Table 1. The prevalence of C. burnetii in sheep abortion
samples by using Real-time PCR.
Table 2. The prevalence ofC. burnetii in abortion samples of cattle using Real-time PCR.
Discussion
The present study was conducted to investigate the prevalence ofC. burnetii in domestic animal abortions in Iran and showed that
24.7% of the collected samples were positive forC. burnetii using Real-time
PCR. According to the results of this study, it is recommended that the
effect of C. burnetii be considered serious in cases of animal
abortion and the possibility of transmission to humans. Despite more
than 50 years have passed since the first report of Q fever, but the
disease is neglected diseases in Iran. On the other hand, despite the
fact that this disease has a very significant seroprevalence among
livestock and human populations, but there is no system for registering
and reporting and a program for diagnosis and prevention in the human
care health system and the veterinary organization in Iran (Mobarez et
al., 2017). Therefore, conducting more studies on suspected patients and
conducting molecular epidemiological research will shed light on the
epidemiological situation of fever in Iran and will encourage more
attention to the human and animal health system towards this disease. It
was recently reported that about 31% of culture-negative endocarditis
caused by C. burnetii in Iran (Moradnejad et al., 2019).
In current study, 21.8% sheep’s aborted samples were positive for ofC. burnetii . Highest
prevalence diagnosed Tehran (54.5%), Mazandaran (50%), West-Azarbaijan
(40%) and Hamadan (38.5%) provinces, respectively. Prevalence in our
study was higher than other similar studies in Iran, so that the
molecular prevalence of C. burnetii in sheep’s abortion in
Mashhad county (north-east of Iran), Sistan region (south-eastern of
Iran) and Fars province (southern of Iran) were reported 17.3%, 16.6%
and 2.7%, respectively (Abiri et al., 2016; Heidari et al., 2018;
Mahdavi Roshan et al., 2018). One of the reasons for the high prevalence
in our study was the using of a much more sensitive method (Real-time
PCR) for detection of C. burnetii . Other reasons include
different study areas and increased prevalence over time. In other
countries, different rates were reported; 33.6% in Egypt(Selim et al.,
2018), 2-11% in Turkey(Gunaydin et al., 2015; Kılıç et al., 2016),
21.5% in Italia(Parisi et al., 2006), 47.6% in Hungary(Kreizinger et
al., 2015) and 44.4% in Switzerland(Magouras et al., 2017). Based on
recent study in Iran, shedding of C. burnetii to milk was
significantly high (35.7%) among sheep with abortion history(Esmaeili
et al., 2019). Therefore, it seems that abortion in sheep due toC. burnetii should be given more attention.
In our study, 21.7% of cattle aborted samples were positive forC. burnetii . Highest
prevalence of C. burnetiiwas detected in Tehran (24.3%), and Alborz (16.7%) provinces,
respectively. However, the very small number of sample s from other
provinces made it difficult to compare in our study. In a study in
Mashhad county, 25% of cattle fetuses were positive for C.
burnetii (Abiri et al., 2016). In other countries, prevalence ofC. burnetii in cattle abortions were 4% in Turkey (Gunaydin et
al., 2015), 11.6% in Italy (Parisi et al., 2006), 25.9% in Hungary
(Kreizinger et al., 2015) and 35% in Cyprus (Cantas et al., 2011).
Also, C. burnetii was detected 33.3% in milk samples of cattle
with abortion history in Iran (Esmaeili et al., 2019). According to the
findings of this study and other similar studies in Iran and other
countries, it is recommended to take control measures against this
bacterium in order to prevent of cattle abortions in Iran.
The findings of the study demonstrate that C. burnetii have
important role in livestock abortions in Iran and more attention should
be paid to Q fever by the health care system and veterinary
organization. Also, necessary training in the prevention of this disease
should be provided to ranchers and at-risk people.