Browsing by Author "Okumu, Fredros"

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Association between physical activity, nutritional status and cognitive performance among school children in southern Tanzania
(Frontiers, 2025-06-10) Mwakalebela, Fahad; Minja, Elihaika; Mwalugelo, Yohana; Killel, Erick; Rajab, Rehema; Mollel, Getrud; Mponzi, Winifrida; Masanja, Honorati; Okumu, Fredros; Lang, Christin; Gerber, Markus; Utzinger, Jürg; Long, Kurt; Kosia, Efraim; Elisaria, Ester; Finda, Marceline
Background: Physical activity is pivotal in promoting overall health and wellbeing, improving brain function and cognitive performance, and reducing risk of excessive weight and non-communicable diseases. Despite these benefits, physical inactivity among children and adolescents remains a global concern, particularly in low- and middle-income countries (LMICs). Only few studies have explored the association between physical activity, nutritional status, and cognitive performance in LMICs like Tanzania. This study assessed these associations among school children in a rural setting in southern Tanzania. Methods: Physical activity was assessed using an actigraphy device that assessed 7-day average of physical activity among school children aged 6–13 years. Cognitive performance was assessed via the Flanker task, which assessed the executive domain of cognitive functions, specifically information processing and inhibitory control. Weight was determined using Tanita digital scale, and height was measured using measuring board. A multinomial logistic regression model and a gamma generalized linear model with a log link function were used to examine the association between physical activity, nutritional status, and cognitive performance. Results: Among 678 children who participated in the baseline assessment, 77.9% had normal weight, 14.3% were underweight, 5.5% were overweight, and 2.4% were obese. Most (92.6%) of the children engaged in at least 60 min per day of moderate-to-vigorous physical activity (MVPA) as per WHO recommendations. Children who did not meet the recommended MVPA level were nearly three times more likely to be obese compared to those who did. No statistically significant associations were found between physical activity and cognitive performance, or between nutritional status and cognitive performance. Conclusion: This study highlights a high prevalence of normal weight and adherence to WHO-recommended MVPA levels among school children in southern Tanzania. However, children not meeting MVPA criteria were more likely to be obese, indicating the importance of physical activity in maintaining a healthy weight. The lack of association between physical activity or nutritional status and cognitive performance, indicates that there may be additional factors that influence cognitive outcomes. Further research is needed to explore these interactions, particularly in rural LMIC settings.
Dietary diversity among households living in Kilombero district, in Morogoro region, South-Eastern Tanzania
(Elsevier B.V., 2021-06-11) Minja, Elihaika; Swai, Johnson; Mponzi, Winifrida; Ngowo, Halfan; Okumu, Fredros; Gerber, Markus; Pühse, Uwe; Long, Kurt; Utzinger, Jürg; Lang, Christin; Beckmann, Johanna; Finda, Marceline
Background: Adequate nutrition is essential for good health and active life. However, diets in most low and middle-income households lack diversity, especially in settings where people eat predominantly starchy foods. In this study, we assessed the associations between socio-economic status and household dietary diversity in families living in South-eastern Tanzania. Method: A cross-sectional questionnaire was administered to 925 parents of school children in four wards in South-eastern Tanzania, as part of a trial; assessing the effects of physical activity and micronutrient supplementation on overall growth, health and well-being of school children. The dietary intake was assessed by 24-h dietary recall and dietary diversity score (DDS) was calculated. Socio-economic status was derived from a weighted score using principal component analysis (PCA). Multinomial logistic regression was used to investigate the association between dietary diversity and socio-economic status. This baseline data assessment was completed in July and August 2019. Results: Cereals, oils and fats were the most consumed food groups, legumes were the most common source of protein and fish was the most common animal protein. More than three quarters of the households had medium dietary diversity (MDD). Higher household education and large farm size were the only factors significantly associated with having high dietary diversity. Conclusion: A majority of the households in South-eastern Tanzania have medium dietary diversity, comprised of cereal, fats and oils and proteins. Having high dietary diversity was associated with higher education and large farm sizes. Improving community members’ knowledge and awareness of nutritional benefits could improve the dietary diversity at household level.
Effect of a School-Based Physical Activity and Multi-Micronutrient Supplementation Intervention on Cognitive Function and Academic Achievement Among Schoolchildren in Tanzania: Secondary Outcome from the KaziAfya Cluster-Randomized Controlled Trial
(MDPI, 2025-08-27) Minja, Elihaika; Mrimi, Emmanuel; Mponzi, Winfrida; Beckmann, Johanna; Finda, Marceline; Okumu, Fredros; Long, Kurt; Lang, Christin; Utzinger, Jürg; Gerber, Markus
Background: Physical activity (PA) and adequate micronutrient intake are essential for brain development and may influence cognitive function and academic achievement. However, few large-scale studies have assessed the combined effects of PA and multi-micronutrient supplementation (MMNS) in school-age children. Methods: A cluster-randomized placebocontrolled trial in four peri-urban Tanzanian schools assigned children to one of four groups: (i) PA alone; (ii) MMNS alone; (iii) PA plus MMNS; or (iv) placebo. Children were followed over two school years with assessments at baseline, 14 months, and 26 months. Cognitive function was assessed using computerized Flanker tasks. Academic achievement was evaluated through end-of-year exams in mathematics and Kiswahili subject scores. Anthropometric measures determined nutritional status. Data were analyzed using generalized estimated equations (GEE). Results: Complete data from 559 children (326 girls, 233 boys) aged 6–12 years showed differing characteristics across groups, particularly age and body mass index. No significant intervention effects on cognitive function were found. MMNS groups (alone or combined with PA) showed significantly higher Kiswahili scores, while PA alone had the lowest performance compared to placebo. No intervention effect was found in mathematics. Sex, hemoglobin level, and baseline measures were key predictors for cognition or academic performance. Conclusions: PA and MMNS interventions showed no significant cognitive or academic improvements versus placebo. Further research should optimize school-based nutrition and PA programs for improved learning outcomes.
Effects of sample preservation methods and duration of storage on the performance of mid-infrared spectroscopy for predicting the age of malaria vectors
(BMC, 2022-08-06) Mgaya, Jacqueline; Siria, Doreen; Makala, Faraja; Mgando, Joseph; Vianney, John Mary; Mwanga, Emmanuel; Okumu, Fredros
Background Monitoring the biological attributes of mosquitoes is critical for understanding pathogen transmission and estimating the impacts of vector control interventions on the survival of vector species. Infrared spectroscopy and machine learning techniques are increasingly being tested for this purpose and have been proven to accurately predict the age, species, blood-meal sources, and pathogen infections in Anopheles and Aedes mosquitoes. However, as these techniques are still in early-stage implementation, there are no standardized procedures for handling samples prior to the infrared scanning. This study investigated the effects of different preservation methods and storage duration on the performance of mid-infrared spectroscopy for age-grading females of the malaria vector, Anopheles arabiensis. Methods Laboratory-reared An. arabiensis (N = 3681) were collected at 5 and 17 days post-emergence, killed with ethanol, and then preserved using silica desiccant at 5 °C, freezing at − 20 °C, or absolute ethanol at room temperature. For each preservation method, the mosquitoes were divided into three groups, stored for 1, 4, or 8 weeks, and then scanned using a mid-infrared spectrometer. Supervised machine learning classifiers were trained with the infrared spectra, and the support vector machine (SVM) emerged as the best model for predicting the mosquito ages. Results The model trained using silica-preserved mosquitoes achieved 95% accuracy when predicting the ages of other silica-preserved mosquitoes, but declined to 72% and 66% when age-classifying mosquitoes preserved using ethanol and freezing, respectively. Prediction accuracies of models trained on samples preserved in ethanol and freezing also reduced when these models were applied to samples preserved by other methods. Similarly, models trained on 1-week stored samples had declining accuracies of 97%, 83%, and 72% when predicting the ages of mosquitoes stored for 1, 4, or 8 weeks respectively. Conclusions When using mid-infrared spectroscopy and supervised machine learning to age-grade mosquitoes, the highest accuracies are achieved when the training and test samples are preserved in the same way and stored for similar durations. However, when the test and training samples were handled differently, the classification accuracies declined significantly. Protocols for infrared-based entomological studies should therefore emphasize standardized sample-handling procedures and possibly additional statistical procedures such as transfer learning for greater accuracy.
Elevating larval source management as a key strategy for controlling malaria and other vector-borne diseases in Africa
(BMC, 2025-02-07) Okumu, Fredros; Moore, Sarah; Selvaraj, Prashanth; Yafin, Arnon; Juma, Elijah; Shirima, GloriaSalome; Majambere, Silas; Hardy, Andy; Knols, Bart; Msugupakulya, Betwel; Finda, Marceline; Kahamba, Najat; Thomsen, Edward; Ahmed, Ayman; Zohdy, Sarah; Chaki, Prosper; DeChant, Peter; Fornace, Kimberly; Govella, Nicodem; Gowelo, Steven; Hakizimana, Emmanuel; Hamainza, Busiku; Ijumba, Jasper; Jany, William; Kafy, Hmooda; Kaindoa, Emmanuel; Kariuki, Lenson; Kiware, Samson; Kweka, Eliningaya; Lobo, Neil; Marrenjo, Dulcisária; Matoke-Muhia, Damaris; Mbogo, Charles; McCann, Robert; Monroe,n April; Ndenga, Bryson; Ngowo, Halfan; Ochomo, Eric; Opiyo, Mercy; Reithinger, Richard; Sikaala, Chadwick; Tatarsky, Allison; Takudzwa, David; Trujillano, Fedra; Sherrard-Smith, Ellie
Larval source management (LSM) has a long history of advocacy and successes but is rarely adopted where funds are limited. The World Health Organization (WHO) guidelines on malaria prevention recommend the use of LSM as a supplementary intervention to the core vector control methods (insecticide-treated nets and indoor residual spraying), arguing that its feasibility in many settings can be limited by larval habitats being numerous, transient, and difficult to find or treat. Another key argument is that there is insufficient high-quality evidence for its effectiveness to support wide-scale implementation. However, the stagnation of progress towards malaria elimination demands that we consider additional options to the current emphasis on insecticidal commodities targeting adult mosquitoes inside homes. This letter is the result of a global, crossdisciplinary collaboration comprising: (a) detailed online expert discussions, (b) a narrative review of countries that have eliminated local malaria transmission, and (c) a mathematical modeling exercise using two different approaches. Together, these efforts culminated in seven key recommendations for elevating larval source management as a strategy for controlling malaria and other mosquito-borne diseases in Africa (Box 1). LSM encompasses the use of larvicide (a commodity) as well as various environmental sanitation measures. Together, these efforts lead to the long-term reduction of mosquito populations, which benefits the entire community by controlling both disease vector and nuisance mosquitoes. In this paper, we argue that the heavy reliance on large-scale cluster-randomized controlled trials (CRTs) to generate evidence on epidemiological endpoints restricts the recommendation of approaches to only those interventions that can be measured by functional units and deliver relatively uniform impact and, therefore, are more likely to receive financial support for conducting these trials. The explicit impacts of LSM may be better captured by using alternative evaluation approaches, especially high-quality operational data and a recognition of locally distinct outcomes and tailored strategies. LSM contributions are also evidenced by the widespread use of LSM strategies in nearly all countries that have successfully achieved malaria elimination. Two modelling approaches demonstrate that a multifaceted strategy, which incorporates LSM as a central intervention alongside other vector control methods, can effectively mitigate key biological threats such as insecticide resistance and outdoor biting, leading to substantial reductions in malaria cases in representative African settings. This argument is extended to show that the available evidence is sufficient to establish the link between LSM approaches and reduced disease transmission of mosquito-borne illnesses. What is needed now is a significant boost in the financial resources and public health administration structures necessary to train, employ and deploy local-level workforces tasked with suppressing mosquito populations in scientifically driven and ecologically sensitive ways. In conclusion, having WHO guidelines that recognize LSM as a key intervention to be delivered in multiple contextualized forms would open the door to increased flexibility for funding and aid countries in implementing the strategies that they deem appropriate. Financially supporting the scale-up of LSM with high-quality operations monitoring for vector control in combination with other core tools can facilitate better health. The global health community should reconsider how evidence and funding are used to support LSM initiatives.
Heterogeneous impacts for malaria control from larviciding across villages and considerations for monitoring and evaluation
(PLOS Pathogens, 2025-07-28) Smith, Ellie; Fillinger, Ulrike; Jean, Philippe; Winskill, Peter; Koudou, Benjamin; Tchicaya, Emile; Sanou, Antoine; Okumu, Fredros; Opiyo, Mercy; Majambere, Silas; Hamlet, Arran; Giovanni, Charles; Lambert, Ben; Churcher, Thomas
Malaria vector control tools currently focus on insecticide treated nets (ITNs) and indoor residual spraying in malaria-endemic locations, but additional preventative strategies are needed to address protection gaps. Larval source management (LSM) includes larvicide application to aquatic habitat and an array of alternative forms of environmental efforts. An individual-based transmission model for falciparum malaria is used to demonstrate the theoretical benefit of suppressing malaria adult mos- quito vector densities through LSM. The model simulates results of epidemiologicaltrials from Western Kenya (a hilly area with papyrus swamps adjacent to human settlements and moderate to high perennial malaria transmission) and Côte d’Ivoire (an area with Sudanese climate, reducing vegetation cover and high transmission) that applied larvicide alongside ITNs, and investigates whether estimated changes in adult density can be used to project changes in human malaria. In the Western Kenya setting generalised linear models estimate 82% (90% credible intervals: 64% – 92%) and 88% (79% – 94%) reductions in the proportion of adult Anopheles funestus and Anopheles gambiae complex mosquitoes respectively as measured by CDC light traps. In Côte d’Ivoire, an 82% (56% – 93%) reduction of the dominant An. gambiae vector was estimated using standard window trap and pyrethrum spray catch. Both studies had variable village-level impacts. The transmission dynamics model predicted that these entomological impacts would result in a reduction in malaria prevalence in children of 6-months to 10-years of age of 48 – 72% in Kenya, and a 11 – 78% reduction in all-age clinical incidence across villages in Côte d’Ivoire, which are broadly consistent with the empirically observed outcomes. High hetero- geneity between villages within the same study indicate that the relative or absolute reductions in mosquito adult density observed in these trials cannot be simply extrap-olated to other regions. The LSM strategy adopted, unit area covered, and multiple environmental covariates all contribute to differences in indicators that could be used to assess entomological impacts and the corresponding epidemiological outcomes. This important malaria control tool was impactful across all sites examined, though further work is needed to understand how best to use this tool in the fight against malaria.
Heterogeneous malaria transmission patterns in southeastern Tanzania driven by socio-economic and environmental factors
(BMC, 2025-05-29) Mukabana, Linda; Mshani, Issa; Gachohi, John; Minja, Elihaika; Jackson, Frank; Kahamba, Najat; Pinda, Polius; Muyaga, Letus; Msaky, Dickson; Ngowo, Halfan; Mambo, Susan; Olwendo, Amos; Bisanzio, Donal; Okumu, Fredros
Background As malaria-endemic countries progress towards elimination, distinct patterns of heterogeneous transmission are emerging. In south-eastern Tanzania, despite intensive control efforts, localized transmission shows prevalence ranging from under 1% to over 50% among nearby villages. This study investigated the socioeconomic and environmental factors driving this spatial heterogeneity. Methods A cross-sectional survey was conducted in the Kilombero and Ulanga districts of south-eastern Tanzania between 2022 and 2023, screening 3,249 individuals (ages 5–60) across 10 villages for malaria using rapid diagnostic tests (RDTs). Socioeconomic data was collected from all surveyed households and villages via questionnaires, while environmental data were obtained from remote sensing data sources. Associations between socioeconomic factors and malaria infection were analysed using a zero-inflated negative binomial model and employed a generalized additive model (GAM) to assess the impact of rainfall, and temperature on malaria infection. Results Greater elevation and higher rainfall were positively associated with malaria infection (OR = 1.68, 95% CI 1.38–2.05, p < 0.001 and OR = 1.46, 95% CI 1.14–1.87, p < 0.05 respectively), while temperature showed no significant effect (OR = 0.70, 95% CI 0.51–1.13, p = 0.117). Households in densely vegetated areas had higher malaria infections compared to those in more developed, built-up areas. At the individual level, males had a higher prevalence (355; 28.6%) and displayed significantly greater odds of infection (OR = 1.53, 95% CI 1.15–2.03, p < 0.05) than females (433; 21.6%). School-aged children (5–17 years) had a higher prevalence (36.9%) compared to adults (18–60 years) (15.9%). The probability of infection declined with increasing age (OR = 0.28, 95% CI 0.25–0.31, p < 0.001). Larger household sizes (more than four members) were positively associated with malaria infection (OR = 1.72, 95% CI 1.29–2.29, p < 0.001). Open-eave housing was associated with higher odds of malaria, whereas closed eaves (OR = 0.56, 95% CI 0.38–0.82, p < 0.05) and metal roofs (OR = 0.62, 95% CI 0.44–0.87, p < 0.05) were protective factors. Open water sources were positively associated with malaria infection compared to protected water sources (OR = 0.57, 95% CI 0.38–0.85, p < 0.05). Lack of bed net use was positively associated with malaria but this was not statistically significant (OR = 1.54, 95% CI 0.68–3.48, p = 0.299). Conclusion This study highlights the complex interplay between socioeconomic and environmental factors contributing to the fine-scale spatial heterogeneity of malaria in south-eastern Tanzania. Understanding these localized drivers is essential for designing targeted, effective strategies that support broader malaria elimination goals.
The needs and opportunities for housing improvement for malaria control in southern Tanzania
(BMC, 2023-02-27) Bofu, Ramadhani; Santos, Ellen; Msugupakulya, Betwel; Kahamba, Najat; Swilla, Joseph; Njalambaha, Rukiyah; Kelly, Ann; Lezaun, Javier; Christofides, Nicola; Okumu, Fredros; Finda, Marceline;
Background Malaria disproportionately afects low-income households in rural communities where poor housing is common. Despite evidence that well-constructed and mosquito-proofed houses can reduce malaria risk, housing improvement is rarely included in malaria control toolboxes. This study assessed the need, magnitude, and opportuni ties for housing improvement to control malaria in rural Tanzania. Methods A mixed-methods study was conducted in 19 villages across four district councils in southern Tanzania. A structured survey was administered to 1292 community members to assess need, perceptions, and opportunities for housing improvement for malaria control. Direct observations of 802 houses and surrounding environments were done to identify the actual needs and opportunities, and to validate the survey fndings. A market survey was done to assess availability and cost of resources and services necessary for mosquito-proofng homes. Focus group discussions were conducted with key stakeholders to explore insights on the potential and challenges of housing improvement as a malaria intervention. Results Compared to other methods for malaria control, housing improvement was among the best understood and most preferred by community members. Of the 735 survey respondents who needed housing improvements, a majority needed window screening (91.1%), repairs of holes in walls (79.4%), door covers (41.6%), closing of eave spaces (31.2%) and better roofs (19.0%). Community members invested signifcant eforts to improve their own homes against malaria and other dangers, but these eforts were often slow and delayed due to high costs and limited household incomes. Study participants suggested several mechanisms of support to improve their homes, including government loans and subsidies. Conclusion Addressing the need for housing improvement is a critical component of malaria control eforts in southern Tanzania. In this study, a majority of the community members surveyed needed modest modifcations and had plans to work on those modifcations. Without additional support, their eforts were however generally slow; households would take years to sufciently mosquito-proof their houses. It is, therefore, crucial to bring together the key players across sectors to reduce barriers in malaria-proofng housing in endemic settings. These may include government subsidies or partnerships with businesses to make housing improvement more accessible and afordable to residents.
Participatory Development of Practical, Affordable, Insecticide-Treated Mosquito Proofing for a Range of Housing Designs in Rural Southern Tanzania
(Research Square, 2022-02) Msoffe, Rogath; Hewitt, Matilda; Masalu, John; Finda, Marceline; Kavishe, Deogratius; Okumu, Fredros; Mpolya, Emmanuel; Kaindoa, Emmanuel; Killeen, Gerry
Background Insecticidal mosquito-proof netting screens could combine the best features of insecticide treated nets (ITNs) and indoor residual spraying (IRS), the two most important front line vector control interventions in Africa today, and also overcome the most important limitations of these two methods, such as pyrethroid resistance. This study engaged members of a rural Tanzanian community in developing and evaluating simple, affordable and scalable procedures for installing readily available screening materials on eave gaps and windows of their own houses, and then treating those screens with a widely used IRS formulation of the organophosphate insecticide pirimiphos-methyl (PM). Methods A cohort of 54 households were recruited upon consent, following which the structural features and occupant demographics of their houses were surveyed. Indoor mosquito densities were surveyed longitudinally, both before and after a participatory house modification, and screening was done using locally available materials. Each house was randomly assigned to one of three study arms: (1) No screens installed until the end of the study (negative control), (2) untreated screens installed, and (3) screened installed and then those screens treated with PM. The longevity of the activity of the insecticide applied to these screens was assessed using standard WHO cone assays. Results Of the 54 households, 52 participated until to the end, at which point all houses had been successfully screened. In most cases, screening was only installed after making enabling structural modifications that were accepted by the enrolled households. Screening installations almost entirely excluded Anopheles arabiensis (Relative reduction (RR) ≥ 96%, P < < 0.0001), the most abundant malaria vector in the area; but was less effective against Culex quinquefasciatus, a non-malaria vector with significant biting nuisance (RR ≤ 46%, P < < 0.0001). While the PM treatment of these netting screens reduced indoor densities of Cx. quinquefasciatus by only 24%, An. arabiensis was reduced by 63% and treated screens exhibited satisfactory residual efficacy eight months after treatment. Conclusions This study demonstrates that participatory approaches to mosquito proofing houses may be acceptable and effective, and that installed screens may be suitable targets for treatment with residual insecticides.
Perspectives of men and women working in vector control in Africa regarding barriers and opportunities for achieving gender inclusivity
(BMC, 2025-05-11) Ampuriire, Patience; Bofu, Ramadhani; Msugupakulya, Betwel; Mponzi, Winifrida; Matoke-Muhia, Damaris; Finda, Marceline; Okumu, Fredros
Background Gender-inclusive strategies are crucial for tackling vector-borne diseases in Africa, but most programs still overlook the lived experiences of local practitioners regarding cultural norms, power imbalances, gender stereotypes, and workplace dynamics. This study investigated the gender-related perspectives of men and women working in vector control in Africa and their recommendations for effective gender inclusivity. Methods An exploratory mixed-methods study was conducted, starting in Tanzania with 22 in-depth interviews with team leaders, seven focus group discussions with scientists and vector control practitioners and two group discussions with vector control students. This was followed by an online survey of 150 researchers, academics, technicians, students, and vector-control staff from 16 African countries. Data on gender distribution, inclusivity, divergent male–female perspectives, and related experiences, including sexual harassment, were analysed thematically for qualitative responses and descriptively for survey responses. Results The study revealed significant gender disparities in staffing and leadership of vector control programmes in Africa, with 70.3% of men and only 40.7% of women having held leadership roles. Men occupied most vector-control roles, except in acadaemia where parity is maintained until master's degree level but biased towards men at PhD levels. Marriage weighed more heavily on women, with 44.1% of female staff remaining unmarried, compared to only 18.7% of men. Most respondents said mixed-gender teams strengthen community engagement, but they differed on effects for creativity, cost and morale, with some insisting that merit alone matters, while others seeing diversity as essential for better results. Women were more likely than men to dismiss the claims that inclusivity is ineffective or disruptive. Challenges to gender inclusivity included cultural norms limiting women's participation in overnight fieldwork, work-family pressures, and scant workplace accommodations. Men recognized the benefits of working with women but noted challenges related to societal expectations and workplace accommodations. Majority of participants (84.1%) reported had never experienced gender-based violence, but women were more likely than men to report sexual harassment. Over half of respondents believed their manager's gender significantly impacted their work environment; and some women preferred female leaders for relatability and support, while others were indifferent. Conclusion The study reveals wide gender gaps in African vector-control staffing and leadership and provides key insights for stakeholders to develop fairer workplace practices. Although the value of inclusivity is broadly recognized, cultural norms, family demands, and social expectations still weigh more heavily on women. These challenges can be addressed by incorporating a gender lens considering the perspectives of both men and women in vector control.
Prevalence and Determinants of Undernutrition in Schoolchildren in the Kilombero District, South-Eastern Tanzania
(MDPI, 2024-04-25) Minja, Elihaika; Mrimi, Emmanuel; Mponzi, Winfrida; Mollel, Getrud; Lang, Christin; Beckmann, Johanna; Gerber, Markus; Pühse, Uwe; Long, Kurt; Masanja, Honorat; Okumu, Fredros; Finda, Marceline; Utzinger, Jürg
Childhood undernutrition is a major issue in low- and middle-income countries, affecting the health, well-being, and educational outcomes of schoolchildren. This study aimed to assess the prevalence and associated factors of stunting, wasting, and underweight among schoolchildren in peri-urban areas in the south-eastern part of Tanzania. A cross-sectional study was conducted involving 930 children aged 6–12 years from four primary schools from July to August 2019. The WHO Anthro Survey Analyzer was employed to estimate the prevalence of stunting, wasting, and underweight, while logistic regression analyses examined sociodemographic background, malaria infection, anaemia, anthropometric measures, and dietary diversity score as potential factors. The prevalence of stunting, wasting, underweight, overweight, and obesity was 11.8%, 4.3%, 3.9%, 11.1%, and 2.0%, respectively. Overall, 1.5% of the children had malaria, as determined by rapid diagnostic tests, and 0.4% had severe anaemia. Univariate analysis indicated higher odds of undernutrition among children aged 9–12 compared to their younger peers. Stunting was more common among children with low and medium dietary diversity. Anaemia was found in 11.2% of schoolchildren, and severe anaemia was associated with wasting. Multivariate analysis revealed that age and low dietary diversity were significantly associated with undernutrition. These findings emphasise the need for school-based health and nutrition programmes targeting children beyond the age of 5 to improve their nutritional status and mitigate potential adverse effects on health, cognition, and academic achievement. Regular assessment of the nutritional status of schoolchildren is warranted.
Risk of Aedes-borne diseases in and around the Tanzanian seaport of Tanga despite community members being more concerned about malaria
(BioMed Central, 2024-12-18) Abas, Amri; Simfukwe, Alfred; Masalu, John; Kahamba, Najat; Nambunga, Ismail; Msaky, Dickson; Limwagu, Alex; Kipekepeke, Abdallah; Wergin, Carsten; Njalambaha, Rukiyah; Kemibala, Elison; Seleman, Amour; Mlacha, Yeromin; Finda, Marceline; Beisel, Uli; Kimaro, Esther; Ngowo, Halfan; Okumu, Fredros
Background Increased global trade, while beneficial economically, can also increase the spread of vector-borne diseases, particularly those transmitted by Aedes mosquitoes spreading via trade routes. Given the heightened trade- induced activity at ports of entry, it is particularly crucial to assess the risk of mosquito-borne diseases in these set- tings. This study compared the risks of Aedes-borne disease in and around the eastern Tanzanian seaport of Tanga. Methods A 200 m × 200 m grid-based system was used to sample mosquitoes within the port area, and in surround- ing areas at 2 km, 2.5 km, and 5 km away, between June and December 2023. We characterized mosquito breeding habitats, collected mosquito larvae using standard dippers and tested susceptibility of raised adult Aedes aegypti populations to different insecticides. Adult mosquitoes were collected using BG sentinel traps (daytime) and Centers for Disease Control (CDC) light traps (night-time). Additionally, more than 200 port users and neighboring residents were surveyed to assess their experiences with and perceptions of mosquito biting and disease risks. Results There were 2931 breeding sites, with (60.8%, n = 1782) positive for Aedes larvae. The percentage of water- holding containers infested with Aedes immatures, i.e., the container index (CI), was highest in the port area (66.2%), and lowest 5 km away (44.6%). The port area also had a greater proportion of temporary breeding sites (64.9%) than did the surrounding areas. The adult mosquito surveys revealed 20,449 mosquito species including: Culex quinquefasciatus (56.2%), Mansonia uniformis (38.6%), Ae. aegypti (5.1%), Anopheles gambiae (0.1%), and Anoph- eles funestus. Ae. aegypti were more abundant in the port area than in the surrounding areas (P < 0.001), whereas Culex sp., and Mansonia sp., were significantly outside (P < 0.001). Adult Anopheles sp., were found only in the port area, but Anopheles larvae were found both within and outside the port areas. Tests on Ae. aegypti sp., revealed susceptibility to bendiocarb and DDT, and resistance to permethrin. Awareness of mosquito-borne diseases among respondents was high for malaria (64.8%), but low for dengue (26.3%) and Chikungunya (1.7%). Most respond- ents reported being bothered by mosquitoes mostly at night (53.4%) or in the evening (40.7%). In addition to insecti- cidal bednets, which are used primarily against malaria, preventive measures for Aedes-borne diseases are limited. Conclusions This study identified significant potential risk of Aedes species, specifically Ae. aegypti sp., and associated diseases, but low perception of risk and inadequate personal protection measures in the study area. This low percep- tion of risk highlights the need to improve public knowledge of the transmission and control of Aedes-borne diseases.
Societal uses of the main water bodies inhabited by malaria vectors and implications for larval source management
(Springer Nature, 2024-11-09) Kahamba, Najat; Tarimo, Felista; Kifungo, Khamisi; Mponzi, Winifrida; Kinunda, Siaba; Simfukwe, Alfred; Mapua, Salum; Msugupakulya, Betwel; Baldini, Francesco; Ferguson, Heather; Okumu, Fredros; Finda, Marceline
Background: Larval source management (LSM) effectively reduces mosquito populations at their breeding sites, addressing issues like insecticide resistance that limit the effectiveness of primary interventions such as insecticide-treated nets (ITNs). Although traditionally used in urban and dry areas, recent research suggests it might also be effective in rural settings in eastern and southern Africa, where Anopheles funestus thrives in permanent water bodies that sustain year-round transmission. Targeting these habitats could enhance LSM, but it requires understanding local community practices, as mosquito breeding sites often overlap with community water resources. This study examined how communities use aquatic habitats and how these practices may impact LSM strategies, with a focus on habitats used by An. funestus. Methods: This study was conducted in three villages in the Ulanga and Malinyi districts of southeastern Tanzania using a mixed-methods approach. Quantitative data were collected through cross-sectional surveillance, and qualitative data through unstructured interviews, focus group discussions, and field observations. Data analysis integrated both quantitative and qualitative findings to develop a comprehensive understanding of community perspectives. Results: A survey of 931 aquatic habitats found mosquito larvae in 73% of them, with late instar An. funestus present in 23%. River streams made up 41% of the habitats, while ground pools accounted for 4%. Most habitats (90%) were used by communities, including 95% of those with An. funestus larvae, for activities such as domestic chores, agriculture, livestock rearing, brickmaking, and fishing. Focus group discussions revealed a willingness to adopt LSM, with a preference for larviciding and habitat modification over habitat removal, as the water sources were vital for daily use. Community concerns centered on the safety of larvicides for humans and animals, the environmental impact, and the need for better awareness of how LSM affects health and livelihoods. Conclusion: This study highlights community perspectives on LSM, focusing on the dual function of aquatic habitats as mosquito breeding sites and essential community water sources. This dual role presents both challenges and opportunities, suggesting that LSM strategies must balance public health needs with socio-economic realities. There was a clear preference for larviciding and habitat modification over removal, with a strong emphasis on health and environmental safety. The study emphasizes the importance of educating communities on the safety and effectiveness of LSM, and tailoring LSM strategies to fit the needs and preferences of local communities.