The World Health Organization (WHO) has called for country commitment to combat neglected tropical diseases, as the agency braces itself for losing its biggest funder.

The WHO released a short video of director-general Dr Tedros Adhanom Ghebreyesus on World Neglected Tropical Diseases Day (30 January), outlaying the challenges facing programmes that address these types of diseases across the globe.

“These programmes face challenges including funding gaps, service disruptions, and climate change,” Dr Ghebreyesus said.

In a post on X, the WHO outlined the 21 tropical diseases adversely affecting human health. These diseases are called “neglected” because they have historically ranked very low on the global health agenda, leading to little funding and attention.

Mosquito-borne viruses such as dengue and chikungunya, sleeping sickness, and leprosy, amongst others, feature on the list. The agency estimates that 1.5 billion people each year require treatment due to a neglected tropical disease.

The WHO has a roadmap to ensure neglected tropical diseases are controlled, eliminated, or eradicated by 2030. However, as a result of reduced investment and other challenges, the agency states that this goal is at risk of not being achieved.

The organisation receives funding from two main sources, notably member states and voluntary contributions. The US was the largest contributor to the WHO in 2022-2023 under former President Joe Biden, giving the agency $1.28bn. This amounted to 12% of the WHO’s total budget – in comparison, China donated $157m. President Donald Trump has recently signed an executive order detailing the country’s intent to withdraw from the WHO, citing the health agency’s political sways, mishandling of Covid-19, and unfair payment demands.

Trump’s administration has already frozen the supply of HIV, malaria and tuberculosis drugs to countries supported by USAID. Dr Atul Gawande who served as assistant administrator for global health at USAID under the Biden Administration, told PBS News that waivers do not seem to include programmes for eliminating neglected tropical diseases.

The WHO did announce a global health win on the eve of Neglected Tropical Diseases Day, reporting that Guinea has eliminated the gambiense form of sleeping sickness, also known as human African trypanosomiasis. Programmes in the country used insecticides to interrupt contact between infected tsetse flies and humans, along with increasing accessibility to treatment. Then on 30 January, the agency congratulated Niger on becoming the first country in Africa to eliminate onchocerciasis, commonly known as river blindness.

Dr Ghebreyesus said: “To address them, programmes to fight neglected tropical diseases must be integrated into primary healthcare. We also need a ‘One Health’ approach to address the links between the health of humans, animals, and the environment.

“On World Neglected Tropical Diseases Day, we’re calling on all partners to unite, act, eliminate.”

Other tropical diseases such as dengue and chikungunya are more likely to require vaccinations. The WHO has previously called on member states to increase vaccine coverage in countries across the world and has placed importance on children missing out on key vaccinations.

The WHO expanded its partnership with the Global Health Innovative Technology (GHIT) Fund to promote access to safe, effective and affordable drugs, vaccines and diagnostics in the area of neglected tropical diseases. GHIT Fund is a public-private partnership between the Japanese Government, 16 pharmaceutical companies, and non-profits such as the Bill & Melinda Gates Foundation.

WHO’s stance on the critical need for vaccines is set against a changing US public health landscape under the new administration in the US. Neglected Tropical Diseases Day comes a day after Robert F Kennedy (RFK) Jr – Trump’s nominee for secretary for Health and Human Services (HHS) – was questioned over his position on vaccines at a Senate Confirmation Meeting. During the hearing, RFK Jr denied being anti-vaccine, despite senators bringing up previous comments that suggested otherwise.