Neglected tropical diseases: impact of COVID-19 and WHO’s response – 2021 update

Overview

Neglected tropical diseases (NTDs) are a diverse group of conditions of bacterial, viral, parasitic, fungal and noncommunicable origin. Their epidemiology is complex and are often related to environmental conditions. Many are vector-borne, have animal reservoirs and are associated with complex life cycles: all these factors make their public-health control challenging. WHO estimates that over 1.7 billion people require interventions for at least one NTD, every year.

Despite their diversity, NTDs share a common geographical and social context: their burden is predominantly borne in tropical areas across the globe, and they mainly affect resource-poor communities. The correlation with poverty is so close that these diseases are sometimes referred to as diseases of neglected populations. Such entrenchment among disadvantaged people with little public voice contributes to their neglect.

Conservative estimates indicate that NTDs contribute 19 million disability-adjusted life years (DALYs), which represents about 1% of the global burden of disease, although with large variation between tropical and non-tropical countries and between developing and developed areas.

There are 5 core strategic interventions that WHO recommends to reduce the burden of these diseases. These are: preventive chemotherapy (PC); individual case management; vector control; water, sanitation and hygiene (WASH); and veterinary public health.

From 2015–2019, over 1 billion people received one or more of the above interventions for NTDs. As a consequence, great progress has been made to reduce NTD prevalence and incidence. In 2020, special circumstances prevailed, as will be discussed in more detail in this paper.