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Tanga, Tanzania

Swai E.S.,Veterinary Investigation Center | Schoonman L.,Tanga Dairy Trust TADAT
Tropical Animal Health and Production | Year: 2012

A cross-sectional study was conducted between May 2003 and January 2004 on 130 households and 655 (246 indigenous and 409 crossbred) cattle to determine the prevalence of bovine tuberculosis (bTB) and assess risk factors associated with prevalence in smallholder dairy and traditionally managed herds in the Tanga region of North-eastern Tanzania. Random sampling, single intradermal tuberculin (SIT), comparative intradermal tuberculin (SCIT) tests and a questionnaire were used to gather individual animal and herd level information. From 642 animal tested by SIT, 35 (5.4%) were positive reactors for tuberculosis. Out of those 35 bTB positive reactors, eight (1.25%) proved to be positive reactors for tuberculosis upon further testing by SCIT. Based on the SCIT test, individual animal prevalences of bTB in the smallholder dairy and traditionally managed cattle was 2% and 0%, respectively. The corresponding overall herd prevalence was 5.7% and 0%, respectively. In conclusion, bTB prevalence seems low; however, its potential risk to public health is of concern; underscoring the need for further research, active surveillance to better understand the epidemiology of the disease in different cattle production systems in Tanzania. © 2011 Springer Science+Business Media B.V.

Swai E.S.,Veterinary Investigation Center | Schoonman L.,Tanga Dairy Trust TADAT
Asian Pacific Journal of Tropical Biomedicine | Year: 2011

Objective: To evaluate microbial quality and associated health risks of raw milk marketed in the Tanga region of Tanzania. Methods: A microbial quality assessment of marketed raw milk was undertaken by evaluating 59 samples of milk from selling points (collecting centres =15), bicycle boys (12) and kiosks/restaurants (32) in Tanga city during April-May 2005. Quality and milk-borne hazards were assessed using a combination of tests in order to quantify the occurrence of Brucellosis (milk ring test), Escherichia coli (E. coli) O157:H7 (culture), the coliform bacteria as well as standard plate count (SPC). Specific gravity (SG) determination was used as an indicator of adulteration. Results: The mean coliform plate count (c.f.u/mL) of milk handled by bicycle boys (4.2 × 106) was significantly higher than that handled by collecting centres (3.0 × 106) and kiosk/restaurants (1.4 × 106), respectively (P < 0.05). Of the 59 milk samples collected, 33 (56%) were Brucella milk ring test (MRT)-positive and 78% and 17% of the samples graded satisfactorily based on SG and coliform plate counts as prescribed by East African Community standards for raw milk. There was no verocytotoxigenic E. coli (VTEC) O157: H7 in any of the milk samples collected and analysed during the present study. Conclusions: It can be concluded that raw market milk in the study area is of poor bacteriological quality and hazardous for human consumption. This highlights the need to implement good hygiene practices and effective monitoring from production through the delivery chain to the consumer. Further studies are needed for detection of toxins that are produced by E. coli, other pathogenic spore forming bacteria (Bacillus spp. and Clostridium spp.) and other harmful microorganisms. © 2011 Asian Pacific Tropical Biomedical Magazine.

Swai E.S.,Veterinary Investigation Center | Schoonman L.,Tanga Dairy Trust TADAT
Asian Pacific Journal of Tropical Biomedicine | Year: 2012

Objective: To estimate the prevalence of hydatidosis, cysticercosis, tuberculosis, leptospirosis, brucellosis and toxoplasmosis in slaughtered bovine stock (aged J>3 years) at Tanga city abattoir, Tanzania. Methods: Prevalence estimation of the five zoonotic diseases was undertaken through an active abattoir and sero-survey was carried out in Tanga city, during the period of January 2002 and March 2004. Serum samples collected from a sub-sample (n=51) of the slaughter stock were serologically screened for antibodies against brucellosis, leptospirosis and toxoplasmosis using Rose Bengal plate test, microscopic agglutination test (for 5 serovars of Leptospira interrogans) and Eiken latex agglutination test, respectively. The same animals were tested for tuberculosis using the single intradermal tuberculin test. Results: Post mortem examination of 12 444 slaughter cattle (10 790 short horn zebu and 1 654 graded) over a period of twenty two months, showed a prevalence of 1.56% (194) for hydatidosis, 1.49% (185) for cysticercosis and 0.32% (40) for tuberculosis. In all three zoonoses, a statistically significant difference in infection rates was noted between the short horn zebu and graded breeds (P<0.05). The overall seroprevalences of animals with brucellosis, toxoplasmosis and leptospirosis antibodies were found to be 12%, 12% and 51%, respectively. The most common leptospiral antibodies detected were those against antigens of serovars Leptospira hardjo (29%), Leptospira tarassovi (18%), Leptospira bataviae (4%) and Leptospira pomona (0%). With regard to tuberculosis, 10% (n=5) of the animals tested were classified as non-specific reactors or inconclusive. Conclusions: The study findings suggest that brucellosis, toxoplasmosis and leptospirosis are prevalent in Tanga and provide definitive evidence of slaughtered stock exposure to these zoonotic agents with concurrent public health consequences.

Schoonman L.B.,Tanga Dairy Trust TADAT | Wilsmore T.,University of Reading | Swai E.S.,Veterinary Investigation Center
Tropical Animal Health and Production | Year: 2010

In view of the worldwide importance of Toxoplasma gondii and the fragmented information on the seroprevalence of the disease in animals in Tanzania, a study, using the modified Eiken latex agglutination test (LAT), was conducted from May 2003 to January 2004 to determine the prevalence of antibody to T. gondii in 130 randomly selected farms comprising 655 cattle. The overall seroprevalence of T. gondii antibodies in cattle and farms were 3.6% and 13%, respectively. Risk factors for animal and herd-level toxoplasmosis seropositivity were tested using multivariable logistic regression to control for confounding factors. Cattle managed under traditional husbandry practises were more likely to be seropositive than those managed under smallholder practises (48% versus 4.7%; p < 0.01). Herd size of ≥ 9 cattle were at greater risk of acquiring infection than herds holding fewer animals [≤ 9 cattle], (odd ratio [OR] = 3.99; 95% confidence interval [CI], 0.97-16.48; P = 0.001). We concluded that seroprevalence at herd level was high and relatively low at animal level, possibly due to the reduced susceptibility of cattle to T. gondii infection as compared to goats and sheep. The high seroprevalence in animals managed by traditional husbandry practise suggests that the parasite is widely distributed in the environment and could pose a public health threat to the people living in those areas. © Springer Science + Business Media B.V. 2009.

Schoonman L.,Tanga Dairy Trust TADAT | Swai E.S.,Veterinary Investigation Center
Tropical Animal Health and Production | Year: 2010

Leptospirosis is the zoonosis of worldwide distribution and common cause of economic loss and ill health among animals and human populations. A crosssectional seroprevalence study, using a microscopic agglutination test (MAT) with a threshold titre of ≥1:160, to elucidate disease magnitude, distribution and associated risk factors in cattle in Tanga, Tanzania was conducted from May 2003 to January 2004. Serum (n=655) samples collected from randomly selected herds (n=130) were tested for antibodies against four different Leptospira interrogans serovars (Bataviae, Tarassovi, Hardjo and Pomona) used in the agglutination test. Positive titres were detected in 30.3% [95% confidence intervals (CI)=26.7-33.9] of cattle and 58.5% (95% CI=49.5-67.1) of herds, respectively. Of the 198 MAT positive serum samples, 98 (49.5%) were positive against serovar Hardjo, 80 (40.4%) were positive against serovar Tarassovi, 12 (6.1%) was positive against serovar Bataviae and eight (4%) were positive against serovar Pomona. Associations found to be statistically significant in univariate analyses (at P<0.1) were assessed by multivariable logistic regression to control for confounding factors. The results showed that risk factors for cattle were pasture grazing [odd ratio (OR)=2.83, 95% CI=1.57-5.12, P=0.001], presence of goats/sheep on the farm (OR=1.73, 95% CI=1.17-2.56, P=0.001) and age of the animal (OR=2.05, 95% CI=1.42-2.96, P=0.001), while concrete floor housing was protective (OR=0.47, 95% CI=0.30-0.74, P=0.001). Herds managed under pasture grazing system were more likely to be sero-positive than those managed under zero grazed practices (OR=9.31; 95% CI=3.67-23.64 for grazing herd). We concluded that bovine leptospirosis is an endemic and locally widespread disease in Tanga and suggest that it may play a role in zoonotic transmission to humans. © 2010 Springer Science+Business Media B.V.

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