Nationally-representative serostudy of dengue in Bangladesh allows generalizable disease burden estimates

Abstract

Serostudies are needed to answer generalizable questions on disease risk. However, recruitment is usually biased by age or location. We present a nationally-representative study for dengue from 70 communities in Bangladesh. We collected data on risk factors, trapped mosquitoes and tested serum for IgG. Out of 5866 individuals, 24% had evidence of historic infection, ranging from 3% in the north to >80% in Dhaka. Being male (aOR:1.8, [95%CI:1.5–2.0]) and recent travel (aOR:1.3, [1.1–1.8]) were linked to seropositivity. We estimate that 40 million [34.3–47.2] people have been infected nationally, with 2.4 million ([1.3–4.5]) annual infections. Had we visited only 20 communities, seropositivity estimates would have ranged from 13% to 37%, highlighting the lack of representativeness generated by small numbers of communities. Our findings have implications for both the design of serosurveys and tackling dengue in Bangladesh.

Estimating the dengue burden in India

“…We therefore welcome the well designed, nationally representative survey to estimate age-specific sero prevalence of dengue infections in India by Manoj Murhekar and colleagues published in The Lancet Global Health. 5 6 but are much lower than the seroprevalence in most southeast Asian countries where seroprevalence is often documented as above 70% already by the age of 9 years. 7 The estimated number of dengue infections among individuals aged 5-45 years from 30 Indian states in 2017 was 12 991 357 (12 825 128-13 130 258) based on constant force of infection models.…”

“…The seroprevalence was also higher for urban (70•9%) versus rural areas (42•3%), which is in keeping with the observation that urbanisation appears to be one of the main drivers for the increase in dengue incidence. 6,8 Urbanisation in India is occurring at a dazzling rate, and hence India is poised to see further upsurges of dengue.…”

Megacities as drivers of national outbreaks: the role of holiday travel in the spread of infectious diseases

“…This is especially problematic for large megacities such as Dhaka, which are highly connected to the rest of the country and can amplify the spread of local outbreaks. Recent work suggests that the Aedes mosquito species exist in almost all parts of Bangladesh [32], thereby creating the opportunity for local outbreaks to be sparked by imported cases.…”

Intersecting vulnerabilities: Climatic and demographic contributions to future population exposure to Aedes-borne viruses in the United States

“…aegypti exhibits highly anthropophilic biting behavior (Delatte et al, 2009). Urban populations are, therefore, considered more vulnerable than rural ones, as urbanites are more likely to be in contact with Aedes mosquitoes, increasing the potential for virus transmission (Salje et al, 2019). Finally, the elderly are more likely to suffer adverse health effects if infected by Aedes-borne viruses (Brien et al, 2009;Dye, 2014;Badawi et al, 2018), hence making this group highly vulnerable.…”