Browsing by Author "Mathew, C"

Now showing 1 - 12 of 12

Circulating Brucella species in wild animals of the Serengeti ecosystem, Tanzania
(Springer, 2021) Sambu, R. M; Mathew, C; Nonga, H. E; Lukambagire, A. S; Yapi, R. B; Akoko, J; Fokou, G; Keyyu, J. D; Bonfoh, B; Kazwala, R. R
Background: Brucellosis is a bacterial zoonosis of public health and economic importance worldwide. It affects a number of domestic animals, wild animals and humans. Human brucellosis originates from either livestock or wildlife. The species of Brucella circulating in wild animals in Tanzania is largely unknown due to insufficient surveillance. This study was carried out to identify Brucella species found in selected wildlife hosts in the Serengeti ecosystem. Methodology: The study used a total of 189 archived samples that were obtained from cross-sectional studies previously conducted between 2000 and 2017 in the Serengeti ecosystem in Tanzania. Whole blood, serum and amniotic fluid collected from buffalos, lions, wildebeest, impala, zebra and hyena were available for DNA extraction. Multiplex polymerase chain reaction for B. abortus, B. melitensis, B. ovis and B. suis (AMOS PCR) and quantitative real time PCR (qPCR) targeting the bcsp31 and IS711 genes for Brucella genus detection and the IS711 targets alkB for B. abortus and BMEI1162 for B. melitensis were used to detect Brucella strains. Results: Out of the 189 samples tested, 12 (6.35 %) and 22 (11.6 %) were positive to AMOS-PCR and qPCR, respectively. Most of the positive samples were from lions (52.6 %) and buffaloes (19.6 %). Other animals that were positive included: wildebeest (13.6 %), impala (13.6 %), zebra (4.5 %) and hyena (4.5 %). Out of 22 positive samples, 16 (66.7 %) were identified as B. abortus and the other six samples did not amplify for neither B. abortus nor B. melitensis. Conclusions: The detection of Brucella DNA in archived wild animal samples shows testing potential of samples collected from this population. The zoonotic species B. abortus and B. melitensis detected in wild animals have previously been reported in livestock and humans in the region. The findings suggest that, due to the contact network, some of the identified wild animal hosts in this study could be reservoirs for infections in domestic animals and humans within the Serengeti ecosystem while others are likely dead-end hosts. One Health control strategies and continuous surveillance programs in other wildlife reserved areas should be implemented to help predicting transmission in livestock and humans in the region.
Crossing the Line: Seroprevalence and Risk Factors for Transboundary Animal Diseases Along the Tanzania-Zambia Border
(Frontiers in Veterinary Science, 2022-03-11) Lysholm, S; Lindahl, J.F; Munyeme, M; Misinzo, G; Mathew, C; Alvåsen, K; Dautu, G; Linde, S; Mitternacht, L; Olovsson, E; Wilén, E; Berg, M; Wensman, J.J
Transboundary pathogens pose a threat to livelihood security in countries such as Zambia and Tanzania. This study aimed to investigate the seroprevalence of peste des petits ruminants virus (PPRV), foot and mouth disease virus (FMDV), sheep and goat pox virus (SGPV), Rift Valley fever virus (RVFV) and Brucella spp. in sheep and goats along the Tanzania-Zambia border. Another aim was to assess the association between certain predictor variables and seroprevalence, focusing on trade and proximity to an international border, to a town and to the Tanzania-Zambia highway. During September-October 2018, 486 serum samples from small ruminants in Zambia and 491 in Tanzania were collected and analyzed using enzyme-linked immunosorbent assays (ELISA). A questionnaire focused on management strategies was administered to each household. The animal-level seroprevalence in Zambia was 0.21% [95% confidence interval (CI) (0.01–1.14) for PPRV, 1.03% (95% CI 0.33–2.39) for FMDV, 0% (95% CI 0–0.76) for SGPV, 2.26%(95%CI 1.14–4.01) for RVFV and 1.65%(95%CI 0.71–3.22) for Brucella spp.]. In Tanzania, animal-level seroprevalence was 2.85% (95% CI 1.57–4.74) for PPRV, 16.9% (95% CI 13.7–20.5) for FMDV, 0.20% (95% CI 0.01–1.13) for SGPV, 3.26%(95%CI 1.87–5.24) for RVFV and 20.0%(95%CI 14.5–26.5) for Brucella spp. For PPRV (OR 6.83, 95% CI 1.37–34.0, p = 0.019) and FMDV (OR 5.68, 95% CI 1.58–20.3, p = 0.008), herds situated more than 30 km from an international border were more likely to be seropositive, while being located 10–30 km (OR 4.43, 95% CI 1.22–16.1 p = 0.024) from a border was identified as a risk factor for Brucella spp. For FMDV (OR 79.2, 95% CI 4.52–1388.9, p = 0.003), being situated within 30 km from a town was associated with seropositivity.Furthermore, contact with wild ruminants (OR 18.2, 95% CI 1.36–244), and the presence of sheep in the household (OR 5.20, 95% CI 1.00–26.9, p = 0.049), was associated with seropositivity for PPRV, and FMDV. No significantassociations between trade or distance to the Tan-Zam highway and seroprevalence were found. We recommend that the impact of trade and proximity to borders, towns and roads should be further evaluated in larger studies, ideally incorporating aspects such as temporal trade fluctuations.
Detection of serum neutralizing antibodies to Simbu sero-group viruses in cattle in Tanzania.
(BMC Veterinary Research, 2015) Mathew, C; Klevar, S; Elbers, A; van der Poel, W; Kirkland, P; Godfroid, J; Mdegela, R; Mwamengele, G; Stokstad, M
Background: Orthobunyaviruses belonging to the Simbu sero-group occur worldwide, including the newly recognized Schmallenberg virus (SBV) in Europe. These viruses cause congenital malformations and reproductive losses in ruminants. Information on the presence of these viruses in Africa is scarce and the origin of SBV is unknown. The aim of this study was to investigate the presence of antibodies against SBV and closely related viruses in cattle in Tanzania, and their possible association with reproductive disorders. Results: In a cross-sectional study, serum from 659 cattle from 202 herds collected in 2012/2013 were analyzed using a commercial kit for SBV ELISA, and 61 % were positive. Univariable logistic regression revealed significant association between ELISA seropositivity and reproductive disorders (OR = 1.9). Sera from the same area collected in 2008/2009, before the SBV epidemic in Europe, were also tested and 71 (54.6 %) of 130 were positive. To interpret the ELISA results, SBV virus neutralization test (VNT) was performed on 110 sera collected in 2012/2013, of which 51 % were positive. Of 71 sera from 2008/2009, 21 % were positive. To investigate potential cross reactivity with related viruses, 45 sera from 2012/2013 that were positive in SBV ELISA were analyzed in VNTs for Aino, Akabane, Douglas, Peaton, Sabo, SBV, Sathuperi, Shamonda, Simbu and Tinaroo viruses. All 45 sera were positive for one or more of these viruses. Twenty-nine sera (64.4 %) were positive for SBV, and one had the highest titer for this virus. Conclusions: This is the first indication that Aino, Akabane, Douglas, Peaton, Sabo, SBV, Sathuperi, Shamonda and Tinaroo viruses circulate and cause negative effect on reproductive performance in cattle in Tanzania. SBV or a closely related virus was present before the European epidemic. However, potential cross reactivity complicates the interpretation of serological studies in areas where several related viruses may circulate. Virus isolation and molecular characterization in cattle and/or vectors is recommended to further identify the viruses circulating in this region. However, isolation in cattle is difficult due to short viremic period of 2 to 6 days, and isolation in vectors does not necessarily reflect the situation in cattle.
Effect of pond management on prevalence of intestinal parasites in Nile Tilapia (Oreochromis niloticus) under small scale fish farming systems in Morogoro, Tanzania
(Livestock Research for Rural Development, 2011) Mdegela, R H; Omary, AN; Mathew, C; Nonga, HE
A cross-sectional study was conducted in small scale fish farming systems in Morogoro urban and rural area between December 2007 and February 2008 to determine the effect of pond management on prevalence of intestinal parasites in Nile Tilapia (Oreochromis niloticus). Water physicochemical parameters in fish ponds and the risk factors for intestinal parasites were determined. Information on pond type and cleanness, feeding and general pond management was also gathered through questionnaires and participant observations during the sample collection. One fifty three adult O. niloticus from 13 ponds were examined. It was found that most ponds (69%) were small and of earthen type, 77% were clean and were using river water. Up to 92% of farmers changed pond water regularly and almost all farmers reported to use maize bran as the main feed for fish. Farmers used different types of animal manure to fertilize the ponds. The observed water physicochemical levels were within the normal range for fish water ponds as recommended by FAO. The prevalence of intestinal parasites was 16.3%. Specifically, 15% of fish had Eimeria oocysts while 1.3% had unidentified flukes. Prevalence of parasites was significantly higher (P < 0.05) in ponds located in rural (18.7%) than in urban areas (6.7%). Significantly (P<0.05) higher prevalence of parasites was observed in fish ponds using river water (18.8%) than in ponds using rain water (0%). Pond type was also a risk factor as there was a significantly (P < 0.05) higher parasite infection rates in earthen ponds (20.9%) than in fish reared in concrete ponds (4.7%). It is concluded that earthen fishponds, keeping fish in rural areas and using river water in ponds predisposes fish to intestinal parasites. Good water quality management and proper fish husbandry techniques will eliminate most parasitic infection and improve fish production.
First isolation, identification, phenotypic and genotypic characterization of Brucella abortus biovar 3 from dairy cattle in Tanzania
(2015) Mathew, C; Stokstad, M; Johansen, T. B; Klevar, S.; Mdegela, R. H.; Mwamengele, G.; Michel, P.; Escobar, L.; Fretin, D.; Godfroid, J.
Background: Brucellosis is a disease of worldwide public health and economic importance. Successful control is based on knowledge of epidemiology and strains present in an area. In developing countries, most investigations are based on serological assays. This study aimed at investigating a dairy herd experiencing abortions in order to establish within-herd seroprevalence to Brucella spp., identify, characterize Brucella strains by Multiple Loci Variable Number of Tandem Repeats Analysis (MLVA-VNTR) and investigate possible spillover to other species. Results: The within-herd seroprevalence in cattle (n = 200) was 48 % (95 % CI 41–55), using an indirect ELISA, while the Rose Bengal Test (RBT) yielded lower prevalence (21.5 %; 95 % CI 16–27). Two sheep (n = 35) and one goat (n = 50) were seropositive using ELISA while none of the dogs (n = 6) was positive with the RBT. Three Brucella were isolated from an aborted fetus and associated membranes. Real time PCR (IS711), Bruce-ladder and classical biotyping classified the isolates as B. abortus biovar 3. MLVA-VNTR revealed two different but closely related genotypes. The isolates showed unique profiles, providing the first genotypic data from Tanzania. These genotypes were not related to B. abortus biovar 3 reference strain Tulya originally isolated from a human patient in Uganda in 1958, unlike the genotypes isolated and characterized recently in Kenya. High within-herd prevalence, isolation of the pathogen and abortion confirm that B. abortus is circulating in this herd with cattle as reservoir hosts. A low seroprevalence in sheep and goats suggests a spillover of B. abortus from cattle to small ruminants in the herd. Conclusions: This is the first isolation and characterization of B. abortus biovar 3 from a dairy cow with abortion in Tanzania. The origin of the Tanzanian genotypes remain elusive, although they seem to be related to genotypes found in Europe, Turkey and China but not related to B. abortus biovar 3 reference strain or genotypes from Kenya. Importantly, replacement heifers are commonly sourced from large farms like this to smallholder farmers, which poses risk of spread of bacteria to other herds. B. abortus is a significant zoonotic risk and animal health problem in this production system, therefore further studies on humans is recommended.
Molecular epidemiology of Brucella species in mixed livestock-human ecosystems in Kenya
(Nature scientific Report, 2021) Akoko, JM; Pelle, R; Lukambagire, AS; Machuka, EM; Nthiw, D; Mathew, C; Fèvre, EM; Bett, B; Cook, EAJ; Othero, D; Bonfoh, B; Kazwala, R; Shirima, G; Schelling, E; Halliday, JEB; Ouma, C
Brucellosis, caused by several species of the genus Brucella, is a zoonotic disease that affects humans and animal species worldwide. Information on the Brucella species circulating in different hosts in Kenya is largely unknown, thus limiting the adoption of targeted control strategies. This study was conducted in multi-host livestock populations in Kenya to detect the circulating Brucella species and assess evidence of host–pathogen associations. Serum samples were collected from 228 cattle, 162 goats, 158 sheep, 49 camels, and 257 humans from Narok and Marsabit counties in Kenya. Information on age, location and history of abortion or retained placenta were obtained for sampled livestock. Data on age, gender and location of residence were also collected for human participants. All samples were tested using genus level real-time PCR assays with primers specific for IS711 and bcsp31 targets for the detection of Brucella. All genus positive samples (positive for both targets) were further tested with a speciation assay for AlkB and BMEI1162 targets, specific for B. abortus and B. melitensis, respectively. Samples with adequate quantities aggregating to 577 were also tested with the Rose Bengal Test (RBT). A total of 199 (33.3%) livestock and 99 (38.5%) human samples tested positive for genus Brucella. Animal Brucella PCR positive status was positively predicted by RBT positive results (OR = 8.3, 95% CI 4.0–17.1). Humans aged 21–40 years had higher odds (OR = 2.8, 95% CI 1.2–6.6) of being Brucella PCR positive compared to the other age categories. The data on detection of different Brucella species indicates that B. abortus was detected more often in cattle (OR = 2.3, 95% CI 1.1–4.6) and camels (OR = 2.9, 95% CI 1.3–6.3), while B. melitensis was detected more in sheep (OR = 3.6, 95% CI 2.0–6.7) and goats (OR = 1.7, 95% CI 1.0–3.1). Both B. abortus and B. melitensis DNA were detected in humans and in multiple livestock host species, suggesting cross-transmission of these species among the different hosts. The detection of these two zoonotic Brucella species in humans further underpins the importance of One Health prevention strategies that target multiple host species, especially in the multi-host livestock populations.
Pathogenic Escherichia fergusonii and Staphylococcus gallinarum co-infection in a free-ranging domestic chicken
(ROAVS, 2012) Misinzo, G; Mathew, C; Matondo, RB; Jumapili, F; Ludosha, M; Masola, S; Munisi, W; Viaene, W; Doorsselaere, J.
Examination was carried out in an emaciated and depressed free-range domestic chicken from Mpwapwa where multiple cases of a similar condition were observed in 2010. A loosely attached unilateral nodule on the ventral aspect of the right eye and similar other nodules around the base of feathers mainly on dorsal aspects of wings, neck and head were observed. The cut nodules were yellowish with a firm and cheesy consistency surrounded by hyperaemic skin. In addition, multiple grey foci of variable size on liver and localized areas of hyperaemia on duodenal mucosa with mucoid exudates in the lumen were observed. On histopathology, the nodular lesions consisted of hyperplastic feather follicles with broad bands of keratinocytes and extension of follicular epithelium into surrounding dermis. In addition, luminal folliculitis in the skin and hepatic portal vasculitis were observed. Excised lesions from the eye, skin and liver were streaked on bacteriological agar with or without penicillin and streptomycin to isolate bacteria. Bacteria grew in agar without antibiotics but not in agar containing antibiotics. Bacterial colonies were subcultured and passaged four times to obtain pure cultures. Based on colony morphology, two types of bacteria were isolated from each of the organs. DNA was extracted from bacteria followed by amplification and sequencing of the 16S rDNA using 27F and 1492R primers. Sequence similarity search in GenBank showed that the bacteria were Escherichia fergusonii and Staphylococcus gallinarum. The present study shows that the chicken had E. fergusonii and S. gallinarum co-infection sensitive to penicillin and streptomycin
Performance characteristics and costs of serological tests for brucellosis in a pastoralist community of northern Tanzania
(Nature scientific Report, 2021) Lukambagire, AS; Mendes, AJ; Bodenham, RF; McGiven, JA; Mkenda, NA; Mathew, C; Rubach, MP; Sakasaka, P; Shayo, DD; Maro, VP; Shirima, GM; Thomas, KM; Kassanga, CJ; Kazwala, RR; Halliday, JEB; Mmbaga, BT
The control of brucellosis across sub-Saharan Africa is hampered by the lack of standardized testing and the use of tests with poor performance. This study evaluated the performance and costs of serological assays for human brucellosis in a pastoralist community in northern Tanzania. Serum collected from 218 febrile hospital patients was used to evaluate the performance of seven index tests, selected based on international recommendation or current use. We evaluated the Rose Bengal test (RBT) using two protocols, four commercial agglutination tests and a competitive enzymelinked immunosorbent assay (cELISA). The sensitivity, specificity, positive predictive value, negative predictive value, Youden’s index, diagnostic accuracy, and per-sample cost of each index test were estimated. The diagnostic accuracy estimates ranged from 95.9 to 97.7% for the RBT, 55.0 to 72.0% for the commercial plate tests, and 89.4% for the cELISA. The per-sample cost range was $0.69–$0.79 for the RBT, $1.03–$1.14 for the commercial plate tests, and $2.51 for the cELISA. The widely used commercial plate tests performed poorly and cost more than the RBT. These findings provide evidence for the public health value of discontinuing the use of commercial agglutination tests for human brucellosis in Tanzania.
Prevalence and mean intensity of ectoparasite infections in pond reared Nile tilapia (Oreochromis niloticus) in Morogoro Tanzania.
(Tanzania Veterinary Journal, 2014) Mathew, C; Mwamengele, G; Mdegela, R. H.; Kassuku, A. A.
cross sectional study was carried out between September 2007 and September 2008 to investigate the prevalence and mean intensity of ectoparasite infections on the gills and skin of Nile tilapia (Oreochromis niloticus) in Morogoro, Tanzania. A total of 229 fish from 19 ponds were studied. Trichodina spp. and Monogeneans were the only ectoparasites observed. Overall prevalence of ectoparasites in the study area was 68% and the average mean intensity was 5.3. Trichodina spp. were more prevalent (P<0.05) than Monogeneans. Gills were more affected with parasites than the skin (P<0.05). There was no strong relationship between water quality and prevalence and mean intensity of parasites. Prevalence and mean intensity varied in different ponds due to different management practices and the knowledge of fish husbandry. Parasite infection was significantly higher in urban than in rural areas (P<0.05). There is a need for farmers to be trained on proper fish husbandry and pond management in order to reduce the risk of parasite multiplication in the ponds and hence infection rate.
Reproductive infections in cattle in Tanzania – lessons for control priorities
(SOJ Microbiol Infect Dis, 2017) Mathew, C; Klevar, S; Løken, T; Mwamengele, G; Skjerve, E; Godfroid, J; Stokstad, S; Mdegela, R. H.
Reproductive disorders have negative impact on performance in cattle worldwide. Studies on infections causing reproductive disorders in Tanzania are few and fragmented, which complicates targeted disease prevention. To investigate the prevalence of selected infections and their associations with reproductive disorders and risk factors in cattle under different management systems, a cross-sectional study was conducted in two bordering regions in the southern highlands in Tanzania. Herd and individual animal level data were collected by direct observation and a semistructured questionnaire interview of the farmer. Sera from 658 cattle from 202 herds were analyzed using a commercial ELISA kits for antibodies to Bovine Viral Diarrhea Virus (BVDV), Brucella spp. and Neospora caninum. The logistic regression model identified herd size (odds ratio (OR): 14.5), location (OR: 23.1) and management system (grazing strategy) (OR: 22.7) as risk factors for Brucella spp. The same risk factors were also identified for BVDV herd size (OR: 2.8), location (OR: 12.7) and management system (OR: 2.9). History of abortion was associated with seropositivity for Brucella spp. (OR: 4.6). No risk factors, including location and presence of dogs, nor any association with reproductive disorders were identified for N. caninum. In one region the herd level sero-prevalence was 66.7% for BVDV and 36.1% for Brucella spp., while in the other it was 6.5% for BVDV and 0.6% for Brucella spp. In total, BVDV specific antibodies were found in 15.2% of the animals in 17.9% of the herds, and Brucella spp. specific antibodies were detected in 5.4% of the animals in 7.4% of the herds. Anti- N. caninum antibodies were found in 4.5% of animals in 8.4% of the herds. In conclusion, prevalence and impact of BVDV and Brucella spp. differed significantly between geographically closely related areas, most probably due to differences in management system that affects the potential for survival of the agents in the population. This shows that all control measures must be based on accurate epidemiological knowledge of the occurrence of the infection. Low-prevalence areas are highly susceptible for introduction of infection, while in the high-prevalence areas control measures must be implemented to reduce the impact and the risk of transferring Brucella spp. from livestock to humans.
Serological and molecular evidence of brucella species in the rapidly growing pig sector in Kenya
(BMC Veterinary Research, 2020) Akoko, J; Pelle, R; Kivali, V; Schelling, E; Shirima, G; Mathew, C; Kyallo, V; Bonfoh, B; Kazwala, R; Ouma, C; Machuka, E. M.; Fèvre, E. M.; Falzon, L. C.; Lukambagire, A. S.; Halliday, J. E. B.
Background: Brucellosis is an emerging yet neglected zoonosis that has been reported in Kenya. Epidemiological data on brucellosis in ruminants is readily accessible; however, reports on brucellosis in pigs remain limited. This study sought to detect Brucella infection in pig serum by both serological and molecular techniques. Serum from 700 pigs randomly collected at a centralized abattoir in Nairobi region, Kenya were screened in parallel, using both Rose Bengal Test (RBT) and competitive Enzyme-Linked Immuno-sorbent Assay (cELISA) for antibodies against Brucella spp. All sera positive by RBT and 16 randomly selected negative samples were further tested using conventional PCR targeting bcsp31 gene and real-time PCR (RT-PCR) assays targeting IS711 and bcsp31 genes. Results: A prevalence of 0.57% (n = 4/700) was estimated using RBT; none of these samples was positive on cELISA. All RBT positive sera were also positive by both PCRs, while two sero-negative samples also tested positive on RTPCR (n = 6/20). Brucella abortus was detected in four out of the six PCR positive samples through a real-time multiplex PCR. Conclusion: The detection of antibodies against Brucella spp. and DNA in serum from slaughterhouse pigs confirm the presence of Brucella in pigs. Therefore, investigation of the epidemiology and role of pigs in the transmission of brucellosis in Kenya is needed. Further targeted studies would be useful to systematically quantify and identify the spp. of Brucella in pigs.
Seroprevalence of brucellosis in small ruminants and related risk behaviours among humans in different husbandry systems in Mali
(PLoSONE, 2021) Traore, S; Coulibaly, K; Mathew, C; Fokou, G; Bonfoh, B; Yapi, R. B.; Kazwala, R. R.; Alambedji, R. B.
Mali has a high pastoral potential with diverse coexisting production systems ranging from traditional (nomadic, transhumant, sedentary) to commercial (fattening and dairy production) production systems. Each of those systems is characterised by close interactions between animals and humans, increasing the potential risk of transmission of zoonotic diseases. The nature of contact network suggests that the risks may vary according to species, production systems and behaviors. However, the study of the link between small ruminants and zoonotic diseases has received limited attention in Mali. The objective of this study was to assess brucellosis seroprevalence and determine how the husbandry systems and human behaviour expose animal and human to infection risk. A cross-sectional study using cluster sampling was conducted in three regions in Mali. Blood was collected from 860 small ruminants. The sera obtained were analysed using both Rose Bengal and cELISA tests. In addition, 119 farmers were interviewed using a structured questionnaire in order to identify the characteristics of farms as well as the risk behaviors of respondents. Husbandry systems were dominated by agro-pastoral systems followed by pastoral systems. The commercial farms (peri-urban and urban) represent a small proportion. Small ruminant individual seroprevalence was 4.1% [2.8–5.6% (95% CI)]. Herd seroprevalence was estimated at 25.2% [17.7–33.9% (95% CI)]. Peri-urban farming system was more affected with seroprevalence of 38.1% [18.1–61.5 (95% CI)], followed by pastoral farming system (24.3% [11.7–41.2 (95% CI)]). Identified risk behaviors of brucellosis transmission to animals were: exchange of reproductive males (30.2%); improper disposal of placentas in the farms (31.1%); and keeping aborted females in the herd (69.7%). For humans, risk factors were: close and prolonged contact with animals (51.2%); consumption of unpasteurized dairy products (26.9%); and assisting female animals during delivery without any protection (40.3%). This study observed a high seroprevalence of brucellosis in small ruminants and also identified risky practices that allow cross transmission between the two populations. This calls for control strategy using a multi-sectoral and multidimensional approach.