[1] Univ Western Cape, Sch Pharm, ZA-7530 Cape Town, South Africa
[2] Univ Benin, Coll Med Sci, Ctr Excellence Reprod Hlth Innovat CERHI, Dept Publ Hlth, Benin 300001, Nigeria
[3] Univ Benin, Sch Basic Med Sci, Dept Med Biochem, Benin 300001, Nigeria
[4] Univ Ibadan, Coll Med, Fac Publ Hlth, Dept Epidemiol & Med Stat, Ibadan 200284, Nigeria
[5] Univ Western Cape, Sch Publ Hlth, ZA-7535 Cape Town, South Africa
[6] Rivers State Univ, Coll Med Sci, Dept Publ Hlth Sci, Port Harcourt 500101, Nigeria
[7] Rivers State Univ, Coll Med Sci, Dept Community Med, Port Harcourt 500101, Nigeria