The Relationship between Environmental Factors and Hyalomma (Acari: Ixodidae) Community, the Main Vectors of CCHF Virus in Iran

Background: Ticks are among the vectors of pathogens, and they can play a crucial role in the transmission of a wider range of pathogens. The main public health problem and the largest geographic distribution related to tick is Crimean-Congo hemorrhagic fever (CCHF) that the main group of vectors is ticks of the genus Hyalomma spp.Objectives: The impact of environmental factors and host on Hyalomma spp. community structure and abundance in the main CCHF foci of Iran is largely unknown.Materials and Methods: Effect of biotic and abiotic factors, including host, temperature, humidity, altitude, Köppen-Geiger climate types, season, and precipitation on Hyalomma spp. community structure and abundances were investigated in 11 provinces of Iran. Additionally, the possible infection of ticks with CCHF virus was evaluated using reverse transcription PCR technique.Results: Species analyses demonstrated the presence of H. anatolicum, H. marginatum, H. dromedarii, H. asiaticum, H. detritum and H. schulzei in the study areas. H. anatolicum was the dominant species in the southern and northern parts, whereas H. dromedarii was distributed mostly in central parts of the country. The highest tick infestation was recognized in hot season. Spatial variation in tick relative density was observed between habitat types where more ticks were collected in deserts, semi-deserts, and Mediterranean habitats. Except for H. dromedarii, which was more prevalent on camel (P= 0.044), there were no significant variations in the frequencies of other Hyalomma species on different hosts. H. anatolicum and H. dromedarii frequencies had significant positive and negative association with temperature and precipitation respectively. Also humidity has positive impact on H. anatolicum frequency.Conclusion: Data presented here will help improve ecological models to forecast the distribution of Hyalomma spp. ticks, to evaluate the risk of CCHF and other tick-borne diseases, and to design proper vector control measures to suppress Hyalomma populations in Iran.

کلیدواژه ها:

Hyalomma ، Ticks ، Climate ، Host ، Environment