levels of eosinophils (6,45,47--49). The mere presence of fungi in the nasal passages is not indicative of an active infection.
Hypersensitivity pneumonitis (HP), also known as extrinsic allergic alveolitis, is a granulomatous interstitial lung disease (6,17,45,47--49). A wide range of materials, including fungi, can be inhaled and thus sensitize susceptible persons by inducing both antibody and cell-mediated immune responses (6,17,45,47--49). Re-exposure of sensitized persons leads to lung inflammation and disease (6,17,45,47--49). Building-related HP caused by fungi and bacteria has been well documented (6,17). Usually, only a small fraction of those with a given exposure develop HP; therefore, poorly understood host factors play an important role in disease pathogenesis (6,47--49).
The presentation of HP is complex and can be either acute, subacute, or chronic (6,47,48). The acute form is often associated with heavy exposures and characterized by chills, fever, malaise, cough, and dyspnea appearing 4--8 hours after exposure (6,47,48) and is often confused with pneumonia. The chronic form is thought to be induced by continuous low-level exposure. Onset generally occurs without chills, fever, or malaise and is characterized by progressive shortness of breath with weight loss (47,48). Chronic HP can be confused with idiopathic pulmonary fibrosis or other forms of interstitial lung disease (47,48).
The diagnosis of HP, especially the chronic form or when presentation is mild, is often missed early in the course of the disease. If it does occur in the aftermath of major hurricanes or floods, a high degree of clinical suspicion is required for detection. In general, when HP is suspected, a clinical and exposure history should be performed. Patients should be asked about their possible exposure to damp and water-damaged areas, farms, birds, hot tubs, and other environments that might cause HP. Environmental sampling for the presence of microorganisms known to cause HP and serologic testing for circulating precipitins can help to establish causative exposures (47--49). Chest imaging using chest radiographs or high-resolution computed tomography scanning of the thorax, lung-function tests, broncholaveolar lavage, and lung biopsy all have roles in diagnosis (47--49). Although established criteria exist for the diagnosis of hypersensitivity pneumonitis (64,65), in the setting of a documented post-disaster HP outbreak, a noninvasive approach to identifying cases could be more appropriate and cost-effective than requiring conventional diagnostic testing. A recent, large multicenter study indicated that under conditions of low or high prevalence, six predictors could be used in combination for noninvasive diagnosis of HP (66):
exposure to a known offending antigen,
positive precipitating antibodies to the offending antigen,
recurrent episodes of symptoms,
inspiratory crackles on physical examination,
symptoms occurring 4--8 hours after exposure, and
Optimal treatment is elimination of causative exposures. The IOM report (6) provides information about management of building-related HP that is relevant to reoccupation of structures contaminated by fungi after major hurricanes or floods. Such management includes giving standard medical therapy (e.g., systemic corticosteroids and removing sources of fungal contamination from the environment). In some cases, if efforts to remove mold from a building are unsuccessful in relieving symptoms, the patient might need to move to another home or office.
Inhalation fever is a general name given to a variety of influenza-like, self-limited syndromes that might be caused by a variety of stimuli. Two types of inhalation fevers are of potential concern after major hurricanes or floods.
Humidifier fever is characterized by fever, respiratory symptoms, and fatigue with onset within hours after exposure to contaminated humidification systems (6,17,45,47). Obtaining a supportive history is critical to diagnosis. Thermophilic actinomycetes; other bacteria, including species of Legionella and Pseudomonas; and protozoa have been associated with humidifier fever (17). Aerosolized endotoxin derived from Gram-negative bacteria has an important role in this condition (17,47). Although humidifier fever can be confused with acute HP, it is a short-term ailment and removal from exposure is effective treatment (17,47). Humidifier fever is thought to represent a nonspecific inflammatory response to exposure (17,47).
Organic dust toxic syndrome (ODTS) has been reported among workers in a variety of agricultural and industrial settings and is thought to involve inhalation exposure to materials with heavy microbial contamination (67--69). Etiologic exposures that cause ODTS are often a poorly defined mixture of substances, including fungi, bacteria, and microbial constituents such as endotoxin (67--69). ODTS is characterized by fever and influenza-like symptoms, including general weakness, headache, chills, body aches, and cough occurring 4--12 hours after heavy exposure to organic dust (67--69). Dyspnea also is sometimes present. Results of chest auscultation and chest radiographs are usually normal (67,68). The peripheral white blood count is often elevated during attacks. Accurate patient history is critical for making a correct diagnosis. Although the symptoms resemble those of acute HP, they are not caused by response of the immune system to a specific antigen in the environment (67,68). ODTS poses a risk for workers performing renovation work on building materials and is a realistic concern for workers handling heavily contaminated materials in the aftermath of major hurricanes or floods. ODTS is best prevented by minimizing exposure through engineering controls, administrative controls, and respirators (69). For agricultural workers handling organic dusts, CDC recommends using the most practical respirator with the highest assigned protection factor.
Toxic Effects of Fungi
Certain common molds can produce metabolites with a wide range of toxic activities such as antibiotic (e.g., penicillium), immune-suppressive (e.g., cyclosporine), carcinogenic (e.g., aflatoxins), emetic, and hallucinogenic (e.g., ergot alkaloids) (6,11,17,59). Mycotoxins are fungal metabolites that poison humans and animals. Although ingestion is the most common route of exposure, inhalation and dermal contact also are exposures of concern (6,11,17,59). Mycotoxin production is dependent not only on species and strain of mold, but also on environmental conditions (e.g., temperature, water activity, light) and growth substrate (11,17). Thus, the presence of toxin-producing mold species does not necessarily indicate whether mycotoxins are present.
Mycotoxins were prematurely proposed as the cause of a disease outbreak of eight cases of acute pulmonary hemorrhage/hemosiderosis in infants in Cleveland, Ohio, in 1993 and 1994 (70). The cluster was attributed to exposure to mycotoxins produced by Stachybotrys chartarum. Subsequent reviews of the evidence concluded that insufficient information existed and no such association was proven (71).
Almost all of the known effects of mycotoxin exposures are attributable to ingestion of contaminated food (72). Health effects from inhalational exposures to toxins are not well documented. IOM found inadequate or insufficient evidence for a link between exposure to damp indoor environments and molds with a variety of conditions that have been attributed to toxicity (6) (Table 3). Certain case studies of agricultural and remediation workers have described adverse health effects such as skin irritation, skin necrosis, cough, rhinitis, and bloody nasal exudate after inhaling or touching materials with heavy fungal contamination (73--76). Whether these effects resulted from exposure to mycotoxins or from a general overload of organic material is unknown. No commercial clinical diagnostic tools are available to determine whether a person's health effect is related to exposure to mycotoxins. Because of the lack of information about noningestion mycotoxin exposure and adverse health effects in humans, precautions should be taken when handling heavily contaminated building materials.
No reports of increased fungal infections related to floods in the United States exist. However, anecdotal case reports of fungal infection after floods include Apophysomyces elegans wound infection in a man who sustained traumatic injuries after the southeast Asian tsunami in December 2004 (77). A. elegans belongs to the Zygomycetes class of fungi. Infections are most commonly seen in immunocompromised and diabetic patients, and rarely in immunocompetent persons. The cause of infection in immunocompetent persons is usually cutaneous trauma with direct implantation of fungal organisms into the wound from soil contamination (78).
Theoretically, infection with fungal species that contaminate buildings, building constituents, and the environment after major hurricanes or floods is a potential concern. In general, persons with impaired host defenses (especially if impaired because of cell-mediated immunity or neutropenia) suffer the most severe types of fungal infections (6,52,53) (Table 4). However, invasive fungal infections also can occur in persons with normal host defenses and, in certain situations, can be life threatening (52,53) (Table 5). Persons at greatest risk for invasive fungal infection from heavy fungal contamination after major hurricanes or floods are those with impaired host defenses (6,52,53) (Table 4). Any impairment in cell-mediated immunity or neutropenia (e.g., human immunodeficiency virus [HIV] infection, leukemia, lymphoma, and diabetes mellitus) increases risk for many types of invasive fungal infections (52,53). Severely immunosuppressed persons, such as solid-organ or stem-cell transplant recipients or those receiving cancer chemotherapy agents, corticosteroids, or other agents inhibiting immune function, are at much higher risk for locally invasive infections of the lungs, sinuses, or skin and systemic infections (52,53). Aspergillus spp., zygomycetes, and Fusarium spp. are particularly important problems (52,53,56). These serious infections are often fatal, even with aggressive antifungal therapy (52,53,56).
Protective measures, such as HEPA filtration, implemented during periods of extreme susceptibility to invasive fungal infections are well established and effective in hospitals (79). However, preventive measures outside the hospital are less well established. Current guidelines emphasize the importance of avoiding areas of high dust (e.g., excavation sites, building construction or renovation sites, chicken coops, and caves) and factors associated with fungal infections (e.g., foods that increase a person's risk for fungal exposure) (80).
Obstructive pulmonary diseases such as asthma, cystic fibrosis, and COPD, might predispose persons to airway colonization with Aspergillus spp. (6,17,45,47--49). Inflammatory host responses to colonization can lead to ABPA (6,17,45,47--49,52). Aspergillus spp. also can cause invasive or semi-invasive infection in persons with COPD, especially in those being treated with corticosteroids. Chronic necrotizing pulmonary aspergillosis is an indolent condition observed in persons with underlying lung disease (53).
Colonization of lung cavities (e.g., tuberculosis cavities or emphysematous blebs) by Aspergillus spp. can cause pulmonary aspergillomas (fungus balls) (6,52), which are conglomerations of Aspergillus spp. hyphae matted together with fibrin, mucus, and cellular debris. These often do not cause symptoms, but they can be associated with hemoptysis (52,53). An exposure-response relation has never been established linking levels of exposure to Aspergillus spp. with development of any of these conditions. Therefore, to what degree exposure to fungal contamination after major hurricanes or floods would increase any risk is unclear. However, despite unknown benefit, persons with clinically significant obstructive pulmonary diseases (e.g., asthma, cystic fibrosis, COPD), and persons with cavitary lung disease from conditions such as tuberculosis should avoid airborne exposure to materials that have become heavily contaminated with fungal growth in the wake of major hurricanes or floods.
Persons with normal host defenses also are subject to fungal infections (52,53) (Table 5), and persons with impaired host defenses can acquire any of these, often with greater severity. Ocular, skin, and superficial infections occur in those with normal host defenses and range from the relatively common (e.g., ringworm, athlete's foot) to the relatively rare (e.g., sporotrichosis) (52,53). Of particular relevance in areas with fungal contamination after major hurricanes or floods are organisms that cause localized skin and superficial infections following traumatic inoculation with soil and plant saprophytes, which are found in air, soil, and plant materials. For example, Scedosporium apiospermum (Pseudallescheria boydii) can be recovered from polluted water, sewage, swamps, and poultry or cattle manure (52,53,55,58). Although rare in the United States, this organism can cause a soft tissue infection called Madura foot, a mycetoma in which the draining sinuses show white grains containing fungal elements. This organism also can produce septic arthritis or osteomyelitis after penetrating trauma. Sporothrix schenckii is a dimorphic fungus that produces soft tissue infections after traumatic inoculation from a contaminated environmental source (52,53), such as sphagnum moss, roses, plant seedlings, and other vegetation. Lymphocutaneous lesions are the hallmark of sporotrichosis, as the organisms spread through the local lymphatics after primary inoculation. A high degree of clinical suspicion is needed to diagnose the less common, locally invasive fungal infections. Diagnosis is made by histopathology and culture after biopsy of the affected lesion. Histopathology must be performed to verify that a recovered isolate is the cause of disease and not an environmental contaminant. Culture must be performed to identify the agent correctly. Fungal isolates are identified in a clinical mycology laboratory.
Exposures that result in invasive pulmonary mycoses in persons with normal host defenses are generally thought to occur outdoors where active disturbance of a reservoir has occurred (52,53). The mode of transmission is inhalation of fungal spores. Person-to-person transmission of pulmonary mycoses does not occur (53). Diseases relevant to flood prone areas such as the Gulf Coast states include histoplasmosis and blastomycosis. Histoplasmosis is unlikely to be increased as a result of fungal contamination after major hurricanes or floods. The condition is caused by Histoplasma capsulatum, a dimorphic fungus found in soil enriched with the droppings of birds and bats (52,53). Areas with endemic disease in the United States include the Mississippi and Ohio River valleys, but cases have occurred in other parts of the United States. Many persons develop no symptoms when exposed to H. capsulatum in an endemic setting.
Blastomycosis is a potential problem after major hurricanes or floods in areas with endemic disease because it can cause serious disease even in those with normal host defenses (52,53). Blastomycosis is caused by the dimorphic fungus Blastomyces dermatitidis (52,53). The organism is found in moist soil, frequently along streams or rivers enriched with decaying vegetation. In the United States, the organism is most commonly found in states surrounding the Mississippi and Ohio rivers (52,53). An area in Louisiana about 70 miles from New Orleans has endemic blastomycosis (81). In Louisiana, cases occur at an incidence of about 1--10 per year, mostly in the area of Washington Parish where the condition is endemic (81). Outbreaks have been associated with manipulation of decaying vegetation or recreational activity near lakes or rivers (53). The incubation period is not certain but, on the basis of data from outbreaks, appears to be about 45 days (82), ranging from weeks to months.
The clinical spectrum of blastomycosis includes asymptomatic infection, acute or chronic pneumonia, and disseminated disease (52,53). Pulmonary infection can mimic acute bacterial pneumonia or tuberculosis with progression to acute respiratory distress syndrome. Alveolar infiltrates, mass lesions that mimic bronchogenic carcinoma, and fibronodular interstitial infiltrates are the most common radiographic findings (52,53). Disseminated blastomycosis often appears as ulcerative skin lesions with multiple necrotic bone lesions in the vertebrae, skull, or long bones (52,53).
Culture of lesions or histopathologic evidence from infected tissue is required for diagnosis of blastomycosis (52,53). Direct microscopy of pus, scrapings from skin lesions, or sputum showing thick-walled broad-based budding yeast cells 5--15 µm in diameter supports a presumptive diagnosis of blastomycosis and might, in the appropriate clinical setting, prompt the initiation of antifungal therapy (52,53). Serologic tests can be performed on serum from patients showing signs of suspected pulmonary blastomycosis or with suggestive skin lesions. A positive immunodiffusion (ID) test, showing a precipitin band with the Blastomyces A antigen, is highly specific for the disease and does not require paired serum samples (52,53). However, the sensitivity is poor (33%--88%), so a negative ID test does not rule out the disease (52,53). For cases with negative results, the test should be repeated in 3--4 weeks after the initial sampling. The complement fixation (CF) test for blastomycosis has poor sensitivity and specificity.
Fungal brain abscesses are uncommon in healthy persons (52,53,57). The primary infection results from inhalation of infectious conidia from the environment; the route of infection appears to be hematogenous dissemination from the lungs (52,53,57). Of particular interest after major hurricanes or floods is S. apiospermum (P. boydii) (52,53,57). Many case reports document patients with focal neurologic defects caused by multiple brain abscesses weeks or months after nearly drowning. The organism apparently spreads hematogenously after initial aspiration of sewage-laden water (from floods, lagoons, or bayous) into the lungs. Near drowning presumptively results in a massive inoculation of mold into the lungs.
Preventing Adverse Health Effects From Environmental Fungal Contamination After Major Hurricanes or Floods
Persons should reduce their exposure to molds as much as possible (with the realization that fungi are ubiquitous). Persons with underlying or induced immunosuppressed conditions or diseases caused by immune sensitization to fungal constituents present in mold growth should be especially careful to reduce exposure. If exposure to heavily mold-contaminated materials is unavoidable, persons should use appropriate administrative, engineering, and personal protection controls. Because a person's likelihood of developing adverse health effects from mold exposure depends on the type of exposure and on individual susceptibility, precautionary measures need to be customized. Recommended measures are based on professional judgment because of lack of available scientific evidence. For example, no research studies have evaluated the effectiveness of personal protective equipment in preventing illness from mold exposure. Total avoidance of heavily contaminated buildings or other high exposure situations is suggested for persons with specific underlying conditions such as profound immunosuppression. Respiratory protection, dermal protection, and occlusive eye protection recommendations are customized to various populations and exposure-associated activities. Repeated or prolonged exposure probably poses a greater health risk than do exposures of a similar intensity, but short duration. Preventive precautions are especially important for persons who expect to be highly exposed for a long time.
Public Health Strategies and Recommendations for State and Local Officials
Recommendations from CDC are for protecting and monitoring the health and safety of workers and residents who enter, repair, or destroy flooded buildings. The recommendations are focused on limiting human exposure to mold and other microbial agents and preventing any adverse health effects related to such exposure. Several factors are assumed:
In the aftermath of major hurricanes and floods, buildings or materials soaked for >48 hours are contaminated with mold unless proven otherwise by inspection or adequate environmental sampling or cleaned according to the EPAs recommendations (13).
Workers and residents might be exposed to high levels of mold-related contaminants.
Sufficient evidence exists of an association between adverse health outcomes and exposure to damp indoor environments or materials contaminated with fungal growth.
Insufficient evidence exists for establishing health-related guidelines on the basis of concentrations of mold (quantitative measure) or species of mold (qualitative measure) in either indoor or outdoor environments.
Allergen testing to determine the presence of IgE to specific fungi might be a useful component in the complete clinical evaluation and diagnosis of mold-related allergies and in the decision to avoid exposure to fungal allergens that might be causing allergic symptoms. However, testing for IgE sensitization to molds has important limitations. Allergens used in these tests are often poorly standardized and the tests often have unclear sensitivity and specificity. In addition, allergen testing is not relevant to diseases that are not mediated by IgE.
Clear, concise, and practical recommendations and actions are necessary to limit exposure to mold and to prevent mold-related health outcomes where possible.
Assessing Exposure to Mold
Exposure assessment is usually a critical step in determining whether persons are exposed to a hazard at a level that could have an adverse health effect. The mere presence of a chemical or biologic hazard in the environment is insufficient to create a public health hazard. The contaminant must be present in an environmental medium (e.g. air, water, food, and dust) that allows it to come in contact with persons and move along a biologic pathway (e.g., inhalation, ingestion, and absorption). In addition, the concentration of the contaminant must be sufficient to create a biologic response that leads to an adverse health outcome. Mold and its spores exist in damp materials. Disturbing mold releases potentially hazardous particulates into the air, which can then be drawn into the sinuses and lungs. Although molds also might directly attack the skin or openings in the skin, the most common route of exposure is through the air and into the body by inhalation. Environmental sampling for molds has limited value and, in most instances, is not needed after major hurricanes or floods.
Building interiors should be assumed to be substantially contaminated with mold in the following circumstances:
The building was saturated with water for >48 hours.
Visible mold growth is extensive and in excess of that present before a major hurricane or flood
Signs of water damage are visible or mildew odors are strong.
Exposure to materials and structures contaminated with mold should be assumed to present a potential health risk regardless of the type of mold. Risk for illness does not necessarily vary with the type of mold or the extent of contamination.
Preventing Excessive Exposure to Mold
Preventing excessive exposure to mold is the best way to avoid harmful health consequences. The preferred approach to preventing mold exposure is to prevent water from infiltrating a building or damaging household goods and structures. After major hurricanes or floods, substantial water damage and mold growth might occur in many buildings.
If left undisturbed, mold is generally not a hazard, and most persons will not be adversely affected by moderate exposure to mold. However, in the aftermath of a major hurricane or flood, remediation activities within buildings will disturb any mold that is growing and lead to exposure. To prevent excessive exposure to mold in contaminated areas that are disturbed, persons who enter those areas should implement environmental controls (e.g., suppression of dust and isolation of the contaminated area), use PPE, or both. Preventing human exposure to mold and health effects from such exposure depends on three factors:
The likely concentration of mold in or on the building fabric or materials.
The duration and type of activity undertaken in the mold-contaminated area.
The susceptibility of the person entering the area to the various health effects.
Four methods for preventing exposure to mold can be used in combination:
avoiding areas thought to be mold-contaminated,
using environmental controls,
using PPE, and
employing strict personal hygiene.
The following persons should avoid mold-contaminated environments entirely:
transplant recipients, including those who received organ or hematopoietic stem cell transplants during the preceding 6 months or who are undergoing periods of substantial immunosuppression,
persons with neutropenia (neutrophil count <500/µL) attributed to any cause, including neoplasm, cancer chemotherapy, or other immunosuppressive therapy,
persons with CD4+ lymphocyte counts <200/µL attributed to any cause, including HIV infection, and
other persons considered by their physicians to have profoundly impaired antifungal host defenses caused by congenital or acquired immunodeficiency.
The following persons might be able to tolerate limited exposure, but they should consult with their physicians and should consider avoiding areas where moldy materials are disturbed:
persons receiving chemotherapy for cancer, corticosteroid therapy, or other immunosuppressive drug therapy, as long as neutropenia or CD4+ lymphopenia are not present,
persons with immunosuppressive diseases such as leukemia, lymphoma or HIV infection, as long as there is not marked impairment in immune function,
persons aged >65 years,
children aged <12 years, particularly infants, and
persons with chronic, obstructive, or allergic lung diseases.
All buildings with extensive mold contamination require remediation before rehabilitation. Remediation includes structural repairs to prevent additional water intrusion, removal of mold-contaminated materials that cannot be adequately cleaned and decontaminated, and cleaning and decontamination of mold-contaminated materials that can withstand such treatment. Health-care facilities and other locations that house highly susceptible persons require special attention. These facilities must be adequately remediated before being occupied by highly susceptible persons. Guidelines for remediating health-care facilities include:
Remediation and Infection Control Considerations for Reopening Healthcare Facilities Closed due to Extensive Water and Wind Damage (83), and
Check List for Infection Control Concerns when Reopening Healthcare Facilities Closed due to Extensive Water and Wind Damage (84).