parviz saleh infectious diseases department, research center of infection and tropical diseases, tabriz university of medical sciences, tabriz, ir iran hamidreza afsharjoo infectious diseases department, tabriz university of medical sciences, tabriz, ir iran ali ramouz student research committee, faculty of medicine, tabriz university of medical sciences, tabriz, ir iran; student research committee, faculty of medicine, tabriz university of medical sciences, tabriz, ir iran. tel: +98-9143023216, fax: +98-4134413895 mohammad reza bonyadi department of immunology, drug applied research center, tabriz university of medical sciences, tabriz, ir iran mahdie hosseini student research committee, faculty of medicine, tabriz university of medical sciences, tabriz, ir iran fateme mallah gynecology and obstetrics department, al zahra hospital, tabriz university of medical sciences, tabriz, ir iran

B J Marais A C Hesseling R P Gie H S Schaaf D A Enarson N Beyers