Minimizing Health Risks: Controlling Mold in Health Care Settings

Infection Control TodayInfection Control Today, June 2023, (Vol. 27 No. 5)
Volume 27
Issue 5

Mold, a menacing presence that can grow within the walls of your facility, may be lurking and waiting to cause problems. Are you equipped to deal with it?

Close up petri dish with microbe colony  (AdobeStock 258706925 by luchschenF)

Close up petri dish with microbe colony

(AdobeStock 258706925 by luchschenF)

Mold growth is a significant concern in health care facilities because of its potential to cause various health issues and structural damage. Health care facilities are especially susceptible to mold growth because of their unique environmental conditions, including high humidity levels and the presence of water sources. Hospitals possess numerous areas that fulfill the conditions required for mold growth. Mold thrives in darkness and needs organic matter, such as drywall or dust, to sustain its growth. With their intricate designs and large wall and ceiling cavities, health care facilities provide an ideal environment for mold to flourish without detection.1 The introduction of moisture acts as the final component necessary for mold to thrive and proliferate.2 The presence of mold in health care settings can also lead to increased health care–associated infections, which can have severe consequences for patients. Mold is common in our environment; most individuals inhale mold spores regularly without experiencing any adverse effects. However, mold exposure can lead to infections and other health complications for people with compromised immune systems. The immune system protects the body against harmful substances and organisms, including mold. When the immune system is weakened because of underlying medical conditions, medications, or age, it becomes less capable of fighting mold and other threats. As a result, individuals with weakened immune systems are more susceptible to mold-related illnesses, ranging from minor allergic reactions to severe respiratory infections. Therefore, effectively controlling mold growth in health care facilities is crucial for maintaining a safe and healthy environment for patients, staff, and visitors. Sometimes, we are just 1 severe storm away (literally and metaphorically) from mold formation.

To prevent mold growth in facilities, it is imperative to correct conditions that promote the proliferation of spores, such as water leaks, condensation, and flooding.

Facilities can control mold growth by doing the following:

  • Controlling humidity levels.

Humidity sensors can help monitor and maintain optimal humidity levels, alerting facility managers if the levels rise above or fall below recommended thresholds. Humidity control is imperative in all areas of a health care facility, and humidity can have detrimental effects on patients who are in the operating room (OR) or procedure areas. Monitoring humidity levels in the OR is essential for maintaining a safe and sterile environment for surgical procedures. High humidity levels can increase the risk of microbial growth and contamination, compromising the success of surgical procedures and putting patients at risk for postoperative infections. All facilities should conduct a risk assessment by area to determine the appropriate humidity levels and establish the appropriate measures for responding to areas where humidity levels have fallen out of range. Some examples of responses included closing ORs until humidity returns to within range, terminally cleaning affected areas, and closely monitoring patients impacted for potential fungal infections.

Health care facilities should refer to guidelines for temperature and humidity established by the Facility Guidelines Institute,3 The Joint Commission,4 and the Centers for Medicare & Medicaid Services.5

  • Promptly identifying and correcting leaks.

Left unaddressed, leaks can cause damage to the building structure and lead to the development of mold, which can spread quickly and contaminate the air, surfaces, and medical equipment. Although the stained ceiling tiles are not aesthetically pleasing, they can also indicate a growing issue, such as an active leak. Replace all stained ceiling tiles and investigate the cause of the leak immediately. Regular inspections and maintenance of the building structure can help identify leaks before they cause significant damage, and corrective action can be taken promptly to prevent mold growth.

  • Reducing dust during construction.

Preventing dust during hospital construction is critical to minimizing the risk of mold infections. During construction, dust can be generated from various sources, such as cutting or drilling into walls, floors, and ceilings. The dust can contain various particles, including mold spores, which can contaminate the air and surfaces, leading to the growth and spread of mold. Mold can grow on drywall, insulation, ceiling tiles, and carpeting, among other things. If these materials are contaminated with mold spores during construction, the mold can grow and spread, creating a hazardous environment for patients, staff, and visitors. Preventing dust during construction can be achieved through various measures, such as using proper ventilation and air filtration systems, containing the work area with plastic sheeting, and regularly cleaning and disinfecting surfaces. Using high-efficiency particulate air filters can be particularly effective in removing dust particles and mold spores from the air. Dust mitigation during construction should be detailed in the infection control risk assessment written and approved before starting work.

  • Placing immunocompromised patients in positive pressure rooms to reduce the risk of mold infections.

Positive pressure rooms are designed to prevent the infiltration of contaminated air from outside the room. The air inside the room is constantly supplied with fresh, filtered air to maintain a higher pressure than the surrounding areas. Immunocompromised patients may also be given antifungal medicine to prevent infections.6

  • Using other strategies for mold mitigation.

These include air filtration, thoroughly cleaning and drying after flooding, and ventilating areas such as showers, laundry, and cooking areas.6 Ensure all doors and windows are closed and have the appropriate seals. Health care facilities can consult an industrial hygienist with specialized knowledge in assessing and managing indoor air quality, mold prevention, and
remediation strategies.

According to the CDC, the most common indoor molds are Cladosporium,
Penicillium, and Aspergillus. Mold infections are typically caused by Aspergillus, but can be caused by other types of mold, such as mucormycetes.6 Multiple diagnostic tests exist for identifying mold infections in patients, such as bronchoalveolar lavage, biopsies, imaging, and blood tests. After a water intrusion in a health care facility, consider a mold infection in exposed patients who experience symptoms such as fever, cough, night sweats, shortness of breath, and sinus symptoms with no other identifying causes. All health care facilities should track the incidence of mold infections among patients. An uptick in expected cases could indicate a potential source of indoor mold and an outbreak.

Identifying the sources of mold in health care facilities can be a challenging task. Recent hospital mold-related incidents have included outbreaks due to the air handling system in a children’s hospital in Seattle, Washington, contaminated linen,7 and mold behind a sink wall on a maternity floor.8 Identifying the sources of mold in health care facilities is crucial to ensure a safe and healthy environment for patients, staff, and visitors. Recent incidents involving mold in hospitals have emphasized the significance of conducting routine inspections; maintaining heating, ventilation, and air conditioning systems; and inspecting concealed areas of the facility to prevent and manage mold growth. It is essential to have a comprehensive mold response plan in place for your health care facility, especially before rainy and warmer seasons when mold growth is most prevalent.


  1. McCarty C, Favour J. The challenge of mold in modern hospitals and healthcare facilities. Healthcare Facilities Today. March 20, 2020. Accessed April 24, 2023.
  2. Stewart T, McCall JA. How dangerous mold develops. Health Facilities Management. August 16, 2019. Accessed April 25, 2023.
  3. FGI guidelines. Facility Guidelines Institute. Accessed April 25, 2023.
  4. Temperature and humidity - monitoring requirements. The Joint Commission. Accessed April 25, 2023.
  5. Invasive mold infections in immunocompromised people. Centers for Disease Control and Infection. June 6, 2019.
  6. Cheng VCC, Chen JHK, Wong SCY, et al. Hospital outbreak of pulmonary and cutaneous zygomycosis due to contaminated linen items from substandard laundry. Clin Infect Dis. 2016;62(6):714-721. doi:10.1093/cid/civ1006
  7. Masson G. 5 hospitals facing mold issues this year. Becker’s Hospital Review. December 11, 2019. Accessed April 25, 2023.
Recent Videos
Andrea Flinchum, 2024 president of the Certification Board of Infection Control and Epidemiology, Inc (CBIC) explains the AL-CIP Certification at APIC24
Association for Professionals in Infection Control and Epidemiology  (Image credit: APIC)
Lila Price, CRCST, CER, CHL, the interim manager for HealthTrust Workforce Solutions; and Dannie O. Smith III, BSc, CSPDT, CRCST, CHL, CIS, CER, founder of Surgicaltrey, LLC, and a central processing educator for Valley Health System
Jill Holdsworth, MS, CIC, FAPIC, CRCSR, NREMT, CHL, and Katie Belski, BSHCA, CRCST, CHL, CIS
Baby visiting a pediatric facility  (Adobe Stock 448959249 by
Antimicrobial Resistance (Adobe Stock unknown)
Anne Meneghetti, MD, speaking with Infection Control Today
Patient Safety: Infection Control Today's Trending Topic for March
Infection Control Today® (ICT®) talks with John Kimsey, vice president of processing optimization and customer success for Steris.
Related Content