Dengue seroprevalence, seroconversion and risk factors in Dhaka, Bangladesh

Abstract

BackgroundDengue virus (DENV) activity has been reported in Dhaka, Bangladesh since the early 1960s with the greatest burden of dengue fever and dengue hemorrhagic fever cases observed in 2000. Since this time, the intensity of dengue activity has varied from year to year, and its determining factors remained relatively unknown. In light of such gaps in knowledge, the main objectives of this study were to determine the magnitude of seroprevalence and seroconversion among the surveyed population, and establish the individual/household level risk factors for the presence of DENV antibodies among all age groups of target populations in the city of Dhaka.Methodology/Principal findingsConsidering the lack of fine scale investigations on the factors driving dengue activity in Bangladesh, a prospective cohort study involving serological surveys was undertaken with participant interviews and blood donation across the city of Dhaka in 2012. Study participants were recruited from 12 of 90 wards and blood samples were collected during both the pre-monsoon (n = 1125) and post-monsoon (n = 600) seasons of 2012. The findings revealed that the seroprevalence in all pre-monsoon samples was 80.0% (900/1125) while the seropositivity in the pre-monsoon samples that had paired post-monsoon samples was 83.3% (503/600). Of the 97 paired samples that were negative at the pre-monsoon time point, 56 were positive at the post-monsoon time point. This resulted in a seroprevalence of 93.2% (559/600) among individuals tested during the post-monsoon period. Seroprevalence trended higher with age with children exhibiting a lower seropositivity as compared to adults. Results from this study also indicated that DENV strains were the only flaviviruses circulating in Dhaka in 2012. A multivariate analysis revealed that age, possession of indoor potted plants, and types of mosquito control measures were significant factors associated with DENV seroprevalence; while attendance in public/mass gatherings, and use of mosquito control measures were significantly associated with DENV seroconversion after adjusting for all other variables.Conclusions/SignificanceOur study suggests that there is a high level of endemic dengue virus circulation in the city of Dhaka which has resulted in significant DENV seroprevalence among its residents. Seropositivity increased with age, however, a substantial proportion of children are at risk for DENV infections. Our serological analysis also documents considerable DENV seroconversion among study participants which indicates that a large proportion of the population in the city of Dhaka were newly exposed to DENV during the study period (pre-and post-monsoon 2012). High levels of seroconversion suggest that there was an intense circulation of DENV in 2012 and this may have resulted in a significant risk for viral associated illness. Findings of our study further indicated that home-based interventions, such as removing indoor potted plants and increased bed net use, in addition to vector control measures in public parks...

Climatic changes and their role in emergence and re-emergence of diseases

“…albopictus and is responsible for 96 million new infections yearly worldwide annual cases. Out of these, only 500,000 patients develop severe symptoms and 1250 fatalities (Dhar-Chowdhury et al 2017). (3) Ebola haemorrhagic fever and the closely related Marburg fever.…”

Serological evidence of dengue fever and associated factors in health facilities in Borena Zone, Southern Ethiopia.

“…Dengue is a viral disease caused by dengue virus serotypes (DENV1-4) of the genus Flavivirus. Dengue virus is a non-segmented, positive-sense, singlestranded, enveloped RNA virus; transmitted primarily by the bite of Aedes aegypti and Aedes albopictus [2, 3]. Infections can also be transmitted through blood transfusion, organ transplantation and possibly vertically from mother to child [4, 5].…”

High carrier prevalence with poor knowledge of thalassaemia among the university students from indigenous communities in Bangladesh

“…Nearly 90% of these births occur in developing countries [2]. In South Asia, particularly in India, Bangladesh, and Pakistan, thalassaemia has become a silent epidemic with an estimated 45-70 million thalassaemia carriers [3]. In Bangladesh, thalassaemia carriers' prevalence among the general population is estimated to be around 6-12%, which translates into 10-19 million [4,5].…”

“…In Bangladesh, thalassaemia carriers' prevalence among the general population is estimated to be around 6-12%, which translates into 10-19 million [4,5]. An estimated 60,000-70,000 patients have been suffering from severe forms of thalassaemia (β-thalassaemia major and HbE beta) in the country [3]. Despite a higher prevalence of thalassemia carriers, people are mostly unfamiliar with this disease in Bangladesh [6].…”