Tanzania Commission for Science and Technology

In Tanzania, despite the progress in HIV testing and counseling, 39.4% of people living with HIV aged ≥ 15 years were unaware of their HIV status in 2017. HIV testing is a crucial entry point for prevention, early diagnosis, and treatment of HIV to increase survival, improve quality of life, and prevent further transmission. This analysis aimed to estimate the proportion of individuals aged ≥ 15 years living with HIV in Tanzania who were unaware of their HIV status and to determine factors associated with unawareness of HIV-positive status. We analyzed data from the Tanzania HIV Impact Survey 2022-2023, a nationally representative cross-sectional survey which employed a two-stage cluster sampling design and included HIV testing at the household with laboratory confirmation. This analysis focused on individuals aged ≥ 15 years who tested HIV-positive during the survey. Weighted percentages were calculated to summarize demographic information and the proportion unaware of their HIV-positive status. Logistic regression accounting for complex survey design was used to determine factors associated with unawareness of HIV-positive status. A total of 1,850 individuals aged ≥ 15 years tested HIV positive, among which 266 (17.3%) were unaware of their HIV-positive status. Males were more likely to be unaware of their HIV-positive status than females (21.6%, aOR = 1.67, 95% CI: 1.06-2.61, p = 0.029 vs. 15.2%). Young people aged 15 - 24 years were over five times more likely to be unaware of their HIV-positive status (aOR = 5.61, 95% CI: 2.12-14.84, p = 0.001) compared to individuals aged ≥ 55 years. Individuals who reported not using a condom at last sexual intercourse in the past year were more likely to be unaware of their HIV status than those who reported condom use (aOR = 2.36, 95% CI: 1.32-4.20, p = 0.005). Those with at least one partner living with HIV were less likely to be unaware of their HIV-positive status compared to individuals with all sexual partners who were HIV negative (aOR = 0.04, 95% CI: 0.00-0.42, p = 0.009). Despite robust HIV case-finding interventions in Tanzania, 1 in 6 PLHIV were unaware of their HIV-positive status. Targeted HIV case-finding interventions should continue with a focus on reaching men and young people who were more likely to be unaware of their status. HIV prevention strategies, such as condom use, remain crucial, since individual behaviors were linked to awareness of HIV status.

Background: Traditional herbal steam inhalation (Nyungu) is a key healthcare practice in Zanzibar for treating respiratory, febrile, and spiritual ailments. Despite its importance, it remains under documented and underutilized in wellness tourism. This study aimed to document the medicinal plants used in Nyungu and explore opportunities for integration into tourism. Materials and Methods: A cross-sectional ethnobotanical survey was conducted in 26 shehias (14 in Unguja and 12 in Pemba). Sixty-eight traditional healers were purposively selected and interviewed using structured questionnaires. Data on plant use, preparation, treated ailments, and commercialization were analyzed using SPSS and Origin software. Results: The study identified 73 and 75 plant species in Unguja and Pemba, respectively. Commonly cited species included Citrus aurantiacus, Azadirachta indica, and Ocimum americanum. The main ailments treated were runny nose (18%), fever (15%), common cold (13%), and spiritual disorders (12%). Treatment regimens varied: most healers in Unguja preferred one-day sessions, while those in Pemba favored three- to seven-day duration. Polyherbal preparations were widely used. Commercialization was limited, with 60% of healers in Unguja and 84% in Pemba not offering services to tourists. Documentation was low, as only 8% (Unguja) and 17% (Pemba) recorded their practices. Conclusion: Nyungu remains a cornerstone of traditional healthcare in Zanzibar and holds promise for wellness tourism. However, poor documentation, limited commercialization, and lack of standardization hinder its development. Phytochemical validation, cultivation of key species, tourism integration, and supportive policies are recommended for sustainable use and cultural preservation.

Animal rabies remains underreported in low-income countries, hindering effective control. This scoping review aimed to map reported animal rabies cases, identify key reservoir species, and assess gaps in surveillance coverage in mainland Tanzania from 1993 to 2023. Specifically, it addressed the distribution of cases, species involved, and the extent of surveillance coverage during this period. Literature searches in PubMed, Google Scholar, and Science Direct were screened using Rayyan. Twenty articles published between 1993 and 2023 reported 7319 animal rabies cases across the Northern Zone (NZ), Southeastern Zone (SEZ), and Coastal Zone (CZ). In the NZ, domestic dogs accounted for most cases (5387), followed by jackals (225), cats (77), livestock (311), and various wildlife species including African wild dogs, bat-eared foxes, lions, cheetahs, and striped hyenas. Additionally, 102 cases involved unidentified animals. In SEZ, domestic dogs (588) were the primary source, followed by jackals (262), hyenas (8), cats (10), honey badgers (5), and leopards (2). In CZ, domestic dogs accounted for 94 cases. The findings confirm domestic dogs as the main rabies reservoir, highlighting the need for strengthened surveillance and control. The role of wildlife in rabies maintenance and spillover remains poorly understood and warrants further investigation, especially in enzootic hotspots.

This study was conducted in West Usambara to assess the effects of altitude and SAVI (Soil-Adjusted Vegetation Index) on soil organic carbon (SOC) and other soil properties within the plateaued mountainous landscape. Soil sampling, laboratory, and statistical analyses were undertaken. The correlation analysis results demonstrated an increase in SOC and Total Nitrogen (TN) with altitude. Altitude exhibited a negative correlation with available phosphorus, soil pH, exchangeable bases (Ca, K, and Na), and cation exchange capacity (CEC). The SOC and various soil properties, such as TN, exchangeable bases (Ca, K, and Na), and cation exchange capacity (CEC), exhibited an increase in correlation with the SAVI. Soil pH exhibited a decline as SAVI levels increased. The study's results are significant for land management practices, highlighting the importance of considering altitude and SAVI in optimizing SOC and nutrient content to enhance soil fertility and productivity in the study area.

High-dose-rate intracavitary brachytherapy delivers high radiation doses to tumors while minimizing exposure to surrounding normal cells. However, inappropriate administration can lead to radiation-induced toxicity by overdosing organs at risk. This study evaluated and compared the rectum doses planned by treatment planning system and measured using a thermoluminescent dosimeter. Thermoluminescent dosimeters (TLD) were employed to measure radiation dose to the rectum across two patient groups: one treated using first fraction-based planning (FFP), and the other with each fraction planned individually (EFP). The mean dose measured by TLD (3.99 ±1.63 Gy) was higher than the mean dose planned by TPS (3.23 ±1.16 Gy, p < 0.001). The mean dose difference was higher in second fraction (0.87 ±1.89 Gy) for first fraction-based planning group; however, the differences between first and second fractions were not statistically significant in either group. For patients transferred from a brachytherapy couch to a hospital stretcher during applicator insertion and dose delivery, first fraction-based planning is feasible. However, caution is needed to minimize applicator shifts, as these changes can alter the geometric position between fractions.

Postharvest losses (PHLs) of biomaterials, such as vegetables and fruits, significantly impact food security and economic stability in developing nations. In Tanzania, PHLs are estimated to range between 30% and 40% for cereal crops and even higher for perishable crops such as fruits and vegetables. Open‐sun drying (OSD) is the most extensively employed method because of its affordability and simplicity. However, OSD has several drawbacks, including difficulties in managing drying parameters, long drying times owing to adverse weather, and product contamination. The solar‐assisted heat pump dryer (SAHPD) is a technology designed as an alternative solution for drying biomaterials and reducing PHL. A limited number of SAHPDs have been constructed in developing nations. Most of the works have concentrated on the performance analysis of the systems. This neglects the techno‐economic assessment, which is important to provide both a quantitative and qualitative understanding of the financial viability of the technology. The present study therefore investigates the techno‐economic analysis of a novel SAHPD for drying agricultural products, particularly vegetables and fruits. To determine whether the SAHPD technology is technically and economically viable, tomatoes and carrots were dried and analyzed to determine their thermal and economic performance. The results show that the initial moisture contents of tomatoes (Lycopersicum esculentum) and carrots (Daucus carota) were reduced from 93% and 88% to 10% in 11 and 12 h, respectively. The coefficient of performance (COP), drying time (DT), specific moisture extraction ration (SMER) and thermal efficiency (ηT) were found to be 3.4, 2.3 kg/h, 1.33 kg/kWh and 54.0%, respectively. The economic analysis was assessed using the annualized cost, lifecycle savings, and payback period for the dryer's life span of 15 years. The initial investment of the SAHPD was $5221.8 and the annualized cost was $1076.5. The cumulative present worth for 15 years was found to be $23,828.8 and $27,553.1 for tomatoes and carrots, respectively. The payback period for tomatoes was found to be 3 years, whereas for carrots it was 2.6 years. Based on thermal and economic performance assessment results, the developed SAHPD is technically and economically viable to be considered for further investments.

Three brands of NPK fertilizers that contain variable concentrations of natural radioactivity are commonly used in tobacco plantations in Kenya, Tanzania, and Uganda. Tobacco plants are known for hyper-accumulation of natural radionuclides, particularly 238U. This study investigated if the elevated radioactivity in phosphate fertilizers could enhance radioactivity in soils and tobacco plant leaves. The 232Th, 238U, and 40K radionuclide levels in NPK-fertilized soils and tobacco leaves were measured using gamma-ray spectroscopy. The research included a one-year reference experiment with tobacco growing in plots, a ten-year semi-controlled experiment in well-managed tobacco farms, and a field survey of radioactivity in soils and tobacco leaves at three traditional tobacco fields in Migori (Kenya), Urambo (Tanzania), and Kanungu (Uganda). The findings demonstrated that soils and tobacco leaves exposed to NPK fertilizers with increased radioactivity had activity concentrations of 232Th, 238U, and 40K that were considerably higher (at all sites) than in the control samples (with no use of NPK fertilizers). As the continued application of NPK fertilizers raises concentrations of 232Th, 238U, and 40K in agricultural soils, the study assessed radiological risks for humans from exposure to agricultural soils enriched with phosphate fertilizers, and it was found to be below the exposure limit of 1 mSvy-1 suggested by the International Commission on Radiological Protection (ICRP). However, tobacco consumers, both by snuffing and smoking, may face significant radiological risks, as the snuffing and smoking resulted in effective doses that were 2.41 to 6.53 and 1.14 to 2.45 times greater than the average yearly dose that the general public receives from inhalation of natural radionuclides (United Nations Scientific Committee on Atomic Radiations estimates). Furthermore, the results indicate that the lifetime excess cancer risk for tobacco snuffers and smokers ranged from 5 × 10-5 to 24.48 × 10-3 and 2.0 × 10-5 to 9.18 × 10-3, respectively. The influence of phosphorus-derived fertilizer containing relatively high natural radioactivity, potential human radiation exposure, and radiological risk due to gamma radionuclides is estimated and discussed. The results reveal that applying phosphate fertilizers enhances natural radioactivity in soil and is subsequently influenced by soil to tobacco plant uptake. Therefore, the study recommends that countries use fertilizers with lower radionuclide content to conserve soil quality and reduce gamma-emitting radionuclides in tobacco plants.