EFFORTS to expand the scope of surveillance and diagnostic testing for emerging infectious diseases1 also may increase the potential for identifying pseudo-outbreaks2,3 (i.e., increases in incidence that may result from enhanced surveillance) and outbreaks of pseudoinfection (i.e., clusters of false-positives for infection). This report describes the investigations of outbreaks of pseudoinfection with Cyclospora in Florida and Cryptosporidium in New York City in 1995 after health departments in those jurisdictions had initiated surveillance for these emerging organisms. These investigations emphasize (1) the need for laboratory training in the identification of emerging pathogens and (2) the importance of confirmation by reference laboratories as an early step in the investigation of any apparent outbreak caused by an emerging pathogen.
Cyclosporiasis in Florida
Cyclosporiasis is caused by infection with Cyclospora cayetanensis, a recently identified coccidian parasite4 that can cause prolonged, relapsing diarrhea; treatment with trimethoprim-sulfamethoxazole relieves
Outbreaks of Pseudo-Infection With Cyclospora and Cryptosporidium—Florida and New York City, 1995. JAMA. 1997;277(18):1428-1429. doi:10.1001/jama.1997.03540420022009