| Literature DB >> 34798033 |
Jorge Alvar1, Margriet den Boer2, Daniel Argaw Dagne3.
Abstract
East Africa is the world region most affected by visceral leishmaniasis, accounting for 45% of cases globally that were reported to WHO in 2018, with an annual incidence that is only slightly decreasing. Unlike southeast Asia, east Africa does not have a regional approach to achieving elimination of visceral leishmaniasis as a public health problem. The goal of the WHO 2021-30 Neglected Tropical Diseases road map is to reduce mortality caused by the disease to less than 1%. To achieve this goal in east Africa, it will be necessary to roll out diagnosis and treatment at the primary health-care level and implement evidence-based personal protection methods and measures to reduce human-vector contact. Investment and collaboration to develop the necessary tools are scarce. In this Health Policy paper, we propose a strategic framework for a coordinated regional approach in east Africa for the elimination of visceral leishmaniasis as a public health problem.Entities:
Mesh:
Year: 2021 PMID: 34798033 PMCID: PMC8609279 DOI: 10.1016/S2214-109X(21)00392-2
Source DB: PubMed Journal: Lancet Glob Health ISSN: 2214-109X Impact factor: 26.763
Framework for a strategy for preparedness towards visceral leishmaniasis elimination in east Africa
| Case management | Early case detection; improve case management; reduce mortality; prevent stock-out of diagnostics and drugs | Timely forecast and supply of diagnostics and drugs; service decentralisation; development of referral capacity; regular training of health workers; free care for visceral leishmaniasis and comorbidities; screening patients with HIV for visceral leishmaniasis | Number of stock-outs; time from onset to treatment; financial burden to patients; compliance to treatment for visceral leishmaniasis, HIV-visceral leishmaniasis, and PKDL treatment; geographical access to diagnosis and treatment; incidence and mortality rate | Better rapid diagnostic test for visceral leishmaniasis; better (oral) drugs for treatment and prophylaxis of visceral leishmaniasis and PKDL; therapeutic vaccines; better PKDL diagnosis; improved and new visceral leishmaniasis and PKDL test of cure; telemedicine for PKDL diagnosis |
| Integrated vector management | Reduce contact with sandflies; monitor insecticide efficacy and resistance; establish entomology network | Mapping environmental risks; scaling up integrated vector management in different settings; training personnel in vector management; developing regional stocks of insecticide and integrated vector management tools; building entomology research centres and insectaries | Percentage covered by prevention measures; regional stocks of insecticide and integrated vector management tools; patients with visceral leishmaniasis, PKDL, or co-infection with HIV use vector control tools; the presence of a functional entomology network; the presence of a functional vector surveillance system | Vector control operational guidelines and tools; entomology experts and careers; regional centres of excellence |
| Effective surveillance | Map areas by risk level; map visceral leishmaniasis health services; improve epidemiological data on visceral leishmaniasis, case fatality rate, PKDL, and HIV-visceral leishmaniasis; outbreak preparedness and response | Implementing tools for data collection and analysis; outbreak preparedness and response; capacity building in surveillance; identifying the most affected groups | Tools routinely in use; timely response to outbreaks; sufficient personnel trained; case detection in new and existing endemic areas; presence of a functional surveillance system; whether visceral leishmaniasis is a notifiable disease | Tools are partially used; robust information system needed; outbreak response is led by non-governmental organisations; visceral leishmaniasis is not a notifiable disease |
| Social mobilisation | Increase awareness and establish behavioural change in health seeking behaviour and use of prevention tools | Information, education, and communication and behavioural change communication activities; targeted advocacy for the most affected groups; periodic knowledge, attitude, and practice studies | Most affected groups use integrated vector management tools; local activists are in place; most affected groups seek diagnosis and treatment promptly | Multilingual and cultural approach; migrant and displaced populations difficult to reach; most disease occurs in areas that are remote and difficult to access; poor socio-economic and health infrastructure |
| Operational research | Improve visceral leishmaniasis (in the presence and absence of HIV) and PKDL diagnosis and treatment; improve access to diagnosis and treatment; develop innovative vector control tools and test ivermectin for vector control | Studies of access barriers in the most affected groups; studies to improve diagnosis and treatment for visceral leishmaniasis, PKDL, and HIV-visceral leishmaniasis; studies on sandflies bionomics and vector control | Availability of new diagnosis and treatment; availability of new vector control tools; better knowledge of sand fly behaviour, and vector control strategy is planned accordingly; access issues known and strategies developed | Fragile security situation; limited expertise and dependence on external technical and financial support; unknown role of PKDL, asymptomatic carriers, and animal reservoir in transmission |
The overall impact of this strategy would include: new and improved tools for diagnosis and treatment for visceral leishmaniasis and PKDL; incidence and fatality rate reduced and large outbreaks prevented; catastrophic expenses reduced to negligible level; population protected from vector transmission; and fast access to diagnosis and treatment for most affected groups enabled. PKDL=post kala-azar dermal leishmaniasis.
Key differences in visceral leishmaniasis epidemiology, policy strategies, and control in east Africa and southeast Asia, and unmet needs in operational research in east Africa, by strategy phase
| Major endemic countries | Ethiopia, Kenya, Somalia, South Sudan, Sudan, Eritrea, and Uganda | Bangladesh, India, and Nepal | .. | NA | |
| Parasite | .. | NA | |||
| Vectors | |||||
| Main vectors | Bionomy studies of | Preparatory | |||
| Vector behaviour | Exophilic; sylvatic and peridomestic | Endophilic; predominantly indoors but also peridomestic | Insecticide resistance and rotation studies; role of asymptomatic carriers and patients with PKDL in transmission of infection to the vector | Consolidation | |
| Vector control | No proven, effective, or scalable vector control strategy; integrated vector management is recommended | Indoor residual spraying is effective; integrated vector management is recommended | Role of the animal reservoir in transmission | Preparatory | |
| Diagnosis | |||||
| Diagnostic algorithm | Diagnostic algorithm includes clinical assesment followed by a rapid diagnostic test, a direct agglutination test, and parasite detection via microscopy | Clinical and rapid diagnostic tests used; parasite detection via microscopy only used for relapses | .. | NA | |
| Performance of rapid diagnostic tests | Simple point-of-care rK39-antigen-based rapid diagnostic test sensitivity (85%) is lower than that in southeast Asia, but specificity is similar; | Simple point-of-care rK39-antigen-based rapid diagnostic tests have high sensitivity (97%) and specificity (90%) | Improved rapid diagnostic tests with high sensitivity and specificity to decentralise diagnosis | Preparatory | |
| Delay to treatment | Delay from first symptoms to treatment of 1–2 months | Delay from first symptoms to treatment of 1–3 months | Non-invasive test of cure for visceral leishmaniasis and PKDL; non-invasive diagnosis of PKDL; support with telemedicine | Attack | |
| Treatment and prevention | |||||
| Clinical severity | Severe disease; co-infections and comorbidities, and associated malnutrition are common; often needs management in hospital | Moderate disease; can generally be managed at primary health-care level | Biomarkers of evolution of visceral leishmaniasis towards PKDL; oral short course treatments for therapeutic or prophylactic purposes (mass drug administration during transmission season); therapeutic vaccines (visceral leishmaniasis and PKDL); monitoring drug resistance | Consolidation | |
| Treatment | Suboptimal efficacy, administration of multiple injections, long duration, and serious side-effects; sodium stibogluconate plus paromomycin combination as the first-line option has an efficacy rate of 91·4%; liposomal amphotericin B has variable efficacy; treatment is complex and given at a designated hospital or well equipped health centre; clinical mentoring teams ensure standard of care | Highly effective and safe single-dose regimen; single-dose liposomal amphotericin B is the first-line option, with an efficacy of >97%; relapses are treated with multiple doses of liposomal amphotericin B or combinations of miltefosine plus paromomycin; treatment is given at designated primary health-care centres | Establishment of a network of referral centres; monitoring drug efficacy; better understanding of reasons for delay in access to diagnosis and treatment | Preparatory | |
| Epidemiology | |||||
| Epidemiological trends and interventions since 2005 | No significant decline in incident cases; insufficient tools; recurrent epidemics, especially in Kenya, South Sudan, and Ethiopia; some reduction in mortality rate; high | Declining incidence: elimination target achieved in Bangladesh and Nepal pending WHO validation; significant reduction in mortality rate; HIV and | Validation of the historical foci and estimate the population at risk, incidence, and mortality; environmental risk maps to predict outbreaks; viability of mobile clinics for mobile and displaced populations; pharmacovigilance through sentinel sites; to determine the elimination threshold required for resurgence of cases | Preparatory | |
| Most affected groups | Children, low-income households in rural villages, seasonal agricultural workers (in Ethiopia), nomadic pastoralists, and displaced populations | Children and adults, particularly those in low social castes (Musharat) | .. | NA | |
| Transmission dynamics and ecology | Predominantly anthroponotic with zoonotic aspects; lowlands, acacia trees, black cotton soil, and termite hills | Anthroponotic; poor housing conditions and waste management, open sewerage, and cattle sheds | .. | NA | |
| Endemic area | Vast, scattered, and remote; long distances to treatment centres; poor socio-economic infrastructure and health systems | Densely populated areas with good access to primary health-care centres | .. | NA | |
| Programme target or goal | Control, with no defined target threshold | Elimination as a public health problem, defined as <1 case per 10 000 population at implementation-unit level | .. | NA | |
| Regional political commitments | No agreements among endemic countries; no WHO regional resolution or strategic action framework; control programmes rely on external support (from WHO, Médecins Sans Frontières, Drugs for Neglected Diseases initiative, the UK's Foreign, Commonwealth, and Development Office, etc), WHO-led coordination of national programmes and partners (through periodic review meetings) and Drugs for Neglected Diseases initiative-led leishmaniasis east Africa platform (LEAP) for clinical trials on drugs; no long-term donor commitments | Strong political commitment forged; a signed renewable memorandum of understanding among the endemic countries with WHO regional committee resolution; a 5-year rolling strategic framework (WHO) and a high level Regional Technical Advisory Group reporting to the Regional Director; donation programme for first-line treatment | .. | NA | |
| Programme strategy for access to care | Passive case detection; diagnosis and treatment provided for free; largely no support for bed occupancy fees and provision of meals, comorbidities, or transport; active case detection only in the event of outbreaks | Active case detection as a programme strategy; diagnosis and treatment provided for free, plus cash transfers for patients completing treatment as compensation for wage losses | .. | NA | |
PKDL=post kala-azar dermal leishmaniasis. NA=not applicable.