Browsing by Author "Buza, Joram"

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Advancing the development and implementation of regional, national tuberculosis control programs in livestock in Africa, Asia, and Latin America
(Frontiers in Veterinary Science, 2023-04-18) Bakker, Douwe; Buza, Joram; Álvarez, Julio; Kapur, Vivek
Tuberculosis in livestock caused by members of the Mycobacterium tuberculosis (MTb) complex is a notifiable zoonotic animal disease (1), which has been eradicated or held to very low prevalence levels in many high-income economies. Successful campaigns were all build on a very strict test-and-slaughter strategy using the tuberculin PPD skin tests as diagnostic tool. However, tuberculosis in livestock remains endemic in most Low- and Middle-Income Countries (LMICs). This not only represents a threat to public health in those countries but also places a significant burden on their economies due to a negative impact on livestock productivity and the resources invested in healthcare, prevention, surveillance, and, when present, control and/or eradication programs. Moreover, tuberculosis in livestock affects a wide variety of species as well as breeds, raised in a wide variety of farming systems, in a broad range of different climates, thus ruling out a “one size fits all” approach for disease control. Since “traditional” test and cull programs are costly, very demanding on the livestock holder and may be ruled out as option for religious reasons, such programs must be tailored to ensure they are fit for purpose considering the respective socio-economic context in which they have to be implemented in each country.
Antimicrobial Activity of Tetradenia riparia (Hochst.) Lamiaceae, a Medicinal Plant from Tanzania
(European Journal of Medicinal Plants, 2014-08-08) Njau, Efrem-Fred; Alcorn, Jane-Mary; Buza, Joram; Chirino-Trejo, Manuel; Ndakidemi, Patrick
Aims: To evaluate the antibacterial activity of Tetradenia riparia crude extracts against Escherichia coli, Staphylococcus aureus and Enterococcuss faecalis. The phytochemicals that are responsible for the bioactivity were also screened. Study Design: In vitro assay of antibacterial properties. Place and Duration of Study: Samples were collected from Njari village at Uru North in Moshi district located in north eastern Tanzania. Extraction and phytochemical analyses were conducted at the College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada. Antimicrobial assay was carried out at Department of Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada between March 2013 and August 2013. Methodology: Agar well diffusion test was used to determine antimicrobial activity of the plant extracts. Ethanol, methanol, hexane and distilled water were used as extracting solvents. These extracting solvents were removed by vacuo evaporator. The resulting concentrated gummy-like materials were dissolved in Dimethysulfoxide (10% DMSO). Chemical tests were used to determine the group of phytochemicals present in the sample extracts. Results: Sensitivity testing results indicated that S. aureus was found to be more sensitive than E. coli and E. faecalis. Tetradenia riparia methanolic extracts from the root were the most active with zone of inhibition values of 29.33±0.88mm, 21.33±0.33mm and 20.0±1.0mm in diameter against S. aureus, E. faecalis and E. coli respectively. The relative inhibitory zone diameter (RIZD) was calculated. The highest percentage values of relative inhibition zone diameter of 84±5.06% (S. aureus) and 76±6.86% (E. coli) were demonstrated by T. riparia root methanolic extracts. However, T. riparia leaf and root extracts using hexane as well as leaf extracts using water did not show any antibacterial activity against E. faecalis. Root methanolic and ethanolic extracts demonstrated the minimum inhibitory concentrations ranging from 1.25mg/ml to 5.00mg/ml. Phytochemical screening of crude extracts from leaf and root of T. riparia revealed the presence of alkaloids, flavonoids, phenolics, saponins, tannins and sterols. Conclusion: The study findings suggest likelihood of designing and developing potentially active antibacterial drug from T. riparia. Further studies should concentrate on the investigations of not only leaf but also the root part of the plant.
Antimicrobial and Antioxidant Activity of Crude Extracts of Rauvolfia caffra var. caffra (Apocynaceae) From Tanzania
(Canadian Center of Science and Education, 2014-09-24) Njau, Efrem-Fred; Alcorn, Jane; Ndakidemi, Patrick; Chirino-Trejo, Manuel; Buza, Joram
As part of an effort to search for extracts and compounds with new antimicrobial efficacy to fight against bacterial resistance, the antibacterial activity of Rauvolfia caffra var. caffra (Sond.), a plant of family Apocynaceae used in Traditional Medicine in Tanzania, was investigated. Ethanol, methanol and water extracts from leaf, stem and root barks were tested against three species of bacteria namely Escherichia coli (ATCC 25922) (Gram -ve), Staphylococcus aureus (ATCC 25923) (Gram +ve) and Enterococcus faecalis (ATCC 51299) (Gram +ve) using Agar-well diffusion assay method and minimum inhibitory concentration on Mueller-Hinton Agar plates. The extracting solvents were removed by vacuo evaporator to obtain gummy-like extracts. This was then dissolved in dimethylsulfoxide (10% DMSO). The DMSO without plant extracts was used as a negative control whereas Gentamicin® as the standard antibiotic was used as a positive control. The Zone of Inhibition (ZOI) measured in mm and Relative Inhibitory Zone Diameter (RIZD) was calculated. Results showed that R. caffra exhibited antimicrobial inhibitory activity at a range of 1.25 to 5.0 mg/ml with activity most prominent with methanol extract (ZOI of 28.33± 0.33 mm and RIZD of 95% for S. aureus; and ZOI of 26.66 ± 0.33 mm for E.coli and 19.0 ± 0.57 mm for E. faecalis at P< 0.05). To characterize further, the alkaloid from the root bark was extracted according to the standard procedure. The antioxidant activity of the alkaloids and ethanolic extracts was determined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and reducing capacity assays. The results indicated that alkaloid fraction of the root and 80% ethanolic extracts of stem bark exhibited high antioxidant activity. The phytochemical analysis indicated that R. caffra is rich in alkaloids, anthraquinones, anthocyanoides, flavonoids, saponins, tannis and reducing sugars. This study provides supportive evidence that methanol and ethanol extracts of R. caffra can be used as herbal medicine in control of E.coli, S. aureus and E. faecalis.
Antimicrobial resistant enteric bacteria are widely distributed amongst people, animals and the environment in Tanzania
(Springer Nature Limited, 2020-01-13) Subbiah, Murugan; Caudell, Mark; Mair, Colette; Davis, Margaret; Matthews, Louise; Quinlan, Robert; Quinlan, Marsha; Lyimo, Beatus; Buza, Joram; Keyyu, Julius; Call, Douglas
Antibiotic use and bacterial transmission are responsible for the emergence, spread and persistence of antimicrobial-resistant (AR) bacteria, but their relative contribution likely differs across varying socio-economic, cultural, and ecological contexts. To better understand this interaction in a multi-cultural and resource-limited context, we examine the distribution of antimicrobial-resistant enteric bacteria from three ethnic groups in Tanzania. Household- level data (n = 425) was collected and bacteria isolated from people, livestock, dogs, wildlife and water sources (n = 62,376 isolates). The relative prevalence of different resistance phenotypes is similar across all sources. Multi-locus tandem repeat analysis (n = 719) and whole-genome sequencing (n = 816) of Escherichia coli demonstrate no evidence for host- population subdivision. Multivariate models show no evidence that veterinary antibiotic use increased the odds of detecting AR bacteria, whereas there is a strong association with livelihood factors related to bacterial transmission, demonstrating that to be effective, interventions need to accommodate different cultural practices and resource limitations.
Antimicrobial use in the poultry industry in Dar-es-Salaam, Tanzania and public health implications
(American Journal of Research Communication, 2014) Mubito, Ezekiel; Shahada, Francis; Kimanya, Martin; Buza, Joram
A structured questionnaire was administered to Dar es Salaam poultry farmers and pharmaceutical outlets/shops to obtain information on antibiotic usage, awareness of withdrawal periods and public health concerns on drug residues. Of 100 layer’s chicken production farmers interviewed in this study, 54% were females and 46% males. The average flock size was 560. All interviewed participants apply antibiotics through oral route of drug administration. Of these participants, 93% treat their chicken in accordance with directives from veterinary drug vendors, 4% follow the manufacturer’s instructions and 3% depends on their own experience. The survey found that most frequently used antibiotic drugs belong to the group of tetracycline and sulfonamides. Furthermore, some prohibited antimicrobial agents like furazolidone were found in some veterinary drug stores and poultry farms. All interviewed poultry farmers were aware of drug withdrawal period but none of them declared to observe this requirement because they fear investment losses. It was concluded that there is high risk of exposure to unacceptable levels of drug residues from poultry products, as a result of failure to observe antibiotic withdrawal periods. Consulted efforts involving various stake holders such the producers of poultry products, consumers and regulatory authorities are needed to bring awareness on public health implications associated with drug residues in foods.
Association of Chicken Mx1 Polymorphisms with Susceptibility in Chicken Embryos Challenged with Virulent Newcastle Disease Virus
(Science Alert, 2020) Mpenda, Fulgence; Lyantagaye, Sylvester; Buza, Joram
Background and Objective: Genetic selection of chicken genotypes that are less susceptible to Newcastle disease virus (NDV) is a promising option. The present study aimed to investigate polymorphism of chicken Mx1 gene G2032A SNP in different chicken breeds in Tanzania and association with chicken embryos susceptibility to virulent NDV. Materials and Methods: A total of 355 (87 Sasso, 129 Kuroiler and 139 local) 16 days old chicken embryos were infected with 0.1 mL minimum lethal dose (103/0.1 mL) of virulent NDV suspension. The time of death was recorded and selective genotyping was deployed where chicken embryos from high (15%) and less (15%) susceptible cohorts were genotyped by PCR-length polymorphism. Two forward and a reverse primers were used to generate 2 different sizes of PCR product of A and G alleles of chicken Mx1 gene G2032A SNP. Results: As expected chicken embryos survival was highly variable within a breed. The frequency of allele A was higher than allele G in chicken breeds. Furthermore, using Pearson’s X2 test of independence, it was demonstrated that chicken Mx1 gene G2032A genotypes (AA, AG and GG) were associated (p<0.05) with chicken embryos susceptibility to virulent NDV infection. The frequency of genotype AA was higher in less susceptible chicken embryos, whereas, frequency of genotype GG and AG was higher in high susceptible chicken embryos. Conclusion: Results from the present study provide valuable information on the potential role of Mx1 gene polymorphism for selection of chickens that are resistant to virulent NDV infection.
Association of LEI0258 Marker Alleles and Susceptibility to Virulent Newcastle Disease Virus Infection in Kuroiler, Sasso, and Local Tanzanian Chicken Embryos.
(Hindawi, 2020-04-08) Mpenda, Fulgence; Tiambo, Christian; Kyallo, Martina; Juma, John; Pelle, Roger; Lyantagaye, Sylvester; Buza, Joram
Newcastle disease (ND) control by vaccination and an institution of biosecurity measures is less feasible in backyard chicken in developing countries. Therefore, an alternative disease control strategy like the genetic selection of less susceptible chicken genotypes is a promising option. In the present study, genetic polymorphism of LEIO258 marker and association with susceptibility to virulent Newcastle disease virus (NDV) infection in Kuroilers, Sasso, and local Tanzanian chicken embryos were investigated. Samples from high (15%) and less (15%) susceptible cohorts were genotyped by sequencing of LEI0258 marker. A total of 75 DNA sequences comprised of 29 Kuroiler, 29 local Tanzanian chickens, and 17 Sasso were analyzed. Neighbor-joining phylogenetic trees were constructed to depict the clustering of LEI0258 marker alleles and relationship with susceptibility. Alleles with frequency ≥3 were considered for association with susceptibility by the use of the inference technique. The present findings suggest that some LEI0258 marker genetic polymorphisms apart from LEI0258 marker allelic based on sizes may be linked with chicken MHC-B haplotypes that confer chickens variability in resistance or susceptibility to infections. Furthermore, these results demonstrate the presence of relationship between LEI0258 marker polymorphisms and variations in chicken susceptibility to NDV infection, which could be utilized in breeding programs designed to improve chicken disease resistance.
Bacterial contamination of pork carcasses from Arusha, Tanzania
(Global Journal of Advanced Research, 2016-09-30) Luanda, Catherine; Buza, Joram; Mwanyika, Gaspary; Lyimo, Beatus; Mrutu, Rehema
Consumer demand for pork in Tanzania is driving growth of an increasing number of poorly equipped formal and informal slaugther facilities. To assess the potential public health challenges from these developments, we assessed the magnitude of microbial contamination of pork carcases from slaughterhouses in urban Arusha. Carcasses surface swabs (n = 90) from three slaughterhouses (designated A, B and C with carcass turnover of 1-30, 30-50 and 50-100 per day, respectively) were sampled and E. coli and Salmonella isolates (n = 1,632 and n = 177, respectively) were tested against a panel of 11 antibiotics using breakpoint assays. On average, E. coli and Salmonella were recovered from 71.1% and 66.7% of carcasses, respectively. Prevalence was highest (E. coli, 90.0% and Salmonella, 90.0%) for carcasses from site B, a facility where all slaughter operations, including eviscerations, were completed on the floor. The lowest prevalence (E. coli, 43.3% and Salmonella, 36.7%) was recorded for carcasses from Site C, a facility where most operations were completed with the carcasses hanging from overhead rails. Resistance to at least one antibiotic was observed in 71.2% of the E. coli isolates, most commonly to ampicillin (53.2%) followed by amoxicillin (38.8%) and sulfamethoxazole (31.0%). Approximately 45.2% of Salmonella isolates were resistant to at least one antibiotic while 23.2% were resistant to two or more of the tested antibiotics. Resistance to streptomycin (19.8%), trimethoprim (18.6%), ampicillin (16.9%) and sulfamethoxazole (13.6%) were most common. All isolates were susceptible to cefotaxime, ceftazidime, and chloramphenicol. These findings associate poor slaughter practices with bacterial carcass contamination and provide evidence for potential to contract antimicrobial resistant E. coli and Salmonella.. General Terms: Microbial load, multidrug resist
Blood cytokine responses to early secreted protein antigen-6/culture filtrate protein-10 tuberculosis antigens 2 months after antituberculosis treatment among patients with drug-susceptible pulmonary tuberculosis.
(Wolters Kluwer - Medknow, 2019-03-12) Mvungi, Happiness; Mbelele, Peter; Buza, Joram; Mpagama, Stellah; Sauli, Elingarami
Background: Human tuberculosis is a chronic inflammatory disease caused by mycobacterium tuberculosis. Pulmonary tuberculosis is the result of the failure of host immune system to control mycobacterium tuberculosis. The aim of the study was to asses the changes of the cytokines in active pulmonary tuberculosis patients before and after the use of anti-TB therapy. Methods: Multiple cytokine responses in active tuberculosis (TB) patients were investigated in this study following anti-TB drug therapy after 2 months. Ninety-six participants with pulmonary TB were engaged in the study between May 2018 and October 2018. Samples of blood were taken early before treatment at 0 and 2 months after using anti-TB therapy. The levels of interferon-gamma (IFN)-γ, interleukin-4 (IL-4), IL-6, IL-10, and tumor necrosis factor (TNF)-α in whole blood plasma collected from the QuantiFERON-TB Gold Plus were measured. Results: Compared with baseline levels, TNF-α, IL6 and IL10 were significantly lower following treatment whereas the IFN-γ and IL-4 increased significantly after treatment. The responses of five cytokines varied significantly after treatment (P < 0.0001) where IFN-γ was highest compared to other cytokines with 123.6%, AUC=0.757 and P < 0001, TNF-α AUC: 0.529 and P = 0.743, IL-4 AUC:0.557 and P = 0.514, IL-6 AUC:0.629 and P = 0.047, IL-10 AUC:0.549 and P = 0.581. Conclusion: It is concluded that changes of cytokines that observed during the treatment of TB patients play a very important role in monitoring pulmonary TB and can be suitable biomarkers to assess the effectiveness of anti-TB therapy in patients with TB.
CD14+ cells are required for IL-12 response in bovine blood mononuclear cells activated with Toll-like receptor (TLR) 7 and TLR8 ligands
(Elsevier, 2008) Buza, Joram; Benjamin, Ponn; Zhu, Jianzhung; Wilson, Heather; Lipford, Grayson; Krieg, Arthur; Babiuk, Lorne; Mutwiri, George
Single-stranded viral RNA (ssRNA) was recently identified as the natural ligand for TLR7 and TLR8. ssRNA sequences from viruses, as well as their synthetic analogues stimulate innate immune responses in immune cells from humans and mice, but their immunostimulatory activity has not been investigated in ruminants. In the present investigations, we tested whether synthetic RNA oligoribonucleotides (ORN) can activate immune cells from cattle. In vitro incubation of bovine peripheral blood mononuclear cells (PBMCs) with ORN-induced production of IL-12, IFN-g and TNF-a. No significant induction of IFN-a was observed. Depletion of CD14+ cells from PBMC abrogated the IL-12 response and consequently the IFN-g response, suggesting that CD14+ cells are required for PBMC immune activation with ORN. Consistent with these findings, the putative receptors for ORN (TLR7 and TLR8) were expressed at higher levels in the CD14+ fraction than the CD14 PBMC fraction. Pre-treatment of PBMC with bafilomycin (an inhibitor of phagosomal acidification) prior to stimulation with ORN abolished the cytokine responses, confirming that the receptor(s) which mediate the ORN-induced responses are intracellular. These results demonstrate for the first time that the TLR7/8 agonist ORN’s have strong immune stimulatory effects in cattle, and suggest that further investigation on the potential of TLR7/8 ligands to activate innate and adaptive immune responses in domestic animals are warranted.
CD5+ B lymphocytes are the main source of antibodies reactive with non-parasite antigens in Trypanosoma congolense-infected cattle
(Blackwell Science Ltd, 1997) Buza, Joram; Sileghem, Maarten; Gwakisa, Paul; Naessens, Jan
Mice infected with African trypanosomes produce exceptionally large amounts of serum IgM, a major part of which binds to non-trypanosome antigens such as trinitrophenol and single-strand DNA. In this paper, we describe that in cattle infected with Trypanosoma congolense and T. vivax, similar antibodies are found, although they bind mainly to protein antigens, such as b-galactosidase, ovalbumin and ferritin. The parasite non-specific IgM antibodies appear around the same time as the parasite-specific antibodies, but their origin and function are not clear.We tested the hypothesis that CD5+ B cells (or B-1 cells), which increase during trypanosome infections in cattle, are responsible for production of antibodies to non-trypanosome antigens. Splenic CD5+ and CD5− B cells from infected cattle were sorted and tested in a single cell blot assay. The numbers of immunoglobulin-secreting cells were similar in both B-cell populations. However, antibodies with reactivity for non-trypanosome antigens were significantly more prevalent in the CD5+ B-cell fraction and were exclusively IgM. The preference for production of these antibodies by CD5+ B cells and the expansion of this subpopulation during infections in cattle, strongly suggest that CD5+ B cells are the main source of trypanosome non-specific antibodies. We propose that these antibodies are natural, polyreactive antibodies that are predominantly secreted by CD5+ B cells. Since B-1 cells are up-regulated in many states of immune insufficiency, the immunosuppression associated with trypanosome infections may be responsible for the increase of this subset and the concomitant increase in trypanosome non-specific antibodies.
Challenges in Diagnosis of Febrile illnesses in Tanzania in the Era of Declining Malaria Epidemiology
(American Journal of Research Communication, 2015) Seth, Misago; Mdetele, Daniel; Phillips, Scott; Buza, Joram
Malaria and other febrile illnesses are very common especially in children in developing countries. Due to reliance on clinical algorithms for diagnosis in resource-poor settings, most febrile episodes have always been attributed to malaria. However, continuous malaria monitoring and recent improvements in malaria diagnosis have revealed a progressive decline in malaria and significant involvement of non-malarial etiologies in most febrile cases. This paper highlights the situation of malarial and non-malarial fevers, challenges facing the health sector, and possible approaches to addressing these challenges for better diagnosis of non-malarial febrile illnesses in Tanzania.
Chapter 11 - Brucellosis in Tanzania and Rwanda: Current status, challenges, and control strategies
(Elsevier B.V., 2026) Katani, Robab; Buza, Joram; Hudson, Peter; Ntawubizi, Martin; Byukusenge, Maurice; Ntivuguruzwa, Jean; Kapur, Vivek
Brucellosis remains a significant but inadequately addressed zoonotic disease in Tanzania and Rwanda, exemplifying the complex challenges faced by low- and middle-income countries in controlling neglected zoonoses. This chapter provides a comprehensive analysis of brucellosis in these East African nations, examining its epidemiology, economic impact, and control challenges through a One Health lens. In Tanzania, cattle seroprevalence ranges from 1% to 30%, while in Rwanda, it varies between 1.7% and 19%, with significant knowledge gaps in both countries hampering effective surveillance and control efforts. The economic burden is substantial but poorly quantified, affecting livestock productivity through reduced milk yield, high abortion rates, and decreased fertility, while also impacting human health and limiting international trade opportunities. Risk factors identified include limited community awareness, diverse livestock management practices, wildlife-livestock interfaces, and cross-border movements. Cultural practices and gender roles significantly influence disease transmission, with women being particularly vulnerable due to their traditional responsibilities in livestock management. Current control strategies, including vaccination and test-and-slaughter programs, face considerable implementation challenges due to resource constraints, cultural barriers, and limited surveillance systems. The chapter emphasizes the need for context-specific interventions that acknowledge local cultural practices while promoting evidence-based disease control measures. It concludes by advocating for increased research funding, enhanced surveillance systems, and stronger regional cooperation to address this significant public health challenge through a comprehensive One Health approach.
Classification and characterisation of livestock production systems in northern Tanzania.
(PLOS ONE, 2020-12-30) de Glanville, William; Davis, Alicia; Allan, Kathryn; Buza, Joram; Claxton, John; Crump, John; Halliday, Jo E B; Johnson, Paul; Kibona, Tito; Mmbaga, Blandina; Swai, Emmanuel; Uzzell, Christopher; Yoder, Jonathan; Sharp, Jo; Cleaveland, Sarah
Livestock keepers in sub-Saharan Africa face a range of pressures, including climate change, land loss, restrictive policies, and population increase. Widespread adaptation in response can lead to the emergence of new, non-traditional typologies of livestock production. We sought to characterise livestock production systems in two administrative regions in northern Tanzania, an area undergoing rapid social, economic, and environmental change. Questionnaire and spatial data were collected from 404 livestock-keeping households in 21 villages in Arusha and Manyara Regions in 2016. Multiple factor analysis and hierarchical cluster analysis were used to classify households into livestock production systems based on household-level characteristics. Adversity-based indicators of vulnerability, including reports of hunger, illness, and livestock, land and crop losses were compared between production systems. Three distinct clusters emerged through this process. The ethnic, environmental and livestock management characteristics of households in each cluster broadly mapped onto traditional definitions of 'pastoral', 'agro-pastoral' and 'smallholder' livestock production in the study area, suggesting that this quantitative classification system is complementary to more qualitative classification methods. Our approach allowed us to demonstrate a diversity in typologies of livestock production at small spatial scales, with almost half of study villages comprising more than one production system. We also found indicators of change within livestock production systems, most notably the adoption of crop agriculture in the majority of pastoral households. System-level heterogeneities in vulnerability were evident, with agro-pastoral households most likely to report hunger and pastoral households most likely to report illness in people and livestock, and livestock losses. We demonstrate that livestock production systems can provide context for assessing household vulnerability in northern Tanzania. Policy initiatives to improve household and community well-being should recognise the continuing diversity of traditional livestock production systems in northern Tanzania, including the diversity that can exist at small spatial scales.
Colorectal Cancer Epidemiology in Tanzania: Patterns in Relation to Dietary and Lifestyle Factors
(American Society of Clinical Oncology, 2018-09-28) Katalambula, Leonard; Petrucka, Pammla; Buza, Joram; Ngoma, Twalib
Background: Chronic noncommunicable diseases are increasingly captured as contributing to morbidity and mortality in low and middle income countries. Aim: This study aimed to investigate the epidemiology of colorectal cancer and the potential modifiable local risk factors in Tanzania. Methods: A cross sectional retrospective chart audit study was conducted to establish the pattern and distribution of colorectal cancer, The Food Frequency Questionnaire and the Step® survey tool were used to collect data. Descriptive statistics, χ2 tests, and regression analysis were used and augmented by data visualization to display risk variable differences. Results: Tanzania's colorectal cancer incidence has increased six times in the last decade in which major towns and cities of Dar es Salaam (20.2 per 100,000), Pwani (7.2 per 100,000), Kilimanjaro (4.4 per 100,000), Arusha (4.2 per 100,000), and Morogoro (3.6 per 100,000) had the highest percentage. This study reported that, almost 45% of the participants were hypertensive. Two major dietary patterns, namely “healthy” and “western”, existed among the study sample. Obesity was found in 25% of participants, whereas overweight was present in 28%; of note, the prevalence was higher in females (26.9%) than in males (23.6%) respectively. The prevalence of alcohol consumption was 21.5%, with a significantly lower rate of smoking (12.2%) noted within the study subjects. Both alcohol consumption and tobacco smoking were more common in men than women (22.7 vs. 20.6% and 24.5 vs. 3.2%, respectively). The prevalence of vigorous, moderate, and low physical activity for both sexes was 18.6%, 54.1% and 42.3%, respectively. Conclusion: Evidence from this study demonstrate that, like other NCDs CRC is increasing in Tanzania. Colon cancer is increasing at higher rate than rectal cancer seeming to align with change in lifestyle. Major towns and cities had the highest share of CRC patients. Diet, obesity, tobacco smoking, alcohol consumption, and sedentary behavior have potential role to play in the rising trend of CRC and other NCDs. We recommend a large longitudinal study with robust methodology which can establish cause and effect relationships between specific lifestyle behaviors and the incidence of colorectal cancer.
Community knowledge, perceptions and water contact practices associated with transmission of urinary schistosomiasis in an endemic region: a qualitative crosssectional study
(BMC Public Health, 2019-06-07) Angelo, Teckla; Kinung’hi, Safari; Buza, Joram; Mwanga, Joseph; Kariuki, Henry; Wilson, Shona
Background: In an effort to complement the current chemotherapy based schistosomiasis control interventions in Shinyanga district, community knowledge, perceptions and water contact practices were qualitatively assessed using focus group discussions and semi structured interviews involving 271 participants in one S. haematobium prevalent community of Ikingwamanoti village, Shinyanga district, Northwestern, Tanzania. Methods: In October, 2016 we conducted 29 parent semi structured interviews and 16 focus group discussions with a total of 168 parent informants. Adult participants were conveniently selected from three sub-villages of Butini, Miyu, and Bomani of Ikingwamanoti village, Shinyanga district. In March, 2017, a total of 103 children informants participated in 10 focus group discussions and 20 semi structured interviews, administered to children from standard four, five, six and seven attending Ikingwamanoti Primary School. Note taking and digital recorders were used to collect narrative data for thematic analysis of emergent themes. Results: Among participants, 75% parents and 50% children considered urinary schistosomiasis as a low priority health problem. Of the informants, 70% children and 48.3% parents had misconceptions about the cause, modes of transmission and control of schistosomiasis demonstrating gaps in their biomedical knowledge of the disease. Assessment of treatment seeking behavior for urinary schistosomiasis revealed a combination of traditional and modern health care sectors. However, modern medicines were considered effective in the treatment of urinary schistosomiasis. Lack of alternative sources of water for domestic and recreational activities and unhygienic water use habits exposed community members to high risk of acquiring urinary schistosomiasis. Conclusion: Use of Schistosoma haematobium contaminated water sources for daily domestic and recreational use facilitated contraction of urinary schistosomiasis among community members in Shinyanga district. People’s perceptions of urinary schistosomiasis as a less priority health problem promoted persistence of the disease. Future efforts to control urinary schistosomiasis should take into account integrated approaches combining water, sanitation and hygiene, health education, alternative sources of clean and safe water to facilitate behavior change.
A comparative approach of analyzing data uncertainty in parameter estimation for a Lumpy Skin Disease model
(Elsevier, 2025-01-20) Renald, Edwiga; Amadi, Miracle; Haario, Heikki; Buza, Joram; Tchuenche, Jean; Masanja, Verdiana
The livestock industry has been economically affected by the emergence and reemergence of infectious diseases such as Lumpy Skin Disease (LSD). This has driven the interest to research efficient mitigating measures towards controlling the transmission of LSD. Mathematical models of real-life systems inherit loss of information, and consequently, accuracy of their results is often complicated by the presence of uncertainties in data used to estimate parameter values. There is a need for models with knowledge about the confidence of their long-term predictions. This study has introduced a novel yet simple technique for analyzing data uncertainties in compartmental models which is then used to examine the reliability of a deterministic model of the transmission dynamics of LSD in cattle which involves investigating scenarios related to data quality for which the model parameters can be well identified. The assessment of the uncertainties is determined with the help of Adaptive Metropolis Hastings algorithm, a Markov Chain Monte Carlo (MCMC) standard statistical method. Simulation results with synthetic cases show that the model parameters are identifiable with a reasonable amount of synthetic noise, and enough data points spanning through the model classes. MCMC outcomes derived from synthetic data, generated to mimic the characteristics of the real dataset, significantly surpassed those obtained from actual data in terms of uncertainties in identifying parameters and making predictions. This approach could serve as a guide for obtaining informative real data, and adapted to target key interventions when using routinely collected data to investigate long-term transmission dynamic of a disease.
Comparison of antibiotic resistant Escherichia coli obtained from drinking water sources in northern Tanzania: a cross-sectional study
(BMC Microbiology, 2016) Lyimo, Beatus; Buza, Joram; Subbiah, Murugan; Smith, Woutrina; Call, Douglas
Background: Antimicrobial resistance (AMR) is a growing and significant threat to public health on a global scale. Escherichia coli comprises Gram-negative, fecal-borne pathogenic and commensal bacteria that are frequently associated with antibiotic resistance. AMR E. coli can be ingested via food, water and direct contact with fecal contamination. Methods: We estimated the prevalence of AMR Escherichia coli from select drinking water sources in northern Tanzania. Water samples (n = 155) were collected and plated onto Hi-Crome E. coli and MacConkey agar. Presumptive E. coli were confirmed by using a uidA PCR assay. Antibiotic susceptibility breakpoint assays were used to determine the resistance patterns of each isolate for 10 antibiotics. Isolates were also characterized by select PCR genotyping and macro-restriction digest assays. Results: E. coli was isolated from 71 % of the water samples, and of the 1819 E. coli tested, 46.9 % were resistant to one or more antibiotics. Resistance to ampicillin, streptomycin, sulfamethoxazole, tetracycline, and trimethoprim was significantly higher (15–30 %) compared to other tested antibiotics (0–6 %; P < 0.05). Of the β-lactam-resistant isolates, blaTEM-1 was predominant (67 %) followed by blaCTX-M (17.7 %) and blaSHV-1 (6.0 %). Among the tetracyclineresistant isolates, tet(A) was predominant (57.4 %) followed by tet(B) (24.0 %). E. coli isolates obtained from these water sources were genetically diverse with few matching macro-restriction digest patterns. Conclusion: Water supplies in northern Tanzania may be a source of AMR E. coli for people and animals. Further studies are needed to identify the source of these contaminants and devise effective intervention strategies.
Comparison of the prevalence of antibiotic-resistant Escherichia coli isolates from commercial-layer and free-range chickens in Arusha district, Tanzania
(African Journal of Microbiology Research, 2016-09-14) Rugumisa, Bernadether; Call, Douglas; Mwanyika, Gaspary; Subbiah, Murugan; Buza, Joram
The antibiotic susceptibility of fecal Escherichia coli isolates from commercial-layer and free-range chickens in Arusha district, Tanzania were compared. All the chickens were raised by individual households, but commercial-layer chickens were purchased from commercial vendors, whereas no systematic breeding system was used to produce free-range chickens. A total of 1,800 E. coli isolates (1,200 from commercial-layer chickens and 600 from free-range chickens) were tested for susceptibility to 11 antibiotics by breakpoint assays. All E. coli isolates were susceptible to gentamicin, ceftazidime and cefotaxime. Isolates from commercial-layer chickens had a high prevalence of resistance (32.4- 74.5%) for amoxicillin, ampicillin, ciprofloxacin, tetracycline, streptomycin, trimethoprim and sulfamethoxazole, while the prevalence of resistance to these antibiotics was lower (7-31.5%) for freerange chickens (P<0.05). Both groups had a similar prevalence of resistance to chloramphenicol (1.17- 1.5%; P>0.05). For antibiotic resistant strains, 64.1 and 91.5% of free-range and commercial-layer isolates, respectively, were resistant to ≥ 2 antibiotics. Commercial-layer chickens harbored significantly more resistant E. coli isolates (P<0.001) than free-range chickens, consistent with more exposure to antibiotics when compared with free-range chickens. Efforts should be directed towards motivating household owners to limit the use of antibiotics when they are investing in these breeds.
Conserved, breed-dependent, and subline-dependent innate immune responses of Fayoumi and Leghorn chicken embryos to Newcastle disease virus infection.
(Scientific Reports, 2019-05-10) Schilling, Megan; Memari, Sahar; Cavanaugh, Meredith; Katani, Robab; Deist, Melissa; Radzio-Basu, Jessica; Lamont, Susan; Buza, Joram; Kapur, Vivek
Newcastle disease virus (NDV) is a threat to the global poultry industry, but particularly for smallholder farmers in low- and middle-income countries. Previous reports suggest that some breeds of chickens are less susceptible to NDV infection, however, the mechanisms contributing to this are unknown. We here examined the comparative transcriptional responses of innate immune genes to NDV infection in inbred sublines of the Fayoumi and Leghorn breeds known to differ in their relative susceptibility to infection as well as at the microchromosome bearing the major histocompatability complex (MHC) locus. The analysis identified a set of five core genes, Mx1, IRF1, IRF7, STAT1, and SOCS1, that are up-regulated regardless of subline. Several genes were differentially expressed in a breed- or subline-dependent manner. The breed-dependent response involved TLR3, NOS2, LITAF, and IFIH1 in the Fayoumi versus IL8, CAMP, and CCL4 in the Leghorn. Further analysis identified subline-dependent differences in the pro-inflammatory response within the Fayoumi breed that are likely influenced by the MHC. These results have identified conserved, breed-dependent, and subline-dependent innate immune responses to NDV infection in chickens, and provide a strong framework for the future characterization of the specific roles of genes and pathways that influence the susceptibility of chickens to NDV infection.