Leprosy and Buruli ulcer: similarities suggest combining control and prevention of disability strategies in countries endemic for both diseases

Leprosy and Buruli ulcer (BU), after tuberculosis (TB), are the 2 and 3 most common mycobacterial diseases in humans, and are included in the World Health Organization’s (WHO) list of 17 neglected tropical diseases (NTD). Despite the declaration of leprosy elimination by WHO in 2000 in most countries, leprosy incidence remains fairly stable, highlighting the unintended consequences (e.g. prematurely shutting down control programmes), of randomly setting targets to eliminate complex infectious diseases like leprosy. Continued case notifications arising among children moreover suggest ongoing transmission. Elimination targets also put undue pressure on national programmes to reach elimination, decreasing the incentive to find and report new cases, resulting in underreporting. By comparison, BU is far less common and found in far fewer countries. BU is considered a re-emerging disease attributed to environmental factors such as deforestation, artificial topographic alterations (dams and irrigation systems), increasing populations engaged in basic manual agriculture in wetlands. Financial support for leprosy research has dramatically diminished over the past three decades, and this decline is reasonably attributed to the elimination targets of WHO. In contrast for BU, there has been a spectacular increase in the number of peer reviewed papers since the creation of the WHO Global BU Initiative (GBUI) in 1998, thanks to notable financial support by nongovernmental (NGO) and international organisations. Leprosy and BU are complex diseases with specific clinical similarities and differences (Table 1). For leprosy, invasion of nerves by Mycobacterium leprae in untreated patients, and uncontrolled inflammatory immune reactions, which may develop in patients on treatment, may lead to permanent peripheral neuropathy, blindness, or both. The WHO strategy for leprosy from 2011 to 2015 includes efforts to focus on and reduce Grade 2 disability, but the benefits to patients may be much delayed. For BU, severe scarring with limb contractures Lepr Rev (2015) 86, 1–5