IISc demonstrates the evolution of the dengue virus in India through computer analysis.

The viral population has several strains of each serotype at any one time.
IISc demonstrates the evolution of the dengue virus in India through computer analysis.

Researchers at the Indian Institute of Science (IISc), Bengaluru are leading a multi-institution study on dengue that demonstrates how the virus that causes the illness has changed significantly over the past several decades across the Indian subcontinent.

Dengue cases, a virus spread by mosquitoes, have consistently climbed during the past 50 years, mostly in South-East Asian nations. Despite the fact that several vaccinations have been developed in other nations, there are currently no dengue vaccines that have been authorised for use in India.

Researchers looked at all (408) genetic sequences of Indian dengue strains that had been gathered from sick patients between 1956 and 2018 by the team as well as by others.

The dengue virus is divided into four major serotype categories (Dengue 1, 2, 3 and 4). The scientists used computational analysis to determine how much each of these serotypes differed from their global sequence ancestor, from other serotypes, and from each other.

Dengue 1 and Dengue 3 were the most prevalent types in India up to 2012. Dengue 4 was originally thought to be the least contagious, but the researchers discovered that Dengue 2 has recently gained ground nationwide while Dengue 4 is now carving out a niche for itself in South India. The research team was looking into what characteristics determine which strain is prevalent at any particular time. Antibody Dependent Enhancement may be one contributing element (ADE).

These discoveries can only be made by researching the illness in nations like India that have genetic surveillance, where infection rates have traditionally been high and where a large portion of the population still has antibodies from prior infections.