Serological evidence of Coxiella burnetii, Leptospira Hardjo, Neospora
caninum and bovine pestivirus infections in a dairy cattle herd from the
United Arab Emirates
Abstract
To date, no epidemiological studies have evaluated bovine abortion in
the UAE. Therefore, the present study evaluated the serostatus of five
abortigenic agents in a dairy cattle herd from Al Ain region, UAE.
Additionally, the association of abortion history with Coxiella burnetii
seropositivity was also evaluated. Indirect ELISA screened 350 sera from
dairy cattle for C. burnetii, Leptospira Hardjo, Neospora caninum, and
Brucella abortus antibodies while a sandwich ELISA tested the samples
for bovine virus diarrhoea virus (BVDV) antigen. The serological data
were summarized by descriptive statistics and the Z test of two
proportions applied to assess the statistical significance between the
proportions of C. burnetii-seropositive cattle with and without abortion
history. Of the 350 cattle, 41.4%, 1.7%, 1.4%, 0.3%, and 0.0% were
seropositive to C. burnetii, L. Hardjo, N. caninum, BVDV, and B. abortus
respectively. Furthermore, of the 105 cattle with history of abortion,
61.9%, 2.9%, 1.0%, 0.0%, and 0.0% were seropositive to these
pathogens respectively. Conversely, of the 245 seropositive cattle with
no history of abortion 32.7%, 1.2%, 1.6%, 0.0% and 0.0% were
seropositive to these pathogens respectively. Further still, the z-test
showed the proportion of C. burnetii seropositive cattle with a history
of abortion to be significantly higher than the C. burnetii seropositive
animals without abortion history with a difference between the
proportions of 29.3% [p-value < 0.01; 95% CI: 18.2% to
40.2%]. Compared to the other four pathogens, the C. burnetii
infection level in the dairy herd was relatively higher. As C. burnetii
is abortigenic, it may have causally contributed to reproductive failure
in the cattle herd. Additional epidemiological studies are needed to
further elucidate the abortigenic significance of C. burnetii and the
other four pathogens in the national dairy cattle herd. Besides, the
public health implications of C. burnetii and Leptospira need to be
evaluated.