Epidemiology and Infection

Original Papers

Cryptosporidiosis and toxoplasma

Multiple risk factors associated with a large statewide increase in cryptosporidiosis

A. L. VALDERRAMAa1a2 c1, M. C. HLAVSAa3, A. CRONQUISTa4, S. COSGROVEa4, S. P. JOHNSTONa3, J. M. ROBERTSa3, M. L. STOCKa5, L. XIAOa3, K. XAVIERa4 and M. J. BEACHa3

a1 Division for Heart Disease and Stroke Prevention, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA, USA

a2 Epidemic Intelligence Service, Career Development Division, Office of Workforce and Career Development, Centers for Disease Control and Prevention, Atlanta, GA, USA

a3 Division of Parasitic Diseases, National Center for Zoonotic, Vector-Borne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA

a4 Colorado Department of Public Health and Environment, Denver, CO, USA

a5 Division of Global Migration and Quarantine, National Center for Preparedness, Detection, and Control of Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA

SUMMARY

Cryptosporidium species have emerged as a major cause of outbreaks of diarrhoea and have been associated with consumption of contaminated recreational and drinking water and food as well as contact with infected attendees of child-care programmes. In August 2007, the Colorado Department of Public Health and Environment detected an increase in cryptosporidiosis cases over baseline values. We conducted a case-control study to assess risk factors for infection and collected stool specimens from ill persons for microscopy and molecular analysis. Laboratory-confirmed cases (n=47) were more likely to have swallowed untreated water from a lake, river, or stream [adjusted matched odds ratio (aOR) 8·0, 95% confidence interval (CI) 1·3–48·1], have had exposure to recreational water (aOR 4·6, 95% CI 1·4–14·6), or have had contact with a child in a child-care programme or in diapers (aOR 3·8, 95% CI 1·5–9·6). Although exposure to recreational water is commonly implicated in summertime cryptosporidiosis outbreaks, this study demonstrates that investigations of increased incidence of cases in summer should also examine other potential risk factors. This study emphasizes the need for public health education efforts that address the multiple transmission routes for Cryptosporidium and appropriate prevention measures to avoid future transmission.

(Accepted April 29 2009)

(Online publication May 27 2009)

Correspondence:

c1 Author for correspondence: A. L. Valderrama, Ph.D., R.N., National Center for Chronic Disease Prevention and Health Promotion, 4770 Buford Hwy, NE, Atlanta, GA 30341, MS K-47. (Email: AValderrama@cdc.gov)

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