Research Repository :: Browsing by Author "Bakuza, Jared S."

Browsing by Author "Bakuza, Jared S."

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Are small-scale coffee farmers in Tanzania safe from potential agrochemical health hazards? Week in Review, Biosciences for Farming in Africa (B4FA).
(Biosciences for Farming in Africa, 2016-01-15) Bakuza, Jared S.
http://b4fa.org/are-small-scale-coffee-farmers-in-tanzania-safe-from-potential-agrochemical-health-hazards/
Assessing S. mansoni prevalence in Biomphalaria snails in the Gombe region of Western Tanzania: the importance of DNA sequence data for clarifying species identification
(Parasite & Vectors, 2017) Bakuza, Jared S.; Gilespie, Robert; Nkwengulila, Gamba; Adam, Aileen; Kilbride, Elizabeth; Mable, Marble K.
Distribution Patterns of Gastrointestinal Parasites in Vervet Monkeys (Chlorocebus pygerythrus) at Gombe National Park, Tanzania
(Tanzania Journal of Science, 2018) Bakuza, Jared S.
Vervet monkeys at Gombe National Park in western Tanzania constitute a key component of the park’s ecosystem through interactions with other animals and people in the area. However, the parasite fauna of these animals has not been investigated. Thus, 21 faecal samples obtained from the animals in September 2010 were examined for parasites using formol-ethyl technique. The parasites observed included Trichuris spp., Physaloptera spp., hookworms and unidentified nematodes. While egg counts for unidentified nematodes did not vary with vervet monkey communities (z = 0.759, p = 0.448), other parasites were significantly higher among vervets at north of the park near Mwamgongo village compared to those at southern park border close to Mtanga village (Trichuris spp.: z = 2.443, p = 0.0146; Hookworms: z = 2.084, p = 0.0371). This is the first baseline study on vervet monkey parasites at Gombe and it broadens our understanding of the animals’ ecology and health. The observed parasites namely Trichuris and hookworms are also common in human populations in the area, and this suggests a potential health risk given the existing animal-human interactions. This stresses the need to better understand how these findings
Estimating the prevalence and intensity of Schistosoma mansoni infection among rural communities in Western Tanzania: The influence of sampling strategy and statistical approach
(PLOS Neglected Tropical Diseases, 2017-09-21) Bakuza, Jared S.; Nkwengulila, Gamba; Denwood, Matthew J.; Mable, Barbara K
Background Schistosoma mansoni is a parasite of major public health importance in developing countries, where it causes a neglected tropical disease known as intestinal schistosomiasis. However, the distribution of the parasite within many endemic regions is currently unknown, which hinders effective control. The purpose of this study was to characterize the prevalence and intensity of infection of S. mansoni in a remote area of western Tanzania. Methodology/Principal findings Stool samples were collected from 192 children and 147 adults residing in Gombe National Park and four nearby villages. Children were actively sampled in local schools, and adults were sampled passively by voluntary presentation at the local health clinics. The two datasets were therefore analysed separately. Faecal worm egg count (FWEC) data were analysed using negative binomial and zero-inflated negative binomial (ZINB) models with explanatory variables of site, sex, and age. The ZINB models indicated that a substantial proportion of the observed zero FWEC reflected a failure to detect eggs in truly infected individuals, meaning that the estimated true prevalence was much higher than the apparent prevalence as calculated based on the simple proportion of non-zero FWEC. For the passively sampled data from adults, the data were consistent with close to 100% true prevalence of infection. Both the prevalence and intensity of infection differed significantly between sites, but there were no significant associations with sex or age. Conclusions/Significance Overall, our data suggest a more widespread distribution of S. mansoni in this part of Tanzania than was previously thought. The apparent prevalence estimates substantially underestimated the true prevalence as determined by the ZINB models, and the two types of sampling strategies also resulted in differing conclusions regarding prevalence of infection. We therefore recommend that future surveillance programmes designed to assess risk factors should use active sampling whenever possible, in order to avoid the self-selection bias associated with passive sampling.
Extent of Morbidity Associated with Schistosomiasis Infection in Malawi: A Review Paper
(BioMed Central, 2015) Mtethiwa, Austin H. N.; Nkwengulila, Gamba; Bakuza, Jared S.; Sikawa, Daniel; Kazembe, Abigail
Data on the extent of the burden due to schistosomiasis is sparse in most Sub-Saharan African countries. However, this data is crucial for triggering medical attention. A review of extent of morbidity and determinants associated with schistosomiasis in Malawi was therefore conducted to quantify the infection in order to concretise the need for medical intervention. A systematic and traditional search strategy was used to find literature for the review, whilst exclusion and inclusion criteria were used to identify appropriate articles. Logistic regression curves of epidemiological model Y = (a + bxc )/(1 + bxc ) and the recommendation that schistosomiasis prevalence can be used to estimate morbidity were employed to quantify morbidity at various infection stages. Morbidity was quantified as a direct proportion of the population and the respective national schistosomiasis prevalence. Findings showed that both S. mansoni and S. haematobium are present in Malawi with the latter highly prevalent (50%). Furthermore, out of the estimated population of 16,829 million, approximately 8.4 million have schistosomiasis, with about 4.4 million of these aged 18 years and below. The most frequent manifestation is Katayama syndrome, while ascites is the lowest, impacting about 3.0 million and 960 individuals, respectively. Localised studies on association of schistosomiasis infection to risk factors such as occupation, age and gender found odds ratio (OR) ranging from 1.29 to 5.37. Morbidity due to schistosomiasis is high in Malawi. It is therefore recommended that a more detailed study on the determinants of high schistosomiasis and re-evaluation of the current control measures be conducted if the current morbidity statistics are to be remarkably reduced.
Prevalence and Intensity of Schistosomiasis in Communities around Water Reservoirs in Malawi
(Journal of Tropical Diseases, 2015) Mtethiwa, Austin; Nkwengulila, Gamba; Bakuza, Jared S.
Although schistosomiasis is endemic in Malawi, its epidemiology at water reservoir communities is not known. However, there are more than 750 water reservoirs spread throughout the country, providing water for various activities. The present study was conducted to determine schistosomiasis infection at reservoir communities in Malawi. Methods: This was across sectional study conducted during the rainy and dry seasons at three water reservoir communities. A total of 1594 individuals aged from 1 to 78 years from 1-2km, >2-5km and 5km away from the reservoir were randomly selected and enrolled into the study. They provided stool and urine samples which were examined for Schistosoma eggs using Kato-Katz and sedimentation methods, respectively. Results: An overall prevalence of 47.4% was found with 51.2% for S. haematobium and 9.5% for S. mansoni. Prevalence was significantly higher during the dry season (58.5%) than the rainy season (36.6%) (P=0.01). Prevalence was significantly higher in communities living 0-2km away from the reservoir than in those living > 5km away (P=0.00). Prevalence of S. haematobium was significantly different higher at Mlala reservoir than at Ukonde and Njala reservoirs (P=0.043). Prevalence of S. Mansoni was significantly higher at Ukonde reservoir than at Mlala and Njala reservoirs (P=0.037). Prevalence among different age groups was not significantly different (P=0.29). Age group of 6-15 years had significantly higher infection intensity, in both S. mansoni (129±3.6 epg) and S. haematobium (63.3±2.3 eggs/10ml of urine), than the other age groups. Conclusion: Water reservoirs are infested with Schistosoma cercariae and the communities are at risk. The closer to the reservoir, the higher the chances of being infected. We recommend annual MDA, since the prevalence found is within the ≥50% WHO recommended threshold for MDA. We also recommend a health education to the communities on transmission and prevention of schistosomiasis.
Prevalence and Intensity of Schistosomiasis in Communities around Water Reservoirs in Malawi
(2015) Mtethiwa, Austin H.N.; Bakuza, Jared S.; Nkwengulila, Gamba
Although schistosomiasis is endemic in Malawi, its epidemiology at water reservoir communities is not known. However, there are more than 750 water reservoirs spread throughout the country, providing water for various activities. The present study was conducted to determine schistosomiasis infection at reservoir communities in Malawi. This was across sectional study conducted during the rainy and dry seasons at three water reservoir communities. A total of 1594 individuals aged from 1 to 78 years from 1-2km, >2-5km and 5km away from the reservoir were randomly selected and enrolled into the study. They provided stool and urine samples which were examined for Schistosoma eggs using Kato-Katz and sedimentation methods, respectively. An overall prevalence of 47.4% was found with 51.2% for S. haematobium and 9.5% for S. mansoni. Prevalence was significantly higher during the dry season (58.5%) than the rainy season (36.6%) (P=0.01). Prevalence was significantly higher in communities living 0-2km away from the reservoir than in those living > 5km away (P=0.00). Prevalence of S. haematobium was significantly different higher at Mlala reservoir than at Ukonde and Njala reservoirs (P=0.043). Prevalence of S. Mansoni was significantly higher at Ukonde reservoir than at Mlala and Njala reservoirs (P=0.037). Prevalence among different age groups was not significantly different (P=0.29). Age group of 6-15 years had significantly higher infection intensity, in both S. mansoni (129±3.6 epg) and S. haematobium (63.3±2.3 eggs/10ml of urine), than the other age groups. Water reservoirs are infested with Schistosoma cercariae and the communities are at risk. The closer to the reservoir, the higher the chances of being infected. We recommend annual MDA, since the prevalence found is within the ≥50% WHO recommended threshold for MD
Socioecological correlates of clinical signs in two communities of wild chimpanzees (Pan troglodytes) at Gombe National Park, Tanzania
(American Journal of Primatology, 2016) Lonsdorf, Elizabeth V.; Gilespie, Thomas R.; Wolf, Tiffany M; Lipende, Idd; Raphael, Jane; Bakuza, Jared S.; Murray, Carson; Wilson, Michael; Kamenya, Shadrack; Mjungu, Deus; Collins, D Anthony; Gilby, Ian; Stanton, Margaret; Terio, Karen; Barbian, Hannah; Li, Yingying; Krupnick, Alexander; Seidl, Emily; Goodall, Jane; Hahn, Beatrice; Pusey, Anne; Dominic, Travis
Disease and other health hazards pose serious threats to the persistence of wild ape populations. The total chimpanzee population at Gombe National Park, Tanzania, has declined from an estimated 120 to 150 individuals in the 1960's to around 100 individuals by the end of 2013, with death associated with observable signs of disease as the leading cause of mortality. In 2004, we began a non-invasive health-monitoring program in the two habituated communities in the park (Kasekela and Mitumba) with the aim of understanding the prevalence of health issues in the population, and identifying the presence and impacts of various pathogens. Here we present prospectively collected data on clinical signs (observable changes in health) in the chimpanzees of the Kasekela (n=81) and Mitumba (n=32) communities over an 8-year period (2005–2012). First, we take a population approach and analyze prevalence of clinical signs in five different categories: gastrointestinal system (diarrhea), body condition (estimated weight loss), respiratory system (coughing, sneezing etc.), wounds/lameness, and dermatologic issues by year, month, and community membership. Mean monthly prevalence of each clinical sign per community varied, but typically affected <10% of observed individuals. Secondly, we analyze the presence of clinical signs in these categories as they relate to individual demographic and social factors (age, sex, and dominance rank) and simian immunodeficiency virus (SIVcpz) infection status. Adults have higher odds of being observed with diarrhea, loss of body condition, and wounds or lameness when compared to immatures, while males have a higher probability of being observed with wounds or lameness than females. In contrast, signs of respiratory illness appear not to be related to chimpanzee-specific factors and skin abnormalities are very rare. For a subset of known-rank individuals, dominance rank predicts the probability of wounding/lameness in adult males, but does not predict any adverse clinical signs in adult females. Instead, adult females with SIVcpz infection are more likely to be observed with diarrhea, a finding that warrants further investigation. Comparable data are needed from other sites to determine whether the prevalence of clinical signs we observe are relatively high or low, as well as to more fully understand the factors influencing health of wild apes at both the population and individual level.
Trematodes of Primates. The International Encyclopedia of Primatology
(JohnWiley & Sons, Inc, 2017) Gilespie, Thomas R.; Bakuza, Jared S.
Variation over Time in Parasite Prevalence Among Free-ranging Chimpanzees at Gombe National Park, Tanzania
(Springer, 2009) Bakuza, Jared S.; Nkwengulila, Gamba
From January to September, 2005, we collected fecal samples from 60 chimpanzees at Gombe National Park, Tanzania and examined them for parasites. We compared current parasite prevalence data with previous studies to obtain a pattern of parasitism over time. There were considerable similarities in the parasite species composition and prevalence, although we noted some variations. Generally, parasite prevalence decreased over time, with the present prevalence being lower than in previous surveys. We identified 8 types of parasites, all of which had previously been documented in the chimpanzees of Gombe. Three nematodes — Oesophagostomum sp., Strongyloides fulleborni, and Abbreviata caucassica— occurred at higher prevalence (41.2–45.5%) but relatively lower than previous findings of 50–91%. We also diagnosed unidentified strongyles at a moderate prevalence (33%), lower than a previous record of 41%. Probstmayria gombensis occurred at relatively low prevalence (16.4%) vs. past observations (23–59%), while the prevalence of Trichuris sp. (7.3%) was closely similar to previous records of 5–9%. We also observed unidentified ciliate at 9% within the same range as in previous studies (5–28%). The prevalence of Troglodytella abrassarti was 78%, closely similar to previous findings of 75%. There was no significant variation in parasite prevalence between chimpanzees of the Kasekela community and those of the Mitumba community, although the former tended to have higher prevalence of helminths than the latter. The causes of the similarities and variations in parasite prevalence over time are discussed. The study provides baseline data for monitoring of chimpanzee health at Gombe.
Variation over Time in Parasite Prevalence Among Free-ranging Chimpanzees at Gombe National Park, Tanzania
(International Journal of Primatology, 2009) Bakuza, Jared S.; Nkwengulila, Gamba
From January to September, 2005, we collected fecal samples from 60 chimpanzees at Gombe National Park, Tanzania and examined them for parasites. We compared current parasite prevalence data with previous studies to obtain a pattern of parasitism over time. There were considerable similarities in the parasite species composition and prevalence, although we noted some variations. Generally, parasite prevalence decreased over time, with the present prevalence being lower than in previous surveys. We identified 8 types of parasites, all of which had previously been documented in the chimpanzees of Gombe. Three nematodes — Oesophagostomum sp., Strongyloides fulleborni, and Abbreviata caucassica— occurred at higher prevalence (41.2–45.5%) but relatively lower than previous findings of 50–91%. We also diagnosed unidentified strongyles at a moderate prevalence (33%), lower than a previous record of 41%. Probstmayria gombensis occurred at relatively low prevalence (16.4%) vs. past observations (23–59%), while the prevalence of Trichuris sp. (7.3%) was closely similar to previous records of 5– 9%. We also observed unidentified ciliate at 9% within the same range as in previous studies (5–28%). The prevalence of Troglodytella abrassarti was 78%, closely similar to previous findings of 75%. There was no significant variation in parasite prevalence between chimpanzees of the Kasekela community and those of the Mitumba community, although the former tended to have higher prevalence of helminths than the latter. The causes of the similarities and variations in parasite prevalence over time are discussed. The study provides baseline data for monitoring of chimpanzee health at Gombe.

Browsing by Author "Bakuza, Jared S."

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