Twelve people, including children, have died, and 59 others have been infected with the Japanese encephalitis (JE) virus since the start of the monsoon in June this year.

Twenty-nine districts, including those in the Kathmandu Valley, have reported infection from the deadly virus, while eight districts—Kailali, Kapilvastu, Palpa, Chitwan, Rautahat, Sarlahi, Siraha, and Sunsari—have reported deaths from the infection.

“September and October are the peak months for outbreaks of the JE virus,” said Dr Bibek Kumar Lal, director of the Family Welfare Division at the Department of Health Services. “We have already stepped up surveillance and activated measures to break the transmission cycle of the deadly virus.”

Japanese encephalitis is a viral brain infection caused by the JE virus, which is endemic in Asia and parts of the Western Pacific. According to the World Health Organization, it is a mosquito-borne flavivirus, belonging to the same family as dengue, Zika, yellow fever, and West Nile viruses. The virus kills a third of those who fall ill and leaves up to half of those who survive with severe life-long disabilities, according to the UN health body.

Health officials say this year’s death rate from the JE virus has exceeded 20 percent, and among the deceased, the number of children under 15 years of age is very high.

Nepal has included the vaccine in its routine immunisation list, which the government provides free of cost to all children.

The country started administering the vaccine doses in 2006, eight years before the World Health Organization officially issued prequalification certification, as the infection and death rates of the JE virus were very high then.

In 2005, JE infections killed nearly 2,000 people in Nepal—mostly children from the districts of Tarai region.

In the first phase, all populations of the highly-affected four districts, Banke, Bardia, Dang, and Kailali, were inoculated with the JE vaccine. Later, the vaccination programme was expanded to 19 other affected districts, and children under 15 were inoculated.

The government integrated the JE vaccine into the routine immunisation list in 2015. However, data provided by the Health Ministry shows that only 50 percent of the infected patients were inoculated with the vaccine.

Doctors say the disease has no cure, so treatment focuses on managing symptoms. However, safe and effective vaccines are available to prevent infection.

Even though the vaccine is included in the regular immunisation list, several people still die and dozens get infected by the deadly virus every year.

“Now is the right time to vaccinate all those at risk,” said Dr Shyam Raj Upreti, an expert on immunisation. “Even if the vaccine does not help in outbreak management, it provides immunity from future infections. Authorities concerned must explore sources to finance vaccines and immunisation.”

Health officials said they are aware of the deadly disease outbreak and have already started consulting aid agencies for help to finance the JE vaccination programme.

“We have raised the issue with officials from the Global Alliance for Vaccine and Immunisation and requested their support,” said Lal. “We are also exploring other options to secure vaccine doses to help prevent future outbreaks.”

Health officials said they have stepped up surveillance measures and requested help from other agencies concerned to break the chain of disease transmission. The JE virus is transmitted to humans through the bite of infected Culex mosquitoes. Pigs and ducks are considered natural reservoirs of the virus.

Doctors advise taking precautions to avoid mosquito bites, such as using mosquito repellents, wearing long-sleeved clothes, and getting vaccinated if one lives in or is travelling to disease-endemic areas. They also stress the importance of awareness and timely treatment to prevent infections and deaths.

An estimated 12.5 million people are thought to be at high risk of JE infection in Nepal.