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The World Health Organization (WHO) alms to reduce new leprosy cases by 70% by 2030, necessitating advancements In leprosy diagnostics. Here we discuss the development of two WHO's target product profiles for such diagnostics. These profiles define criteria for product use, design, performance, configuration and distribution, with a focus on accessibility and affordability. The first target product profile outlines requirements for tests to confirm diagnosis of leprosy in individuals with clinical signs and symptoms, to guide multidrug treatment initiation. The second target product profile outlines requirements for tests to detect Mycobacterium leprae or M. lepromatosis infection among asymptomatic contacts of leprosy patients, aiding prophylactic interventions and prevention. Statistical modelling was used to assess sensitivity and specificity requirements for these diagnostic tests. The paper highlights challenges in achieving high specificity, given the varying endemicity of M. leprae, and identifying target analytes with robust performance across leprosy phenotypes. We conclude that diagnostics with appropriate product design and performance characteristics are crucial for early detection and preventive intervention, advocating for the transition from leprosy management to prevention. Abstracts in [phrase omitted], Francais, [phrase omitted] and Espanol at the end of each article. [phrase omitted] L'Organisation mondiale de la Sante (OMS) vise a reduire le nombre de nouveaux cas de lepre de 70% d'ici 2030, ce qui necessite un meilleur diagnostic de la maladie. Dans le present document, nous evoquons le developpement de deux profils de produit cible etablis par l'OMS a cette fin. Ces profils definissent des criteres en matiere d'utilisation, de conception, de performances, de configuration et de distribution du produit, en accordant une attention particuliere a l'accessibilite et a l'abordabilite. Le premier profil de produit cible decrit les exigences pour les tests servant a confirmer le diagnostic de la lepre chez les individus qui presentent des signes cliniques et des symptomes, afin d'orienter l'instauration d'un traitement a base de plusieurs medicaments. Le second profil de produit cible decrit les exigences pour les tests servant a detecter une infection a Mycobacterium leprae ou M. lepromatosis parmi les contacts asymptomatiques de patients lepreux, ce qui contribue a l'adoption de mesures prophylactiques et a la prevention. Nous avons eu recours a une modelisation statistique pour evaluer les exigences de sensibilite et de specificite de ces tests diagnostiques. Cet article met en evidence les obstacles a l'atteinte d'un niveau eleve de specificite en raison de l'endemicite variable de M. leprae, et a l'identification d'analytes cibles offrant de bons resultats chez les phenotypes lepreux. Nous concluons qu'un diagnostic reposant sur des caracteristiques de performance et de conception appropriees est essentiel pour detecter rapidement la maladie et intervenir en amont, et nous plaidons pour une prevention plutot qu'une gestion de la lepre. [phrase omitted] La Organizacion Mundial de la Salud (OMS) pretende reducir los nuevos casos de lepra en un 70% para 2030, lo que requiere avances en el diagnostico de la lepra. Aqui se analiza el desarrollo de dos perfiles de productos objetivo de la OMS para este tipo de diagnosticos. Estos perfiles definen los criterios de uso, diseno, rendimiento, configuracion y distribucion de los productos, centrandose en su accesibilidad y asequibilidad. El primer perfil de producto objetivo describe los requisitos de las pruebas para confirmar el diagnostico de la lepra en personas con signos y sintomas clinicos, con el fin de orientar el inicio del tratamiento con multiples farmacos. El segundo perfil de producto objetivo describe los requisitos de las pruebas para detectar la infeccion por Mycobacterium leprae o M. lepromatosis entre los contactos asintomaticos de los pacientes con lepra, para facilitar las intervenciones profilacticas y la prevencion. Se utilizaron modelos estadisticos para evaluar los requisitos de sensibilidad y especificidad de estas pruebas diagnosticas. El articulo destaca las dificultades para lograr una alta especificidad, dada la diferente endemicidad de M. leprae, y para identificar analitos diana con un rendimiento solido en todos los fenotipos de lepra. Concluimos que los diagnosticos con un diseno de producto y unas caracteristicas de rendimiento adecuados son fundamentales para la deteccion precoz y la intervencion preventiva, lo que favorece la transicion del manejo de la lepra a la prevencion., Introduction Leprosy, a neglected tropical disease, is caused by Mycobacterium leprae or less often by M. lepromatosis. (1) The disease is a chronic, moderately infectious condition affecting mostly skin, peripheral [...]

On 8 June 2022, the World Health Organization (WHO) released pivotal guidance, "Ending the neglect to attain the Sustainable Development Goals: A strategic framework for integrated control and management of skin-related neglected tropical diseases." Skin-related neglected tropical diseases, or skin NTDs, comprise a group of NTDs that produce signs and symptoms on the skin and include at least 9 diseases or disease groups. Moving away from disease-specific approaches, it is anticipated that synergies will be identified and integrated building on this shared feature, where possible, to achieve a greater health impact. This paper intends to draw attention to the prospects created by this scheme. The framework is a key basis for a proposal produced by WHO dedicated to skin NTD integration and describes the practical opportunities for this evolving strategy. It underlines the wider health benefits that will follow, thus working towards Universal Health Coverage and skin health for all. [ABSTRACT FROM AUTHOR]

Rhodesiense human African trypanosomiasis is a lethal parasitic infection caused by Trypanosoma brucei rhodesiense and transmitted by tsetse flies in eastern and southern Africa. It accounts for around 5% of all cases of human African trypanosomiasis. Currently, there is no simple serological test for rhodesiense human African trypanosomiasis and diagnosis relies on microscopic confirmation of trypanosomes in samples of blood or other tissues. The availability of a simple and accurate diagnostic test would aid the control, surveillance and treatment of the disease. A subcommittee of the World Health Organization's Neglected Tropical Diseases Diagnostics Technical Advisory Group has developed a target product profile for a diagnostic tool to identify T. b. rhodesiense infection. The optimum tool would have a sensitivity and specificity above 99% for detecting T. b. rhodesiense, but be simple enough for use by minimally trained health-care workers in unsophisticated peripheral health facilities or mobile teams in villages. The test should yield a qualitative result that can be easily observed and can be used to determine treatment. An antigen test would be preferable, with blood collected by finger-prick. Ideally, there should be no need for a cold chain, instrumentation or precision liquid handling. The test should be usable between 10 °C and 40 °C and between 10% and 88% relative humidity. Basic training should take under 2 hours and the test should involve fewer than five steps. The unit cost should be less than 1 United States dollar. [ABSTRACT FROM AUTHOR]

Having caused devastating epidemics during the 20th century, the incidence of life-threatening human African trypanosomiasis has fallen to historically low levels as a result of sustained and coordinated efforts over the past 20 years. Humans are the main reservoir of one of the two pathogenic trypanosome subspecies, Trypanosoma brucei gambiense, found in western and central Africa. The expected advent of a safe and easy-to-use treatment to be given to seropositive but microscopically unconfirmed individuals would lead to further depletion; in the meantime, the presence of T. b. gambiense infection in the community must be monitored to allow the control strategy to be adapted and the elimination status to be assessed. The World Health Organization has therefore developed a target product profile that describes the optimal and minimal characteristics of an individual laboratory-based test to assess T. b. gambiense infection in low-prevalence settings. Development of the target product profile involved the formation of a Neglected Tropical Diseases Diagnostics Technical Advisory Group and a subgroup on human African trypanosomiasis diagnostic innovation needs, and an analysis of the available products and development pipeline. According to the product profile, the test should ideally: (i) require a minimally invasive or non-invasive specimen, collectable at peripheral facilities by minimally trained health workers; (ii) demonstrate good sensitivity and high specificity; (iii) have a stability of samples allowing transfer to reference laboratories preferably without cold chain; (iv) be stable over a wide range of environmental conditions for more than 2 years; and (v) after marketing, be available at low cost for at least 7 years. [ABSTRACT FROM AUTHOR]

Human African trypanosomiasis is a life-threatening parasitic infection endemic to sub-Saharan Africa. Around 95% of cases are due to Trypanosoma brucei gambiense, found in western and central Africa. Clinical signs and symptoms are nonspecific, current diagnostic tests are not sufficiently accurate, and parasitological confirmation of infection requires microscopic examination of body fluids and specialized techniques for concentrating parasites. Moreover, current treatment is not recommended on the basis of suspicion alone because it is not sufficiently safe. The availability of a simple and accurate diagnostic test to identify individuals harbouring parasites would widen treatment and help decrease disease prevalence. A subcommittee of the World Health Organization's Neglected Tropical Diseases Diagnostics Technical Advisory Group has developed a target product profile for a diagnostic tool to identify T. b. gambiense infection. This tool should have a high sensitivity for detecting T. b. gambiense but be simple enough to use in rural Africa. Ideally, the tool could be applied by any minimally trained individual in an unsophisticated peripheral health facility, or a mobile team in a village with little infrastructure. The test should be able to function under hot and humid conditions. Basic training should take under 2 hours and the test should involve fewer than five steps. There should be no need for instrumentation or precision liquid handling. The test should yield a qualitative result in under 20 minutes that can be easily observed, and one test should be sufficient for determining treatment. A unit cost below 1 United States dollar (US$) would enable mass screening. [ABSTRACT FROM AUTHOR]

Human African trypanosomiasis is a life-threatening parasitic infection transmitted by the tsetse fly in sub-Saharan Africa. The most common form is caused by Trypanosoma brucei gambiense , with humans as the main reservoir. Diagnosis in the field requires microscopic examination performed by specifically trained personnel. After over two decades of sustained efforts, the incidence of the disease is strongly declining, and some historically endemic countries are no longer detecting cases. The World Health Organization (WHO) has targeted the elimination of transmission of gambiense human African trypanosomiasis by 2030, defined as zero autochthonous cases for at least five consecutive years. Endemic countries reaching this goal must maintain dedicated surveillance to detect re-emergence or re-introduction. With this new agenda, new tools are needed for verification of the absence of transmission. WHO has therefore developed a target product profile calling for development of a method for population-level cross-cutting surveillance of T. b. gambiense transmission. The method needs to be performed in national or sub-national reference laboratories, and to test in parallel numerous samples shipped from remote rural areas. Among other characteristics the product profile specifies: (i) a simple specimen collection procedure; (ii) no cold-chain requirement to transfer specimens to reference laboratories; (iii) high sensitivity and specificity; (iv) high-throughput, substantially automatized; (v) low cost per specimen, when analysed in large batches; and (vi) applicable also in animals., ((c) 2023 The authors; licensee World Health Organization.)