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.