Odisha may be staring at a more dangerous outbreak with dengue changing its course and presenting itself with different strains in different pockets. With multiple serotypes being detected, possibilities of severe clinical manifestations are being warned.
There are four serotypes of dengue virus, but different pockets have reported different strains or their combination in the past four years which has raised the threat perception. This year, Serotype I and III and their combinations have been detected among the patients.
The SCB’s Microbiology department has submitted 124 serum samples for investigation to the Regional Medical Research Centre (RMRC). Of the stereotyping completed in 32 samples, according to SCB sources, combination of Serotype I and III were found in at least 16 cases. In six cases, it was either Serotype I or III. Ten samples tested negative.
Experts are of the view that infection due to a second serotype in presence of antibody during the past infection in an individual can give rise to severe clinical complications. “This year and in subsequent years, there is a possibility of double serotype infection raising the chance of severe clinical issues such as haemorrhage and shock. This needs adequate preparation for management and provision of blood and platelet transfusion,” said a source in the SCB Medical College.
Interestingly, the dengue history in Odisha reveals that the virus has been present in all its four strains, but in different regions. It was in 2010 that dengue was first reported from Malkangiri and the same year, two villages of Gajapati were affected by the infection which lasted for a short time.
However, the next year, as many 25 districts were affected and Anugul, Dhenkanal, Jagatsinghpur, Jajpur and Puri districts were pre-dominantly hit. Overall, dengue infection was 58 per cent of suspected cases. During 2010 and 2011, Serotype II was the only strain circulating in Odisha.
In 2012, the disease’s epicentre was twin in nature __ Ganjam and Balasore, and sporadic cases were reported from coastal pockets. While the infection rate was 43 per cent of suspected cases, all four serotypes were detected.
Last year, Serotype II was present in around 80 per cent cases either as single Serotype or in combination with Type I, III or IV. Serotype circulation in Ganjam was mostly Type II and I, whereas in Balasore, it was Type II, I, III and IV. The strains were genetically closer to the ones circulating in Southern India, indicative of entry of infection from other endemic regions of the country. That is not all. Dengue is found to be capable of indigenous transmission in the State. The RMRC investigation has found virus from the adult female mosquito transmitted to their offsprings which has the potential to maintain the infection in the mosquito pool during inter-epidemic periods and transmit it to human population.