Molecular detection of Coxiella burnetii in horse sera in Iran.

Coxiella burnetii is a zoonotic bacterium that can infect a wide range of animals including horses. However, its circulation dynamics in and through horses are still unclear. The aim of this study was to evaluate prevalence of C. burnetii and its genomic characteristics in horse sera samples in the North of Iran (Golestan Province). The samples were collected in 2018 and the age, sex, and breed of each animal were recorded. Nested-PCR was used to detect C. burnetii based on the presence of the transposable gene IS1111. The results showed that 7.50 % (P < 0.05; 95 % CI: 0.5 %-0.12 %) of the examined sera samples were positive for C. burnetii. Based on the resuls, prevalence of C. burnetii in the age groupof < Years 1-5 (p-value <0.05, 95 % CI: 1 %-8 %) was less than the age group of >6 years old (p-value <0.05, 95 %, CI: 7 %-19.8 %). In previous studies, it was concluded that the horses' population in Golestan Province should be considered as an important factor in the epidemiology of Q fever and consequently in public health. Further studies should be implemented to evaluate if horses may be relevant indicators of zoonotic risk in urban and suburban endemic areas.

Prevalence of C. burnetii DNA in sheep and goats milk in the northwest of Iran.

Q fever is a common zoonotic disease with worldwide distribution. The causative agent of Q fever is Coxiella burnetii, a gram-negative and polymorphic rod bacterium. Sheep and goats are the primary reservoirs of this disease, although a variety of animal species can be infected. The main route of Q fever transmission from animals to humans is the inhalation of contaminated aerosols with C. burnetii. The bacterium is excreted in milk of infected animals and therefore; the consumption of unpasteurized milk and dairy products might be a route of coxiella burnetii transmission from animals to humans. The present study was conducted to determine the prevalence of C. burnetii in milk samples collected from sheep and goats in west Azerbaijan province, Iran. During 2018, a total number of 420 milk samples were collected from sheep (n = 210) and goats (n = 210) of different regions of the province. All milk samples were subjected to DNA extraction and examined by a highly and specific nested-PCR method. The results showed that 51 (12.1%) (95% CI: 9.3%-15.6%) examined samples [sheep; n = 16 (7.6%) and goat; n = 35 (16.6%)] were positive for C. burnetii. The prevalence of C. burnetii in goat milk samples was significantly higher than sheep milk samples (P < 0.05). The shedding of C. burnetii in milk was significantly higher in summer (25%) (P < 0.05, 95% CI: 17.7%-34%) than the other seasons. It was concluded that sheep and goat populations in west Azerbaijan play an important role in the epidemiology of Q fever.