[Leptospirosis seroprevalence and associated features in rice farmers of tropical region of Peru]. / Seroprevalencia de leptospirosis y características asociadas en agricultores de arroz de una región tropical del Perú

OBJECTIVES: To estimate the seroprevalence of leptospirosis in rice farmers of the Alto Mayo Valley in the Peruvian region of San Martín and to identify factors associated with infection. MATERIALS AND METHODS: A cross-sectional study was conducted between October and November of 2010 on a sample of 254 farmers from eleven irrigation committees in the Alto Mayo Valley. A blood sample was collected as well as sociodemographic, household and labor characteristics in the form of a questionnaire. The presence of antibodies against leptospira was determined using the microscopic agglutination test and the IgM ELISA. RESULTS: The seroprevalence by agglutination was 64.6% (95% CI: 58.6-70.6). The IgM ELISA test was reactive in 15,0% (95% CI: 10.5-19.5). The most frequent serovar were Icterohaemorrhagiae, Autumnalis, Australis, Panama and Grippotyphosa. Independently associated factors were handling rodents (adjusted OR (aOR): 7.9; 95% CI: 1.6-37.9), working barefoot (aOR: 2.9; 95% CI: 1.2-6.8) and male sex (aOR: 4.5; 95% CI: 1.3-15.3). CONCLUSIONS: The Alto Mayo Valley is a hyperendemic for leptospirosis. The most important factors were associated with working barefoot and handling rodents in crop fields. Consequently, it is recommended to implement interventions that affect these two factors in order to reduce the risk of infection in rice farmers.

Seroprevalencia de leptospirosis y características asociadas en agricultores de arroz de una región tropical del Perú / Leptospirosis seroprevalence and associated features in rice farmers of tropical region of Peru

Objetivos . Estimar la seroprevalencia de leptospirosis en agricultores dedicados al cultivo de arroz del valle del Alto Mayo, región San Martín e identificar anticuerpos para los serovares circulantes y los factores asociados a la infección. Materiales y métodos. Se realizó un estudio transversal entre octubre y noviembre de 2010 en una muestra de 254 agricultores procedentes de las once comisiones de regantes del valle de Alto Mayo. Se recolectó una muestra de sangre y se aplicó un cuestionario que incluyó variables sociodemográficas, y características del hogar y del trabajo. Se determinó la presencia de anticuerpos contra leptospira usando la prueba de microaglutinación y ELISA IgM. Resultados. La seroprevalencia determinada por microaglutinación fue del 64,6% (IC 95%: 58,6-70,6). La prueba ELISA IgM fue reactiva en 15,0% (IC 95%: 10,5-19,5). Los tipos de serovar más frecuentes fueron Icterohaemorrhagiae, Autumnalis, Australis , Panama y Grippotyphosa. Los factores asociados independientemente fueron la manipulación de roedores (OR ajustado [ORa] de 7,9, IC 95%: 1,6-37,9), trabajar descalzo (ORa de 2,9, IC 95%: 1,2-6,8) y el sexo masculino (ORa de 4,5, IC 95%: 1,3-15,3). Conclusiones . El valle del Alto Mayo es un área hiperendémica de leptospirosis. Los factores asociados más importantes fueron la práctica de trabajar descalzo y la de manipular roedores en los campos de cultivo. En consecuencia, se recomienda implementar intervenciones que incidan en estos dos factores a fin de reducir el riesgo de infección en los cultivadores de arroz.

Objectives. To estimate the seroprevalence of leptospirosis in rice farmers of the Alto Mayo Valley in the Peruvian region of San Martín and to identify factors associated with infection. Materials and methods. A cross-sectional study was conducted between October and November of 2010 on a sample of 254 farmers from eleven irrigation committees in the Alto Mayo Valley. A blood sample was collected as well as sociodemographic, household and labor characteristics in the form of a questionnaire. The presence of antibodies against leptospira was determined using the microscopic agglutination test and the IgM ELISA. Results. The seroprevalence by agglutination was 64.6% (95% CI: 58.6-70.6). The IgM ELISA test was reactive in 15,0% (95% CI: 10.5-19.5). The most frequent serovar were Icterohaemorrhagiae, Autumnalis, Australis, Panama and Grippotyphosa. Independently associated factors were handling rodents (adjusted OR (aOR): 7.9; 95% CI: 1.6-37.9), working barefoot (aOR: 2.9; 95% CI: 1.2-6.8) and male sex (aOR: 4.5; 95% CI: 1.3-15.3). Conclusions. The Alto Mayo Valley is a hyperendemic for leptospirosis. The most important factors were associated with working barefoot and handling rodents in crop fields. Consequently, it is recommended to implement interventions that affect these two factors in order to reduce the risk of infection in rice farmers.