Prevalence of vaccine-derived polioviruses in the environment.
A survey of poliovirus in river and sewage water was conducted from October 1993 to September 1995 in Toyama Prefecture, Japan. In this study, 25 isolates differentiated as type 2 vaccine-derived polioviruses (VDPVs) were characterized using mutant analysis by PCR and restriction-enzyme cleavage (MAPREC) to estimate the ratio of 481-G revertants correlated to neurovirulence in a virus population. Of these isolates, 23 (92%) comprised between 44 and 96% 481-G revertants by MAPREC. The other two isolates had revertant percentages close to the 0.6% of the attenuated reference strain. It was presumed that these 23 isolates would be variant with potential neurovirulence by MAPREC analysis. Of the 23 isolates, three were isolated from river water. Moreover, our results by MAPREC showed that type 2 poliovirus was phenotypically more variable than type 1 (69%) or type 3 (55%), as determined in previous studies. The prevalence of virulent-type VDPVs in river and sewage water suggested that the oral poliovaccine itself had led to wide environmental pollution in nature. To terminate the cycle of virus transmission in nature, the ecology of VDPVs should be studied further. A hygiene programme, inactivated poliovirus vaccine immunization and well-maintained herd immunity may play key roles in reducing the potential risk of infection by virulent VDPVs.
Yoshida
Hiromu
H
Department of Virology II, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashimurayama, Tokyo 208-0011, Japan1.
Horie
Hitoshi
H
Japan Poliomyelitis Research Institute, Kumegawa 5-34-4, Higashimurayama, Tokyo 189-0003, Japan2.
Matsuura
Kumiko
K
Department of Virology, Toyama Institute of Health, Nakataikoyama, Kosugi-machi, Imizu-gun, Toyama 939-0363, Japan3.
Kitamura
Takashi
T
Department of Virology, Toyama Institute of Health, Nakataikoyama, Kosugi-machi, Imizu-gun, Toyama 939-0363, Japan3.
Hashizume
So
S
Japan Poliomyelitis Research Institute, Kumegawa 5-34-4, Higashimurayama, Tokyo 189-0003, Japan2.
Miyamura
Tatsuo
T
Department of Virology II, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashimurayama, Tokyo 208-0011, Japan1.
D005618:Fresh Water / Q000821:virology; D006801:Humans; D011051:Poliomyelitis / Q000517:prevention & control; D017955:Poliovirus / Q000302:isolation & purification*; D011054:Poliovirus Vaccine, Inactivated / Q000276:immunology; D015995:Prevalence; D012722:Sewage / Q000821:virology; D014611:Vaccination
D011054:Poliovirus Vaccine, Inactivated; D012722:Sewage