Research Highlight

Poor access to tap water linked to dengue risk

doi:10.1038/nindia.2021.27 Published online 13 February 2021

Poor access to tap water in densely populated urban areas of Delhi increases the risk of dengue, a study reveals1.

The lack of access to tap water results in greater use of water-storing containers, which could help breed dengue-virus-spreading mosquitoes, a team of international researchers has found.  

Improved access to tap water, the researchers say, could lead to a reduction in dengue risk, not only for those who are directly affected but also for the general population.

Previous studies, while assessing dengue prevalence in Delhi, have left out the social-economic risk factors that help spread the dengue virus.

Scientists, including researchers from the National Institute of Malaria Research in Delhi, measured dengue antibodies in 2,107 individuals and mosquito larval prevalence in 18 areas within Delhi. They also analysed social and environmental risk factors for the virus.

Of the tested individuals, 160 were positive for dengue virus antibodies, indicating a recent or current infection.

Colonies with less than 61 per cent having access to tap water had higher abundances of mosquito larvae, suggesting a higher risk of dengue. Despite better infrastructure and lower mosquito densities, wealthy colonies had a higher risk of recent infection than the poor ones.

The researchers report that infected commuters who move into high-income areas during the day import the dengue virus to the wealthy areas, contributing to that higher risk.

Strategies to reduce mosquito densities in socially deprived areas may eliminate the reservoir of dengue virus, now circulating at low levels in winter, they say. 


1. Telle, O. et al.  Social and environmental risk factors for dengue in Delhi city: a retrospective study.  PLoS. Negl. Trop. Dis. 15:e0009024 (2021)Doi:10.1371/journal.pntd.0009024