A few weeks ago, a 14-year-old girl from Sangurigadhi Rural Municipality in Dhankuta district was taken to BP Koirala Institute of Health Sciences after she suffered from continuous high fever.

When she was brought to the hospital, her spleen and stomach had enlarged alarmingly and the haemoglobin level in her blood was on the lower side, which indicated that the patient was suffering from kala-azar, according to the doctor who attended the patient.

“The condition of the patient was serious,” Dr Surendra Uranw, a kala-azar researcher and public health epidemiologist at BP Koirala Institute of Health Sciences, who attended the patient, told the Post over the phone from Dharan.

Kala-azar, also known as visceral leishmaniasis or black fever, is transmitted through the bite of infected female phlebotomine sandfly. Loss of appetite, weight loss, weakness, cough, continuous fever and enlargement of spleen and stomach are common symptoms of the disease.

The patient was a teenager who got treated and discharged from the hospital but a significant number of children under five years old are getting infected from the deadly parasitic disease of late, alarming epidemiologists and entomologists.

According to the data provided by the Epidemiology and Disease Control Division, 57 children under five years old were infected with kala-azar in 2021. The number was 42 in 2020 and 22 in 2019.

“Overall cases of kala-azar have been rising but the number of patients under five years old is significant,” said Dr Gokarna Dahal, the chief of the Vector-borne Disease Control Section at the Epidemiology and Disease Control Division. “We too do not know the cause of the infection.”

Of the two types of sandflies—phlebotomus adlerious and phlebotomus major—experts attributed phlebotomus adlerious as responsible for the surge in infection among children.

Although the reason behind the infection mostly in children under five years old is yet to be established, phlebotomus adlerious is now found in the hilly and mountainous areas.

“Vectors of kala-azar have been present throughout the country. What is needed is the source of infection and if infected people travel, the risk of infection spread increases,” said Uranw, an expert on kala-azar who has also been carrying out a study on the vector. “Phlebotomus adlerious sandfly is also causing infection in children in other countries as well.”

Nepal had also committed to eliminating kala-azar by 2023 but rise in cases in the area considered non-endemic in the past poses a serious challenge to meeting the target, officials concede.

As many as 257 new cases of kala-azar infection were reported last year. The number is expected to rise this year, as the cases have been reported from many districts.

“If cases continuously rise in the places considered non-endemic in the past, we cannot meet the target of eliminating the disease from the country,” said Sishir Panta, an entomologist at Vector Borne Disease Research and Training Centre in Hetauda.

Earlier, kala-azar cases would not be found in areas above 650 metres from the sea level based on the belief that female phlebotomine sandflies do not survive at such altitudes.

But the Health Ministry’s data shows that the vector has been found in places located in altitudes of upto 2,000 metres such as Bajura, Dailekh, Pyuthan and Kalikot. Although the Health Ministry has declared 23 districts (mostly in the Tarai) as endemic to kala-azar, its cases have been reported from over 70 districts.

Manang, Mustang, Lamjung, Parbat and Myagdi are the only districts that have not reported any kala-azar cases until now.

Detection of kala-azar cases in unfamiliar places like Kalikot, where the elevation ranges from 738 metres to above 4,000 metres, indicates that phlebotomine sandflies are moving to higher altitudes as temperatures rise because of climate change.

The Health Ministry said that many cases have been reported from the Karnali and Sudurpaschim provinces.

A recent United Nations report ‘Climate Change 2022: Impacts, Adaptation and Vulnerability’ also states that at least six major vector-borne diseases, affected by the climate drivers, have recently emerged in Nepal and are now considered endemic.

Vector-borne diseases are spread by carriers like mosquitoes, sandflies, kissing bugs and ticks.

Experts say the parasitic disease disproportionately affects the poor and marginalised people.

They say that early diagnosis and treatment is necessary to save people from the infection of the deadly disease.

“If not treated on time the disease has up to 95 percent fatality rate,” said Uranw.