Clinical perspective

In all settings, a detailed travel, social and contact history can accurately predict the risk of exposure. Moet et al. showed that the most important determinants of clinical disease include i) the intensity of contact and ii) inherited susceptibility including HLA-DR2 and non-HLA polymorphism e.g. in TNF-α [6]. Seropositivity represents a 20-fold increased risk of developing clinical leprosy [7, 8] whilst the bacterial load, as measured by a skin smear can predict the transmission risk [6]. Differential diagnoses for multibacillary lepromatous skin lesions include scleroderma, mycosis fungoides, pellagra, asteatosis, ichtyosis and eczema or contact dermatitis. The primary neurological symptoms resemble common mononeuropathies. Where there is systemic involvement, clinicians should consider systemic lupus erythematosus, rheumatoid arthritis, dermatopolymyositis and systemic vasculitis.

Ideally, leprosy should be confirmed by the presence of acid-fast bacilli in skin biopsies or split skin smears. M. Leprae is a gram variable organism and can be decolourised by a Ziehl-Neelsen stain thus a modified Fite stain should be used. Skin biopsies should be taken from the centre of skin plaques or nodules in lepromatous leprosy and the periphery of tuberculoid lesions. Despite being a major referral centre, this district hospital did not have the laboratory facilities to perform split skin smears or skin biopsies. Whilst the WHO standard diagnostic criteria state that these investigations are not required to make a formal diagnosis (Table 1), this situation highlights the inadequacy of laboratory provisions in the Lilongwe health district. To achieve eradication targets, these secondary care institutions require access to reliable, definitive laboratory investigations. Boyce et al. demonstrate that strategies to improve investment at a national and district level are a cost-effective means of increasing detection rates, reducing misdiagnosis and improving the follow up of treatment [9].

Public health perspective

The WHO’s ‘Strategic Plan for Leprosy Elimination 2000–2005’ made a commitment to eliminate leprosy through control measures that are accessible at all local health facilities [10]. These control measures emphasised facilities to diagnose and treat patients with multidrug chemotherapy, patient and family counselling, community education, disability support, rehabilitation and referrals for complications. In some nations, the uptake of these strategies was slow and in 2006, the WHO published a revised plan; ‘The Global Strategy for Further Reducing the Leprosy Burden and Sustaining Leprosy Control Activities 2006–2010’ [11]. This focused on ‘morbidity control’ to further promote the timely detection of new cases, their treatment with effective multidrug chemotherapy, the prevention of disability and rehabilitation. The strategy emphasised equitable resource distribution and the provision of affordable and easily accessible care. Leprosy has long been a source of stigma thus socio-educational programmes were prioritised to dispel fear and motivate individuals to seek treatment.

Leprosy is a leading communicable cause of neurological disability throughout the globe [12]. As with this gentleman, ensuring timely diagnosis and treatment is the most effective way of mitigating damage to the sensory, motor and autonomic function of peripheral nerves. The WHO definition of Grade 2 disability (G2D) has been proposed as a more robust indicator of international progress than leprosy prevalence because it is less susceptible to operational factors such as treatment duration and case-finding methodology. In 2012 Msyamboza showed that 21 % of patients in their community-based cross sectional study in Malawi had a G2D [13]. The Enhanced Global Strategy for Further Reducing the Disease Burden due to Leprosy for 2011–2015, set a target to reduce new cases of leprosy with G2D per 100 000 total population by 35 % relative to 2010. Looking forward, their aim is to reduce the burden to 1 new G2D case per one million population by 2020 [14]. However, a criticism of the indicator is that such a neurological assessment may be too complex for some developing settings, especially for clinicians that haven’t received specific training and have no means of monitoring local prevalence [15].

The WHO has defined the elimination of leprosy as a ‘national prevalence of less than 1 case per 10 000 population’ [16]. Malawi fulfils this criteria, however Msyamboza et al. showed that between 2006 and 2011, the prevalence and detection rates actually increased [11]. Furthermore, cure rates for paucibacillary (1–5 lesions) and multibacillary (>5 lesions) leprosy were 63 and 33 % respectively; substantially below the expected 80 % [13]. This gentleman was misdiagnosed at the community health centre which indicates that despite global initiatives, cases of lepromatous leprosy are still missed in this region of Malawi. Attributable factors may include a lack of decentralisation to health centres for diagnosis and treatment, insufficient knowledge and skills of health centre staff, poor registration and recording systems, and a lack of political commitment by government and health partners [13]. However, to our knowledge there are no recent studies investigating these potential issues in Malawi. In addition to global efforts, individualised, national systems of detection, contact tracing and the provision of affordable treatments are needed to definitively eradicate leprosy in these settings [17].