New strain of dengue in Bengaluru

New strain of dengue in Bengaluru

An Aedes aegypti mosquito under the microscope at the Bangalore Medical College

Though state health officials proclaimed imminent victory over mosquito-borne diseases in Karnataka, the city reported a new strain of the dengue virus found nowhere else in the state, gripping health officials and researchers in panic.

Dr M S Sathyanarayan, assistant professor at the Department of Microbiology at Victoria Hospital, said the new serotype, categorised as ‘Den-4’, less virulent than the Den-2 serotype responsible for afflicting a majority of cases in Bengaluru, has been found in parts of the city, including Adugodi.

“We are yet to ascertain the cause of this new strain in the city and where it came from,” Dr Sathyanarayan told DH, speaking at the sidelines of a national conference on dengue in the city on Thursday.

State health officials, nevertheless stressed that incidences of mosquito-borne diseases in the state had come down. Dr Shivaraj Shetty, joint director of the National Vector Borne Disease Control Programme (NVBDCP), added that health officials had managed to bring about a 75% reduction of such viral cases in Karnataka.

According to figures from Dr Mahmood Shariff, research officer, NVBDCP, the state has made significant reductions in mosquito-borne diseases since 2014. In 2014, the state had 14,794 malaria cases against 621 this year (until April); concerning Japanese Encephalitis, while the state had 133 cases and 34 deaths in 2014, it registered 124 cases and zero deaths this year. In 2014, there were 942 Chikungunya cases. Today there are 400.

Dr Sunanda Reddy, chief vigilance officer for the city’s District Surveillance Unit, added that the dengue incidence rate had reduced sharply since its peak three years ago. “In 2017, figures for dengue in the state were at their highest with 17,844 cases (out of 1,88,401 cases in India). This year, till May 13, we have had 773 cases in the state,” said Dr Reddy.

In Bengaluru, the situation is different. As the Department of Health and Family Welfare showed 9 cases in Bengaluru (Urban) since January, BBMP wards reported 383 cases during the same period, less than the total of 1,554 cases reported last year.