As dengue cases continue to rise globally, a recent study has challenged the commonly held belief that severe dengue cases are primarily linked to secondary infections. The study led by researchers from the Delhi-based International Centre for Genetic Engineering and Biotechnology (ICGEB) highlighted that even primary dengue infections can result in severe cases and fatalities.
This finding has important implications for public health and in developing and implementing effective and safe vaccine strategies for controlling dengue.
Over the past two decades, dengue infections have greatly increased in India. Dengue patients fall into two categories -- those experiencing the infection for the first time, known as primary infections and those who get re-infected after a previous exposure, known as secondary infections.
After analyzing severe dengue cases in a group of children in India, showing that more than half could be attributed to primary rather than secondary infection, the team emphasised the need to re-evaluate the understanding of dengue and the strategies employed to combat the viral disease cause by the dengue virus (DENV), transmitted to humans through the bite of infected mosquitoes.
"Dengue virus infection is a huge public health problem in India. Many patients develop severe diseases that can also be sometimes fatal," said lead author of the study, Anmol Chandele, from ICGEB. The research was published recently in the journal Nature Medicine.
"However, much of the ongoing vaccine intervention research is based on the currently widely held global belief that primary dengue infections are not usually dangerous and that the severe dengue disease is mainly due to secondary infections," Chandele said.
Italy is a striking example of the expansion of dengue as also evidenced by a recent study on which Alessandro Marcello, head of the ICGEB Molecular Virology laboratory operating in the Area Science Park in Trieste, Italy, collaborated.
"During 2023, in Italy, we had the highest number of cases and autochthonous transmissions of dengue so far. Climate change, above all, but also the movement of people, are the biggest contributors to the circulation of dengue in new areas. The study by our Indian colleagues shows us the need to protect our population also from the first encounter with the virus," Marcello said.
For the study, Chandele collaborated with researchers from Emory School of Medicine, US, the All India Institute Of Medical Sciences (AIIMS), New Delhi, and St. John's National Academy of Health Sciences, Bengaluru.