Widespread Detection of Multiple Strains of Crimean-Congo Hemorrhagic Fever Virus in Ticks, Spain

Human cases of Crimean-Congo hemorrhagic fever (CCHF) were first detected in Spain in 2016. National human and animal health authorities organized a large, multidisciplinary study focusing on ticks as sentinels to determine the nationwide distribution of ticks with CCHF virus. Ticks were collected from animals and vegetation, samples pooled (12,584 ticks; 4,556 pools), and molecular methods used to look for the virus. We detected the virus in 135 pools from most of the regions studied, indicating that it is widespread in Spain. We found sequences of CCHF virus genotypes I, Ill, and IV in the tick species collected, most commonly in Hyalomma lusitanicum, suggesting this tick has a prominent role in the virus's natural cycle. The red deer (Cen/us elaphus) was the host that most frequently yielded positive ticks. Our study highlights the need for larger studies in Spain to ascertain the complete risk to public health.

Automated summary

This study found that Crimean-Congo hemorrhagic fever (CCHF) virus is widespread in Spain, predominantly in the tick species Hyalomma lusitanicum. Red deer were identified as the host most frequently carrying positive ticks.