Dengue cases have shown a consistent upward trajectory over the past four years.

Delhi is heading into the early mosquito season with a noticeable spike in dengue cases, reporting 52 infections in April 2026, the highest for the month in the last five years, according to Municipal Corporation of Delhi data. The rise has raised concern as vector-borne diseases are appearing earlier than usual this year.

Health officials say the pattern suggests an early onset of mosquito activity, with conditions becoming favourable even before the peak monsoon period. The trend suggests a possible longer transmission window for dengue in 2026.

Dengue cases have shown a consistent upward trajectory over the past four years. In April 2025, the city recorded 42 cases, while the figure stood at 31 in 2024, 24 in 2023, and just 12 in 2022, reflecting a steady year-on-year increase.

In contrast, malaria has shown a mixed but relatively contained pattern. The city reported 29 malaria cases up to April 2026, lower than 39 cases in the same period last year and 35 in 2024, but higher than 15 cases recorded in 2023.

Officials have attributed the early rise in infections partly to intermittent rainfall in April, which created stagnant water and ideal breeding conditions for mosquitoes across several parts of the city.

To control the spread, the Municipal Corporation has intensified anti-larval measures, fogging operations, and field inspections in residential colonies and construction sites.

More than 12.15 lakh households have already been inspected this year, as authorities step up surveillance ahead of the upcoming monsoon season.