Shedding light on the burden of dengue in Bangladesh

May 24, 2019

Dengue, also known as dengue fever, is a viral disease transmitted to humans by mosquitoes of the genus Aedes. The incidence of dengue is currently increasing dramatically, and it is now one of the diseases said to be re-emerging. In Bangladesh, sporadic cases were reported in the 1960s and a major outbreak occurred in 2000, with clinical cases reported annually since then. However, the burden of dengue is unclear. Researchers at the Institut Pasteur have conducted a study to determine the burden of dengue in Bangladesh and identify key risk factors for infection.

Dengue virus continues to infect millions of people each year, with resource poor countries often disproportionally affected. In order to direct precious resources to tackle the virus in the most efficient way, researchers at the Institut Pasteur, in collaboration with teams at Johns Hopkins University, icddr,b and the Bangladesh Institute of Epidemiology, Disease Control and Research, wanted to know where the risk is the greatest and identify subsets of the population at increased risk. However, this is rarely known, especially in settings with limited surveillance capabilities. For example, in Bangladesh, where the study was performed, there was essentially no understanding of where dengue virus circulated outside of the capital Dhaka.

"In this context, seroprevalence studies can help. Once infected, individuals develop long-lived antibodies that can be detected by specific tests" explains Henrik Salje, head of the Mathematical Modelling of Infectious Diseases Group at the Institut Pasteur. However, seroprevalence studies are nearly only done in single places, which means their findings are unlikely to be applicable to the wider population. By contrast, in this study, the researchers visited 70 different communities from all around Bangladesh, and invited over 5,000 individuals of all ages to provide blood samples, which were tested for evidence of dengue antibodies. They also asked individuals about themselves, including their age, sex and travel history, and trapped mosquitoes.

Modeling the introduction and spread of dengue

Researchers estimated that 24% of the Bangladesh population has been infected by dengue in their lifetime. However, this ranged from 3% to villages in the north of the country to close to 90% in the large urban hubs. They used mathematical models to estimate the number of annual infections and built maps that predicted where risk was concentrated. They estimated that there was an average of 2.4 million infections each year, mainly concentrated to the cities of Dhaka, Chittagong and Khulna. Outside these urban hubs, there was still some exposure to dengue, with risk concentrated in men, who tended to travel more. The main dengue mosquito, Aedes aegypti, was mainly found in urban cities, suggesting its current absence from many rural communities acts as a barrier to broad nationwide epidemics. Had researchers visited only a small number of communities, the resulting national estimates would have been very different, highlighting the danger in extrapolating findings from just a few communities to the whole country.

"Our findings will allow public health agencies in Bangladesh to concentrate their efforts to battle dengue and also suggests that monitoring where Aedes are found will help identify populations at risk" concludes Henrik Salje. The study design and analytical approaches researchers from the Institut Pasteur implemented are easily transportable to other countries and to different pathogens.
-end-


Institut Pasteur

Related Dengue Fever Articles from Brightsurf:

Researchers validate rapid tests to detect dengue, Zika, yellow fever and other viruses
The method identifies and distinguishes between flaviviruses that cause many diseases in humans and animals in Brazil.

Breakthrough on curbing dengue
Scientists from Australia's national science agency, CSIRO, and the University of California San Diego have engineered the first breed of genetically modified mosquitoes resistant to spreading all four types of the dengue virus.

Mosquitoes engineered to repel dengue virus
An international team of scientists has synthetically engineered mosquitoes that halt the transmission of the dengue virus.

Cellular culprit suspected of pushing dengue fever from bad to worse is cleared by transcripts
No one knows what makes a mild dengue viral infection morph into a severe and sometimes deadly dengue hemorrhagic fever/dengue shock syndrome.

Forecasting dengue: Challenges and a way forward
International collaboration is finding new ways to improve how scientists develop and test models to forecast dengue infection.

Anemia may contribute to the spread of dengue fever
Mosquitoes are more likely to acquire the dengue virus when they feed on blood with low levels of iron, researchers report in the 16 September issue of Nature Microbiology.

People's initial immune response to dengue fever analyzed
Researchers have come one step closer to understanding how our immune system responds to acute dengue fever, a disease that has affected hundreds of thousands of people in Southeast Asia this summer alone.

Possible treatment on the horizon for severe dengue disease
New study reveals enzyme plays key role in potentially fatal dengue haemorrhagic fever and shock; suggests clinically approved tryptase inhibitor could be key in future targeted treatment.

A new picture of dengue's growing threat
New research shows the expanded risk of dengue virus infection through 2080, with detailed maps for 2020, 2050 and 2080.

Shedding light on the burden of dengue in Bangladesh
Dengue, also known as dengue fever, is a viral disease transmitted to humans by mosquitoes of the genus Aedes.

Read More: Dengue Fever News and Dengue Fever Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.