[1] Golestan Univ Med Sci, Fac Med, Dept Microbiol, Gorgan, Iran
[2] Golestan Univ Med Sci, Fac Hlth, Environm Hlth Res Ctr, Dept Biostat & Epidemiol, Gorgan, Iran
[3] Univ Oslo, Div Paediat & Adolescent Med, Oslo, Norway
[4] Univ Botswana, Dept Paediat & Adolescent Hlth, Gaborone, Botswana
[5] Golestan Univ Med Sci, Infect Dis Res Ctr, Gorgan, Iran
[6] Golestan Univ Med Sci, POB 4934174515, Gorgan, Iran
[7] Univ Oslo, Inst Clin Med Head Global Paediat Signatory Theme, Fac Med, Ctr Global Hlth,Div Paediat Adolescent Med, POB 4956 Nydalen OUS, N-0424 Oslo, Norway