Climate change delivers disease to Nepal’s mountain communities

OKHALDHUNGA, Nepal — About 1,300 meters above sea level, nestled into the foothills of the Himalayas, is the cliffside village of Manebhanjyang, located in the district of Okhaldhunga in eastern Nepal. As the sun comes up, the temperature sits at a chilly 10 degrees Celsius, but accustomed to the cool mornings, 45-year old Samal Dhan Rai, his wife, elderly uncle, and 8-year-old daughter are nonplussed.

Barefoot and dressed in light clothing, they get on with the day’s activities: tending to their goats, making plates out of leaves, and cooking breakfast. The average temperature is in fact slightly warmer than it used to be. In the past it seldom rose above 23°C, but at times now climbs over 30°C — and while this may be more comfortable, those degrees of difference are ushering in diseases this location has never experienced before.

One of those is visceral leishmaniasis, commonly known as kala-azar, which translates as “black fever.” 

“The rate at which people around me are getting infected … might cause massive challenges," said Samal, who belongs to the Indigenous Rai community. He had the disease in June 2020 and endured its debilitating effects for three months before receiving a diagnosis. Within two years, Samal’s nephew and elder brother — who live in a sand-colored home made of mud on the mountainside below — also contracted the disease.

Visceral leishmaniasis is a neglected tropical disease, or NTD, transmitted by the bite of infected adult female sand flies. It manifests initially as a fever and loss of appetite before eventually taking root in the internal organs, darkening its victims’ skin. If left untreated, visceral leishmaniasis is fatal in over 95% of cases.

Samal said he became unrecognizable when he contracted the disease, losing over 15 kilograms. He tried to keep the symptoms at bay with paracetamol and visits to a shaman before eventually traveling to Okhaldhunga Community Hospital, over an hour’s walk and another hour’s drive away.

Climate change’s impact on disease dynamics

Neither Samal nor his brother Shanta Bahadur Rai knows how they fell ill or why this disease has suddenly emerged in their community, but someone who does is Surendra Uranw, an assistant professor at the B. P. Koirala Institute of Health Sciences in Nepal, who works to generate evidence to support the visceral leishmaniasis elimination initiative led by the government. 

“Nepal is one of the top five countries [where] there are several consequences due to climate change’s impacts on vector-borne disease,” he said, adding that research shows that rising temperatures are changing the disease’s transmission dynamics.

Sand flies thrive in dark and humid environments where temperatures rise above 24°C; an environment that was previously only found in Nepal’s lowlands. Today, as temperatures increase, sand flies’ breeding grounds have swept up into the higher elevations of Nepal, exposing historically cooler communities that have never even heard of visceral leishmaniasis. 

These communities tend to be “the poorest of the poor,” said Uranw, explaining that visceral leishmaniasis is most common among people who live in mud-made houses where sand flies can hide in the cracks and crevices in the walls and bite those sleeping on the ground or working outdoors.

Using a bed net, sleeping above the ground, filling any household cracks, and improving personal hygiene can stave off the infectious bite. But many in more remote communities may not be able to afford bed nets or haven’t been made aware of these preventative methods. “If you talk about the hilly and mountainous districts, awareness about disease and its prevention is still very poor. They don't know about the disease because it has [only] been reported for [the last] five [to] seven years,” said Uranw.

Stemming the spread of NTDs

“Ultimately, more funding is needed,” Thoko Elphick-Pooley, the executive director of Uniting to Combat NTDs, said in a statement, adding that NTDs are historically underfunded yet perpetuate the cycle of poverty. Commitments like those recently made at the United Nations Climate Change Conference in Dubai, where $777 million was pledged to control, eliminate, and eradicate NTDs, are an example of what can be achieved when different stakeholders work together, Elphick-Pooley said.

The World Health Organization's 2021–30 NTD road map sets out a goal of less than 1% mortality due to visceral leishmaniasis in 56 counties by 2025 but very few organizations are focused on the disease, Uranw said, leaving the bulk of the work up to the central government, which is limited in what it can do. He believes partner NGOs and the international community could play a role in strengthening the capacity of health care workers in the hilly and mountain districts, and in supporting the government in developing a better elimination strategy that considers the disease as a byproduct of a warming atmosphere.

“If we can tackle or mitigate the effects of climate change, in particular vector-borne diseases, we can save thousands of people's lives,” Uranw said.