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Vitamin D Deficiency Among Pregnant Women In Dodoma, Tanzania: Prevalence, Knowledge, Attitude, Practices And Associated Factors
(NM-AIST, 2026-07) Anatoli, Antony
Vitamin D deficiency is a critical health challenge among pregnant women with significant implications for maternal and foetal health outcomes globally. It is linked to adverse health outcomes for both mother and foetus, yet data on vitamin D status among pregnant women in Tanzania is limited. A cross-sectional study was conducted from July to August 2024 to assess knowledge, attitudes, practices, prevalence and factors associated with vitamin D deficiency among pregnant women attending antenatal clinics in selected public health centres in Dodoma, Tanzania. Structured questionnaires were used for the interviews, and blood samples were
collected from 60 pregnant women for testing vitamin D deficiency. Results showed that, according to pilot findings, the prevalence of vitamin D deficiency, insufficiency and sufficiency was 5.0%, 26.7% and 68.3%, respectively. Furthermore, 48.7% had poor knowledge, 60.9% had moderate practices, and 60.9% had a positive attitude regarding vitamin D deficiency. Vitamin D deficiency was potentially associated with indoor work (p = 0.001), low monthly household income (p = 0.013), low physical activity (p = 0.001), and obesity (p = 0.038). The findings revealed low knowledge, moderate practices, and a generally positive
attitude regarding vitamin D deficiency among pregnant women. In addition, vitamin D deficiency and insufficiency were observed in this group. These results highlight the need for interventions aimed at improving knowledge and practices related to vitamin D deficiency, while promoting adequate sun exposure among indoor workers, healthy weight management, and regular physical activity participation.
Evaluating The Effect Of Pyriproxyfen Exposure On Anopheles Arabiensis Susceptibility And Fitness Parameters Under Semi-Field Setting
(NM-AIST, 2026-07) Twaha, Simoni
Pyriproxyfen (PPF), a juvenile hormone analogue is a promising chemistry for autodissemination strategies, where mosquitoes aid in transferring insecticides to their breeding sites. This study evaluated the effects of sub-lethal PPF exposure on Anopheles arabiensis fitness (fecundity, fertility and body size) and pyrethroids susceptibility across three generations. Laboratory-reared, pyrethroid-resistant mosquito larvae were exposed once to sub-lethal PPF concentrations of (0.0003, 0.0006, 0.0008 and 0.001 mg a.i./L), that causing emergence inhibition of 5%,10%,15% and 20%, respectively, alongside a control group. Emergent adults were tested for susceptibility to 0.75% permethrin, 3.75% permethrin and 0.05% deltamethrin using WHO tube bioassays. Knockdown was recorded at 1 h, mortality at 24 h post-exposure, while fecundity, fertility and body size were measured across three generations. First generation mosquitoes exposed to PPF showed reduced susceptibility to 0.75% permethrin and 0.05% deltamethrin (p < 0.05), which declined in the second and third generations (p > 0.05). Knockdown at one hour was significantly reduced in the first generation following PPF exposure when tested with 0.75% permethrin and 0.05% deltamethrin (P < 0.001). However, no significant differences were observed in the second and third generations compared to the control (P > 0.05). Notably, 3.75% permethrin resulted in complete knockdown and 100% mortality, regardless of whether mosquitoes emerged from PPF treated or control groups. The PPF exposure also significantly reduced fecundity, fertility and body size respectively. These findings suggest that sub-lethal PPF doses can temporarily enhance insecticide resistance without leading to heritable resistance and negatively impact key mosquito fitness traits. The PPF may thus be a valuable addition to integrated vector management strategies.
Impact Of Arthemether Lumefantrine Treatment, Circadian Rhythm And Serum Replacement On The Mosquito Infectiousness Of Wild P. Falciparum Gametocytes To Anopheles Gambiae Sensu Stricto Mosquitoes
(NM-AIST, 2026-02) Mmasi, Dorin
Asymptomatic gametocytemic carriers serve potential harbour for Plasmodium falciparum gametocyte stage V, and a threat for malaria transmission from infected humans to Anopheles mosquitoes. Therefore, it is important to optimise direct membrane feeding assays (DMFAs) to evaluate transmission blocking interventions (TBIs) on the infectiousness of wild P. falciparum gametocytes to Anopheles mosquitoes. This study assessed the impact of artemether-lumefantrine (AL) treatment, mosquito feeding time (day vs. night), and serum replacement on the infectiousness of wild P. falciparum gametocytes to Anopheles gambiae sensu stricto (s.s) mosquitoes. To conduct this experiment, 6 gametocytemic carriers were found to be eligible and donated 4 mL of venous blood. This blood was offered to female
Anopheles gambiae s.s mosquitoes via DMFA under controlled conditions. Oocyst prevalence and intensity were determined on fed mosquitoes: 1) 9 days post AL treatment, 2) day versus night feeds, and 3) with and without serum replacement. Mosquito infection rates declined post-AL treatment, with significantly fewer mosquitoes infected (odds ratio (OR) = 0.20, 95% confidence interval (CI) = 0.13-0.31, p=0.001) compared to day 0. Feeding during the mosquito night-time did not significantly affect mosquito infection rates (OR=0.77, 95% CI: 0.53-1.12, p=0.175). Lastly, serum replacement increased infection rates (OR = 1.73, 95% CI:
1.33-2.25, p = 0.001) compared to whole blood. In conclusion, we confirm that DMFA should be conducted using blood from gametocytemic participants without a recent history of AL treatment, using serum replacement to enhance infection success. In this setting, assays could be conducted during the daytime without affecting results.
Integrated Management Of Powdery Mildew In Mung Bean Using Resistant Genotypes And Botanical Extracts In Tanzania
(NM-AIST, 2026-07) Kitomari, Doring
Powdery mildew is a severe mung bean disease. Using plant extracts and screening mung bean genotypes with good morpho-agronomic traits is a crucial first step in creating an efficient disease management strategy. The study involved 132 genotypes and three checks laid in an augmented incomplete design to assess diversity through 42 morpho-agronomic traits. Additionally, screening for powdery mildew disease resistance in mung bean was conducted. This study also investigated factors affecting mung bean productivity, particularly powdery mildew disease among farmers, and the disease prevalence was scored in Kilimanjaro, Tabora, and Mtwara. The information was gathered from 240 mung bean farmers using a semistructured questionnaire. Five plant extracts were screened using leaf disc bioassay for preventative effects, and three of the best plant extracts were used in the potted plants in a completely randomized design to achieve both curative and preventive effects. The results indicated that the screened genotypes exhibited a broad range of qualitative traits. A significant difference was observed among genotypes, block effects and between seasons. Many traits showed notable distinctions concerning the contrast among genotypes, among checks and between genotypes and checks. For powdery mildew screening, one genotype showed resistance under field conditions. The first four principal components, as per the principal component analysis, accounted for 59.77% of the overall variation among the studied genotypes. Furthermore, cluster analysis grouped all genotypes into four primary clusters. Moreover, several socio-economic and biophysical constraints that limit the production of mung bean production were identified. The current study’s findings indicated the presence of powdery mildew in all surveyed locations where mung bean was cultivated. Furthermore, three
plant extracts, Azadirachta indica, Ocimum suave and Lippia javanica, showed higher preventative effects. Further, in potted seedling assays of these three plants extracts had not only preventative effects but also curative effects. The observed variability and resistance of the disease may help develop breeding schemes for mung bean cultivars with high yield and powdery mildew resistance. Furthermore, these findings could serve as a foundation for developing a natural fungicide against powdery mildew in mung bean.
Genetic Diversity And Genome Wide Association Studies Of Drought Tolerance And Bruchid Resistance In Lablab (Lablab Purpureus L.)
(NM-AIST, 2026-07) Lekasio, Elice
Lablab (Lablab purpureus L.) is an underutilized, drought-tolerant legume with potential to improve food and nutritional security. However, its improvement is limited by inadequate information on genetic diversity, population structure, drought tolerance and resistance to bruchids. This study assessed genetic diversity and population structure, estimated broad-sense heritability (H²) for drought tolerance and bruchid resistance traits and identified single nucleotide polymorphisms (SNPs) associated with these traits using genome-wide association studies (GWAS). A total of 281 lablab accessions sourced from genebanks and Tanzanian farmer collections were evaluated using phenotypic and genotypic approaches. Genotyping was conducted using 15 125 SNPs generated through the Illumina NovaSeq platform. Drought tolerance, measured as wilting percentage at week four, showed very low heritability (H² = 0.01), indicating strong environmental influence. Bruchid resistance traits showed low to high heritability, with H² values of 0.36, 0.29, 0.39 0.32 and 0.74 for number of eggs, percentage
adult emergence, weight loss, growth index and mean development period, respectively. Genetic diversity analysis revealed variation among accessions suggesting possible partial outcrossing in lablab. Population structure analysis identified 7 distinct genetic clusters with no clear association between genetic structure and geographic origin. The GWAS identified 8 significant SNPs associated with bruchid resistance, while no significant SNPs were detected for drought tolerance. Key SNP on chromosome 10 mapped to a region containing a peroxidase P7-like gene, suggesting a potential role in bruchid resistance. These findings provide support for germplasm conservation, selection of genetically diverse accessions, and marker-assisted breeding and further studies for drought adaptation and bruchid resistance.