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A comparative epidemiological study of hepatitis B and hepatitis D virus infections in Yanomami and Piaroa Amerindians of Amazonas State, Venezuela
Author(s) -
Duarte María Carolina,
Cardothalia,
Poblete Fresia,
González Kenia,
García Mayila,
Pacheco Milian,
Botto Carlos,
Pujol Flor H.,
Williams John R.
Publication year - 2010
Publication title -
tropical medicine and international health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.056
H-Index - 114
eISSN - 1365-3156
pISSN - 1360-2276
DOI - 10.1111/j.1365-3156.2010.02560.x
Subject(s) - hbsag , medicine , epidemiology , hepatitis b virus , outbreak , virology , coinfection , hepatitis b , hepatitis d virus , vaccination , transmission (telecommunications) , demography , virus , sociology , electrical engineering , engineering
Summary Objectives To report the prevalences of hepatitis B (HBV) and hepatitis D (HDV) infections in remote and more accessible Yanomami and Piaroa Venezuelan Amazonian Amerindian populations; to estimate incidence per susceptible. Methods Clinico‐epidemiological evaluation was carried out in 9 Piaroa villages. Blood samples were tested for HBV core antibody (anti‐HBc), surface antigen (HBsAg) and HDV antibody (anti‐HDV). Results were analysed using logistic regression, and estimates made of HBV forces of infection (FOI). Prevalences and FOI were also estimated for 4 Yanomami villages. Results Mean Piaroa anti‐HBc and HBsAg prevalences were 27.4% and 5.1%, respectively (up to 53% and 19% in the remote Autana region). Mean Yanomami anti‐HBc and HBsAg prevalences were, respectively, 58.0% (range 43–70%) and 14.3% (31% in the village with highest HBsAg). No significant difference was found between sexes, with age and maternal HBsAg the only risk factors for HBV identified in multivariate regression of Piaroa data. Only 4 Piaroa and 2 Yanomami individuals were anti‐HDV positive. Conclusion Piaroa HBV prevalences were generally higher in remote villages than in less remote ones, with prevalences in Yanomami villages even higher. Anti‐HBc prevalence was 47% in one Yanomami village with a history of HBV vaccination but no HBsAg cases were identified, suggestive of previously cleared or possibly transient infection or vaccine escape. Despite a past history of HDV epidemic outbreaks and HBsAg levels in some villages appearing sufficient to facilitate HDV transmission, anti‐HDV prevalence was low; it remains to be established why no recent outbreaks have been reported.