Publications by authors named "Humphrey Mkali"

As part of malaria nationwide monitoring and evaluation initiatives, there is an increasing trend of incorporating malaria rapid diagnostic tests (mRDTs) in surveys conducted within primary schools to detect malaria parasites. However, mRDTs based on the detection of histidine-rich protein 2 (HRP2) are known to yield false-positive results due to persistent antigenemia, and false-negative results may result from low parasitemia or Plasmodium falciparum hrp2/3 gene deletion. We evaluated diagnostic performance of an HRP2 and pan-parasite lactate dehydrogenase (HRP2/pLDH) mRDT against polymerase chain reaction (PCR) for detection of P.

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Testing and treating asymptomatic populations have the potential to reduce the population's parasite reservoir and reduce malaria transmission. Zanzibar's malaria case notification (MCN) platform collects detailed sociodemographic and epidemiological data from all confirmed malaria cases to inform programmatic decision-making. We describe the design and operationalization process of the platform and other malaria surveillance resources that are enabling Zanzibar's progress toward malaria elimination.

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In 2018, Zanzibar developed a national malaria strategic plan IV (2018-2023) to guide elimination of malaria by 2023. We assessed progress in the implementation of malaria activities as part of the end-term review of the strategic plan. The review was done between August and October 2022 following the WHO guideline to assess progress made towards malaria elimination, effectiveness of the health systems in delivering malaria case management; and malaria financing.

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Achieving malaria elimination requires considering both Plasmodium falciparum and non-P. falciparum infections. We determined prevalence and geographic distribution of 4 Plasmodium spp.

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Background: Insecticide resistance is a serious threat to the continued effectiveness of insecticide-based malaria vector control measures, such as long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS). This paper describes trends and dynamics of insecticide resistance and its underlying mechanisms from annual resistance monitoring surveys on Anopheles gambiae sensu lato (s.l.

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Background: Despite high coverage of malaria interventions, malaria elimination in Zanzibar remains elusive, with the annual number of cases increasing gradually over the last 3 years.

Objective: The aims of the study were to (1) assess the spatiotemporal dynamics of malaria in Zanzibar between 2015 and 2020 and (2) identify malaria hotspots that would allow Zanzibar to develop an epidemiological stratification for more effective and granular intervention targeting.

Methods: In this study, we analysed data routinely collected by Zanzibar's Malaria Case Notification (MCN) system.

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Background: Tanzania has made remarkable progress in reducing malaria burden and aims to transition from malaria control to sub-national elimination. In 2013, electronic weekly and monthly reporting platforms using the District Health Information System 2 (DHIS2) were introduced. Weekly reporting was implemented through the mobile phone-based Integrated Disease Surveillance and Response (eIDSR) platform and progressively scaled-up from 67 to 7471 (100%) public and private health facilities between 2013 and 2020.

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Background: Transmission of malaria in sub-Saharan Africa has become increasingly stratified following decades of malaria control interventions. The extent to which environmental and land cover risk factors for malaria may differ across distinct strata of transmission intensity is not well known and could provide actionable targets to maximize the success of malaria control efforts.

Methods: This study used cross-sectional malaria survey data from a nationally representative cohort of school-aged children in Tanzania, and satellite-derived measures for environmental features and land cover.

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Background: Over the past two decades, Zanzibar substantially reduced malaria burden. As malaria decreases, sustainable improvements in control interventions may increasingly depend on accurate knowledge of malaria risk factors to further target interventions. This study aimed to investigate the risk factors associated with malaria infection in Zanzibar.

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As countries transition toward malaria elimination, malaria programs rely on surveillance-response systems, which are often supported by web- and mobile phone-based reporting tools. Such surveillance-response systems are interventions for elimination, making it important to determine if they are operating optimally. A metric to measure this by is timeliness.

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Background: Mass drug administration (MDA) has the potential to interrupt malaria transmission and has been suggested as a tool for malaria elimination in low-endemic settings. This study aimed to determine the effectiveness and safety of two rounds of MDA in Zanzibar, a pre-elimination setting.

Methods: A cluster randomised controlled trial was conducted in 16 areas considered as malaria hotspots, with an annual parasite index of > 0.

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Background: Mass drug administration (MDA) appears to be effective in reducing the risk of malaria parasitaemia. This study reports on programmatic coverage and compliance of MDA using artemisinin-based combination therapy (ACT) in four shehias (smallest administration unit) that had been identified as hotspots through Zanzibar's malaria case notification surveillance system.

Methods: Mass drug administration was done in four shehias selected on the basis of: being an established malaria hot spot; having had mass screening and treatment (MSaT) 2-6 weeks previously; and exceeding the epidemic alert threshold of 5 cases within a week even after MSaT.

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Purpose: Following surveys in 2004-2006 in 50 high-risk districts of mainland Tanzania, trachoma was still suspected to be widespread elsewhere. We report on baseline surveys undertaken from 2012 to 2014.

Methods: A total of 31 districts were surveyed.

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Malaria morbidity and mortality data from clinical records provide essential information towards defining disease burden in the area and for planning control strategies, but should be augmented with data on transmission intensity and serological data as measures for exposure to malaria. The objective of this study was to estimate the malaria burden based on serological data and prevalence of malaria, and compare it with existing self-treatment practices in Magugu in Babati District of northern Tanzania. Prospectively, 470 individuals were selected for the study.

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A 1-year longitudinal study was conducted in Magugu in Babati district, northern Tanzania to determine malaria vector population structure and malaria transmission indices. Mosquitoes were sampled using the Centre for Disease Control (CDC) light traps. A total of 110,357 adult female mosquitoes were collected.

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This study aimed at determining whether the predisposition of a mutation at position 179 of the ICAM-1 gene to child hospitalization due to malaria was mediated by changes in adherence properties of IRBCs to ICAM-1. ICAM-1 genotypes were determined by nested polymerase chain reaction of isolated DNA from filter blood spots followed by Restriction Fragment Length Polymorphism (RFLP). Plasmodium falciparum adherence assays were done on immobilized purified ICAM-1.

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Background: Low density Plasmodium falciparum infections, below the microscopic detection limit, may play an important role in maintaining malaria transmission in low endemic areas as well as contribute to the maintenance of acquired immunity. Little is known about factors influencing the occurrence of sub-microscopic parasitaemia or the relation with immune responses.We investigated possible associations between the occurrence of sub-microscopic P.

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