We investigated a dengue outbreak in Dar es Salaam, Tanzania, in 2014, that was caused by dengue virus (DENV) serotype 2. DENV infection was present in 101 (20.9%) of 483 patients. Patient age and location of residence were associated with infection. Seven (4.0%) of 176 patients were co-infected with malaria and DENV.

Background Despite high coverage and successes in malaria control strategies, some areas of Tanzania have indicated stagnantion or revesal of malaria burden. In malaria research, most studies are designed to assess drivers of malaria transmission focusing only on one dimension, single location while very few studies assess multiple components and their interactions. This article describes the protocol used to assess intrinsic and extrinsic drivers of persistent malaria transmission (hotsposts) in four regions from northwestern (Geita and Kigoma) and southern (Ruvuma and Mtwara) Tanzania.Results: Preliminary results show that 6,297 HHs and 28,361 individuals with median age of 16yrs (IQR= 7-35yrs) were registered from the 16 villages. Over 49% of individuals used bed-nets in the previous night before the survey and 43.9% of HHs had bed-nets covering two members per household. For parasitological survey, 25.8% of registered individuals (n=7,313) were selected from 2,527 HHs (40.1%) and invited for assessment and sampling. The positivity rate (PR) by mRDTs was 33.3% (range = 21.9% to 41.1%); while by microscopy, the PR was 20.6% and varied from 8.0% to 29.0%. Socio-anthropology interviews were conducted with a total of 1,687 heads/representatives of HHs. For qualitative surveys 32 Focus group discussion (two from each village) and 16 key informant interviews (two per district) were conducted. Thirty-one health facilities were visited for health system survey; 19.4% (n=6) were hospitals; 41.9% (n=13) health centres and 38.7% (n=12) dispensaries. For entomological survey, 8,891 adult mosquitoes were collected, whereby Anopheles gambiae complex, An. funestus group and other mosquitoes accounted for 12.0%, 49.7% and 38.3%, respectively.Conclusion: An analysis plan using data from the five components surveyed has been proposed and results from this study are expected to determine factors potentially responsible for persistence of malaria (hotspots) in the study areas. Rather than the traditional methodology of focusing on one metric, the approach will triangulate observations from all five components, highlighting understanding of potential drivers while studying their complex interactions and map spatial heterogeneity. This study will provide an important framework and data which will guide future studies and malaria surveillance in Tanzania and other malaria endemic countries.

Background It has been more than 20 years since the malaria epidemiologic shift to school-aged children was noted. In the meantime, school-aged children (5–15 years) have become increasingly more vulnerable with asymptomatic malaria prevalence reaching up to 70%, making them reservoirs for subsequent transmission of malaria in the endemic communities. Intermittent Preventive Treatment of malaria in schoolchildren (IPTsc) has proven to be an effective tool to shrink this reservoir. As of 3rd June 2022, the World Health Organization recommends IPTsc in moderate and high endemic areas. Even so, for decision-makers, the adoption of scientific research recommendations has been stifled by real-world implementation challenges. This study presents methodology, challenges faced, and mitigations used in the evaluation of the implementation of IPTsc using dihydroartemisinin-piperaquine (DP) in three councils (Handeni District Council (DC), Handeni Town Council (TC) and Kilindi DC) of Tanga Region, Tanzania so as to understand the operational feasibility and effectiveness of IPTsc on malaria parasitaemia and clinical malaria incidence. Methods The study deployed an effectiveness-implementation hybrid design to assess feasibility and effectiveness of IPTsc using DP, the interventional drug, against standard of care (control). Wards in the three study councils were the randomization unit (clusters). Each ward was randomized to implement IPTsc or not (control). In all wards in the IPTsc arm, DP was given to schoolchildren three times a year in four-month intervals. In each council, 24 randomly selected wards (12 per study arm, one school per ward) were chosen as representatives for intervention impact evaluation. Mixed design methods were used to assess the feasibility and acceptability of implementing IPTsc as part of a more comprehensive health package for schoolchildren. The study reimagined an existing school health programme for Neglected Tropical Diseases (NTD) control include IPTsc implementation. Results The study shows IPTsc can feasibly be implemented by integrating it into existing school health and education systems, paving the way for sustainable programme adoption in a cost-effective manner. Conclusions Through this article other interested countries may realise a feasible plan for IPTsc implementation. Mitigation to any challenge can be customized based on local circumstances without jeopardising the gains expected from an IPTsc programme. Trial registration clinicaltrials.gov, NCT04245033. Registered 28 January 2020, https://clinicaltrials.gov/ct2/show/NCT04245033

Background: Rift Valley fever (RVF) is a mosquito-borne viral zoonotic disease. Rift Valley fever virus (RVFV) has been isolated from more than 40 species of mosquitoes from eight genera. This study was conducted to determine the abundance of potential mosquito vectors and their RVFV infection status in Ngorongoro District of northern Tanzania.Methods: Adult mosquitoes were collected outdoors using the CDC light traps baited with carbon dioxide in five randomly selected villages namely, Meshili, Malambo, Osinoni, Endulen and Nainokanoka. The study was carried out towards the end of rainy season in May 2013. The traps were set in proximity to potential breeding sites and cattle kraals. The collected mosquitoes were identified to genus and species using morphological keys. They were tested for RVFV RNA  using  real time reverse transcription-polymerase chain reaction (rRT-PCR).Results: A total of 2,094 adult mosquitoes belonging to three genera and nine species were collected. Most of them (87.5%) were collected in Meshili, followed by Malambo (8.2%) and Osinoni (4%) villages. No single mosquito was collected in Nainokanoka or Endulen. The nine species collected were Culex pipiens complex, Cx. antennatus, Cx. tigripes, Cx. annulioris, Cx. cinereus, Anopheles arabiensis, An. squamosus, An. pharoensis and Mansonia uniformis. No RVFV RNA was detected in the mosquito specimens.Conclusion: Various RVFV potential mosquito species were collected from the study villages. These mosquito vectors were heterogeneously distributed in the district suggesting a variation in RVF transmission risk in the study area.

Background: Despite 20 years of ivermectin mass distribution in the Mahenge area, Tanzania, the prevalence of onchocerciasis and epilepsy has remained high in rural villages. Objectives: We investigated the efficacy of ivermectin in reducing Onchocerca volvulus microfilariae and predictors for parasitic load following ivermectin treatment in persons with (PWE) and without epilepsy (PWOE). Methods: Between April and September 2019, 50 PWE and 160 randomly selected PWOE from Msogezi and Mdindo villages participated in a follow-up study. Skin snips were obtained pre (baseline) and three months post-ivermectin treatment. Results: The overall prevalence of O. volvulus positive skin snips at baseline was 49% (103/210), with no significant difference between PWE (58.0%) and PWOE (46.3%); p=0.197. The overall mean microfilarial density was significantly higher at baseline 1.45(95%CI:0.98-2.04)) than three-month post-ivermectin treatment (0.23(95%CI:0.11-0.37), p<0.001. Three months after ivermectin, the microfilarial density had decreased by ≥80% in 54 (81.8%, 95%CI: 72.3-91.4) of the 66 individuals with positive skin snips at baseline. High microfilarial density at baseline was the only significant predictor associated with higher microfilarialdensity in the post-ivermectin skin snips. Conclusion: Our study reports a decrease in microfilarial density following ivermectin treatment in most individuals. Optimizing ivermectin coverage will address the ongoing onchocerciasis transmission in Mahenge. Keywords: Onchocerciasis, ivermectin; treatment response, epilepsy; Tanzania.