Survey of US Public Health Laboratories: Microbial Pathogens on the CCL

Abstract

The Safe Drinking Water Act (SDWA) amendments of 1996 mandated that the US Environmental Protection Agency (USEPA) develop a list of unregulated drinking water contaminants to be evaluated for potential regulation. In 1998, USEPA published the first Contaminant Candidate List (CCL) to meet this SDWA requirement. The microbial pathogens included on the CCL have various methods of transmission to humans, including drinking water, but few are included on statewide or national disease reporting systems. Thus, USEPA cannot estimate the illness caused by these pathogens or their overall effect on public health. The authors conducted a comprehensive survey of state public health laboratories (SPHLs) for fiscal‐year 1999 to determine which SPHLs received and analyzed human specimens for CCL pathogens, to determine the number of samples analyzed for each pathogen and the number of specimens that tested positive, and to document the analytical methods used. Ninety‐four percent of the SPHLs participated in the survey, but the number of specimens, verified pathogens, and analytical methods varied. Fewer than 5% of clinical specimens yielded evidence of infection with a CCL pathogen ‐ except for analysis of calicivirus, which was detected 40% of the time. Most SPHLs used polymerase chain reaction (PCR) to analyze samples for only calicivirus. Because PCR can detect a variety of CCL pathogens, the authors concluded that SPHLs were underutilizing the sensitive PCR techniques for detection of CCL pathogens. This survey is a first step in evaluating the impact of CCL pathogens on public health, but further studies are needed to identify additional laboratories to participate in surveys and examine the potential human health risk factors that resulted in the identified pathogen infection.