RESUMO
BACKGROUND & OBJECTIVES: Infections caused by arboviruses and transmitted by Aedes species mosquitoes are a serious health concern. India is endemic for diseases like Dengue, Chikungunya and recently Zika has been reported from few states. Vector control is the only way to contain these diseases, however, data regarding vectors from central India is lacking; to fulfill the lacuna we conducted this study. METHODS: Entomological surveys were conducted from November 2017 to December 2018 for Aedes species in Dengue endemic areas of central India. The mosquitoes were identified, pooled and tested for the presence of Dengue, Chikungunya and Zika viruses by RT-PCR. The PCR products were sequenced to identify serotypes and genotypes of viruses. RESULTS: A total of 2991 adults of Aedes specimens were collected and tested. Ae. aegypti (94.6%) was found to be the most abundant species. Highest mosquito density was recorded in the monsoon periods. Dengue (n=5) and Chikungunya (n=4) virus were detected from pools of female Ae. aegypti. One pool of male Ae. aegypti was positive for Dengue virus-3 and Chikungunya virus. Zika virus was not detected from any pool. INTERPRETATION & CONCLUSION: The findings suggest that Ae. aegypti is the principal vector of Dengue and Chikungunya, which is capable to transmit these viruses vertically. The findings have epidemiological importance and will be helpful to program managers.
Assuntos
Aedes , Febre de Chikungunya , Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Animais , Febre de Chikungunya/epidemiologia , Dengue/epidemiologia , Vírus da Dengue/genética , Feminino , Masculino , Mosquitos Vetores , Zika virus/genética , Infecção por Zika virus/epidemiologiaRESUMO
BACKGROUND AND OBJECTIVES: Epidemiology and transmission of malaria vary within the tribal areas with the variation in topography, forest cover and type of forest. For the control of disease, understanding of the dynamics of transmission in the varied ecological situation is essential. This study was carried out in the two distinct tribal areas- Baiga Chak (thick forested area) of Dindori district and Bichhia block (forest fringe area) of Mandla district, Madhya Prasdesh, India, to understand the epidemiology and transmission dynamics of malaria. METHODS: Mosquitoes were collected using hand catch and whole night collections to determine the proportion of vectors, their density and seasonality. Vector incrimination was done by sporozoite ELISA and feeding preferences of vector by gel diffusion method. Active fever surveys were carried out fortnightly to determine the age specific malaria parasite rates among the inhabitants of two areas. RESULTS: Density of Anopheles culicifacies was significantly higher in Bichhia while the density of An. fluviatilis was higher in Baiga Chak. An. culicifacies was incriminated from both the areas while An. fluviatilis was incriminated from Baiga Chak only. Malaria slide positivity rate (SPR) was significantly higher (OR=3.7 95%CI, 3.1-4.4) in Baiga Chak (28.2%) than Bichhia (9.6%). INTERPRETATION & CONCLUSIONS: The features of malaria transmission in tribal areas differed from those reported in rural or semirural population. Site-specific and region-specific studies are required to develop appropriate intervention measures to control malaria.