Expansion of Aedes africanus (Diptera: Culicidae), a sylvatic vector of arboviruses,into an urban environment of Abidjan,Côte d'Ivoire

In 2008, an outbreak of yellow fever occurred in Abidjan. The entomological investigations confirm that Abidjan is at risk of yellow fever with a suspicion of the National Park of Banco (NPB) forest as a likely area of re‐emergence. This study aims to assess the dispersion of sylvatic vectors of arboviruses from the NPB forest to the surrounding areas (Andokoi and Sagbé). The sampling was done in the rainy season using the WHO layer‐traps technique. Among the six species of Aedes sampled, Aedes aegypti and Aedes africanus were the potential vectors of arboviruses. Both species were collected in Sagbé but only Ae. aegypti in Andokoi. Only Ae. aegypti were present 400 and 800 m from NPB forest, but at 200 m, it showed respective proportions of 75.5% and 87.5% in Sagbé and Andokoi. In the NPB forest, however, Ae. africanus has been the predominant species. The study showed the presence of Ae. aegypti in Andokoi and Sagbé. However, Ae. africanus was found in the NPB forest and in the 200 m radius in Sagbé. The establishment of an entomological surveillance program in all areas would therefore be essential for the prevention of arboviruses outbreaks in Abidjan.     

Prevalence of endoparasitic mites on four West African leaf‐litter frogs depends on habitat humidity

Amphibian species are known to carry endoparasitic mites. The infestation probability, prevalence, and intensity of mites vary among species and habitats. Mites of the genus Endotrombicula are known to infest African and Malagasy frogs. However, the factors leading to an increase in the probability of mite infestation are unknown. To test for inter‐ and intraspecific differences in infestation probability and its potential correlation with sex, age, habitat preferences, and/or season within a species‐rich West African leaf‐litter frog assemblage, we examined more than 6,800 individual frogs for the presence of mites throughout two independent time increments, 1999–2000 and 2016–2017. We found only members of the leaf‐litter frog genus Phyrnobatrachus to be infested, while other syntopically occurring genera were not affected. Within Phrynobatrachus, only four out of eight species were infested. Mites prevalence differed between species (highest P. phyllophilus, followed by P. alleni), sex (males higher than females in P. alleni and P. phyllophilus), and age (adults higher than juveniles in P. alleni), as well as season (more mites during wet than dry season in P. phyllophilus). The prevalence of mite infestation did not influence mate choice in P. alleni. Increased humidity showed a clear positive effect on infestation prevalence. We also detected a marked decrease in the prevalence of mites from 1999–2000 to 2016–2017, a period during which climatological changes within the study area have been reported with a tendency toward drier conditions. The decrease in mite infestation prevalence over time might be a signal of increasingly drier conditions.     

Diarrhea, pneumonia, and infectious disease mortality in children aged 5 to 14 years in India

Background

Little is known about the causes of death in children in India after age five years. The objective of this study is to provide the first ever direct national and sub-national estimates of infectious disease mortality in Indian children aged 5 to 14 years.

Methods

A verbal autopsy based assessment of 3 855 deaths is children aged 5 to 14 years from a nationally representative survey of deaths occurring in 2001–03 in 1·1 million homes in India.

Results

Infectious diseases accounted for 58% of all deaths among children aged 5 to 14 years. About 18% of deaths were due to diarrheal diseases, 10% due to pneumonia, 8% due to central nervous system infections, 4% due to measles, and 12% due to other infectious diseases. Nationally, in 2005 about 59 000 and 34 000 children aged 5 to 14 years died from diarrheal diseases and pneumonia, corresponding to mortality of 24·1 and 13·9 per 100 000 respectively. Mortality was nearly 50% higher in girls than in boys for both diarrheal diseases and pneumonia.

Conclusions

Approximately 60% of all deaths in this age group are due to infectious diseases and nearly half of these deaths are due to diarrheal diseases and pneumonia. Mortality in this age group from infectious diseases, and diarrhea in particular, is much higher than previously estimated.