Investigations of clinical isolations of oral poliovirus vaccine strains between 2000 and 2005 in southern Taiwan.
BACKGROUND
In Taiwan, trivalent oral poliovirus vaccine (tOPV) is in the routine immunization schedule, but its association with illnesses had not been examined.


OBJECTIVE
To investigate clinical presentations and viral characteristics of patients with poliovirus isolates.


METHODS
Clinical data, vaccination records and viral sequences were retrospectively analyzed for patients from whom polioviruses were isolated during 2000-2005.


RESULTS
OPV-like strains were the only pathogen identified in 208 children who were diagnosed with lower respiratory tract infection (24.5%), acute gastroenteritis (16.8%) or upper respiratory tract infection (10.6%). Timing of poliovirus isolation relative to the tOPV vaccination was unusual in 59 patients, including 6 before any dose and 53 more than 10 weeks after the 3rd or later dose of tOPV. Sequence analyses of the VP1, 2C and 3C/D regions for 19 poliovirus isolates revealed that 4 had previously reported neurovirulence reversions, 1 had intertypic recombination, and 6 had both. No patient had neurological complications, but 3 died of myocarditis, including 2 with recombinant strains and 1 who never received OPV.


CONCLUSIONS
This study describes the isolation of OPV-like strains from patients with a variety of illnesses, raising concerns about their pathogenic potential in an area where tOPV is routinely administered. The detection of genetic variations among OPV-like strains warrants continuing surveillance for these variants in patients with severe illnesses besides neurological complications.
Chi
Chia-Yu
CY
Division of Infectious Diseases, National Health Research Institutes, 367 Sheng-Li Road, Tainan 704, Taiwan.
Tseng
Fan-Chen
FC
Liu
Ding-Ping
DP
Chang
Ya-Wen
YW
Wu
Han-Chieh
HC
Huang
Yung-Feng
YF
Hwang
Kao-Pin
KP
Hsu
Yun-Wei
YW
Wang
Shih-Min
SM
Liu
Ching-Chuan
CC
Wu
Ho-Sheng
HS
Yang
Jyh-Yuan
JY
Yang
Chen-Fu
CF
Wang
Jen-Ren
JR
Su
Ih-Jen
IJ
D002648:Child; D002675:Child, Preschool; D005260:Female; D005759:Gastroenteritis / Q000821:virology; D006801:Humans; D007223:Infant; D008297:Male; D010802:Phylogeny; D011014:Pneumonia / Q000821:virology; D017955:Poliovirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D011055:Poliovirus Vaccine, Oral / Q000009:adverse effects*; D012367:RNA, Viral / Q000235:genetics; D012141:Respiratory Tract Infections / Q000821:virology; D017422:Sequence Analysis, DNA; D013624:Taiwan
D011055:Poliovirus Vaccine, Oral; D012367:RNA, Viral