Abstract:
A cross sectional study was conducted from April 2012 to July 2012 to
determine the prevalence of Haemonchus contrtus infection in sheep and associated
risk factors in North Kordofan state, Sudan. A total of 360 sheep fecal samples were
collected and examined using standard parasitological procedures including egg count
using Mc Master method and then culture of feces.
The study revealed that the overall prevalence of sheep haemonchosis was
36.4%. The distribution of haemonchosis according to localities was: 59.9% in Barra,
59.1% in Sheikan, 31.8% in En-nuhod, 20.3% in Abuzabd and 15.7% in Umrwaba.
Regarding distribution by sex, the prevalence of haemonchosis was 37.7% in females
and 31.6% in males. The prevalence of haemonchosis according to age of sheep was
42.9% in sheep more than 3 years, 32.4% in animals aged 1 to 3 years, and 21.1% in
animals aged <1 years. According to breed, the higher prevalence was recorded in
Kabashi breed )59.7%(, followed by Hamarri breed )31.1%(. Regarding body
condition, our study showed that a prevalence of 96.6% in bad condition, 65.9% in
moderate condition, and 8.3% in good condition. Distribution of haemonchosis
according to flock size of sheep was 43.2% in small flock size )1to 35(, 37.3% in
medium flock size )36 to 70(, and 30.8% in large flock size )>70(. The presence of
haemonchosis in various months was 40.0% during wet months, and 34.3% during dry
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months. The distribution of haemonchosis according to source of addition to the flock
was 47.8% in animals purchased from local farm in area, 39.5% in animals purchased
from other farm in other areas, and 33.2% in animals raised on farm.
The prevalence of haemonchosis in various rainfall level was 40.0% in
presence of rainfall, and 34.3% in absence of rainfall. Distribution of H. contortus
infection according to temperature ranges was 52.9% in low temperature )<36°C(,
31.8% in moderate temperature )36 to 40°C(, and 33.1% in high temperature )>40°C(.
The results of our study, showed that the prevalence of H.contortus infection within
different humidity ranges of animal areas was 48.8% in high humidity )>40%(, 32.2%
in moderate humidity )30 to 40%(, and 33.1% in low humidity )<30%(. The prevalence
of H. contortus infection with regard to housing was 47.5 % when the animals were
found indoor compared with 33.3% in animals found outdoor. In our study, a higher
prevalence of infection was found in animals suffering from other diseases )77.6%(,
than the animals free of other diseases )16.8%(. In this study, the prevalence of H.
contortus infection in diarrheatic animal was 75.0%, 42.2% in animals with soft feces,
and 28.6% in animals with normal feces.
According to grazing type, the higher prevalence of infection was found in
semi-nomadic system )43.2%( compared to nomadic system )34.2%(. The prevalence
of H. contortus infection was 12.4% in animals whose owners used drugs and 73.2%
in animals whose owners did not use drugs. The prevalence of H. contortus infection
according to vegetation was 40.0% in good vegetation was 34.3% in poor vegetation.
Our result showed that infection was more prevalent in sheep raised with other animals
)40.3%(, than animals that are not raised with other animals )35.6%(. This study
showed that the prevalence of haemonchosis in different soil types was 40.0% in loam
soil, while 34.3% in sand soil.
Statistical significant associations )P-value ≤ 0.25( with being positive in the
univariate analysis using Chi square )χ2( test were found to be locality )χ2=52.224,
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p=0.00(, age )χ2=8.131, p=0.017(, breed )χ2=19.328, p=0.000(, body condition
)χ2=1.978, p=0.000(, flock size )χ2=3.582, p=0.167(, source of addition to the flock
)χ2=3.962, p=0.138(, temperature )χ2=10.229, p=0.000(, humidity )χ2=7.327,
p=0.026(, housing )χ2=5.486, p=0.019(, other diseases )χ2=1.255, p=0.000(, fecal
consistency )χ2=30.650, p=0.000(, grazing type )χ2=2.322, p=0.128(, and use of drugs
)χ2=137.6, p=0.000(. In the final multivariate models using logistic regression
)P-value ≤ 0.05(, risk factors found associated with the disease included locality: Barra
)Exp B =8.148(, Sheikan )Exp B =7.944(, and body condition: moderate )Exp B
=21.241(, bad )Exp B =313.500(, Age: > 3 years )Exp B =6.629(, and use drugs: did
not used drugs )Exp B =19.361(. A statistical significant association was not observed
)P-value> 0.05( in the prevalence with others potential risk factors.