Epidemioloy of Brucellosis in Cattle and its Sero Prevalence in Animal Health professional in Sidama Zone, Southern Ethiopia
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Date
2004-06
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Addis Ababa University Faculty Of Veterinary Medicine
Abstract
ABSTRACT
Brucellosis is a widespread infectious disease of livestock and wild life with serious economic
and public health impact. Bovine brucellosis causes diminution of much needed human food
(milk and meat). Besides, being transmitted to man, it is one of the most important causes of
abonion, stillb irth and infertility in cattle. The objectives of this study were, to investigate th e
current epidemiological picture of brucellosis in cattle in intensive and extensive management
systems, identify and describe some of the associated intrinsic and extrinsic risk factors and to
see the zoonotic imporlance of the disease.
The study was conducted from September 2003 to April 2004, in Sidama Zone (Southern
;ations Nationalities Peoples Regional state). In the study area, six out of ten Waredas were
considered for the investigation. Breeding cattle (n=2438 ) above six months of age were
drawn in from both management systems with no history of vaccination. To this effect, a
total of811 Frisian and their CTOsses from intensive and 1627 indigenous zebu from extensive
management system were considered . Furthennore 38 individuals thought to be at risk due 10
their occupational nature, with particular emphasis given to Veterinarians, Animal health
Assistants. Animal Health Technicians, Anificial Insemination Technicians and Meat
Inspectors were made part of the study.
Serum samples collected from both animals and humans were screened using Rose Bengal
Plate Test (RBPT). Positive reactors were further subjected to Complement Fixation Test to
maximize specifiry and positive predictive value.
In this study, an over all prevalence of 2.46% in intensive and 1.66% in extensive
management systems has been established .. Among the risk factors investigated (Age, sex,
herd size and management). only age was found to be associated with the infection (P<0.05).
Orthe total herds in vestigated , 9. 22 % (n=347) of them were confimled to consist at least one
infected animal. The herd level infection rates were 6. 72 % (n=223) and 13.70 % (11=124) for
intensive and extensive management, respecti vely. Infected herds have been detected from all
Woredas except Arroresa. Accordingly, the rate of seroreactor herds observed were, 33.3%
(n~) for Awassa, 15.3 % (n~26) for Yirgalem. 13.15 % (n~38) for Aletawendo. 14.29 %
(n=14) for Hagereselam and 18.18 % (n=22) for Arbegona in extensive management. In the
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intensive countcr part 8% (n~125) ror Yirgal em and 5. 1% (n~98) ror Awassa have been
established.
As th e observed average herd size was different for either of the management systems,
categorizations into sm all , medium and large herd s was done differently. Consequently. in
intens ive managemen t system, 2.87 %, 9.58% and 33.36% were the infectio n rate for small,
medium and large herds, respec ti ve ly. In the extensive system the result was, 4. 81 % for sma ll ,
50% for medium and 70% for large he rd s. In both intensive and extensive management
systems, the va riati on between small and large was stat isticall y significant (P <O.O I).
In intensive urban and periurban dairy, 17.4 8% of the herd s reported at least on e of the
reproductive disorders (abo rt ion, st ill birth and fetal me mb ran e reten tion with or with out any
or the disorders).
5.3% of the occupationally risked individuals' sera produced evidence of infection. In the
situation where individual animal level infection rate was fond to be low, detection of reactors
with thi s ma gnitude shows brucellosi s being an occupational hazard .
In general the study concluded that, brucellosis is prevalent at low (individual), relatively high
(herd) and wid e (Geographical) distributio n. The infection has involved both management
systems (intensive and extensive) and occupat ionally exposed individuals. The disease among
professionally exposed groups needs furthe r val id at ion by including more numbers
Description
Keywords
Brucellosis, RBPT , eFT, Survey. Zo onoses, Reproductive disorders, serial testing, Inten sive management , Extensive management, Occupat ional groups