1. Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
2. The Pediatric Infectious Disease Unit, Soroka University Medical Center, Beer-Sheva, Israel
3. Clinical Virology Laboratory, Soroka University Medical Center, Beer-Sheva, Israeland
4. Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA