While the State has been witnessing a wane in COVID-19 cases, the number of dengue cases are on the rise since January this year. With 939 cases being reported from January till March 31, the rise is significantly high compared to the corresponding period the previous year. In 2021, as many as 510 cases had been reported from January till March 31.
Of the 939, the highest (384) were reported in February while 264 were recorded in March. However, there have been no deaths so far. State health officials said the rise in cases is seen mainly in urban areas, where construction work has begun after the decline in COVID-19 cases.
State Health Commissioner Randeep D. said there is an increase in the number of dengue cases mainly in BBMP, Udupi, Mysuru, Chitradurga, Ballari and Koppal districts from January to March compared to corresponding period in the previous year. “We are reviewing the weekly situation for prevention and control (source reduction) activities. We have stepped up surveillance and intensified preventive measures and have geared up to tackle any outbreaks of dengue,” he said.
With nearly 22% (205) of the State’s total cases in 2022 (January to March) being reported in BBMP areas, Bengaluru city continued to record the highest number of positive cases. During the corresponding period in 2021, BBMP had recorded just 38 cases.
Hospitals in the city are getting sporadic cases with suspected dengue almost every day. Doctors, who said they are seeing such patients in the out-patient department, pointed out that there is no notable jump in admissions.
Cases in districts
According to data from the State Health and Family Welfare Department, Mysuru has recorded the highest number (83) - from January to March - among districts other than Bengaluru. Mysuru is followed by Ballari and Chitradurga that have recorded 68 cases each.
Health officials said dengue in Karnataka has been following a pattern of spiking every alternate year. According to data, 393 cases were recorded during the first three months (January to March) in 2019. While 1,539 were recorded in 2020 during the same period, 510 were recorded in 2021 in the first three months. However, the significantly low number of cases in 2020 could also be due to the pandemic restrictions, said a senior health official from the National Vector Borne Disease Control Programme (NVBDCP).
Surveillance should be similar to COVID-19
Susanta Kumar Ghosh, former Scientist and Head, field station of ICMR-National Institute of Malaria Research in Bengaluru, said dengue surveillance should be similar to COVID-19.
“Although, dengue spurt is usually seen in early May and then peaks during September-October, this year the rise is seen early, especially because all COVID restrictions have been relaxed and people have been moving around,” he said.
Asserting that there are similarities between dengue and COVID-19, Dr Ghosh said: “Both dengue and COVID-19 are single-stranded positive sense RNA viruses that have animal origin linkage. Epidemiologically, both the diseases present over 80% asymptomatic cases. COVID-19 is an air-borne respiratory disease; while dengue is transmitted mainly by day biting A edes aegypti mosquitoes.”
“Most dengue control programmes now are based on reducing transmission at home. However, the findings of a study published on March 2 this year in Lancet Infectious Diseases suggest that a renewed focus on transmission reduction programmes at public places should be given priority,” he said.
“In view of the Lancet study it is suggested that two additional parameters - ‘Premise Condition Index’ and ‘Breeding percentage’ should be added under the neighbourhood surveillance system of Aedes mosquitoes. This will provide tempo-spatial data for better dengue control and management,” Dr. Ghosh added.
