[Risk factors and frequency of positive antibodies for leptospirosis in a sub urban population near Santiago]. / Prevalencia y presencia de factores de riesgo de leptospirosis en una población de riesgo de la Región Metropolitana.

BACKGROUND: Leptospirosis is a zoonotic disease and its incidence is known in Chile since 2002, when it was incorporated as a disease that must be reported to health authorities. A serologic survey for leptospirosis was performed in humans and animals from a farm in a semi urban area in Santiago Chile, after the death of a farmer due to Weil disease in that place. AIM: To report the prevalence of antibodies against leptospirosis and to determine exposure to infection risk factors in the humans and domestic animals studied in this survey. MATERIAL AND METHODS: Antibodies were detected by IgM immunodot and indirect haemagglutination test in 61 humans (43 male, aged 5 to 70 years) and by microscopic agglutination test (MAT) in 44 animals. A questionnaire was applied to determine their exposure to risk factors for infection with Leptospira. RESULTS: Seventy two percent of the studied population were farm workers and 70% had activities that required contact with water from canals, 41% cleaned closed places where rodents were present. Other risk factors detected were lack of sewage and waste disposal, high level of rodent infestation and disposal of faeces into canals used for watering. Two humans (3.3%) and six animals (1 bovine and 5 rodents) had positive antibodies. Among animals, antibodies against Leptospira serovar pomona and icterohaemorragiae were detected. CONCLUSIONS: In Chile, leptospirosis exists not only in rural areas but semi urban ones close to Santiago, although the prevalence is low. Education is necessary among semi urban population to avoid infection.

Prevalencia y presencia de factores de riesgo de leptospirosis en una población de riesgo de la Región Metropolitana / Risk factors and frequency of positive antibodies for leptospirosis in a sub urban population near Santiago

Background:Leptospirosis is a zoonotic disease and its incidence is known in Chile since 2002, when it was incorporated as a disease that must be reported to health authorities. A serologic survey for leptospirosis was performed in humans and animals from a farm in a semi urban area in Santiago Chile, after the death of a farmer due to Weil disease in that place. Aim: To report the prevalence of antibodies against leptospirosis and to determine exposure to infection risk factors in the humans and domestic animals studied in this survey. Material and methods: Antibodies were detected by IgM immunodot and indirect haemagglutination test in 61 humans (43 male, aged 5 to 70 years) and by microscopic agglutination test (MAT) in 44 animals. A questionnaire was applied to determine their exposure to risk factors for infection with Leptospira. Results: Seventy two percent of the studied population were farm workers and 70 percent had activities that required contact with water from canals, 41 percent cleaned closed places where rodents were present. Other risk factors detected were lack of sewage and waste disposal, high level of rodent infestation and disposal of faeces into canals used for watering. Two humans (3.3 percent) and six animals (1 bovine and 5 rodents) had positive antibodies. Among animals, antibodies against Leptospira serovar pomona and icterohaemorragiae were detected. Conclusions: In Chile, leptospirosis exists not only in rural areas but semi urban ones close to Santiago, although the prevalence is low. Education is necessary among semi urban population to avoid infection.

Brote de shigellosis en una escuela de educación básica / Shigella outbreak in an elementary school

Se analiza un brote de gastroenteritis por shigella sonnei, ocurrido en una escuela básica de una comuna de Santiago, en marzo de 1997. En esta escuela, con una matricula de 1470 niños entre 5 y 14 años de edad, 350 se beneficiaban con el programa de alimentación escolar (pae) y almorzaban en el establecimiento. Treinta y cinco de los 350 niños del pae presentaron simultáneamente gastroenteritis que motivó consulta en un servicio de emergencia, 2 de los cuales presentaron diarrea con sangre requiriendo hospitalización. Durante los cinco días posteriores se registraron 189 nuevos casos en la escuela. Frente a la notificación, se efectuó visita epidemiológica a la escuela, obteniéndose muestras de deposición para estudio de bacterias y virus enteropatógenos en 65 niños sintomáticos y en los tres manipuladores de alimentos. Se identificó s. sonnei en 20,5 porciento de los coprocultivos y todas las cepas tenían el mismo antibiotipo. La búsqueda de virus entéricos (rotavirus, calcivirus) dio resultados negativos. En los manipuladores de alimentos no se detectó enteropatógenos bacterianos ni virales. La presentación del brote plantea una toxiinfección por s. sonnei, iniciada probablemente por ingestión de alimentos (tasa de ataque primario 10 porciento) y luego transmisión persona a persona (tasa de ataque secundario 16,9 porciento) Para controlar el brote se reforzaron medidas de higiene personal y de saneamiento ambiental a través de educación a toda la comunidad escolar y el control sanitario del establecimiento. A partir del quinto día de iniciado el primer caso, se administró cotrimoxazol, durante cinco días, sólo a los casos sintomáticos. El brote se controló al noveno día