Dengue y leptospirosis compartiendo el mismo nicho ecológico en la localidad ribereña de Carmen del Paraná (Itapúa) / Dengue and leptospirosis share the same ecological niche in Carmen del Paraná (Itapua), a riverside locality

Para conocer la prevalencia de dengue y leptospirosis en pobladores de Carmen del Paraná (Itapúa) realizamos un estudio transversal descriptivo. Aplicamos un cuestionario y toma de muestras sanguíneas, mediante un muestreo por hogares. Los jefes de familia fueron informados sobre la metodología, beneficios, posibles riesgos a fin de decidir su participación o de sus familiares en el estudio. Por el método de ELISA determinamos la presencia de anticuerpos IgG anti-leptospira en 211 mujeres y 107 varones, contra el virus del dengue en 255 mujeres y 142 varones. Hallamos una seroprevalencia de dengue de 25% (IC 95%:20,7-29,4), no habiendo diferencia entre varones y mujeres. La prevalencia de leptospirosis fue de 24,1% (IC95%:19,6-29,2), siendo mayor en mujeres que en varones (28,4% vs 15,9%; p <0,05). La seroprevalencia de dengue fue más alta en los mayores de 35 años (36% vs 17%, p<0,001), mientras que la leptospirosis lo fue en menores de 15 años (48% vs 21,6%, p<0,001). El 8% de los individuos tenía serología positiva tanto para leptospira como para dengue. En esta comunidad, un importante número de individuos tiene riesgo de desarrollar dengue hemorrágico. La coexistencia de dengue y leptospirosis en el mismo nicho ecológico es importante porqueal presentar características clínicas semejantes, implican un problema para el médico al momento de establecer el diagnóstico oportuno y el tratamiento apropiado, entonces sería importante el desarrollo de estrategias integrales de vigilancia epidemiológica, prevención y control de estas enfermedades que se basen en la participación conjunta del personal de salud, autoridades y comunidad.

This cross-sectional descriptive study was carried out to know the prevalence of dengue and leptospirosis in the inhabitants of Carmen del Paraná (Itapúa). Through a house hold sampling, we applied a questionnaire and collected blood samples. The heads of the families were informed about the methodology, benefits and possible risks so that they could decide about the participation of their families in the study. The presence of anti-leptospira IgG antibodies was determined by ELISA method in 320 individuals (211women and 107 men) and anti-dengue virus antibodies in 399 individuals (255 women and 142 men). We found a dengue virus seroprevalence 25% (IC 95 %:20.7-29.4) without any differences between men and women. The prevalence of leptospirosis was24.1% (IC95 %:19.6-29.2), higher in women than in men (28.4 % vs. 15.9 %; p value <0.05). Dengue seroprevalence was higher in the age group older than 35 years old(36% vs. 17%, value of p <0.001), where as leptospirosis was more prevalent in those younger than 15 years old (48% vs 21.6%, p value <0.001). Eight percent of the individuals who were leptospira positive were also dengue positive. In this community, there is an important number of individuals who has a risk of developing hemorrhagicdengue. The coexistence of dengue and leptospirosis in the same ecological niche is important because both diseases presented similar clinical characteristics, implying a problem for the physician at the time of determining the appropriate diagnosis andtreatment. Therefore, it would be important to develop integral strategies of epidemiological surveillance, prevention and control of these diseases, based on the jointparticipation of healthcare personnel, authorities and community.

Reproductive biology of the Neotropical electric fish Brachyhypopomus draco (Teleostei: Hypopomidae) from southern Brazil

The reproductive biology of a population of the weakly electric fish Brachyhypopomus draco from southern Brazil is described. Information is provided on the establishment of the reproductive period in this species and its relations with environmental and feeding factors, as well as on the absolute and relative fecundities, spawning type, sex ratio and sexual dimorphism. The species exhibits a relatively long reproductive period, a relative fecundity of 0.173 oocytes per mg of female total weight, and fractional spawning. The sex ratio did not differ from 1:1 during all sampled months. Sexual dimorphism related to hypertrophy of the male's distal portion of caudal filament was observed and males grew to greater lengths than females. Male gonadosomatic index (GSI) was significantly related to water depth, oxygen saturation and temperature. Female GSI was significantly related to water depth and hepatosomatic index.(AU)

Descreve-se a biologia reprodutiva de uma população do peixe elétrico Brachyhypopomus draco do sul do Brasil. São apresentadas informações a respeito do período reprodutivo estabelecido e suas relações com fatores ambientais e alimentares, bem como a fecundidade absoluta e relativa, tipo de desova, proporção sexual e dimorfismo sexual. A espécie apresentou um período reprodutivo relativamente longo, uma fecundidade relativa de 0,173 ovócitos por mg de peso total da fêmea e uma desova do tipo parcelada. A proporção sexual encontrada foi de 1:1 durante todos os meses amostrados. Dimorfismo sexual relacionado com a hipertrofia da porção distal do filamento caudal dos machos e com o tamanho total dos espécimes - machos atingindo tamanhos maiores do que as fêmeas - foi encontrado. O IGS dos machos foi significativamente relacionado com a profundidade da água, a saturação de oxigênio e a temperatura; o IGS das fêmeas foi significativamente relacionado com a profundidade da água e o índice hepatossomático.(AU)