Cyclospora cayetanensis and AIDS

A 32-year-old Hispanic woman with AIDS presented with a 1-month history of diarrhea; abdominal bloating and cramps; loss of appetite; and pronounced fatigue, malaise, and weight loss. She had no fever or chills and was not vomiting. Her CD4+ cell count was 12/µL. Results of a routine microscopic examination of stool for ova and parasites were negative; an acid-fast stain of stool demonstrated oocytes of Cyclospora cayetanensis measuring 8.8 mm in diameter (pictured, magnification ×1,000). This is about twice the size of the Cryptosporidium parvum oocyte, which typically is 4 to 5 mm.

Drs Gamil Kostandy, Salama Salama, Maged Ghaly, Bruce Sosler, William Miller, and Fernando Pujol; and Matei Weiner write that Cy cayetanensis is newly recognized as a protozoan parasite that causes illness in humans. Waterborne and foodborne transmission can occur, but person-to-person spread is not likely because oocysts passed in stool are not infectious and sporulation requires days to weeks. Following an incubation period of about 1 week, patients present with flu-like symptoms, diarrhea, and other symptoms common to infection with small-bowel pathogens.

Outbreaks of cyclosporiasis were traced to the consumption of raspberries from Guatemala, but Dr Kostandy and colleagues note that their patient denied eating raspberries or any food containing this fruit. She responded to 1 double-strength tablet of trimethoprim-sulfamethoxazole (TMP-SMX)-160 mg of TMP and 800 mg of SMX-qid for 10 days, followed by 1 tablet three times a week for 2 weeks.