Poliomyelitis in Russia in 1998-1999

After introducing surveillance for poliomyelitis and AFP cases in the Russian Federation in 1998, 740 AFP cases have been registered in 1998-1999, and 18 of that number were considered as vaccine-associated paralytic poliomyelitis (VAPP). Of 18 cases 11 were classified as VAPP of vaccine recipients and confirmed by virus isolation; from two of the vaccine recipients virus was not isolated, and five were poliomyelitis cases in contact non-vaccinated children. In all the cases the disease was characterised with the typical clinical picture with residual pareses and paralyses. One case was fatal. Vaccine virus type 3 has been isolated from all the vaccine recipients. The MAPREC test has shown that the quality of monovaccine type 3 bulks used for vaccinating these children did not differ from the quality of other bulk vaccines produced by the Chumakov Institute of Poliomyelitis. Patients surveyed for gammaglobulin were positive. Polioviruses type 1 isolated from two of the contact cases had changed antigenic properties and were recombinants of types 1 and 2.