Tanzania Veterinary Laboratory Agency TVLA

Dar es Salaam, Tanzania

Tanzania Veterinary Laboratory Agency TVLA

Dar es Salaam, Tanzania
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Elisa M.,BecA ILRI Hub | Elisa M.,Sokoine University of Agriculture | Hasan S.D.,BecA ILRI Hub | Hasan S.D.,Veterinary Research Institute VRI | And 4 more authors.
Parasitology | Year: 2015

This study investigated the genetic and antigenic diversity of Theileria parva in cattle from the Eastern and Southern zones of Tanzania. Thirty-nine (62%) positive samples were genotyped using 14 mini- and microsatellite markers with coverage of all four T. parva chromosomes. Wright's F index (F ST = 0 × 094) indicated a high level of panmixis. Linkage equilibrium was observed in the two zones studied, suggesting existence of a panmyctic population. In addition, sequence analysis of CD8+ T-cell target antigen genes Tp1 revealed a single protein sequence in all samples analysed, which is also present in the T. parva Muguga strain, which is a component of the FAO1 vaccine. All Tp2 epitope sequences were identical to those in the T. parva Muguga strain, except for one variant of a Tp2 epitope, which is found in T. parva Kiambu 5 strain, also a component the FAO1 vaccine. Neighbour joining tree of the nucleotide sequences of Tp2 showed clustering according to geographical origin. Our results show low genetic and antigenic diversity of T. parva within the populations analysed. This has very important implications for the development of sustainable control measures for T. parva in Eastern and Southern zones of Tanzania, where East Coast fever is endemic. © Cambridge University Press 2014.


Kazungu Y.E.M.,Nelson Mandela African Institution of Science and Technology | Mwega E.,Sokoine University of Agriculture | Neselle M.O.,Sokoine University of Agriculture | Sallu R.,Tanzania Veterinary Laboratory Agency TVLA | And 3 more authors.
Ticks and Tick-borne Diseases | Year: 2015

This study was conducted to assess the incremental effect of natural tick challenge on the infection and treatment method-induced immunity against T. parva under agro-pastoral systems in Simanjiro district, Northern Tanzania. T. parva specific antibody percent positivity and prevalence of T. parva parasites were studied in relation to duration post vaccination and proximity to Tarangire National park. A total of 381 cattle were included in this study, of which 127 were unvaccinated and 254 had been vaccinated at different time points between 2008 and 2014. Antibody percent positivity (PP) determined by the PIM-based T. parva ELISA and the prevalence of T. parva parasites detected by a nested PCR based on the p104 gene were used to compare vaccinated and unvaccinated cattle. Results showed that seroprevalence was significantly higher in vaccinated than unvaccinated cattle (OR 10.89, p = 0.0341). Only 1.6% (6/381) of all cattle were seronegative and 5/6 of these were unvaccinated. Prevalence of T. parva parasites was significantly higher in vaccinated (50.39%) than unvaccinated (19.69%) cattle (OR 2.03, p = 0.0144). While there was a positive association between PP and duration post vaccination but the latter was inversely associated with T. parva parasite prevalence. This study also showed that cattle which were closer to the park had higher antibody PP and T. parva prevalence. It is concluded that duration post vaccination as well as proximity from the wildlife in Tarangire National park together may exert an incremental effect on the outcome of ECF vaccination by influencing stronger antibody immunity of cattle and ability to withhold high T. parva infection pressure under constant field tick challenge. Further, the high seroprevalence in vaccinated and unvaccinated cattle suggests a likely state of endemic stability to T. parva in the study area. © 2015 Elsevier GmbH.


PubMed | Tanzania Veterinary Laboratory Agency TVLA, Sokoine University of Agriculture and Nelson Mandela African Institution of Science and Technology
Type: Journal Article | Journal: Ticks and tick-borne diseases | Year: 2015

This study was conducted to assess the incremental effect of natural tick challenge on the infection and treatment method-induced immunity against T. parva under agro-pastoral systems in Simanjiro district, Northern Tanzania. T. parva specific antibody percent positivity and prevalence of T. parva parasites were studied in relation to duration post vaccination and proximity to Tarangire National park. A total of 381 cattle were included in this study, of which 127 were unvaccinated and 254 had been vaccinated at different time points between 2008 and 2014. Antibody percent positivity (PP) determined by the PIM-based T. parva ELISA and the prevalence of T. parva parasites detected by a nested PCR based on the p104 gene were used to compare vaccinated and unvaccinated cattle. Results showed that seroprevalence was significantly higher in vaccinated than unvaccinated cattle (OR 10.89, p = 0.0341). Only 1.6% (6/381) of all cattle were seronegative and 5/6 of these were unvaccinated. Prevalence of T. parva parasites was significantly higher in vaccinated (50.39%) than unvaccinated (19.69%) cattle (OR 2.03, p = 0.0144). While there was a positive association between PP and duration post vaccination but the latter was inversely associated with T. parva parasite prevalence. This study also showed that cattle which were closer to the park had higher antibody PP and T. parva prevalence. It is concluded that duration post vaccination as well as proximity from the wildlife in Tarangire National park together may exert an incremental effect on the outcome of ECF vaccination by influencing stronger antibody immunity of cattle and ability to withhold high T. parva infection pressure under constant field tick challenge. Further, the high seroprevalence in vaccinated and unvaccinated cattle suggests a likely state of endemic stability to T. parva in the study area.


Swai E.S.,Ministry of Livestock Development and Fisheries MoLDF | Swai E.S.,Veterinary Investigation Center | Kaaya J.E.,Veterinary Investigation Center | Noah E.Y.,Tanzania Veterinary Laboratory Agency TVLA
Tropical Animal Health and Production | Year: 2013

Contagious caprine pleuropneumonia (CCPP), an Office International des Epizooties listed disease, can cause significant levels of morbidity and mortality in goats in Africa, the Middle East, and Western Asia. A cross-sectional study was conducted to determine the seroprevalence of CCPP, in two contrasting administrative districts of northern Tanzania, namely, Babati and Arumeru. A total of 337 serum samples were collected from January to July 2010, from apparently clinically healthy unvaccinated dairy goats breeds of different ages and sexes. Samples were subjected to monoclonal antibody-based competitive enzyme-linked immunosorbent assay for the specific measurement of antibodies to Mycoplasma capricolum subsp. capripneumoniae bacterium. The overall animal flock and village-level seroprevalence of CCPP was found to be 3.3 % [95 % confidence interval (CI) = 1.6-5.8], 9.6 % (95 % CI = 4.7-16.9), and 31.5 % (95 % CI = 15.6-56.5), respectively. There was no evidence (p = 0.659) of differences in seroprevalence between samples from the two administrative locations. Despite the fact that there was no significant difference (p > 0.05) in seropositivity between sex and age and between breeds sampled, there was a significant difference (p < 0.05) in seropositivity between the different physiological status groups examined with the non-lactating (dry) category of goats showing a higher seroprevalence. The findings of this survey revealed evidence of dairy goat exposure to M. capricolum subsp. capripneumoniae, although at a low prevalence. It is therefore advisable to include CCPP serology in the seromonitoring program so as to give a better indication of flock immunity. This should lead to the establishment of appropriate CCPP control measures in smallholder dairy goat flocks, which are increasingly being recognized for their value as a vital source of livelihood for resource poor livestock keepers in Tanzania. © 2013 Springer Science+Business Media Dordrecht.


Manangwa O.,Vector and Vector Borne Disease Institute | Ouma J.O.,Africa Technical Research Center | Ouma J.O.,Kenya Agricultural Research Institute | Malele I.,Vector and Vector Borne Disease Institute | And 3 more authors.
Livestock Research for Rural Development | Year: 2016

Tsetse flies transmit trypanosomes which affect livestock and human health in sub Saharan african countries including Tanzania.The wide occurrence of this disease in people and their livestock has negatively impacted the development of viable agricultural systems in many areas of great agricultural potential including areas of the Lake Victoria basin in Tanzania.The present study investigated trypanosome infection rate in G. f. fuscipes in Kirongwe, Masonga, Rasi Nyabero and Tobwe River in Rorya district, Msozi village in Ukerewe district and Kemondo in rural Bukoba district during the dry and wet seasons. Trypanosome infection in cattle was also investigated in the same villages except Kemondo village with a view to understand the risk of the disease to livestock and humans in the study area.Tsetse flies were collected using biconical and pyramidal traps in Kirongwe, Masonga, Rasi Nyabero and Tobwe River.Twenty traps were deployed after every 150 to 200 meters during the dry season and wet season. A total of 120 flies were examined microscopically and 215 by Polymerization Chain Reaction (PCR) for trypanosome infection. Trypanosomes infection in cattle was also assessed in order to understand the risk of the disease to cattle and humans in the study area. Blood was collected from 116 cattle and examined under microscope for trypanosome infection. Some blood was stored in FTA cards for trypanosome infection rate analysis using PCR. No infection was detected microscopically but PCR showed (2%) of G. f. fuscipes was infected by T. b. brucei at Rasi Nyabero village during the dry season. Similarly, for the wet season, one female fly (2.5%) out of 40 was found positive for T. congolense Kilifi in Msozi village. Microscopic examination showed no cattle were infected but PCR indicated one female cow out of 116 cows (0.86%) at Rasi Nyabero village was infected with T. vivax. Generally, trypanosome prevalence in G. f. fuscipes and cattle was low for all seasons. The low infection rate should not be taken for granted, regular surveillance is important in monitoring the problem in the study area since the Lake Victoria shore is known to be a risk area for trypanosomiasis. © 2016, Fundacion CIPAV. All rights reserved.


Mwambene P.L.,Tanzania Livestock Research Institute TALIRI Uyole | Chawala A.,Tanzania Livestock Research Institute TALIRI Mpwapwa | Illatsia E.,Kenya Agricultural Research Institute | Das S.M.,Tanzania Veterinary Laboratory Agency TVLA | And 2 more authors.
Livestock Research for Rural Development | Year: 2014

A study to describe key dairy traits of selected indigenous cattle populations was conducted in the Southern Highlands and Eastern of Tanzania. Four districts, namely Njombe and Mufindi in the Southern Highlands, and Bagamoyo and Muheza in the Eastern zone were selected for data collection. A questionnaire was used to extract information from 122 farmers with respect to household characteristics of the respective farming communities and dairy attributes of their local cattle, as well as their production environments, production systems, production potentials, milk marketing and production challenges. Physical measurements on body weight, body length, heart girth and height at withers were also taken on 483 mature (> 4 years) animals, while their main body colours and colour patterns were appraised from 965 animals found in all the Southern Highlands' selected cattle herds. Most of the farmers were keeping indigenous cattle mainly for drought purpose, milk production and for socio-economic and cultural purposes. The majority of the farmers kept indigenous cattle, mainly the Tanzania Shorthorn Zebu (TSZ) and a few of them had some crosses of exotic and TSZ. All the farmers used natural bulls for breeding purposes. Mating practice was random among the majority of the farmsteads owing to grazing and watering on communal rangelands. Selection of breeding bulls was rarely rationally done. The average age at first calving was 50 ± 1.3 months, while the mean lactation length and calving interval were 148 ± 2.8 days and 16 ± 0.6 months, respectively. Mean daily milk yield at peak was about 3±0.15 litres. Kraals made of untreated thorny bushes were the predominant shelters used for cattle by all of the respondents. The majority of respondents mentioned diseases/parasites, shortages of breeding bulls of high vigour and feeds during the dry season as the main production challenges. Both location and sex influenced all the body measurements, with bulls superseding cows. Most measurements were positively and highly correlated, with the body weight being predicted more accurately from the heart girth. The animals from Njombe and Mufindi districts had also variable body colour patterns, but being predominantly red, black, pied red and white, pied black and white and spotted red and white. Most animals had medium-sized teats and udders. Thus the cattle populations in the study can be classified as medium-sized strains with considerable variation in body size, morphological features and dairy production potential within and between districts. Variation in indigenous cattle in dairy traits can be capitalized for improvement of dairy production through selective breeding.


PubMed | Tanzania Veterinary Laboratory Agency TVLA, Sokoine University of Agriculture and Kenya International Livestock Research Institute
Type: Journal Article | Journal: Parasitology | Year: 2015

This study investigated the genetic and antigenic diversity of Theileria parva in cattle from the Eastern and Southern zones of Tanzania. Thirty-nine (62%) positive samples were genotyped using 14 mini- and microsatellite markers with coverage of all four T. parva chromosomes. Wrights F index (F(ST) = 0 094) indicated a high level of panmixis. Linkage equilibrium was observed in the two zones studied, suggesting existence of a panmyctic population. In addition, sequence analysis of CD8+ T-cell target antigen genes Tp1 revealed a single protein sequence in all samples analysed, which is also present in the T. parva Muguga strain, which is a component of the FAO1 vaccine. All Tp2 epitope sequences were identical to those in the T. parva Muguga strain, except for one variant of a Tp2 epitope, which is found in T. parva Kiambu 5 strain, also a component the FAO1 vaccine. Neighbour joining tree of the nucleotide sequences of Tp2 showed clustering according to geographical origin. Our results show low genetic and antigenic diversity of T. parva within the populations analysed. This has very important implications for the development of sustainable control measures for T. parva in Eastern and Southern zones of Tanzania, where East Coast fever is endemic.


PubMed | Tanzania Veterinary Laboratory Agency TVLA, Enigma Diagnostics, Sokoine University of Agriculture and The Pirbright Institute
Type: | Journal: Transboundary and emerging diseases | Year: 2015

Capripoxviruses, comprising sheep pox virus, goat pox virus and lumpy skin disease virus cause serious diseases of domesticated ruminants, notifiable to The World Organization for Animal Health. This report describes the evaluation of a mobile diagnostic system (Enigma Field Laboratory) that performs automated sequential steps for nucleic acid extraction and real-time PCR to detect capripoxvirus DNA within laboratory and endemic field settings. To prepare stable reagents that could be deployed into field settings, lyophilized reagents were used that employed an established diagnostic PCR assay. These stabilized reagents demonstrated an analytical sensitivity that was equivalent, or greater than the established laboratory-based PCR test which utilizes wet reagents, and the limit of detection for the complete assay pipeline was approximately one log


PubMed | Tanzania Veterinary Laboratory Agency TVLA, Sokoine University of Agriculture, Veterinary Research Institute VRI and Kenya International Livestock Research Institute
Type: | Journal: Veterinary parasitology | Year: 2016

A population genetic study of Theileria parva was conducted on 103 cattle and 30 buffalo isolates from Kibaha, Lushoto, Njombe Districts and selected National parks in Tanzania. Bovine blood samples were collected from these study areas and categorized into 5 populations; Buffalo, Cattle which graze close to buffalo, Kibaha, Lushoto and Njombe. Samples were tested by nested PCR for T. parva DNA and positives were compared for genetic diversity to the T. parva Muguga vaccine reference strain, using 3micro and 11 minisatellite markers selected from all 4 chromosomes of the parasite genome. The diversity across populations was determined by the mean number of different alleles, mean number of effective alleles, mean number of private allele and expected heterozygosity. The mean number of allele unique to populations for Cattle close to buffalo, Muguga, Njombe, Kibaha, Lushoto and Buffalo populations were 0.18, 0.24, 0.63, 0.71, 1.63 and 3.37, respectively. The mean number of different alleles ranged from 6.97 (Buffalo) to 0.07 (Muguga). Mean number of effective alleles ranged from 4.49 (Buffalo) to 0.29 (Muguga). The mean expected heterozygosity were 0.07 0.29, 0.45, 0.48, 0.59 and 0.64 for Muguga, cattle close to buffalo, Kibaha, Njombe, Lushoto and Buffalo populations, respectively. The Buffalo and Lushoto isolates possessed a close degree of diversity in terms of mean number of different alleles, effective alleles, private alleles and expected heterozygosity. The study revealed more diversity in buffalo isolates and further studies are recommended to establish if there is sharing of parasites between cattle and buffaloes which may affect the effectiveness of the control methods currently in use.

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