In sub-Saharan Africa (SSA), onchocerciasis control has been implemented for many decades, beginning in 1974 under the Onchocerciasis Control Programme in West Africa (OCP) and in 1995 in Central and East Africa (plus Liberia) under the African Programme for Onchocerciasis Control (APOC). Since the establishment of the Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN) in 2016, data on mass drug administration (MDA) with ivermectin has been centrally compiled for all endemic countries at implementation unit (IU) level, beginning in 2013. This paper presents HISTONCHO, a dataset collating detailed information on interventions, including vector control, from 1975 through to 2022, using the ESPEN portal (2013-2022), regional and country reports, implementation partners' records, and published literature. Reconstructing such intervention histories is crucial for an understanding of their evolution, modelling their impact, and tailoring future interventions. We discuss strengths and limitations associated with the ESPEN database, and how HISTONCHO can be improved to support modelling of intervention strategies as well as onchocerciasis control and elimination efforts by endemic country programmes.
Background Skin neglected tropical diseases (NTDs) such as cutaneous leishmaniasis, lymphatic filariasis, mycetoma, and podoconiosis affect millions in endemic regions, but are under-recorded despite causing significant burdens. Predictive modelling has been used to estimate the distribution and prevalence of some of these diseases, and predictions may be useful for identifying at-risk populations and guiding interventions. This review synthesises the literature on modelling approaches to predict skin NTD distributions, aiming to identify prevalent methodologies, evaluate their strengths and limitations, highlight research gaps, and provide recommendations for enhancing their utility.Methods We conducted a systematic literature review from three databases and included studies published from 2000-2024. Studies were included if they employed statistical models or machine learning algorithms to predict the distribution of skin NTDs. Two independent reviewers screened titles, abstracts, and full texts. Data extracted included disease, study region, source of epidemiological data, model types and predictors.Results From 2,870 retrieved records, 68 met the inclusion criteria. The most modelled skin NTDs were cutaneous leishmaniasis (n = 26) and lymphatic filariasis (n = 18). Geostatistical modelling was the most common approach, followed by ecological niche modelling, with MaxEnt and generalised linear models constituting the predominant model types. Common environmental covariates included climate, land cover and land use, elevation, and soil data. The types of epidemiological data varied, with many studies relying on passive surveillance and pseudoabsence data. The risk of bias was high among ecological niche models.Conclusions Environmental and geostatistical models can inform targeted interventions for skin NTDs, aiding efficient resource allocation and public health planning. However, data limitations, especially the absence of true absence data, underreporting and variations in surveillance sensitivity, can reduce model accuracy and undermine decision-makers' confidence. Future studies should focus on incorporating information about case identification into modelling frameworks, including a broader spectrum of environmental and socio-economic determinants, and ensuring validation across diverse geographic regions.
The 2025 Annual Meeting of National Neglected Tropical Disease (NTD) Programme Managers (2025 PMM) in the WHO African Region convened stakeholders in Lomé, Togo, under the theme “Innovating for Acceleration: Pathway to NTD Elimination.” A key focus was the changing funding environment and the necessity for enhanced integration of NTD services within health systems to guarantee sustainable advancement toward the 2030 elimination goals. The conference was convened in the context of substantial disruptions stemming from the USAID funding pause, which interrupted essential mass drug administration (MDA) programmes and epidemiological monitoring activities across multiple nations. Country experiences highlighted the fragility of external funding dependence and underscored the importance of domestic resource mobilization, decentralized implementation, and programmatic integration. Strategic discussions highlighted opportunities to incorporate NTD services into national health financing mechanisms, and routine health campaigns, alongside leveraging digital tools and partnerships. Participants emphasized the urgency of political commitment, sustained investments, and integrated service delivery models to build resilience and close equity gaps. The meeting further underscored the need for bold, country-led responses and multisectoral collaboration to advance NTD elimination efforts in a rapidly evolving global health financing environment.
Abstract Background Accelerated efforts to eliminate lymphatic filariasis (LF) as a public health problem have been supported by the introduction of the triple-drug regimen of ivermectin, diethylcarbamazine and albendazole (IDA) in endemic settings. In São Tomé and Príncipe, nationwide mass drug administration (MDA) with diethylcarbamazine and albendazole was implemented in 2018, followed by IDA in 2019 and 2020. This study assesses progress towards elimination using post-MDA impact assessment surveys conducted after cessation of treatment. Methods Cross-sectional surveys were conducted among adults aged 20 years and older in 2022 and again between December 2024 and January 2025. Circulating filarial antigen (CFA) was detected using the filarial test strip (FTS). Individuals who tested positive were examined for microfilaremia using nocturnal calibrated thick blood smear microscopy. Additionally, programme data on MDA coverage and morbidity were obtained from national surveillance records. Results Three rounds of nationwide MDA achieved high epidemiological coverage (86.4% in 2018, 74.2% in 2019 and 80.0% in 2020). The impact assessment surveys conducted in 2022 evaluated 14 132 adults, with 21 individuals (0.15%) testing positive for CFA, while the follow-up survey conducted between December 2024 and January 2025 assessed 14 653 adults and detected seven positive cases (0.05%). No microfilariae were detected among the 28 antigen-positive individuals examined using nocturnal calibrated thick blood smears. National morbidity records documented 190 cases of lymphoedema and nine cases of hydrocoele. Conclusions Infection indicators remain well below WHO decision thresholds, suggesting that LF transmission is unlikely to be sustained. São Tomé and Príncipe appears to be close to eliminating LF as a public health problem. However, strengthening morbidity management services will be essential to support the preparation of the national elimination dossier. Author summary Lymphatic filariasis is a parasitic disease transmitted by mosquitoes that can cause chronic swelling of the limbs (lymphoedema) and scrotal swelling (hydrocoele). In 2000, WHO launched the Global Programme to Eliminate Lymphatic Filariasis (GPELF) to interrupt transmission through MDA and provide care for affected individuals. Between 2018 and 2020, São Tomé and Príncipe implemented nationwide treatment campaigns using WHO-recommended drug combinations. To evaluate the reduction in transmission, surveys were conducted among adults in 2022 and again from 2024 to 2025. Very few people tested positive for infection: 21 out of 14 132 adults (0.15%) in 2022 and seven out of 14 653 (0.05%) in the 2024–2025 follow-up survey. No microfilariae were detected among antigen-positive individuals, and national records reported relatively low numbers of lymphoedema (190 cases) and hydrocoele (nine cases). Taken together, the findings indicate that ongoing transmission is very unlikely. They also suggest that parasite transmission is unlikely to persist and that São Tomé and Príncipe is close to eliminating lymphatic filariasis as a public health problem. However, it remains necessary to enhance services for the management of chronic disease manifestations.
OBJECTIVES:Zimbabwe is endemic for lymphatic filariasis (LF) with 39 districts identified for mass drug administration (MDA) in 2014. The objective of this study was to reassess the current population requiring MDA. METHODS:The LF confirmatory mapping method was used to evaluate the prevalence of circulating filarial antigens among school-aged children (9-14 years) in previously endemic districts. This was achieved through a cross-sectional survey between 2021 and 2023, applying a cluster sampling approach across 39 districts, targeting 18,720 children to assess ongoing LF transmission. RESULTS:The findings revealed a significant decline in LF prevalence, with an overall rate of 0.43%. Importantly, 82.05% of districts previously identified as endemic were reclassified as nonendemic. Only seven districts retained endemic status, necessitating continued MDA using the triple-drug therapy regimen. Population estimates based on 2022 census data indicated that 1.19 million individuals across these districts require MDA, representing an 84.4% reduction compared to previous estimates. Despite the progress, the persistence of low-level transmission in certain districts highlights the need for sustained surveillance and morbidity management services, including hydrocele surgery and lymphedema care. CONCLUSION:There was a significant reduction in the number of people requiring MDA. The decline in LF endemicity is attributed to a combination of factors, including prior rounds of MDA and vector control initiatives including historical interventions, such as dichlorodiphenyltrichloroethane spraying against human African trypanosomiasis.
BackgroundOnchocerciasis and lymphatic filariasis (LF) are endemic in Equatorial Guinea with notable variations in disease incidence between island and mainland regions. Historically, efforts to control and map these diseases were concentrated in Bioko Island, where loiasis is absent, allowing for targeted onchocerciasis interruption strategies. With the cessation of onchocerciasis transmission on Bioko and no reported cases on Annobon island, assessing the transmission status in the previously unaddressed mainland region has become imperative. Mapping efforts in mainland Equatorial Guinea have proven low to moderate level of transmission for LF and onchocerciasis, although the results so far have not been very conclusive. The current study aims to update the prevalence estimates for onchocerciasis and LF in mainland Equatorial Guinea using various diagnostic techniques.MethodsThis is the first cross-sectional study carried out to estimate the prevalence of onchocerciasis and LF in the mainland area of Equatorial Guinea, from September to December 2019, based on the combination of skin snip biopsies, thick blood smears, laboratory serological tests (ELISA tests for the detection of IgG4 antibodies against Onchocerca volvulus recombinant antigen Ov16 and Wuchereria bancrofti recombinant antigen Wb123) and molecular laboratory tests. Frequencies and prevalence rates, along with 95% confidence intervals for interval estimation of a binomial proportion, were computed.ResultsThe overall onchocerciasis seroprevalence calculated for the study was 0.3% (95% CI: 0.1 to 0.5%). Microscopic examination of skin biopsies from the eight individuals seropositive for Ov16, out of the 3951 individuals initially tested, revealed no O. volvulus microfilariae. However, DNA extracted from one skin snip was successfully amplified, with subsequent sequencing confirming the presence of O. volvulus. Among the 3951 individuals, 182 were found to have anti-Wb123 antibodies, suggesting exposure to W. bancrofti, with an estimated seroprevalence of 4.6% (95% CI: 4.0 to 5.3%). Microscopy and Filaria-real time-PCR (F-RT-PCR) analysis for W. bancrofti were negative across all samples.ConclusionsThe findings indicate that onchocerciasis may no longer constitutes a public health problem in Equatorial Guinea, positioning the country on the verge of achieving elimination. Additionally, the mapped prevalence of LF will facilitate the formulation of national strategies aimed at eradicating filariases countrywide.
Background Lymphatic filariasis (LF) is a neglected tropical disease targeted for elimination as a public health problem by 2030. Although mass treatments have led to huge reductions in LF prevalence, some countries or regions may find it difficult to achieve elimination by 2030 owing to various factors, including local differences in transmission. Subnational projections of intervention impact are a useful tool in understanding these dynamics, but correctly characterizing their uncertainty is challenging. Methods We developed a computationally feasible framework for providing subnational projections for LF across 44 sub-Saharan African countries using ensemble models, guided by historical control data, to allow assessment of the role of subnational heterogeneities in global goal achievement. Projected scenarios include ongoing annual treatment from 2018 to 2030, enhanced coverage, and biannual treatment. Results Our projections suggest that progress is likely to continue well. However, highly endemic locations currently deploying strategies with the lower World Health Organization recommended coverage (65%) and frequency (annual) are expected to have slow decreases in prevalence. Increasing intervention frequency or coverage can accelerate progress by up to 5 or 6 years, respectively. Conclusions While projections based on baseline data have limitations, our methodological advancements provide assessments of potential bottlenecks for the global goals for LF arising from subnational heterogeneities. In particular, areas with high baseline prevalence may face challenges in achieving the 2030 goals, extending the “tail” of interventions. Enhancing intervention frequency and/or coverage will accelerate progress. Our approach facilitates preimplementation assessments of the impact of local interventions and is applicable to other regions and neglected tropical diseases.
Background Lymphatic filariasis (LF) is a debilitating, poverty-promoting, neglected tropical disease (NTD) targeted for worldwide elimination as a public health problem (EPHP) by 2030. Evaluating progress towards this target for national programmes is challenging, due to differences in disease transmission and interventions at the subnational level. Mathematical models can help address these challenges by capturing spatial heterogeneities and evaluating progress towards LF elimination and how different interventions could be leveraged to achieve elimination by 2030. Methods Here we used a novel approach to combine historical geo-spatial disease prevalence maps of LF in Ethiopia with 3 contemporary disease transmission models to project trends in infection under different intervention scenarios at subnational level. Results Our findings show that local context, particularly the coverage of interventions, is an important determinant for the success of control and elimination programmes. Furthermore, although current strategies seem sufficient to achieve LF elimination by 2030, some areas may benefit from the implementation of alternative strategies, such as using enhanced coverage or increased frequency, to accelerate progress towards the 2030 targets. Conclusions The combination of geospatial disease prevalence maps of LF with transmission models and intervention histories enables the projection of trends in infection at the subnational level under different control scenarios in Ethiopia. This approach, which adapts transmission models to local settings, may be useful to inform the design of optimal interventions at the subnational level in other LF endemic regions.
Abstract Background Over the past two decades, preventive chemotherapy (PC) with Praziquantel is the major strategy for controlling schistosomiasis in Senegal. This data analysis was aimed at updating the endemicity of schistosomiasis at community level for better targeting of mass treatment with Praziquantel in Senegal. Methods Demographic and epidemiological data from 1610 community health areas were analyzed using the WHO/AFRO schistosomiasis sub-district data optimization tool 2021. The tool appliease a WHO/AFRO decision tree for areas without epidemiological data to determine if mass tretaments should be continued at community level. Results Overall, the endemicity of the 1610 community health areas (CHA) were updated based on the data in JRSM form (40.5%) and the use of endemicity at implementation unit (IU) (33.5%). Up to 282 (17.5%) and 398 (24.7%) community health areas were classified as moderate and high endemicity. 41.1% of communities were non endemic. High endemicity was more important in Tambacounda, Saint Louis, Matam, Louga and Kedougou. A change in endemicity category was observed when data was disagregted from district level to community level. The number of implementation units classified as non endemic was higher at community level (n = 666) compared to district level (n = 324). Among 540 areas previously classified as high endemic by district level data aggregation, 392 (72.6%) remained high prevalence category, while 92 (17%) became moderate, 43 (8.0%) low and 13 (2.4%) non-endemics at community level. Number of IU requiring PC was more important at district level (1286) compared to community level (944). Number of SAC requiring treatment was also more important at district level compared to community level. Conclusion The analysis to disaggregate data from district level to community level using the WHO/AFRO schistoisomiasis sub-district data optimization tool has allowed to target schistisomiasis interventions, optimize use of available PZQ and exposed data gaps.
The early termination of the Accelerating the Sustainable Control and Elimination of Neglected Tropical Diseases (Ascend) programme by the UK government in June 2021 was a bitter blow to countries in East and West Africa where no alternative source of funding existed. Here we assess the potential impact the cuts may have had if alternative funding had not been made available by new development partners and outline new strategies developed by affected countries to mitigate current and future disruptions to neglected tropical disease control programmes.
Abstract Background Understanding and accurately predicting the environmental limits, population at risk and burden of podoconiosis are critical for delivering targeted and equitable prevention and treatment services, planning control and elimination programs and implementing tailored case finding and surveillance activities. Methods This is secondary analysis of a nationwide podoconiosis mapping survey in Kenya. We combined national representative prevalence survey data of podoconiosis with climate and environmental data, overlayed with population figures in a geostatistical modelling framework, to predict the environmental suitability, population living in at-risk areas and number of cases of podoconiosis in Kenya. Results In 2020, the number of people living with podoconiosis in Kenya was estimated to be 9344 (95% uncertainty interval 4222 to 17 962). The distribution of podoconiosis varies by geography and three regions (Eastern, Nyanza and Western) represent >90% of the absolute number of cases. High environmental suitability for podoconiosis was predicted in four regions of Kenya (Coastal, Eastern, Nyanza and Western). In total, 2.2 million people live in at-risk areas and 4.2% of the total landmass of Kenya is environmentally predisposed for podoconiosis. Conclusions The burden of podoconiosis is relatively low in Kenya and is mostly restricted to certain small geographical areas. Our results will help guide targeted prevention and treatment approaches through local planning, spatial targeting and tailored surveillance activities.
Background Despite the low to moderate intensity of malaria transmission present in Ethiopia, malaria is still a leading public health problem. Current vector control interventions, principally long-lasting insecticidal nets and indoor residual spraying, when deployed alone or in combination, are insufficient to control the dominant vector species due to their exophagic and exophilic tendencies. Zooprophylaxis presents a potential supplementary vector control method for malaria; however, supporting evidence for its efficacy has been mixed. Methods To identify risk factors of malaria and to estimate the association between cattle and Anopheles vector abundance as well as malaria risk, a cross-sectional study was conducted in a village near Arba Minch, Ethiopia. Epidemiological surveys (households = 95, individuals = 463), mosquito collections using CDC light traps and a census of cattle and human populations were conducted. To capture environmental conditions, land cover and water bodies were mapped using satellite imagery. Risk factor analyses were performed through logistic, Poisson, negative binomial, and spatial weighted regression models. Results The only risk factor associated with self-reported malaria illness at an individual level was being a child aged 5 or under, where they had three times higher odds than adults. At the household level, variables associated with malaria vector abundance, especially those indoors, included socioeconomic status, the proportion of children in a household and cattle population density. Conclusions Study results are limited by the low abundance of malaria vectors found and use of self-reported malaria incidence. Environmental factors together with a household's socioeconomic status and host availability played important roles in the risk of malaria infection in southwest Ethiopia. Cattle abundance in the form of higher cattle to human ratios may act as a protective factor against mosquito infestation and malaria risk. Humans should remain indoors to maximize potential protection against vectors and cattle kept outside of homes.
Background Impact evaluation of most water, sanitation and hygiene (WASH) interventions in health are user-centered. However, recent research discussed WASH herd protection – community WASH coverage could protect neighboring households. We evaluated the effect of water and sanitation used in the household and by household neighbors in children’s morbidity and mortality using recorded health data. Methods We conducted a retrospective cohort including 61,333 children from a district in Mozambique during 2012–2015. We obtained water and sanitation household data and morbidity data from Manhiça Health Research Centre surveillance system. To evaluate herd protection, we estimated the density of household neighbors with improved facilities using a Kernel Density Estimator. We fitted negative binomial adjusted regression models to assess the minimum children-based incidence rates for every morbidity indicator, and Cox regression models for mortality. Results Household use of unimproved water and sanitation displayed a higher rate of outpatient visit, diarrhea, malaria, and anemia. Households with unimproved water and sanitation surrounded by neighbors with improved water and sanitation high coverage were associated with a lower rate of outpatient visit, malaria, anemia, and malnutrition. Conclusion Household and neighbors’ access to improve water and sanitation can affect children’s health. Accounting for household WASH and herd protection in interventions’ evaluation could foster stakeholders’ investment and improve WASH related diseases control. Graphical Abstract Distribution of main water and sanitation facilities used during study period.
ABSTRACT. Soil-transmitted helminth (STH) cornerstone control strategy is mass drug administration (MDA) with benzimidazoles. However, MDA might contribute to selection pressure for anthelmintic resistance, as occurred in livestock. The aim of this study is to evaluate the treatment response to albendazole and the relationship with the presence of putative benzimidazole resistance single-nucleotide polymorphisms (SNPs) in the β-tubulin gene of STH in Southern Mozambique. After screening 819 participants, we conducted a cohort study with 184 participants infected with STH in Manhiça district, Southern Mozambique. A pretreatment and a posttreatment stool samples were collected and the STH infection was identified by duplicate Kato-Katz and quantitative polymerase chain reaction (qPCR). Cure rate and egg reduction rates were calculated. Putative benzimidazole resistance SNPs (F167Y, F200T, and E198A) in Trichuris trichiura and Necator americanus were assessed by pyrosequencing. Cure rates by duplicate Kato-Katz and by qPCR were 95.8% and 93.6% for Ascaris lumbricoides , 28% and 7.8% for T. trichiura , and 88.9% and 56.7% for N. americanus . Egg reduction rate by duplicate Kato-Katz was 85.4% for A. lumbricoides , 34.9% for T. trichiura , and 40.5% for N. americanus . Putative benzimidazole resistance SNPs in the β-tubulin gene were detected in T. trichiura (23%) and N. americanus (21%) infected participants at pretreatment. No statistical difference was observed between pretreatment and posttreatment frequencies for none of the SNPs. Although treatment response to albendazole was low, particularly in T. trichiura , the putative benzimidazole resistance SNPs were not higher after treatment in the population studied. New insights are needed for a better understanding and monitoring of human anthelmintic resistance.
Background Soil-transmitted helminths (STH), Schistosoma spp. and Plasmodium falciparum are parasites of major public health importance and co-endemic in many sub-Saharan African countries. Management of these infections requires detection and treatment of infected people and evaluation of large-scale measures implemented. Diagnostic tools are available but their low sensitivity, especially for low intensity helminth infections, leaves room for improvement. Antibody serology could be a useful approach thanks to its potential to detect both current infection and past exposure. Methodology We evaluated total IgE responses and specific-IgG levels to 9 antigens from STH, 2 from Schistosoma spp., and 16 from P. falciparum, as potential markers of current infection in a population of children and adults from Southern Mozambique (N = 715). Antibody responses were measured by quantitative suspension array Luminex technology and their performance was evaluated by ROC curve analysis using microscopic and molecular detection of infections as reference. Principal findings IgG against the combination of EXP1, AMA1 and MSP2 (P. falciparum) in children and NIE (Strongyloides stercoralis) in adults and children had the highest accuracies (AUC = 0.942 and AUC = 0.872, respectively) as markers of current infection. IgG against the combination of MEA and Sm25 (Schistosoma spp.) were also reliable markers of current infection (AUC = 0.779). In addition, IgG seropositivity against 20 out of the 27 antigens in the panel differentiated the seropositive endemic population from the non-endemic population, suggesting a possible role as markers of exposure although sensitivity could not be assessed. Conclusions We provided evidence for the utility of antibody serology to detect current infection with parasites causing tropical diseases in endemic populations. In addition, most of the markers have potential good specificity as markers of exposure. We also showed the feasibility of measuring antibody serology with a platform that allows the integration of control and elimination programs for different pathogens.
Introduction Skin melanoma incidence has risen in the last decades becoming a major public health problem in many regions of the world. Geographic variation of rates is not well understood. Purpose To assess the spatial distribution of skin melanoma in Gran Canaria Island (Canary Islands, Spain) and to evaluate the role of environmental, socio-economic, and demographic factors in this distribution. Methods We performed a small-area study with disease mapping at the census-tract level (CT) in Gran Canaria between 2007 and 2018. After testing for spatial autocorrelation, we integrated individual-level health data with census-based demographic and socio-economic indicators, and satellite-based environmental data. Finally, we assessed the role of demographic, socio-economic and environmental factors on skin melanoma incidence using a Bayesian analytical framework, with options for non-spatial and spatial random effects. Results 1058 patients were diagnosed with invasive skin melanoma in the study period and geolocated to a CT (number of CT in Gran Canaria = 565). We found evidence of global spatial autocorrelation in skin melanoma incidence (Moran’s I = 0.09, pseudo p -value = 0.001). A few hotspots were detected, fundamentally in urban northern tracts. A radial pattern of high values was also observed in selected ravines with historical isolation. Multivariable conditional autoregressive models identified urbanicity, percent of females, and a high socio-economic status as risk factors for disease. Solar radiation did not show a significant role. Conclusion Urbanicity and a high socio-economic status were identified as the main risk factors for skin melanoma. These associations might reflect differential melanoma susceptibilities or be explained by health inequalities in detection. This study also uncovered high-risk areas in particular ravines. Future targeted research in these regions might help better understand the role of genetic and toxic factors in melanoma pathogenesis.
Background Limited understanding exists about the interactions between malaria and soil-transmitted helminths (STH), their potential geographical overlap and the factors driving it. This study characterised the geographical and co-clustered distribution patterns of malaria and STH infections among vulnerable populations in sub-Saharan Africa (SSA). Methodology/Principal findings We obtained continuous estimates of malaria prevalence from the Malaria Atlas Project (MAP) and STH prevalence surveys from the WHO-driven Expanded Special Project for the Elimination of NTDs (ESPEN) from Jan 1, 2000, to Dec 31, 2018. Although, MAP provides datasets on the estimated prevalence of Plasmodium falciparum at 5km x 5km fine-scale resolution, we calculated the population-weighted prevalence of malaria for each implementation unit to ensure that both malaria and STH datasets were on the same spatial resolution. We incorporated survey data from 5,935 implementation units for STH prevalence and conducted the prevalence point estimates before and after 2003. We used the bivariate local indicator of spatial association (LISA analysis) to explore potential co-clustering of both diseases at the implementation unit levels among children aged 2-10 years for P. falciparum and 5-14 years for STH, living in SSA. Our analysis shows that prior to 2003, a greater number of SSA countries had a high prevalence of co-endemicity with P.falciparium and any STH species than during the period from 2003-2018. Similar prevalence and distribution patterns were observed for the co-endemicity involving P.falciparum-hookworm, P.falciparum-Ascaris lumbricoides and P.falciparum-Trichuris trichiura, before and after 2003. We also observed spatial variations in the estimates of the prevalence of P. falciparum-STH co-endemicity and identified hotspots across many countries in SSA with inter-and intra-country variations. High P. falciparum and high hookworm co-endemicity was more prevalent in West and Central Africa, whereas high P. falciparum with high A. lumbricoides and high P. falciparum with high T. trichiura co-endemicity were more predominant in Central Africa, compared to other sub-regions in SSA. Conclusions/Significance Wide spatial heterogeneity exists in the prevalence of malaria and STH co-endemicity within the regions and within countries in SSA. The geographical overlap and spatial co-existence of malaria and STH could be exploited to achieve effective control and elimination agendas through the integration of the vertical control programmes designed for malaria and STH into a more comprehensive and sustainable community-based paradigm.
Background Women are at risk of severe adverse pregnancy outcomes attributable to Plasmodium spp. infection in malaria-endemic areas. Malaria control efforts since 2000 have aimed to reduce this burden of disease. Methods We used data from the Malaria Atlas Project and WorldPop to calculate global pregnancies at-risk of Plasmodium spp. infection. We categorised pregnancies as occurring in areas of stable and unstable P. falciparum and P. vivax transmission. We further stratified stable endemicity as hypo-endemic, meso-endemic, hyper-endemic, or holo-endemic, and estimated pregnancies at risk in 2000, 2005, 2010, 2015, 2017, and 2020. Findings In 2020, globally 120.4M pregnancies were at risk of P. falciparum, two-thirds (81.0M, 67.3%) were in areas of stable transmission; 85 2M pregnancies were at risk of P. vivax, 93.9% (80.0M) were in areas of stable transmission. An estimated 64.6M pregnancies were in areas with both P. falciparum and P. vivax transmission. The number of pregnancies at risk of each of P. falciparum and P. vivax worldwide decreased between 2000 and 2020, with the exception of sub-Saharan Africa, where the total number of pregnancies at risk of P. falciparum increased from 37 3M in 2000 to 52 4M in 2020. Interpretation Historic investments in malaria control have reduced the number of women at risk of malaria in pregnancy in all endemic regions except sub-Saharan Africa. Population growth in Africa has outpaced reductions in malaria prevalence. Interventions that reduce the risk of malaria in pregnancy are needed as much today as ever.
Mycetoma is widespread in tropical and subtropical regions favouring arid areas with low humidity and a short rainy season. Sudan is one of the highly endemic countries for mycetoma. Estimating the population at risk and the number of cases is critical for delivering targeted and equitable prevention and treatment services. In this study, we have combined a large dataset of mycetoma cases recorded by the Mycetoma Research Centre (MRC) in Sudan over 28 years (1991-2018) with a collection of environmental and water and hygiene-related datasets in a geostatistical framework to produce estimates of the disease burden across the country. We developed geostatistical models to predict the number of cases of actinomycetoma and eumycetoma in areas considered environmentally suitable for the two mycetoma forms. Then used the raster dataset (gridded map) with the population estimates for 2020 to compute the potentially affected population since 1991. The geostatistical models confirmed this heterogeneous and distinct distribution of the estimated cases of eumycetoma and actinomycetoma across Sudan. For eumycetoma, these higher-risk areas were smaller and scattered across Al Jazirah, Khartoum, White Nile and Sennar states, while for actinomycetoma a higher risk for infection is shown across the rural districts of North and West Kurdufan. Nationally, we estimated 63,825 people (95%CI: 13,693 to 197,369) to have been suffering from mycetoma since 1991 in Sudan,51,541 people (95% CI: 9,893-166,073) with eumycetoma and 12,284 people (95%CI: 3,800-31,296) with actinomycetoma. In conclusion, the risk of mycetoma in Sudan is particularly high in certain restricted areas, but cases are ubiquitous across all states. Both prevention and treatment services are required to address the burden. Such work provides a guide for future control and prevention programs for mycetoma, highly endemic areas are clearly targeted, and resources are directed to areas with high demand.
Background Limited understanding exists about the interactions between malaria and soil-transmitted helminths (STH), their potential geographical overlap and the factors driving it. This study characterised the geographical and co-clustered distribution patterns of malaria and STH infections among vulnerable populations in sub-Saharan Africa (SSA). Methodology/Principal findings We obtained continuous estimates of malaria prevalence from the Malaria Atlas Project and STH prevalence surveys from the WHO-driven Expanded Special Project for the Elimination of NTDs (ESPEN) covering 2000-2018 and used spatial autocorrelation methods to identify statistically significant clusters for both diseases across SSA. We used the inverse distance weighted kriging (interpolation) methods to estimate STH prevalence. We calculated the population-weighted prevalence of malaria and STH co-infection, and used the bivariate local indicator of spatial association (LISA analysis) to explore potential co-clustering of both diseases at the implementation unit levels. Our analysis shows spatial variations in the estimates of the prevalence of Plasmodium falciparum -STH co-infections and identified hotspots across many countries in SSA with inter-and intra-country variations. High P. falciparum and high hookworm co-infections were more prevalent in West and Central Africa, whereas high P. falciparum , high Ascaris lumbricoides , high P . falciparum, and high Trichuris trichiura co-infections were more predominant in Central Africa, compared to other sub-regions in SSA. Conclusions/Significance Wide spatial heterogeneity exists in the prevalence of malaria and STH co-infection within the regions and within countries in SSA. The geographical overlap and spatial co-existence of malaria and STH could be exploited to achieve effective control and elimination agendas through the integration of the vertical programmes designed for malaria and STH into a more comprehensive and sustainable community-based paradigm.