1,721,004 research outputs found
Characterization of some Brucella species from Zimbabwe by biochemical profiling and AMOS-PCR
No full textPublisher's PDF version,Background: Bovine brucellosis caused by Brucella abortus is endemic in most large commercial and smallholder cattle farms of Zimbabwe, while brucellosis in other domestic animals is rare. The diagnosis of brucellosis is mainly accomplished using serological tests. However, some Brucella spp.
have been isolated from clinical cases in the field and kept in culture collection but their biochemical profiles were not documented. We report biochemical profiling and AMOS-PCR characterization of some of these field isolates of Brucella originating from both commercial and smallholder cattle
farming sectors of Zimbabwe.
Findings: Fourteen isolates of Brucella from culture collection were typed using biochemical profiles, agglutination by monospecific antisera, susceptibility to Brucella-specific bacteriophages and
by AMOS-PCR that amplifies species- specific IS711. The results of the biochemical profiles for B.abortus biovar 1 (11 isolates) and biovar 2 (2 isolates) were consistent with those of reference strains. A single isolate from a goat originating from a smallholder mixed animal farm was identified
as B. melitensis biovar 1. The AMOS-PCR produced DNA products of sizes 498 bp and 731 bp for B. abortus (biovar 1 and 2) and B. melitensis biovar 1, respectively.
Conclusion: We concluded that the biochemical profiles and AMOS-PCR characterization were
consistent with their respective species and biovars. B. abortus biovar 1 is likely to be the predominant cause of brucellosis in both commercial and smallholder cattle farms in Zimbabwe
EPIZOOTOLOGICAL STUDIES AND DIAGNOSTIC APPROACHES TOWARDS CATTLE BRUCELLOSIS IN THE SMALLHOLDER DAIRY SECTOR OF ZIMBABWE
No full textA cross-sectional study was conducted to study the epizootology and diagnostic approaches of cattle brucellosis in six smallholder cattle farming areas of Zimbabwe. Specifically, the seroprevalence and risk factors for brucellosis were investigated. Serological diagnostic tests were evaluated and bacteriological investigations of herds and characterisation of Brucella spp. were carried out.
The overall mean individual animal and herd-level seroprevalences were 5.6% (95% CI: 4.4%, 6.8%) (81/1440) and 25.0% (95% CI: 18.1%, 31.9%), (52/203) respectively. The seroprevalence differed significantly (P7 years). Animals in the age group 5.5-7 years were found to be approximately 5 times (OR=4.9, 95% CI: 2.0, 11.6) more likely to have aborted compared to those of the age group 2-4 years, but the risk subsequently decreased with increasing age. Keeping mixed cattle breeds was associated with increased risk of brucellosis (OR= 8.5; 95% CI: 2.7, 26.5). Seropositivity (OR = 3.0, 95% CI: 1.4, 6.6) and mixed breed herds (OR = 2.3, 95% CI: 1.1, 4.9) were respectively found to be associated with increased risk of abortions. The kappa statistic test indicated good agreement among the c-ELISA, RBT and the FPA. The FPA had a higher specificity compared to RBT. The biochemical profiles of the B. abortus biovar 1 (11 isolates) and biovar 2 (2 isolates) typed in this study were typical of those of the genus. In conclusion, brucellosis was present in all study areas. The age of cattle and the mixing cattle breeds are important risk factors for brucellosis. The FPA could be used as a confirmatory test for bovine especially in the field. It is likely that B. abortus biovar 1 is the predominant cause of brucellosis in smallholder cattle. Further tests are required to study molecular biology and the epizootology of B. abortus
Prevalence of antibodies to Brucella spp. and individual risk factors of infection in traditional cattle, goats and sheep reared in livestock–wildlife interface areas of Zambia
No full textPre-print to the original published by SpringerLink accessible on: http://www.springerlink.com/content/8r11190t71tg0080/,A cross-sectional study was performed in the livestock–wildlife interface areas of Lochinvar and Blue Lagoon National Parks and the non-interface area of Kazungula to determine the prevalence of antibodies to Brucella spp. in domestic ruminants and identify individual animal risk factors of infection. Atotal of 1245 cattle from 124 herds and 280 goats and sheep from 29 flocks were tested sequentially for Brucella antibodies using the Rose Bengal test (RBT) and competitive ELISA. In cattle, individual seroprevalence ranged from 14.1% to 28.1%, while herd sero–prevalence ranged from 46.2% to 74.0% in the three study areas. No goat or sheep tested positive for Brucella antibodies. Three types of cattle grazing strategies were encountered: locally grazed herds (LGH), transhumantly grazed herds (TGH) and river flood plain grazed herds (FGH). Brucella seroprevalence was seen to vary according to area and grazing strategy: Lochinvar and transhumant grazed herds recorded the highest figures, respectively. Age, sex and history of abortion were found to have independent effects on individual seroprevalence. This study establishes that brucellosis is endemic in domestic animals in the livestock–wildlife interface areas of Blue Lagoon and Lochinvar national parks and the disease is also present in Kazungula. We observed that type of grazing strategy had significant impact on cattle Brucella seroprevalence and that transhumant herds were at high risk of being infected
Effectiveness of Rose Bengal test and fluorescence polarization assay in the diagnosis of Brucella spp. Infections in free range cattle reared in endemic areas in Zambia
No full textPre-print to the Original article in SpringerLink: http://www.springerlink.com/content/8xt726t61163n561/,The effectiveness of Rose Bengal test (RBT) and fluorescence polarization assay (FPA) in diagnosing cattle brucellosis in endemic areas was assessed and RBT and FPA test agreement was
compared (n=319). The sensitivity of RBT and FPA in detecting low Brucella titres were evaluated in paired sera (n=34). A logistic regression model was constructed to predict cattle test result in FPA using RBT as the main predictor and incorporating bio-data and animal history. There was 79.3% agreement between the RBT and FPA (Kappa = 0.59; Std error = 0.05; p = 0.000) and a high correspondence between high RBT scores and positive FPA results suggesting that sera with high RBT score may not require confirmation with tests such as competitive-ELISA or CFT. High FPA cut-off points were more likely to miss animals with low antibody titres. The RBT had a reduced ability in detecting low antibody titres compared to the FPA. FPA test interpretation was improved if a priori information, such as sex and age was used. Under the challenging disease surveillance conditions prevailing in rural Africa, field-testing methods that are sensitive and specific, allow single animal contact, low technical skills in data interpretation are suitable
Epizootological Studies and Diagnostic Approaches towards Cattle Brucellosis in the Smallholder Dairy Sector of Zimbabwe
No full textA cross-sectional study was conducted to study the epizootology and diagnostic
approaches of cattle brucellosis in six smallholder cattle farming areas of Zimbabwe.
Specifically, the seroprevalence and risk factors for brucellosis were investigated.
Serological diagnostic tests were evaluated and bacteriological investigations of herds
and characterisation of Brucella spp. were carried out.
The overall mean individual animal and herd-level seroprevalences were 5.6% (95% CI:
4.4%, 6.8%) (81/1440) and 25.0% (95% CI: 18.1%, 31.9%), (52/203) respectively. The
seroprevalence differed significantly (P<0.05) among the study areas. Young animals
(2-4 years) were found to be 5 times (OR=5.0, 95% CI: 1.4, 16.7) more likely to be
positive compared to old animals (>7 years). Animals in the age group 5.5-7 years were
found to be approximately 5 times (OR=4.9, 95% CI: 2.0, 11.6) more likely to have
aborted compared to those of the age group 2-4 years, but the risk subsequently
decreased with increasing age. Keeping mixed cattle breeds was associated with
increased risk of brucellosis (OR= 8.5; 95% CI: 2.7, 26.5). Seropositivity (OR = 3.0,
95% CI: 1.4, 6.6) and mixed breed herds (OR = 2.3, 95% CI: 1.1, 4.9) were respectively
found to be associated with increased risk of abortions. The kappa statistic test indicated
good agreement among the c-ELISA, RBT and the FPA. The FPA had a higher
specificity compared to RBT. The biochemical profiles of the B. abortus biovar 1 (11
isolates) and biovar 2 (2 isolates) typed in this study were typical of those of the genus.
In conclusion, brucellosis was present in all study areas. The age of cattle and the
mixing cattle breeds are important risk factors for brucellosis. The FPA could be used as
a confirmatory test for bovine especially in the field. It is likely that B. abortus biovar 1
is the predominant cause of brucellosis in smallholder cattle. Further tests are required
to study molecular biology and the epizootology of B. abortus
A comparative study of the seroprevalence of brucellosis in commercial and small-scale mixed dairy-beef cattle enterprises of Lusaka province and Chibombo district, Zambia
No full textPre-print to the Original article in SpringerLink: http://www.springerlink.com/index/a1552t5171670g21.pdf,A cross-sectional study was conducted between January 2007 and February 2008 to estimate seroprevalence of brucellosis and identify risk factors associated with Brucella infections in commercial cattle in 3 districts of Lusaka province (Chongwe, Luangwa, Kafue; n=849) and in one rural district from the Central province (n=48). A total of 897 serum samples were randomly collected from 55 farms along with animal level data such as sex, age and parity. Sera were screened for presence of anti-Brucella antibodies using Rose Bengal Test (RBT) and positive samples were confirmed using competitive enzyme linked immunosorbent assay (c-ELISA). At animal level, seroprevalence was estimated at 7.9 % (95% CI: 4.4-11.4%) in the Lusaka province and 18.7 % (95% CI: 7.5-29.9%) for Chibombo district. Brucellosis seroprevalence varied according to district, with Chongwe district recording the highest compared to other districts. Seroprevalence also varied according to sex with bulls (n =96) having higher seroprevalence (12.5%; 95% CI: 3.8-21.1 %) compared to females (8.1%; 95% CI: 4.6-11.6). Similarly, seroprevalence varied according to age groups, with the age category 1-4 years recording the highest (10.7%). The study recorded relatively low Brucella seroprevalence in commercial farms in Lusaka, compared to the traditional small-scale farms. We suggest that testing and stamping out of infected animals is likely to improve the situation and significantly reduce the public health risk associated with Brucella infections in animals
Milk producers’ awareness of milk-borne zoonoses in selected smallholder and commercial dairy farms of Zimbabwe
No full textPre-print to the Original article in SpringerLink: http://www.springerlink.com/,A cross-sectional questionnaire-based study was conducted to assess milk producers’ awareness of milk-borne zoonoses in selected smallholder and commercial dairy farms of Zimbabwe. The questionnaire was designed to obtain information on dairy breeds, milk production, dairy farmers’ knowledge and awareness of zoonoses with particular emphasis on milk-borne zoonoses and farmers’ behavioural practices that may lead to increased risk of milk-borne zoonoses transmission. A total of 119 dairy farmers were interviewed and 41.5% were aware of milk-borne zoonoses with a significantly (P<0.01) higher percentage of commercial dairy farmers (65.0%) being aware compared to smallholder dairy farmers (36.7%). The behavioural practices of dairy farmers observed to increase the risk of milk-borne zoonoses transmission were; consumption of raw milk (68.1%), sale of raw milk to the local public (25.2%), lack of cooling facilities by smallholder farmers (98%), and no routine testing (84.9%) and medical check-ups (89.1%) for milk-borne zoonoses. General hygienic and disease control practices need to be integrated in the milk production process particularly at the smallholder level. Awareness, teaching and training programs for smallholder dairy farmers can improve disease control in animals and reduce the public health risk of milk-borne zoonoses
Responses to tuberculin among Zebu cattle in the transhumance regions of Karamoja and Nakasongola district of Uganda
No full textPre-print to the original available via the link: http://www.springerlink.com/content/x5wh40ru78785n40/,Responses to tuberculin in Zebu cattle of the transhumant pastoral farming system in Karamoja
region and Nakasongola district in the north-eastern and mid-central regions in Uganda, respectively, were investigated using a comparative intradermal tuberculin skin test. Of the 1864 cattle tested from 30 large units (superherds) in Karamoja and 7 herds in Nakasongola, a total of 28 animals from 19 herds (51.4%) tested positive. Inter-district tuberculin reactor prevalence variations seemed to be influenced by climate, with impact on both the management patterns and transmissibility of agent. High herd tuberculin reactor prevalence (51.4%) was attributed to widespread contacts and mixing of animals between herds. Low individual animal tuberculin test positivity (mean=1.4%) was attributed to low transmissibility of the agent under the Karamoja climate, which is semi-arid, and to increased resistance due to non-specific response to environmental mycobacteria and natural selection, since there was no active control against bovine tuberculosis. Owing to similarities in management practices in Karamoja and widespread risk factors, it was difficult to identify which were more important, but variations in sources of drinking water pointed to provision of lake and borehole water during dry season as reducing the risk. Positive bovine tuberculin reactor prevalence and skin reactor status were related to age
Seroprevalence of brucellosis and its associated risk factors in cattle from smallholder dairy farms in Zimbabwe
No full textPre-print to the original available via the link: http://www.springerlink.com/,A cross sectional study was conducted to investigate seroprevalence of brucellosis and the associated risk factors in cattle from smallholder dairy farms in Gokwe, Marirangwe, Mushagashe, Nharira, Rusitu and Wedza areas of Zimbabwe. A total of 1440 cattle from 203 herds were tested serially for Brucella antibodies using Rose Bengal test (RBT) and the competitive ELISA (c-ELISA). Weighted seroprevalence estimates were calculated and risk factors in individual cattle investigated using logistic regression analysis. The overall individual animal brucellosis seroprevalence was low, with mean of 5.6 % (95 % CI: 4.4 %, 6.8 %). Gokwe had the highest individual (12.6%; 95 % CI: 3.9 %, 21.4 %) and herd-level (40.0%; 95 % CI: 22.1%, 58.0 %), while Wedza had the lowest individual (2.3 %; 95 % CI: 0 %, 5.3 %) and herd-level (8.0%; 95% CI: 0.0 %, 18.9 %) brucellosis seroprevalence, respectively. In individual cattle, the area of origin, age and history of abortion were independently associated with brucellosis seroprevalence. While the seroprevalence was independent of sex, it decreased with increasing age. Cattle 2-4 years old had higher odds (OR = 3.2; 95 % CI: 1.1, 9.1) of being seropositive compared to those > 7 years. Cows with a history of abortion were more likely to be seropositive (OR= 7.9; 95 % CI: 3.1, 20.1) than controls. In conclusion, the area-to area variation of brucellosis may be linked to ecological factors and differences in management practices. The implementation of stamping out policy, bleeding and testing animals before movement and promoting the use self-contained units are likely to significantly reduce the public health risks associated with Brucella infections in cattle
Effectiveness of Rose Bengal test and fluorescence polarization assay in the diagnosis of Brucella spp. Infections in free range cattle reared in endemic areas in Zambia
No full textPre-print to the Original article in SpringerLink: http://www.springerlink.com/content/8xt726t61163n561/The effectiveness of Rose Bengal test (RBT) and fluorescence polarization assay (FPA) in diagnosing cattle brucellosis in endemic areas was assessed and RBT and FPA test agreement was
compared (n=319). The sensitivity of RBT and FPA in detecting low Brucella titres were evaluated in paired sera (n=34). A logistic regression model was constructed to predict cattle test result in FPA using RBT as the main predictor and incorporating bio-data and animal history. There was 79.3% agreement between the RBT and FPA (Kappa = 0.59; Std error = 0.05; p = 0.000) and a high correspondence between high RBT scores and positive FPA results suggesting that sera with high RBT score may not require confirmation with tests such as competitive-ELISA or CFT. High FPA cut-off points were more likely to miss animals with low antibody titres. The RBT had a reduced ability in detecting low antibody titres compared to the FPA. FPA test interpretation was improved if a priori information, such as sex and age was used. Under the challenging disease surveillance conditions prevailing in rural Africa, field-testing methods that are sensitive and specific, allow single animal contact, low technical skills in data interpretation are suitable
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