Hurricane-Associated Mold Exposures Among Patients at Risk for Invasive Mold Infections After Hurricane Harvey — Houston, Texas, 2017

Discussion

This investigation of mold exposures and PPE use after Hurricane Harvey found that a convenience sample of immunosuppressed adult residents were exposed to mold and water-damaged areas. Immunosuppressed persons are at risk for invasive mold infections (primarily respiratory) with mortality rates as high as 50%.^[6] Although federal agencies recommend that immunosuppressed persons avoid flooded and mold-contaminated buildings,^[9] approximately half of survey participants engaged in cleanup activities, with approximately half of those who engaged in heavy cleanup and most of those engaged in light cleanup reporting not wearing respiratory protection; gloves were the most frequently reported PPE used.

In disaster settings such as Hurricane Harvey, immunosuppressed residents might experience difficulty in adhering to recommendations about avoiding mold-contaminated sites if the majority of homes in the community are affected. In such cases, proper use of an appropriate respirator and other PPE during reentry to the home might reduce mold exposure.

No participants reported websites or social media as sources of information about what one should wear during cleanup of mold and floodwater. This could reflect a unique demographic profile in this group; however, the profile could not be assessed because demographic information was not obtained as part of the survey.

The findings in this report are subject to at least three limitations. First, survey participants were not representative of all immunosuppressed patients in the Houston area because the participants consisted of a convenience sample of patients with specific conditions from three hospital systems. Although these findings cannot be extrapolated to all immunosuppressed residents in the Houston area during and after Hurricane Harvey, they suggest that a substantial number of immunosuppressed persons were exposed to mold and flood-damaged areas and that PPE use among some immunosuppressed persons who engaged in cleanup activities was low. Second, although it was ascertained that the three hospital systems had not conducted systematic, hospital-wide messaging about avoiding mold exposure before Hurricane Harvey, survey participants were not asked whether they had been told by a health care provider to avoid exposure to mold. Thus, it was not possible to determine whether survey participants who were exposed to mold were aware of federal recommendations. Finally, eligibility criteria included immunosuppressive medications for health conditions of varying severity, and information on specific conditions was not collected. For example, some participants were prescribed a tumor necrosis factor inhibitor for rheumatoid arthritis, whereas others received cyclosporine for a solid organ transplant. It is possible that immunosuppressed persons in better physical health were more likely to consent to the survey. As a result, these findings might overestimate the percentage of immunosuppressed persons performing cleanup activities.

Among a sample of immunosuppressed Houston area residents, many were exposed to mold and flood-damaged homes after Hurricane Harvey. Many residents at high risk for invasive mold infections engaged in activities to clean up mold and flood-damaged areas without wearing PPE recommended for otherwise healthy persons. Although recommendations for immunosuppressed persons are to avoid mold-contaminated sites, these findings might help prompt future studies on the knowledge, attitudes, and practices of PPE use among immunosuppressed persons in posthurricane settings and other locations experiencing flooding when complete avoidance of mold-contaminated sites is difficult. In turn, these studies could help inform future decisions about PPE recommendations for this population.

Morbidity and Mortality Weekly Report. 2019;68(21):469-473. © 2019 Centers for Disease Control and Prevention (CDC)