Emergent spotted fever group Rickettsiae infections among hard ticks in Islamic Republic of Iran

Tick-borne rickettsioses have become a health concern worldwide following the increasing incidence in recent decades. However, there is limited information about these diseases in Islamic Republic of Iran. This cross-sectional study was conducted to estimate the Rickettsia infection among ixodid ticks collected from cattle, sheep and goats in Islamic Republic of Iran. The DNA of ixodid ticks collected from cattle, sheep and goats in 54 villages of Zanjan Province, Islamic Republic of Iran, were collected and analysed using a spectrophotometer. Rickettsial-positive samples were screened by targeting the htrA gene and fragments of gltA gene were analysed. The variables were analysed using descriptive statistics and the χ test was used to compare the variables. A total of 528 ticks were tested. Overall, Rickettsia infection rate was 6.44%. Nine of the 12 tick species were infected. Rickettsial positive rates in Hyalomma marginatum and Dermacentor marginatus were 21.33% and 12.77%, respectively. R. aeschlimannii, the predominant rickettsia, was detected only in Hy. marginatum. R. raoultii, R. sibirica and R. slovaca comprised about half of the positive ticks and were recovered from more than one tick species. Considering the discovery of infected ticks in the Islamic Republic of Iran, there is a need to establish a tick control programme in the country, paying attention to populations at high-risk.