Dengue cases in the city have dropped sharply this year, with the district recording 24 positive cases till September, the lowest figure for the corresponding period in the past four years. However, health officials and experts have cautioned that the decline should be viewed carefully as the monsoon and post-monsoon transmission period is still underway.
According to district health data, Mohali recorded 486 dengue-positive cases during January-September in 2023, followed by 320 cases in 2024 and 58 in 2025. This year, the figure stands at 24, nearly 59 % lower than last year and more than 90 % lower than the corresponding figures of 2023 and 2024.
The month-wise data shows that cases remained low during the first half of the year but began rising gradually. Mohali reported zero cases in January, February and March, followed by two in April, one in May, three in June, and four in July. August recorded the highest monthly count so far at 10 cases, while four provisional cases have been reported in September.
The comparison data also shows that 7,011 samples were tested in 2023, 10,553 in 2024 and 10,945 in 2025. In September alone, the district had recorded 308 positive cases in 2023, 268 in 2024 and 27 in 2025.
With cases showing an increase, the district health department has intensified house-to-house surveillance in high-risk and vulnerable areas. Teams are checking coolers, flower pots, containers and other potential breeding sites where stagnant water can collect, besides educating residents about preventive measures.
{{/usCountry}}With cases showing an increase, the district health department has intensified house-to-house surveillance in high-risk and vulnerable areas. Teams are checking coolers, flower pots, containers and other potential breeding sites where stagnant water can collect, besides educating residents about preventive measures.
{{/usCountry}}Rainfall, temperature, and humidity are important factors
Civil surgeon Dr. Sangeeta Jain said the possibility of dengue mosquito breeding increases during this period and that the department was closely monitoring the situation despite the low number of cases. District epidemiologist Dr. Anamika Soni said teams were regularly checking water-collection points and taking appropriate measures wherever stagnant water or mosquito larvae were found.
Dr. Rajesh Gera, director and head, internal medicine and infectious diseases, Park Hospital, Panchkula, said weather conditions, particularly rainfall, temperature and humidity, play an important role in dengue transmission. “Dengue transmission depends on the availability of suitable breeding sites and climatic conditions. Excessive rainfall can sometimes wash away mosquito larvae, while lower-than-expected or poorly distributed rainfall may create fewer breeding opportunities. Temperature is equally important, as mosquitoes require a suitable range of temperature and humidity for survival and breeding. Changes in these conditions can therefore affect mosquito density and dengue transmission.”
He added that dengue has four major serotypes and infection with one serotype generally provides lifelong immunity against that particular serotype, but does not provide complete protection against the others.
Dr. Varsha, head of department, microbiology, Government Medical College and Hospital, Sector 32, Chandigarh, said the lower dengue incidence depends on multiple factors, involving vector density, climatic conditions, population susceptibility and dengue serotype circulation. She cautioned that the decline should be interpreted carefully as the post-monsoon transmission period is still ongoing.