AN OUTBREAK OF POLIOMYELITIS IN TAJIKISTA N, 1991, CAUSED BY POLIOMYELITIS VIRUS TYPE-I IN CONCOMITANT INFECTION WITH ECHO-19 VIRUS

In 1991 in Tajikistan 36 cases of acute poliomyelitis were recorded (s pinal form 27, bulbospinal 3, pontospinal 6 cases) in children ranging in ages from 6 months to 6 years. The outcome of the disease was fata l in 4 cases and with crude residual effects in 32 children. Out of 23 children examined, poliomyelitis virus type I was isolated from 13, a ntibodies to poliovirus type I in titres 1:16 to 1:1024 were detected in 21 children, ECHO 19 virus was isolated from 5 children and antibod ies to this virus in titres 1:16 to 1:8192 were demonstrated in 13 chi ldren. The fresh isolates of poliomyelitis virus type I had rct+, DSand N+ markers. The strains of ECHO 19 virus were highly pathogenic fo r monkeys causing deaths of the animals within 3-4 days. It is assumed that the main causative agent of the Tajikistan outbreak of poliomyel itis was a virulent <<wild>> variant of poliovirus type I. The precedi ng or concomitant infection with ECHO 19 virus (considering the data f rom the literature and the demonstrated high virulence of this agent f or monkeys) could exert an aggravating effect on the course of poliomy elitis or, in some cases, be an independent cause of the disease and, possibly, death of the children.