Officials from the Epidemiology and Disease Control Division recently returned from Sankhuwasabha, a mountain district, which witnessed a massive dengue outbreak this year.

Over 1,200 people tested positive for the disease from the district, which was previously considered non-endemic to dengue infections.

Along with Sankhuwasabha, all 77 districts including mountainous districts have reported the dengue virus.

“All our presumptions and beliefs have become irrelevant in the case of the dengue virus,” said Dr Gokarna Dahal, chief of the Vector Control Section at the division. “This year too all mountain districts reported dengue infection, and people from mountainous districts like Sankhuwasabha were the most affected.”

At least 20 have died and over 50,000 people tested positive for the virus this year and it continues to spread despite the decline in the onset of winter.

Public health experts suspect health authorities are understating the number of dengue-related deaths, as in several districts there are reports of more casualties than what has been officially confirmed. They say the real number of infected persons could be several times higher, as the government’s case reporting system is ineffective and more than 80 percent of cases are asymptomatic. Many people infected with dengue show mild symptoms and do not need treatment or can be treated with paracetamol at home.

Officials at the Health Ministry had hoped that the spread of the virus would stop once the temperature dipped. However, new dengue cases are being reported from various districts every single day.

“Dengue has become endemic in our country, as people are being infected with the virus throughout the year for the past few years,” said Dahal. “We held meetings with the agencies concerned and stakeholders of the highly affected districts and discussed measures to cut down on the infection rate.”

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

Last year, 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.

In 2019, the disease killed at least six people and more than 16,000 were hospitalised across the country. The virus had spread to 68 districts at the time.

Epidemiologists as well as virologists said dengue virus has of late emerged as a major public health problem in Nepal. They also said that despite thousands of persons getting infected and scores dying from the disease, the authorities have not taken it seriously. They believe that this lackadaisical approach is responsible for the spread of the virus. They said measures such as search-and-destroy and awareness drives should be initiated to contain the spread of virus-spreading vectors.

A report by the United Nations titled “Climate Change 2022: Impacts, Adaptation and Vulnerability” states that at least six major vector-borne diseases have recently emerged in Nepal and are now considered endemic, with climate change implicated as the primary driver.

The report also showed increasing evidence that climate change has extended the elevational distribution of Anopheles, Culex and Aedes mosquitoes, which carry viruses to above 2,000 metres in Nepal.

Dengue-transmitting mosquitoes breed in clean water and bite people in daylight. Uncovered water tanks and other discarded objects such as plastic cups and bottles could be breeding grounds for the dengue-carrying mosquitoes.

Symptoms of dengue include mild to high fever, severe muscle pain, rashes, severe headache and pain in the eyes, doctors say. Patients with these symptoms are advised to seek immediate treatment. While there is no specific cure for the disease, early detection and access to proper medical care can prevent death.