Open Access Research article

Human leptospirosis in The Federated States of Micronesia: a hospital-based febrile illness survey

Susannah Colt1, Boris I Pavlin2*, Jacob L Kool3, Eliaser Johnson4, Judith P McCool5 and Alistair J Woodward5

Author Affiliations

1 The Institute for Immunology and Informatics, Department of Cell and Molecular Biology, University of Rhode Island, Providence, RI, USA

2 Office of the WHO Representative in Papua New Guinea, World Health Organization, Port Moresby, Papua New Guinea

3 Division of Pacific Technical Support, World Health Organization, Suva, Fiji

4 Pohnpei Department of Health Services, Kolonia, Pohnpei State, Federated States of Micronesia

5 School of Population Health, University of Auckland, Auckland, New Zealand

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BMC Infectious Diseases 2014, 14:186  doi:10.1186/1471-2334-14-186

Published: 7 April 2014



Human leptospirosis is an emerging infectious disease of global significance, and is endemic to several countries in the Pacific. Zoonotic transmission dynamics combined with diagnostic challenges lead to difficulties in prevention and identification of cases. The Federated States of Micronesia (FSM) lacks surveillance data for human leptospirosis. This hospital-based serologic survey sought to estimate the burden of leptospirosis, collect information relating to associated factors, and assess the leptospirosis point-of-care rapid diagnostic test (RDT) commonly used in FSM.


A four-month hospital-based survey was conducted in Pohnpei State, FSM in 2011. Patients with undifferentiated fevers presenting to hospital were referred for enrolment by physicians. Consenting participants provided paired blood specimens 10–30 days apart, and responded to interview questions regarding demographics, clinical symptoms, exposure to animals, and environmental exposure. Blood samples were subjected to immunochromatographic RDT and confirmed by microscopic agglutination test (MAT).


Of 54 participants tested by MAT, 20.4% (95% confidence interval [CI] 10.1–30.6%) showed serologic evidence of acute infection. Occupation student (odds ratio [OR], 17.5; 95% CI: 1.9–161.1) and recreational gardening (OR, 8.6; 95% CI: 1.0-73.8), identified by univariate logistic regression, were associated with infection. The local rapid diagnostic test (RDT) performed with a sensitivity of 69.2 (42.3-89.3 CI) and specificity of 90.0 (81.6-95.6 CI) compared to MAT.


This study demonstrated a high burden of leptospirosis in Pohnpei. Further work is warranted to identify additional risk factors and opportunities to control leptospirosis in Pohnpei and other Pacific settings.

Leptospirosis; Pohnpei; Federated States of Micronesia; Serosurvey