Zambia: A Narrative Review of Success and Challenges in Lymphatic Filariasis Elimination.

The establishment of the Global Programme to Eliminate Lymphatic Filariasis (GPELF) to stop the transmission of infection has significantly reduced the incidence of lymphatic filariasis, a debilitating mosquito-borne neglected tropical disease. The primary strategies that have been employed include mass drug administration (MDA) of anthelminthics and morbidity management and disability prevention (MMDP). While some countries have been able to reach elimination status in Africa, there is still active transmission of LF in Zambia. The nematode responsible for the disease is Wuchereria bancrofti, which is transmitted by Anopheles mosquitoes. To alleviate the suffering of those infected by the disease, the Zambian Ministry of Health launched a program to eliminate LF as a public health problem in 2003. This project reviewed the efforts to achieve the elimination of LF in Zambia, past and present government policies, and the anticipated challenges. MDAs have been conducted since 2014 and coverage has been between 87% and 92%. Zambia has now moved towards pre-transmission assessment surveys (PRETAS) and transmission assessment surveys (TAS). MMDP is a major priority and planned to be conducted between 2022 and 2026. COVID-19 presented a new challenge in the control of LF, while climate change, immigration, co-infections, and funding limitations will complicate further progress.

Lymphatic filariasis in Zambia: A scoping review protocol.

BACKGROUND: Zambia is among the countries making major progress in limiting cases of the neglected tropical disease lymphatic filariasis on the path to reaching global elimination targets. For this trend to continue, it is essential for strategies and policies targeting the disease in Zambia to be based on the most recent and relevant literature. The scope of research on lymphatic filariasis in the Zambian context is currently poorly understood. Therefore, this study describes a scoping review protocol which will be used to analyze the body of literature on lymphatic filariasis in Zambia. METHODS: The scoping review protocol was developed following the PRISMA reporting guidelines for Scoping Reviews (PRISMA-ScR) and the JBI Scoping Review Methodology Group's guidance on conducting scoping reviews. In consultation with a research librarian, these guidelines will be applied to a literature search of articles from peer-reviewed journals, or government and international regulatory bodies using PubMed, Embase, Web of Science, Cochrane CENTRAL, WHO ICTRP, Pan African Clinical Trials Registry, and ClinicalTrials.gov. Each record will be screened at the abstract and full-text level by two independent reviewers, and results reported via summary statistics. DISCUSSION: Understanding the current state of research on lymphatic filariasis in Zambia will identify major knowledge and intervention gaps in this context, and serve as a source of information for surrounding countries in the region. As the disease prevalence drops, efforts for elimination will require carefully targeted strategies which can be informed from the literature identified in this protocol.

Reach and uptake of mass drug administration for worm infections through health facility-, school-, and community-based approaches in two districts of Zambia: a call for scale-up.

Helminthiases cause significant health deficiencies among children. Mass administration of anthelminthic drugs has had significant results to counter these effects. We assessed the effects on and determinants of treatment coverage of community-directed treatment among children in Zambia, using cross-sectional survey data, and using chi-square test and multilevel mixed-effects model. Of 1,416 children, 51.5% were males and 48.5% were females, while 52.7%, were school-age, and 47.3% were preschool-age. Overall treatment coverage was 53.7% (95% confidence interval (CI) 51.1, 56.4). More preschool-age children were treated compared to school-age ones, 65.2% versus 43.4%, P < 0.001. Similarly, more children under community-directed intervention were treated compared to regular mass drug administration (65.2% versus 51.1 %, P < 0.001). Treatment among school-age participants was associated with being male (Adjusted Odds Ratio (AOR 1.83, 95%CI 1.23-2.72), receiving community-directed treatment (AOR 5.53; 95%CI 3.41-8.97), and shorter distance to health facility (AOR 2.20; 95%CI 1.36-3.56). Among preschool-aged participants, treatment was associated with being residents of Siavonga district (AOR 0.03; 95%CI 0.01-0.04) and shorter distance to health facility (AOR 0.35; 95%CI 0.21-0.59). Community-directed treatment can be used to increase treatment coverage, thereby contribute to 2030 vision of ending epidemics of neglected tropical diseases.

Spatially explicit Schistosoma infection risk in eastern Africa using Bayesian geostatistical modelling.

Schistosomiasis remains one of the most prevalent parasitic diseases in the tropics and subtropics, but current statistics are outdated due to demographic and ecological transformations and ongoing control efforts. Reliable risk estimates are important to plan and evaluate interventions in a spatially explicit and cost-effective manner. We analysed a large ensemble of georeferenced survey data derived from an open-access neglected tropical diseases database to create smooth empirical prevalence maps for Schistosoma mansoni and Schistosoma haematobium for a total of 13 countries of eastern Africa. Bayesian geostatistical models based on climatic and other environmental data were used to account for potential spatial clustering in spatially structured exposures. Geostatistical variable selection was employed to reduce the set of covariates. Alignment factors were implemented to combine surveys on different age-groups and to acquire separate estimates for individuals aged ≤20 years and entire communities. Prevalence estimates were combined with population statistics to obtain country-specific numbers of Schistosoma infections. We estimate that 122 million individuals in eastern Africa are currently infected with either S. mansoni, or S. haematobium, or both species concurrently. Country-specific population-adjusted prevalence estimates range between 12.9% (Uganda) and 34.5% (Mozambique) for S. mansoni and between 11.9% (Djibouti) and 40.9% (Mozambique) for S. haematobium. Our models revealed that infection risk in Burundi, Eritrea, Ethiopia, Kenya, Rwanda, Somalia and Sudan might be considerably higher than previously reported, while in Mozambique and Tanzania, the risk might be lower than current estimates suggest. Our empirical, large-scale, high-resolution infection risk estimates for S. mansoni and S. haematobium in eastern Africa can guide future control interventions and provide a benchmark for subsequent monitoring and evaluation activities.