Man-threatening viruses isolated from ticks in Saudi Arabia

To determine tick viruses transmissible to man in Saudi Arabia.

We collected tick samples for identification from different region of Saudi Arabia during March 1992 - December 1992. Ticks collected from domestic animals were washed with buffer containing antibiotics, macerated, triturated in minimal essential media (MEM), centrifuged and the supernatant inoculated intracerebrally in suckling mice. Brains of mice showing disease signs were similarly treated and the supernatant inoculated on cell cultures. Antigen spot slides were prepared from material of blind-passed cell cultures showing cytopathic effects. The slides were overlaid by group-specific hyperimmune mouse ascetic fluid (HMAF) to different virus groups and stained with antimouse fluorescein isothiocyanate conjugate. Positive slides were retested with monoclonal antibodies or HMAF to individual viruses within the positive group.

Sindbis virus was isolated from Hyalomma dromedarii (H. dromedarii) from Al-Qasim and Jazan regions and Hyalomma impeltatum (H. impeltatum) from Al-Qasim, Ar-Riyadh and Jazan regions. Chick Ross and Kadam viruses were isolated from H. dromedarii from Al-Qasim region. Kadam virus was isolated from Hyalomma anatolicum (H. anatolicum) from Ar-Riyadh region. Dhori virus was isolated from H. impeltatum and Hyalomma schulzei (H. schulzei) from the Eastern region. Other alphaviruses were isolated from H. dromedarii from Al-Qasim and Tabuk regions, H. impeltatum from Jazan region, H. anatolicum from the Eastern region and Rhipicephalus sanguineus from Ar-Riyadh and Eastern regions.

In the Kingdom, ticks harbor viral infections transmissible from wildlife to man and his livestock. Local physicians should be aware of the symptoms and signs of these infections.