SEROEPIDEMIOLOGY OF MERS-CoV AMONG PILGRIMS TO MECCA

The Middle East Respiratory Syndrome Corona Virus (MERS-CoV) is a new Corona virus first identified in 2012. Since then, more than 1,278 laboratory confirmed cases were reported. Most MERS patients developed severe acute respiratory illness with fever, cough ad shortness of breath. Case fatality rate is high (43%). Most cases have been reported from Saudi Arabia but to date the disease has spread to other countries in the Middle East and all over the world. No cases were identified in Israel. The precise ways the virus spreads are not well understood. MERS-CoV has spread from patients to others in healthcare settings, however an ongoing transmission of the virus in the community was not described. Dromedary camels have been suspected as source of human infection but the natural reservoir is not known. Risk factors for MERS-CoV infection are exposure to dromedary camels during two weeks before symptom onset and existing chronic diseases.

We sought to study seropositivity rate among pilgrims returning from the Hajj in Mecca. We hypothesized that this group might be at higher risk for exposure to MERS-CoV due to potential contact with cases of MERS under the crowded living conditions during the stay in Saudi Arabia.

Blood samples have been collected from pilgrims prior to traveling to Mecca and two months following their return. Demographic data and information on illnesses during the visit were collected. Antibodies to MERS-CoV IgG are currently tested using an ELISA assay, and positive sera will be further confirmed using a plaque reduction neutralization assay developed at the Department of Viroscience, Erasmus MC, in Rotterdam, Nederland. To date 176 samples have been obtained 2-4 weeks before traveling and 160 samples 2-3 months following return. Collection of samples continues and sera are being screened by ELISA. Results will be presented.