The Centre has deputed a team of experts to Tamil Nadu to investigate the outbreak of dengue in the state. The team, which includes doctors from All India Institute of Medical Sciences (AIIMS), National Vector Borne Disease Control Programme (NVBDCP), New Delhi, Lady Hardinge Medical College (LHMC) and National Centre for Disease Control (NCDC), New Delhi, will provide technical assistance to the state in dengue case management and vector control. The experts will also assess the situation and provide “necessary guidance” to manage and address the recent upsurge.
According to the data from the ministry of health and family welfare, this year alone, Tamil Nadu has reported 12,324 cases of dengue, and 18 deaths due to the mosquito-borne disease. The state opposition has reportedly claimed that the number is much higher than what is being reported and has been attacking the state government for not being able to control the situation.
Last year, only 2,531 dengue cases were reported from the state. This year, the highest number of cases have been reported from Thoothukudi (1,178), Chennai (1,138), Sankarankoil (1,072), Coimbatore (942), Thirupur (782) and Kanyakumari (777).
Data from the NVBDCP suggests that until October 8, among all states, Kerala has reported the highest number of cases (18,727, as compared to 7,439) in 2016). Karnataka comes a close second with 13,016 cases this year, as compared to 6,083 last year.
Dengue can be caused by the four serotypes of dengue virus (DEV). The way they affect the body's immune system is a complex phenomenon known as antibody-dependent enhancement (ADE). ADE takes place when non-neutralising antiviral proteins help virus entry into host cells, causing increased infectivity in the cells. Instead of neutralising the virus, these antibodies actually help the virus infect more efficiently, and the risk of dengue only rises significantly.
Despite the rise in dengue cases each year, however, a vaccine against the disease is not available in India. There are at least two candidates are in the fray–an indigenous tetravalent vaccine being developed by scientists at ICGEB, and another vaccine developed by France–based Sanofi Pasteur.
On an earlier occasion, Soumya Swaminathan, director general, ICMR, and secretary department of health research had told THE WEEK that over the next year, a seroprevalence study for dengue virus was being conducted in ten states with about 70-80,000 samples. This results of this study would be important in deciding whether a dengue vaccine could be introduced in the country. “We need to invest more in development of a vaccine. Since it's a complex area that requires a lot of research and development, not many good vaccine companies are willing to invest in it. The mosquito (Aedes aegypti) is adapting much faster, and more research in this area is needed,” she said.