Polio eradication: Intratypic characterization of poliovirus strains isolated in Kuwait

It is expected that the circulation of wild-type poliovirus strains will stop world-wide due to the WHO-recommended expanded programme of immunization, In Kuwait the situation is rather unique because thousands of the workforce come from countries where a number of polio cases are reported every year, The question is whether imported wild polio strains can survive in a well-vaccinated population. To answer this question we investigated the vaccine-relatedness of 60 poliovirus strains isolated in Kuwait, Reverse-transcription polymerase chain reaction (RT-PCR) coupled with restriction fragment length polymorphism assay were used for the identification of poliovirus isolates, Fragments obtained after digesting the RT-PCR-amplified product with three restriction enzymes (HaeIII, DdeI, HpaII) were compared with that of standard wild and vaccine type poliovirus strains, Isolates from healthy, vaccinated infants (n = 15), children (n = 15) and from patients with the diagnosis of aseptic meningitis (n = 30) were analysed, Molecular characterization revealed a strict vaccine-relatedness of all the 60 poliovirus isolates, The results suggest that the rigorous vaccination policy implemented in Kuwait provides a high level of immunity which prevents the circulation of wild poliovirus strains in Kuwait.