On Friday, health workers deployed from the Kathmandu Metropolitan City inspected Singha Durbar for potential breeding grounds for dengue-spreading mosquitoes.

The staffers working under the city’s Health Department could inspect only a few offices, but what they saw on the office premises of the government’s central secretariat were alarming.

“We found stagnant water and Aedes mosquito larvae in discarded tyres, plastic cups, bottles, and dumped toilet commodes in almost all offices,” said Rishi Bhusal, an epidemic control inspector at the city office. “We concluded that the offices inside Singhadurbar have also been providing breeding grounds to the virus-spreading vectors.”

Dengue is a viral disease transmitted by female Aedes aegypti and Aedes albopictus mosquitoes. According to the World Health Organisation, the same vector also transmits chikungunya, yellow fever, and the Zika virus.

Health workers deployed by the metropolis for a search-and-destroy drive showed mosquito larvae to officials and bureaucrats and asked them to regularly clean up mosquito breeding sites.

“We also discussed with senior officials and ministers the growing dengue cases in the country,” said Dr Dibas Neupane, an official serving under the department. “They took our initiatives positively and committed to following our requests.”

The metropolis’s Health Department has been carrying out a search-and-destroy drive every Friday in the areas under its jurisdiction. But officials deployed for the campaign have complained that some government officials are not taking their requests positively.

“We also inspected the office of the Nepal Electricity Authority, where we found discarded tyres in open and stagnant water inside the tyres,” said Neupane. “We asked them why they let mosquito larvae develop, but their response was dismissive, and they behaved as if we went there to annoy them because we did not have any other work to do.”

Officials say they later issued a letter of warning to the NEA office.

Some government offices, such as the Election Commission and the Office of the Vice President, have requested fumigation to kill mosquitoes. But health officials say fumigation is not an effective means of dengue control.

The government has directed all offices concerned to destroy mosquito breeding grounds every week, but the KMC’s inspections show that only a few have followed through. Most offices have been keeping the premises clean, but have overlooked discarded tyres, plastic bottles, and cups at certain corners.

Dengue mosquitoes breed in clean water and bite during daytime. Uncovered water tanks and discarded objects such as plastic cups and bottles can serve as breeding grounds.

So far, three people have died and 3,926 people have been hospitalised for treatment of the dengue virus this year, which has spread in 74 districts throughout the country.

In 2024, 15 people died, and 41,865 others were infected as the virus spread to 76 districts. In 2023, 88 persons died and more than 54,000 were infected by the virus, which had spread to all 77 districts. At the time, hospitals in Kathmandu Valley were overwhelmed with dengue patients, and pharmacies had run out of paracetamol, the most widely used medicine to treat fever.

Experts say reported cases may represent only a small fraction of the true scale of infection, as around 90 percent of the infected people are asymptomatic, and many deaths and infections often go unreported.

Many people infected with dengue show mild symptoms, which do not need any treatment or can be managed with paracetamol at home.

Since dengue became endemic in Nepal years ago, meaning people get infected throughout the year, health officials no longer classify it as an outbreak of a deadly virus.

Health officials warn that the risk of dengue infection has not yet passed, as the post-monsoon season, which is considered the peak dengue season, is yet to come.

“A sharp spike in cases is likely once the ongoing rainfall stops for a few days,” said Dr Gokarna Dahal, chief of the Vector Control Section at the Epidemiology and Disease Control Division. “Everyone should be cautious and take initiative to prevent the spread of the dengue virus.”

In the worst-case scenario, over 60,000 people could get infected with the dengue virus in the next three months, according to a projection prepared by the Epidemiology and Disease Control Division.

Doctors say that, along with launching a search-and-destroy drive on a regular basis, authorities should also focus on strengthening the capacity of health facilities to prevent them from being overwhelmed in the event of a possible massive outbreak, experts say.

Symptoms of the disease include mild to high fever, severe muscle pain, rashes, severe headache and pain in the eyes, among other things. Doctors advise those with these symptoms to seek immediate treatment. While there is no specific cure for the disease, early detection and access to proper medical care can lower fatalities.

Nepal reported its first dengue case in a foreigner in 2004 in Chitwan district. Since then, an increasing number of dengue infections, including major outbreaks, have been reported from many districts.

The World Health Organisation says there is no specific cure for severe dengue, but early detection and access to proper medical care can save lives.