OPV strains circulation in HIV infected infants after National Immunisation Days in Bangui, Central African Republic

Fifty three children were enrolled. Sequential stool samples were collected in between National Immunisation Days rounds and then every month during one year. Children were classified into 2 groups: no immunodepression (n = 38), immunodepression (n = 15) according to CD4+ lymphocytes cells count. Thirteen poliovirus strains were isolated from 11 children: 5 Human immunodeficiency virus positive and 6 Human immunodeficiency virus negative. None of the children excreted poliovirus for more than 4 weeks. The restriction fragment length polymorphism analysis showed that all strains were of Sabin origin including a unique Polio Sabine Vaccine types 2 and 3 (S2/S3) recombinant.From these findings we assume that Human immunodeficiency virus positive children are not a high risk population for long term poliovirus excretion. More powerful studies are needed to confirm our findings.Humans are the only host of polioviruses, thus the prospects of global polio eradication look reasonable [1,2]. However the discovery, after years of massive use of oral polio vaccine (OPV), of individuals with immunodeficiencies who were shown to excrete vaccine derived poliovirus (VDPV) for long periods of time led to a reluctance to prolong the vaccination campaign for fear of this end result [3]. Considering the immunodeficiency that prevails in Human immunodeficiency virus (HIV) patients, long term poliovirus excretion would be likely [4,5]. In Africa the OPV is used in mass vaccination campaigns during National Immunization Days (NIDs) notwithstanding HIV status of children. Two recent studies showed that HIV-infected children have low persistence of antibodies to vaccines used in the Expended Program on Immunization (EPI) including OPV [6,7].In Central African Republic (CAR), it have been assessed that the prevalence of HIV infection is 6% in general population [8] thus it would be of interest to study the impact of HIV infection on poliovirus excretion in infants of 0 to 5 years of age rec