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Analysis of the current and future land use/land cover changes in peri-urban areas of Dar es salaam city, Tanzania using remote sensing and GIS techniques
(College of Natural and Applied Sciences, University of Dar es Salaam, 2021) Mnyali, Erick T.; Materu, Silvia F.
A rapid increase in population and urban development has direct impacts on the natural environment of peri-urban areas of big cities, especially in the developing countries. This study examined land use and land cover changes (LULCC) of peri-urban areas of Kinondoni Municipality in Dar es Salaam city for the period between 1999 and 2019 and predicted future changes by 2039. The specific objectives were to; (i) map the spatial-temporal land use and cover changes (ii) analyze settlements (built-up areas) patterns and factors influencing their changes (iii) predict changes that might happen for the next two decades. LULCC for 1999 to 2019 were detected through Maximum Likelihood (ML) supervised classification techniques while Cellular Automata based on Artificial Neural Network (CA-ANN) model was used to predict future changes. Over the past two decades, 33.7% of vegetation has been lost due to increased settlements, as shown by linear development pattern of built-up areas, which has gained about 30% of other land covers. This study predicts that by 2039, built-up areas will increase drastically to occupy 51.6%, while vegetation and water cover will decrease to occupy 40.4% and 1.4%, respectively. Without good planning strategies and land use policies, the control and management of the magnitude and patterns of peri-urban growth and sustainable management of natural and built environments in Tanzania will remain a challenge. This paper seeks to contribute to the body of knowledge required for evidence-based policy formulation and decision making to attain sustainable urbanization through setting suitable management plans for peri-urban areas of Tanzanian cities.
Applicability of a biotest battery developed for temperate regions to tropical environments: implications for sustainable wetland management – a Case study of Kilombero Ramsar Site
(Leuphana Universität Lüneburg, 2015-04) Materu, Silvia F.
The increasing rate at which chemicals are released into the environment in Africa over the past two to three decades has raised a concern about the immediate ecological impacts and associated long-term environmental risks. Toxicity tests, which measure responses of organisms to various contaminants, have the capacity to indicate ecological impacts of chemicals that are released into the environment, and are therefore used in risk assessment studies. Intensive eco-toxicological studies in the developed world have led to establishment of standardized biotest procedures in order to assure reproducible and reliable results for risk assessment and for environmental regulations. Although there are a lot of data and publications on water and sediment quality for temperate countries using bioassays, tropical ecological risk assessment data using bioassays are scarce. The focus of this study was to apply biotests developed in temperate countries on tropical samples and evaluate their suitability for assessing pesticide contamination in soil, water, and sediment from Kilombero Valley Ramsar Site, in Tanzania. A total number of 143 dry and rainy season samples (58 water, 68 sediments and 17 soils) was collected in eight plantations (sugarcane, rice and teak). Toxicities were assessed by a battery of standardized tests comprising the algae growth inhibition test with the freshwater green algae, Pseudokirchneriella subcapitata, the luminescence bacteria test with Vibrio fischeri, and the bacterial sediment contact test with Arthrobacter globiformis. Responses of test organisms to sample matrices were categorized and classified into toxicity classes according to a fuzzy rule based-expert system. Suitability of using the P. subcapitata bioassay for assessing pesticide contamination in tropical agronomic systems based on the results of this study was evaluated. Chemical, geochemical and eco-toxicological analyses were combined in a weight of evidence approach to provide environmental risk information for this Ramsar wetland (wetland of national and international importance according to the Ramsar Convention of 1971). Interviews with plantation managers were conducted in order to get an overview over the application of pesticides in the area. Together with the distribution of measured pesticides, an evaluation of potential human risk has been carried out. Toxicity responses of the three bioassays differed to a considerable extent depending on the sample matrices and season. Dry season samples (soil and sediments) resulted in higher mean inhibition of A. globiformis (25%-31%) than rainy season sediment samples (5%). Neither P. xxSummary subcapitata nor V. fischeri showed a significant difference between rainy and dry season samples (water and sediments) even though there was a trend towards higher inhibition during dry season. Growth of P. subcapitata was stimulated (to an average of 69%) by all dry season soil samples while V. fischeri and A. globiformis were inhibited by the same samples at mean values of 34% and 25%, respectively. The observation that toxicities tended to be higher in dry than in rainy season sediment samples in the three bioassays indicate the presence of bioavailable inhibiting contaminants, which are deposited in the banks of streams or rivers when the flow velocity is slow. Low toxicities of rain season samples probably indicate a lower concentration of pesticides/contaminants due to flooding and increased surface runoff. A few dry season sediment samples collected from the outlets streams that receive drains from the rice paddies, as well as those collected adjacent to pesticide mixing /sprayer filling point, showed elevated toxic responses in three bioassays. However, there were no a direct relationship between such samples and the detected pesticides residuals, suggesting that the toxicity was caused by other contaminants. Fuzzy rule based classification of toxicity responses of the three bioassays showed that 73% of samples posed little or no toxic potential risk, while 25% were identified to pose critical risk and only 1% posed elevated critical risk. The algae growth inhibition test showed stimulation in 131 samples out of 143 rainy and dry season samples (sediments, soil and water). Laboratory experiments to evaluate the source of stimulation in the algae test revealed that nutrients such as organic carbon and Vitamin B in the test medium/matrices could stimulate P. subcapitata growth rate. Kilombero samples, however, had relatively low C/N ratios (according to FAO-classification), varying from 10 to 20 for poorly drained soils, suggesting that there is high decomposition of organic matter (enhanced by tropical climatic conditions) and organic humus is transported from the highlands to these lowland flood plain wetlands, thus enriching its organic nutrients. Experiments were carried out to assess whether the blockage of electron transport system by photosystem II inhibitors (specific herbicides) could have caused the stimulation in the P. subcapitata growth inhibition test. It was revealed that: as opposed to chemicals with different mode of action, the presence of PS-II inhibitors in the test medium stimulated the prompt fluorescence (PF) and inhibited the delayed fluorescence (DF), a pattern that is caused by back reactions when the electron transport system is blocked. Although pesticide residuals such as diuron, glyphosate, AMPA, propoxur, atrazine, 2-hydroxy-atrazin, metribuzin, chlorpyrifos, xxiSummary desmethyldiuron, monuron, hexazinone and ametryin were detected in water, sediment and soil samples, the DF and PF patterns were not detected in the environmental samples as they were with single substance tests. Despite the potential to induce fluorescence, the presence of PSII inhibitors in the samples could thus not be responsible for stimulation in the 72-hour growth inhibition test. In conclusion, V. fischeri and A. globiformis bioassays can be used in tropical climates to identify contaminated hotspots. However, the chronic P. subcapitata bioassay could not provide enough information on the toxicity of sample matrices because of the observed stimulations. Thus, there might be a potential to underestimate the toxicity of samples collected from agricultural fields, especially for sediment and soil samples, which are rich in nutrients and are contaminated with low concentration of pesticides. Supplementing the 72-hour algae test with a short bioassay, detecting photosystem II inhibitors, could provide additional, useful information on the toxicity of herbicides in environmental samples. Another supplementary test with the yeast Saccharomyces cerevisiae showed toxic responses in the same magnitude as in the bacterial bioassays when applied to the Kilombero samples. While promising to become a meaningful addition to the biotest battery to indicate fungicides, this test needs optimization due to unexplained reactions when exposed to organic pesticides. The risks of pesticides in the ecosystem depend on the characteristics of a chemical and on the level and pattern of exposure. Unsafe handling of pesticides in the Kilombero valley, which were revealed during field surveys are: pesticide spillage at retail marketing places, spillage during filling up the sprayers, cleaning of the spraying equipment in open waters, on-farm disposal of the pesticide containers and mixing pesticides close to streams, wetlands and ditches. These water bodies surrounding the surveyed plantations have been used by the adjacent households as a source of water for domestic use. Therefore, continued use and unsafe handling of pesticides in these wetlands pose a great risk to human health, wildlife and aquatic organisms. Ecotoxicology using simple, fast and cost effective bioassays, which are novel to Tanzanian setting, might help to provide strategies for reducing the risk from agrochemicals in the Tanzanian wetland ecosystems.
Artemisinin combination therapies price disparity between government and private health sectors and its implication on antimalarial drug consumption pattern in Morogoro Urban District, Tanzania
(BMC Research Notes, 2012) Malisa, Allen Lewis; Kiriba, Deodatus
Universal access to effective treatments is a goal of the Roll Back Malaria Partnership. However, despite official commitments and substantial increases in financing, this objective remains elusive, as development assistance continue to be routed largely through government channels, leaving the much needed highly effective treatments inaccessible or unaffordable to those seeking services in the private sector. To quantify the effect of price disparity between the government and private health systems, this study have audited 92 government and private Drug Selling Units (DSUs) in Morogoro urban district in Tanzania to determine the levels, trend and consumption pattern of antimalarial drugs in the two health systems. A combination of observation, interviews and questionnaire administered to the service providers of the randomly selected DSUs were used to collect data. ALU was the most selling antimalarial drug in the government health system at a subsidized price of 300 TShs (0.18 US$). By contrast, ALU that was available in the private sector (coartem) was being sold at a price of about 10,000 TShs (5.9 US$), the price that was by far unaffordable, prompting people to resort to cheap but failed drugs. As a result, metakelfin (the phased out drug) was the most selling drug in the private health system at a price ranging from 500 to 2,000 TShs (0.29–1.18 US$). In order for the prompt diagnosis and treatment with effective drugs intervention to have big impact on malaria in mostly low socioeconomic malaria-endemic areas of Africa, inequities in affordability and access to effective treatment must be eliminated. For this to be ensued, subsidized drugs should be made available in both government and private health sectors to promote a universal access to effective safe and affordable life saving antimalarial drugs.
Attitudes and perceived impact of insecticide treated– bed nets on malaria control in rural Tanzania
(Sokoine University of Agriculture, 2019) Alphonce, J.; Maganira, J.; Mwangònde, B. J.
Insecticide-treated nets (ITNs) are the most powerful malaria control tool if used correctly. Yet up to date, utilization is still low. The aim of this study was to investigate the intra-household factors that affect the utilization of ITNs in rural households in MorogoroUrban district. In addition, this study analysed the reasons for ITNs non-use in households with children under five years. Questionnaire, interviews and observation were the key tools for data collection for thestudy. The intra-household factors affecting the utilization of ITNs reported in this study include, chemical substances impregnated in the nets (36%), household financial inadequacy (24%), warmth and discomfort of the nets (24%) and skin irritability (17%), among others. The general community knowledge about mosquito nets was found to be high (91%); however, the knowledge of ITNs was low (30%). In addition, it was found that the ITNs were inadequately accessible in the study community. Based on the results of this study, adequate accessibility of ITNs and community education related to the use and their significance is recommended.
Benthic macroinvertebrate assemblages in mangroves and open intertidal areas on the Dar es Salaam coast, Tanzania
(NISC (Pty) Ltd and Taylor & Francis, 2015) Rumisha, C.; Shukuru, H.; Lyimo, J.; Maganira, Justine Daudi; Nehemia, A.
The assemblages of benthic macroinvertebrates in mangroves and open intertidal areas of the Dar es Salaam coast, Tanzania, was investigated in 2013–2014, revealing 56 species. Higher density, species richness and diversity were recorded in open intertidal areas, compared to nearby mangrove forests. Non-metric multidimensional scaling indicated differences in assemblages between mangrove and open intertidal samples. These differences were confirmed by analysis of similarity. SIMPER identified an average dissimilarity of 97.24% between mangroves and open intertidal samples, most of which were due to the malacostracan Uca annulipes and the gastropod Cerithidea decollata. PRIMER RELATE indicated significant correlation between macroinvertebrate assemblages and the measured physico-chemical parameters salinity, pH, redox potential and sediment particle size, whereas BIOENV and the Monte Carlo permutation test indicated that redox potential, sediment particle size and pH contributed significantly to variation in species composition. Mangroves were dominated by the gastropod C. decollata, and by the malacostracans Neosarmatium africanum and U. annulipes, and open intertidal areas by the bivalves Dosinia hepatica and Eumarcia paupercula. Due to the rich biodiversity in open intertidal ecosystems, it is recommended that conservation efforts along the Tanzanian coast should focus here.
Canonical correlation analysis across vegetation and soil properties of the disturbed and undisturbed coastal forest ecosystems
(Advances in Research, 2019) Ligate, E. J; Chen, C.
This study presents comparative initial information about canonical correlation across forest stand parameters, diversity indices and soil properties in undisturbed forest sites (IFS), agriculture disturbed sites (ADS) and livestock disturbed sites (DGS). Data were collected from Uzigua Forest Reserve in Tanzania. Forty- seven sample plots of 25 m × 25 m were randomly established on IFS, ADS and DGS from which tree inventory data and 141 soil samples were drawn. Data were subjected into Canoco windows 4.5 software for multivariate analyses and comparisons across IFS, ADS and DGS. The correlation of tree stand parameters (TSP) and soil physical properties (SPP) were F=1.207, p=0.242 in IFS, F=2.400, p=0.012 in ADS and F=0.529, p=0.938 in DGS. For soluble bases and TSP were F=2.448, p=0.018 in IFS, F=0.687, p=0.790 in ADS and F=0.743, p=0.808 in DGS. Carbon, nitrogen and potassium (CNP) and TSP were F=0.816, p=0.572 in IFS, F=0.687, p=0.790 in ADS and F=0.070, p=0.020 in DGS. The SPP and Shannon indices had F=1.103,p<0.388 in IFS, F=0.520, p=0.714 in ADS and F=0.932, p=0.444 in DGS. The SPP and Independent Value Index (IVI) were F=0.042, p=0.996 in IFS, F=0.819, p=0.620 in ADS and F=0.633, p=0.724 in DGS. Soluble bases and equitability were F=0.119, p=0.968 in IFS, F=0.001, p=0.001 in ADS and F=0.011, p=0.001 in DGS. The CNP and IVI had F=4.246, p=0.014 in IFS, F=2.729, p=0.018 in ADS and F=2.007, p=0.060 in DGS. The mean higher canonical correlation in the non-disturbed sites indicates that crop-agriculture and livestock grazing affect the interplays between forest vegetation and soil properties. Therefore, human activity disturbs the structure and soil properties.
Carbon stocks potential in regenerating trees of the tropical coastal forest ecosystems
(Book Publisher International, 2020) Ligate, E. J.
Estimation of carbon in the regenerating tropical coastal forest is needed to support conservation and forest monitoring strategies. This chapter presents the determined carbon stocks in regenerating species across forest sites subjected to deforestation because of crop-farming and livestock grazing. The study used thirty-three independent measurements of tree carbon stocks from thirty-three tree families found in the coastal zone of Tanzania. The vegetation was inventoried using a floristic survey of the woody component across intact, crop agriculture and livestock disturbed land-use sites. The biomass was then estimated by employing the existing allometric equations for tropical forests. Thereafter, the above-ground stored carbon was quantified on the sampled tree species found in each land uses. The tree varied (p ≤ .05) in carbon stock across species and land uses. The average carbon (Kg/ha) stored in the regenerated adult trees was 1200 in IFS, 600 in ADS, 400 in LDS. Saplings had 0.43 in LDS, 0.07 in ADS and 0.01 in IFS. Also, seedlings showed an average of 0.41 in IFS, 0.22 in ADS and 0.05 in LDS. It shows that crop-agriculture highly affects the regeneration potential of trees, biomass accumulation and carbon stock than livestock grazing. To restore the carbon storage potential of coastal tropical forests, crop-agriculture must be discouraged, while livestock grazing can be integrated into forest management. Indeed, further studies are required to gauge the integration levels of any anthropogenic activities, so that the natural capacity of coastal tropical forests to regenerate and stock carbon is not comprised further.
A case report of a typhoid fever outbreak with an uncommon vehicle and source of salmonella enterica serotype typhi
(Scientific research and community, 2021-01-19) Mushi, Douglas W.
Two goat caretakers aged 19 and 25 years old were infected with Salmonella enterica serovar typhi (S. typhi); both had eaten raw carrots from a garden enriched with goat faeces in typhoid endemic region of Morogoro, Tanzania. S. typhi strains isolated from garden soils and carrots proved to be from goat faeces. This data provide evidence for the spread of typhoid fever through carrots contaminated by faeces from goats contained transient S. typhi.
Chicken maternal lineage retained long historical relationship between Zanzibar and Oman
(TAJAS, 2021) Lyimo, C.M; Al-Qamashoui, B
The aim of this study is to appreciate the long historical relationship between Zanzibar and Oman, through the investigation of maternal lineage of chickens found in Zanzibar and Oman. Earlier traders and explorer from Arabia, Persian Gulf, West India and China probably visited Zanzibar as earlier as the 1 st Century AD. Oman in Southern Coast of the Arabian Peninsula at the Persian Gulf played a tense relationship between seafaring and commercial people in Indian Ocean. Furthermore, the history of Zanzibar is directly linked to Oman, after Oman Empire expelled and ended the Portuguese dominance of the Indian Ocean trade routes. In 1650 Oman becomes one of the main maritime and mercantile powers in the Persian Gulf and in the Indian Ocean. The sultans of Oman ruled over a substantial part of the Swahili Coast along the Indian Ocean from 1689-1856, controlling elaborate trade routes and cash crop plantations in East Africa. In the mid-1800s, they moved their seat of power from Muscat, Oman, to Stone Town, Zanzibar, and ruled as a constitutional monarchy. This historical relationship can be traced from maternal lineage of chickens that currently exist in Zanzibar and Oman. The mitochondrial genome has been the most widely used system for the investigation of the evolutionary history of species. The high rate of sequence divergence and its uniparental, maternal inheritance can retain evolution relationship as genetic fossils. The Phylogenetic network and Medial-Joining network analysis revealed strong association of evolution relationship between chicken ecotypes from Zanzibar and Oman. The prominent ancestral haplogroups indicated strong association of these chicken populations that were descended from the common ancestry. The Maritime trade interactions and consequences of Oman sultanate regimes in Zanzibar could significantly contributed to the ancestral relationship that existing today between Zanzibar and Oman Chickens.
Comparative analysis of selected factors affecting fruit phenotype and yield of sclerocarya birrea in Tanzania
(Tanzania Journal of Agricultural Sciences, 2014) Andrew, Woiso D.
Knowledge of fruit physical properties and yield is imperative for trees with commercial domestication prospects like Sclerocarya birrea. This study assessed individual fruit weight and diameter as well as yield per tree for the three subspecies of Sclerocarya from two types of land use (farmland and wild). Ten female trees were randomly selected from on-farm and wild sites for each subspecies. From each tree, diameter and weight of 50 randomly selected fruits were measured during a peak fruiting while all fruits per tree were counted and recorded throughout the entire fruiting season for two consecutive years. Results showed that subspecies multifoliolata had significantly heavier fruits and more yield than subspecies birrea and caffra (p < 0.001) Fruits from subspecies birrea were significantly larger than those from the other two subspecies (p < 0.001).Trees from the wild population yielded more fruits that were also heavier that those from on-farm but the difference was only significant for subspecies multifoliolata (p < 0.001) Fruits from on-farm population of subspecies birrea were significantly the largest in diameter (p < 0.001). There was a strong relationship between fruit properties with crown diameter &dbh; and between yield and crown diameter while a decline in rainfall reduced fruit yield across the species and land use. Our results indicate that fruit physical properties and yield have allometric relationship with tree size structure and they vary with rainfall, type of subspecies and probably pollination intensity but not with farmers’ selection pressure and intervention.
Contribution of Tanzania Southern highlands forest diversity to household income and food supplements;The case of Mufindi district in Tanzania
(SCIENCEDOMAIN international, 2017) Msola, D. K; Ligate, E. J.; Chen, C.; Wu, C.
Understanding the role played by forest diversity to supply non-timber forest products for income and food supplements of households is important in forest management and human life. This study was conducted to investigate the role played by non-timber forest products and their implications on income and food supplements in Mufindi District in Tanzania. Methodology: A cross section field survey research methodology was used in this study. Six representative villages in three wards; Rugemba, Igowole and Sadan located within 30 Km to forestreserves were selected. Interviews were conducted to 180 respondents from the three wards. One focus group from each village was conducted while District agricultural officers and village leaders formed a key informant’s category. Quantitative data were analyzed using Statistical Package for Social Science Software and Microsoft excel while memos were produced from qualitative data and used to narrate discussion. Taxonomic plants classification was carried out at Sokoine University of Agriculture botanic laboratory. Results: It was found that non-timber forest products are mostly consumed directly by the people who collect them as a useful dietary supplement, especially when food is scarce. To a lesser extent, they are also sold for cash, but the market for them is badly organized in terms of poor transport and lack of storage facilities, so they are not an important source of income except for people who live near important roads. It was discovered that deforestation and climate change are reducing the potential supply of these products. Conclusions: Given the importance of the sustainable exploitation of non-timber forest products as an incentive for forest conservation, the market for non-timber forest products should be rationalized and expanded. Improvement of the use and role of wild foods should be planned and implemented within a larger scheme of sustainable forest management.
A critical review of policies and legislation protecting Tanzanian wetlands
(Informa UK Limited, trading as Taylor & Francis Group on behalf of the Ecological Society of China., 2018) Materu, Silvia Francis; Urban, Brigitte; Heise, Susanne
Introduction: The benefit of wetlands for reducing poverty depends on the effectiveness of governance systems that influence peoples’ behaviour in the wise use of wetlands. Objectives: This article critically analyses the current poverty reduction strategies, agrarian policies and economic investments governing wetland usage, especially in Tanzania, with regard to their impact on sustainable Ramsar wetlands management. Methodology: It analyses the management structure, domestic policies and legal framework relating to the protection of wetlands in Tanzania in accordance to the wise use concept of the Ramsar Convention. Outcomes: Tanzanian legal provisions for wetland protection are uncoordinated and too limited in their coverage and scope to sufficiently address the destruction of wetland ecosystems. There is no comprehensive national legal framework to guide sustainable management of Ramsar wetlands in Tanzania as laid out by the Ramsar Convention, which the country ratified in the year 2000. Conclusion: Without a sound legislative and policy-making framework, Tanzanian wetlands and their diverse ecosystem services will continue to degenerate with current strategies of increasing agribusiness and other developmental projects or economic investments. This paper provides critical baseline information to inform decision makers to develop appropriate policy and laws, which promote the wise use of wetlands in Tanzania.
Detection of porcine cysticercosis in meat juice samples from infected pigs
(Springer, 2021) Maganira, Justine Daudi; Kidima, Winifrida; Mwita, Chacha John; Höglund, Johan
Background Seroprevalence of porcine cysticercosis has been generally studied using enzyme-linked immunosorbent assays (ELISA) detecting either antigens or antibodies in sera. However, serum is not always readily available. The objective of this study was to assess the diagnostic potential of meat juice in detecting porcine cysticercosis using a cysticercosis antibody ELISA. Methods Sera and meat juice samples from 13 different organs/tissues were collected from nine pigs naturally infected with cysticercosis and from six uninfected pigs reared under hygienic conditions. The sensitivity of the cysticercosis antibody ELISA in detecting porcine cysticercosis in meat juice samples was compared to that in serum samples from the same pigs. Results Using sera, cysticercosis was detected in all nine pigs harbouring cysticerci, but not in those reared under hygienic conditions. The sensitivity of the ELISA was highest in meat juice extracted from the diaphragm (100%), heart (89%) and neck muscle (78%) of the nine infected pigs, whereas it varied between 0 and 44% in the other samples. Conclusion To the best of our knowledge, this is the first study for T. solium cysticercosis serology to use meat juice. Our results show that meat juice from pig carcass organs or muscles is a promising diagnostic specimen for the detection of porcine cysticercosis. More studies including a large sample size of pigs with varying degrees of cysticercosis infection are needed to further prove this concept.
Dhfr and dhps mutations in plasmodium falciparum isolates in Mlandizi, Kibaha, Tanzania: association with clinical outcome
(Tanzania Health Research Bulletin, 2006-05) Kidima, W; Nkwengulila, G.; Premji, Z.; Malisa, A.; Mshinda, H
Sulfadoxine-pyrimethamine (SP), the current first line antimalarial drug in Tanzania, is compromised by evolution and spread of mutations in the parasite's dhfr and dhps genes. In the present study we established the baseline frequencies of Plasmodium falciparum dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) mutant genotypes and their potential for predicting the in vivo efficacy of SP in Mlandizi, Tanzania. The efficacy of SP treatment was by following 116 children with uncomplicated falciparum malaria for 14 days after treatment. Infected blood samples were collected on filter paper at days 0, 3, 7 and 14. Parasite genomic DNA was extracted and point mutations at positions 51, 59, 108 and 164 of the dhfr gene and at 581, 540 and 437 of the dhps gene were analysed by nested Polymerase Chain Reaction/ Restriction Fragment Length Polymorphism. Out of 116 children enrolled, 98 (86%) of eligible children demonstrated an adequate clinical response by day 14. There were 7.3 % early and 6.7% late therapeutic failures. At day 0, only 8.0% (4/50) the parasites showed no mutation at the dhfr locus; for dhps this was 73%. Triple mutant dhfr alleles (Ile 51, Arg 59, Asn 108) occurred in 47%, double mutant dhps (Gly 437, Glu 540) alleles in 7.9%. No mutation was detected at codon 164 of the dhfr gene. The presence of triple dhfr mutant alleles was related to clinical failure, but did not show significant association (Fisher exact test, P=0.166, OR 2.15 0.776.20). The higher rates of mutation on the dhfr do not spell a bright future for SP treatment in Tanzania. It is rational to think of an alternative first line antimalarial drug, while retaining SP for malaria intermittent treatment in pregnancy.
Dietary risk assessment of selected organophosphoris and pyrethoid pesticide residues in fresh harvested tomatoes at Makambako town, Njombe region, Tanzania
(Taylor and Francis, 2022) Bilaro, Jansen S.; Materu, Silvia F.; Temba, Benigni A.
This study aimed to assess the levels of selected pesticides residues in harvested tomatoes and their associated dietary risks to consumers at Makambako Town in Njombe region, Tanzania. Forty-two fresh tomatoes were sampled among tomato farmers during harvesting season and extraction of analytes was done using QuEChERS method and analysed by Gas Chromatography-Mass Spectrometer. Residues of chlorpyrifos, profenofos, gamma cyhalothrin and cypermethrin were alternatingly detected in 78.51% of samples. The average concentrations of residues were 0.014, 0.056, 0.003 and 0.2 mg/kg for chlorpyrifos, profenofos, gamma cyhalothrin and cypermethrin and were all below their respective Codex MRLs. The highest concentration was 0.718 mg/kg for cypermethrin, above the Codex MRL of 0.2 mg/kg. The hazard indexes indicate no potential health hazards to the general population due to the lifetime consumption of fresh tomatoes from the study area. Periodic monitoring of residue levels of pesticides in vegetable fruits, including tomatoes, is recommended.
Distribution and regeneration status of Vitex payos (Lour.) Merr. in Kenyan drylands
(Journal of Horticulture and Forestry, 2014-10) Kimondo, James Munga; Agea, Jacob Godfrey; Okia, Clement Akais; Dino, Andrew Owiso; Abohassan, Refaat Atalla Ahmed; Mulatya, Jackson; Teklehaimanot, Zewge
We investigated the population structure and regeneration status of Vitex payos (Lour.) Merr. in Kenyan drylands. The study quantified the spatial distribution pattern of V. payos tree populations in their natural range; and assessed their regeneration status to determine the stability of the populations Woodlands and farm inventories were conducted in Mbeere, Mwingi and Kitui districts of the Eastern Province of Kenya. The nearest-neighbour sampling method was used to determine tree density and distribution of V. payos in the study sites. The number of seedlings and saplings were counted. The diameters, crown diameter, and tree heights of sampled trees were measured. These morphological parameters were summarized on per hectare basis. The patterns of distribution of V. payos trees showed an aggregation of trees on farms and bushes. Tree densities ranged from 1.6 on farmlands to 20.3 trees per ha in the woodlands. The expected mean distances between nearest neighbouring trees were higher than the observed values on all sites, confirming that V. payos trees were more aggregated than randomly dispersed. The mean tree heights varied from < 5 m to > 9 m cross study sites. The sampled populations were dominated by trees (55%) within the range of 10 to 20 cm dbh. Highhest numbers of seedlings from all origins were recorded in the bushes in Kitui and Mbeere districts 101 and 78 seedlings per hectare, respectively. Sapling population densities were generally low.
Diversity of riparian ground beetles (coleoptera, carabidae) at three altitudes in Uluguru Mountains, Tanzania
(Research Journal of Agricultural and Environmental Sciences, 2015) Maganira, Justine Daudi; Nyundo, B. A.
The diversity of riparian ground beetles at three altitudes (Low: 400-1100m a.s.l., Mid: 1100- 1800 m a.s.l., High: 1800-2500 m a.s.l.) in Uluguru Mountains was investigated. The samples of ground beetles were collected by active searching method from nine sites between May and June 2012. A total of 3261 specimens of ground beetles representing 13 subfamilies and 29 species were recorded. Ground beetle abundance, species richness and diversity were analyzed statistically using Diversity and Richness–2.65, PRIMER 6 and SYSTAT Version 10 software. The abundance of ground beetles was low at mid altitude (n = 499) and high at low and high altitudes (n = 1988; n = 774 respectively). There was significant variation in ground beetle abundance among the three altitudes (Kruskal-Wallis H=84.533, p<0.05). The most abundant species, Trechodes babaulti, was abundant at low and high altitudes (n=1534; 47.04% and n=501; 15.36% of the collected beetles respectively). Both species richness and Shannon-Wiener index of diversity (H') of ground beetles varied between low, mid and high altitudes with the highest species richness and diversity found at mid altitude. Pairwise comparison showed a significant difference in diversity of ground beetle species for all three pairs (high/mid, high/low & mid/low) of altitudes (p<0.05).
Drivers of millet consumption among school aged children in central Tanzania
(Frontiers, 2021) Chande, Monica; Muhimbula, Happiness; Mremi, Ruth; Muzanila, Yasinta C; Kumwenda, Nelson C; Msuya, John; Msere, Harry; Bekunda, Mateete; Okori, Patrick; Gichohi-Wainaina, Wanjiku N
Background: Iron and zinc deficiency are common public health problems in low-income countries largely due to poor consumption of iron and zinc rich foods. It has previously been observed that 57% of school aged children (SAC) in Tanzania suffer from anemia. In addition, estimates indicate that over 25% of the population have inadequate zinc intake. Pearl millet is an example of a nutrient dense, resilient cereal crop, that can be promoted to diversify diets and combat iron and zinc deficiency. This study overall aim was to increase pearl millet consumption among school aged (5 – 12 years) children. As part of the study, we investigated, the drivers of food choice relating to pearl millet consumption. Methods: The study was a cross-sectional study of randomly selected households in Kongwa district, Dodoma region of Tanzania. In total, 128 women of reproductive age (20 – 49 years) were randomly selected for the study. A study questionnaire consisting of 66 items, was developed and validated. The constructs in the questionnaire were categorized in two groups: internal and external factors. Respondents were asked to indicate their level of agreement or disagreement with statements read to them by interviewers. The scores on intention and behavior constructs were based on the number of times caregivers intended to, or had fed their school going children with pearl millet in the referent month. Intention was considered high if it was higher than the median intention score of the group, and low if it was equal to or lower than the median scores. Correlations and multiple linear regressions were performed to measure association between constructs and to identify predictive constructs. The Mann-Whitney U test was used for score comparison. Results: There was a significant difference between intention and behavior among those who did not consume pearl millet (P = 0.003), and those who consumed pearl millet two or more times a week, in the same month (P = 0.01). Knowledge was significantly correlated with behavior identity (ρ = 0.58, P = 0.001), while health behavior identity was significantly correlated with intention (ρ = 0.31, P = 0.001). Intention of caregivers was significantly and positively correlated (ρ = 0.44, P = 0.001) with and predicted consumption of pearl millet (ρ = 0.87, P = 0.067).
Drug coverage in treatment of malaria and the consequences for resistance evolution – evidence from the use of sulphadoxine/ pyrimethamine
(Malaria Journal, 2010) Malisa, Allen L.; Pearce, Richard J.; Abdulla, Salim; Mshinda, Hassan; Kachur, Patrick S.; Bloland, Peter; Roper, Cally
Background: It is argued that, the efficacy of anti-malarials could be prolonged through policy-mediated reductions in drug pressure, but gathering evidence of the relationship between policy, treatment practice, drug pressure and the evolution of resistance in the field is challenging. Mathematical models indicate that drug coverage is the primary determinant of drug pressure and the driving force behind the evolution of drug resistance. These models show that where the basis of resistance is multigenic, the effects of selection can be moderated by high recombination rates, which disrupt the associations between co-selected resistance genes. Methods: To test these predictions, dhfr and dhps frequency changes were measured during 2000-2001 while SP was the second-line treatment and contrasted these with changes during 2001-2002 when SP was used for first-line therapy. Annual cross sectional community surveys carried out before, during and after the policy switch in 2001 were used to collect samples. Genetic analysis of SP resistance genes was carried out on 4,950 Plasmodium falciparum infections and the selection pressure under the two policies compared. Results: The influence of policy on the parasite reservoir was profound. The frequency of dhfr and dhps resistance alleles did not change significantly while SP was the recommended second-line treatment, but highly significant changes occurred during the subsequent year after the switch to first line SP. The frequency of the triple mutant dhfr (N5 ,C59R,S108N) allele (conferring pyrimethamine resistance) increased by 37% - 63% and the frequency of the double A437G, K540E mutant dhps allele (conferring sulphadoxine resistance) increased 200%-300%. A strong association between these unlinked alleles also emerged, confirming that they are co-selected by SP. Conclusion: The national policy change brought about a shift in treatment practice and the resulting increase in coverage had a substantial impact on drug pressure. The selection applied by first-line use is strong enough to overcome recombination pressure and create significant linkage disequilibrium between the unlinked genetic determinants of pyrimethamine and sulphadoxine resistance, showing that recombination is no barrier to the emergence of resistance to combination treatments when they are used as the first-line malaria therapy.
Drug resistance to sulphadoxine-pyrimethamine in Plasmodium falciparum malaria in Mlimba, Tanzania
(Malaria Journal, 2006-10) Mbugi, Erasto V; Mutayoba, Benezeth M; Malisa, Allen L; Balthazary, Sakurani T; Nyambo, Thomas B; Mshinda, Hassan
Background: Sulphadoxine-pyrimethamine (SP) has been and is currently used for treatment of uncomplicated Plasmodium falciparum malaria in many African countries. Nevertheless, the response of parasites to SP treatment has shown significant variation between individuals. Methods: The genes for dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) were used as markers, to investigate parasite resistance to SP in 141 children aged less than 5 years. Parasite DNA was extracted by Chelex method from blood samples collected and preserved on filter papers. Subsequently, polymerase chain reaction (PCR) and restriction fragment length polymorphism (PCR-RFLP) were applied to detect the SP resistance-associated point mutations on dhfr and dhps. Commonly reported point mutations at codons 51, 59, 108 and 164 in the dhfr and codons 437, 540 and 581 in the dhps domains were examined. Results: Children infected with parasites harbouring a range of single to quintuple dhfr/dhps mutations were erratically cured with SP. However, the quintuple dhfr/dhps mutant genotypes were mostly associated with treatment failures. High proportion of SP resistance-associated point mutations was detected in this study but the adequate clinical response (89.4%) observed clinically at day 14 of follow up reflects the role of semi-immunity protection and parasite clearance in the population. Conclusion: In monitoring drug resistance to SP, concurrent studies on possible confounding factors pertaining to development of resistance in falciparum malaria should be considered. The SP resistance potential detected in this study, cautions on its useful therapeutic life as an interim firstline drug against malaria in Tanzania and other malaria-endemic countries.

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