A survey of zoonotic diseases in trade cattle slaughtered at Tanga city abattoir:a cause of public health concern

Objective:To estimate the prevalence of hydatidosis,cysticercosis,tuberculosis,leptospirosis,brucellosis and toxoplasmosis in slaughtered bovine stock(aged≥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 2002and 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.

An abattoir survey of contagious bovine pleuropneumonia lesions in slaughtered cattle in selected districts in Northern Tanzania

Objective:To establish and estimate incidence of contagious bovine pleuropneumonia(CBPP),using abattoir survey as a diagnostic tool in slaughtered cattle in Northern Tanzania.Methods:A total of 4460 cattle were slaughtered in five abattoirs in 3 northern zone regions(Arusha,Kilimanjaro and Tanga)during the period of January to May 2004.They were examined ante-mortem for‘pneumonia signs',and‘characteristic contagious bovine pleuropneumonia(CBPP)lung lesions'.Results:Forty-one(0.91%)of the slaughtered cattle,the majority of which were Tanzania short horn zebu,had gross lung lesions suggestive of CBPP.The prevalence of lesions was significantly(P<0.05)higher in Karatu abattoir compared to others.No animal was detected to have lesion in Bomang'ombe abattoir.The most observed pneumonic signs included labored breathing(90%),dry cough(57%)and mucopurulent nasal discharge(47%).The gross characteristic CBPP pathological lesion,frequently encountered was left lung lesion(47%),pinkish lung(71%)and pleural adhesion(98%).Epidemiological reports show that the CBPP reported outbreaks increased from 19 in 2002,65 in 2003 and 18 in 2004(January-March).The corresponding number of reported deaths increased from 137 in 2002,269 in 2003 and 77 in 2004(January-March).Conclusions:It's concluded from this study that CBPP is a problem in spite of the extensive awareness and vaccination campaigns.Nevertheless,a continued surveillance programme including routine checks of all cattle carcasses at the abattoir and subsequent epidemiological investigation of suspected cases are recommended.

Microbial quality and associated health risks of raw milk marketed in the Tanga region of Tanzania

Objective:To evaluate micmbial 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 milkborne 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 coliforra 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(4.2×10~6) was significantly higher than that handled by collecting centres(3.0×10~6) and kiosk/ restaurants(1.4× 10~6),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.

Prevalence and spectrum of helminths in free-ranging African buffaloes(Syncerus caffer)in wildlife protected areas,Tanzania

Objective:To determine the prevalence and spectrum of helminths in free-ranging African buffaloes in Tanzania by a cross-sectional study.Methods:Faecal samples(n=123)from Arusha National Park and Ngorongoro Crater were examined for helminth eggs using sedimentation and floatation techniques during the period of March to June 2012.Results:Coprological examination revealed that 34.1%(n=42)of the buffaloes excreted nematodes and trematodes eggs and protozoan oocyst in their faces.The pattern of infection was either single or mixed.Single(52.4%)and concurrent infections with two,three,four and five parasites were recorded in 19.0%,11.9%,14.3%and 2.3%respectively of the cases.The nematode eggs encountered were those of Trichostrongylus sp.(20.3%),Oesophagostomum sp.(7.3%),Strongyle sp.(4.1%),Bunostomum sp.(4.1%),Ostertegia sp.(3.3%)and Toxocara sp.(2.4%).The trematode eggs encountered were those of Fasciola sp.(9.8%),Paramphistomum sp.(4.9%),Gastrothylax sp.(1.6%),Ornithobilharzia sp.(0.81%)and Fischoederius sp(0.81%).The protozoan oocyst recorded was that of Eimeria sp.(8.1%).Geographical location of buffaloes had significant influence on the prevalence of infection with Trichostrongylus(P=0.046)and Fasciola(P=0.001),and the mean prevalances in Arusha National Park are significantly higher than those in Ngorongoro Crater.Age had significant influence on infection with Fasciola(P=0.036),and juvenile recorded higher levels of infection than sub-adults.Health status,body condition score and sex-wise prevalence of helminths were not significant(P>0.05).Conclusions:This study indicates that helminths species are numerous and highly prevalent in the two protected areas and may be one of the contributing factors to lower buffalo productivity.