Dengue threat looms as winter nears

Islamabad:As the last rains of the monsoon season hit most parts of the country before winter, the Pakistan Meteorological Department has sounded an alarm about possible dengue outbreaks.

It warned that the mosquito-transmitted disease could emerge in major cities, including the federal capital Islamabad and the neighbouring garrison city Rawalpindi, next month. According to a senior PMD official, in light of historical data analysis, current climate conditions, and future outlooks—particularly regarding the retreat of the monsoon—the atmospheric variables discussed are establishing a favourable environment for a spike in dengue fever cases. "The findings show that from mid-September 2024 onward, the environment has become conducive to dengue's onset, with an expected outbreak in October 2024, especially in 10 major cities, including Islamabad, Rawalpindi, Karachi, Lahore, Peshawar, Hyderabad, Faisalabad, Sialkot, Larkana, and Multan, along with regions impacted by post-monsoon rainfall," he told 'The News'.

The meteorologist urged all stakeholders to implement proactive measures against potential dengue outbreaks and said national health agencies and dengue control centres should stay connected with the PMD for weather updates.

The PMD has already forecast substantial rainfall until October 1 throughout the country, with flood warnings for urban regions in Punjab and advisories for possible landslides in upper Khyber Pakhtun­khwa, Murree, Galiyat, Azad Jammu and Kashmir, and Gilgit-Baltistan regions. The rains falling before September 30 in the country are considered to be monsoon rains, with October, November, and December being predominantly dry months. Health experts say dengue outbreaks usually occur during the post-monsoon season, which lasts from September 20 to December 5. Peak mosquito activity occurs two hours after sunrise and two hours before sunset, and breeding stops when temperatures fall below 16°C, according to them. Epidemiologist Dr Najeeb Durrani noted that early December could be considered the end of the dengue epidemic, primarily due to declining temperatures that made it increasingly difficult for the Aedes mosquito to survive and reduce its biting activity.

He said during that time, mosquitoes tended to seek warmer indoor environments to rest. "The last batch of eggs they have laid or are in the process of laying will remain dormant until conditions—specifically temperature and humidity—become favourable again, likely during the following summer months of August to September," he said.

The epidemiologist stressed the need for carrying out awareness campaigns within the community, encouraging residents to take responsibility for eliminating adult mosquitoes through insecticide residual spraying indoors. He also said as a preventive measure against dengue, it was important to identify and eliminate breeding sites where female mosquitoes might have recently laid eggs, such as in solid waste, water tanks, room coolers, old tyres, and open containers with stagnant water.