Investigations and hospital surveillance of post-flood black water outbreaks


Author address: 

Thammasat University, Pathumthani, Thailand


Background: Black water refers to flood water contaminated with waste from humans and animals. We describe postflood investigations due to molds during the initial 4-month interval after re-opening a Thai hospital. Methods: Thammasat University Hospital was closed due to flooding, withe peak height of 3-meters. CDC checklist was used as a guide to re-open the hospital units. Surveillance for mold-positive clinical cultures was performed after hospital re-open. Interval fungal bioburden measurements were performed using Air Sampler every 4 weeks. The standard reference of 500 CFU/m3. The median time from re-opening a unit to the first case detection of mold was 5 days (range, 3-8 days). The investigation protocol to distinguish an outbreak from a pseudo-outbreak included 1) interviews with physicians and laboratorians, 2) examination of the patients and review of medical records. 3) review of and IC surveillance data, 4) observation in IC and sterilization/disinfection processes as well as re-emphasize on basic IC measures and 5) cultures of relevant equipment, as determined by epidemiology investigations. By multivariate analysis, initial fungal bioburden >500 CFU/m3 per unit was associated with pseudo-fungal case detection (aOR 4.78, 95% CI =1.71-12.72). No post-investigation cases occurred after enhanced compliance with basic IC measures. Conclusion: Given the potential for mold contamination after extensive black water floods, we emphasize the need for early investigation of potential cases attributed to mold in order to avert unnecessary diagnostic work-ups and exposure to antifungal agents.

abstract No: 


Full conference title: 

ID Week 2012
    • IDWeek 2012