Chikungunya cases rise in state ahead of monsoon

MUMBAI: Even before the onset of monsoon, Maharashtra is witnessing a sharp uptick in chikungunya cases, even as malaria and dengue infections remain largely under control. No deaths from any vector-borne disease have been reported in the state so far this year—a marked improvement from the same period in 2024.

Chikungunya is a viral disease transmitted to humans through the bite of infected mosquitoes, primarily Aedes aegypti and Aedes albopictus.

According to the National Center for Vector Borne Disease Control (NCVBDC), Maharashtra recorded 2,726 malaria cases up to April 21 this year, marginally lower than the 2,867 cases in the corresponding period of 2024. Dengue cases declined to 1,373 from 1,639. However, chikungunya infections rose significantly—from 473 cases last year to 658 this year.

Importantly, there have been zero fatalities from malaria, dengue, chikungunya, Zika, or Japanese Encephalitis (JE) in 2025 so far. By contrast, four malaria-related deaths had been reported by April last year.

“The absence of deaths shows that we’re detecting and treating cases early,” said a senior official from the state vector control unit, who requested anonymity. “But the rise in chikungunya is a red flag. As the monsoon nears, intensified surveillance and source reduction efforts are essential.”

Local challenges

Over the past decade, Maharashtra has made substantial progress in combating malaria. Cases have fallen from 56,603 in 2015 to 21,078 in 2024—a 62.7% reduction. The Annual Parasite Incidence (API) has dropped from 0.47 in 2015 to 0.1 since 2022.

Despite this, localised outbreaks persist. Gadchiroli district accounts for more than 75% of rural malaria cases, while Greater Mumbai reports nearly 70% of urban cases.

Officials credit the progress to sustained interventions; declaring malaria a notifiable disease in December 2021, strengthening case reporting across public and private facilities, scaling up rapid diagnostic testing, and deploying community-level health workers to detect fever cases early.

Expanding vector control and surveillance

Statewide vector control operations now span 801 villages and 15 cities. Measures include indoor residual spraying, larvicidal treatments, and use of biological agents like Gambusia fish. In 2024 alone, over 4.95 lakh insecticide-treated bed nets were distributed—more than 2.12 lakh in Gadchiroli district.

To monitor trends, 89 sentinel surveillance sites have been set up, allowing near real-time tracking of outbreaks. Coordination across departments has also been bolstered: the state formed a high-level Communicable Diseases Prevention & Control Committee in August 2024, followed by the reconstitution of a special malaria task force for Gadchiroli in March 2025 under public health expert Dr Abhay Bang.

In October 2024, the state passed a resolution urging urgent chikungunya and dengue control measures in urban municipalities, anticipating future surges.

While current data offers some reassurance, health authorities warn that the peak transmission season is still ahead.

“Zero deaths is an achievement,” said a senior official from the state health department. “But the virus doesn’t wait. The next 60 days will be the real test.”