[1] Alex Ekwueme Fed Univ, Teaching Hosp Abakaliki, Dept Community Med, Abakaliki, Nigeria
[2] Alex Ekwueme Fed Univ, Teaching Hosp Abakaliki, Dept Paediat, Abakaliki, Nigeria
[3] Univ Antwerp, Vaccine & Infect Dis Inst VAXINFECTIO, Fac Med & Hlth Sci, Lab Med Microbiol, Antwerp, Belgium
[4] Lagos Univ, Teaching Hosp, Dept Microbiol, Surulere, Nigeria
[5] Ebonyi State Univ, Dept Community Med, Abakaliki, Nigeria
[6] Alex Ekwueme Fed Univ, Teaching Hosp Abakaliki, Dept Community Med, Abakaliki 480214, Nigeria