Transactions of the Royal Society of Tropical Medicine and Hygiene (2007) 101, 1018—1024 available at www.sciencedirect.com journal homepage: www.elsevierhealth.com/journals/trst Epidemiology of Cyclospora cayetanensis infection in San Carlos Island, Venezuela: strong association between socio-economic status and infection Leonor Chac´ ın-Bonilla a,b,* , Fernando Barrios c , Yulaicy Sanchez b a Postgrado de Inmunolog´ ıa, Facultad de Medicina, Universidad del Zulia, Apartado Postal 15165, Maracaibo, Venezuela b Instituto de Investigaciones Cl´ ınicas, Facultad de Medicina, Universidad del Zulia, Apartado Postal 23, Maracaibo, Venezuela c Departamento de Microbiolog´ ıa, Facultad de Odontolog´ ıa, Universidad del Zulia, Apartado Postal 926, Maracaibo, Venezuela Received 9 January 2007; received in revised form 22 May 2007; accepted 22 May 2007 Available online 25 July 2007 KEYWORDS Cyclospora cayetanensis; Cyclosporiasis; Epidemiology; Risk factors; Transmission; Venezuela Summary The epidemiology of Cyclospora cayetanensis is not well understood. Few community-based studies have addressed this issue. A study was conducted to determine the prevalence and risk factors for cyclosporiasis in San Carlos Island, Venezuela. A sample of 515 subjects (mean ± SD: 21.4 ± 17.8 years) was surveyed. For identification of the parasite, stools were examined with modified Ziehl—Neelsen carbolfuchsin staining of formalin-ether concen- trates. Infections with Cyclospora (43 of 515, 8.3%) were common. There were differences in prevalence of the parasite among sectors of the community: 30 out of 43 (69.8%) cases of cyclosporiasis clustered in two sectors with extreme poverty. Living in these sectors versus the remainder, living in a hut or small residence versus a concrete or larger house, using an area of backyard rather than a toilet or latrine for defecation, and having contact with soil contami- nated with human feces were factors strongly associated with the infection (P < 0.01). Contact with soil contaminated with human feces might be an important mode of transmission, and poverty a predisposing factor, for the infection. © 2007 Published by Elsevier Ltd on behalf of Royal Society of Tropical Medicine and Hygiene. 1. Introduction The epidemiology of Cyclospora cayetanesis (Cyclospora) is not well understood. Significant gaps remain in our knowl- edge about its geographic distribution, factors that influence infectivity, seasonality and modes of transmission (Mansfield and Gajadhar, 2004). In developed countries, risk factors ∗ Corresponding author. Tel.: +58 61 7933564; fax: +58 61 7835587. E-mail address: leonorbonilla42@yahoo.com (L. Chac´ ın-Bonilla). and the modes of transmission for the infection are well known. Most of the cases have been related to interna- tional travel or to food-borne outbreaks caused by imported produce from endemic areas (Herwaldt, 2005). Exposure to contaminated drinking or recreational water or to sewage have been involved in the spread of the infection to a lesser extent (Shields and Olson, 2003). A study of an outbreak of cyclosporiasis in Florida (USA) suggests that soil contact may be a risk factor for infection (Koumans et al., 1998). In developing areas, the epidemiology of Cyclospora infection is less well understood. It is known to be endemic in 0035-9203/$ — see front matter © 2007 Published by Elsevier Ltd on behalf of Royal Society of Tropical Medicine and Hygiene. doi:10.1016/j.trstmh.2007.05.008 Downloaded from https://academic.oup.com/trstmh/article/101/10/1018/1895351 by KIM Hohenheim user on 23 April 2022