Related Experiment Videos
[Analysis of 4 clustered high risk acute flaccid paralysis cases in Shanxi Province in 2006]
Dong-mei Yan1, Yong Zhang, Dong-yan Wang
1World Health Organization Western Pacific Region Regional Reference Polio Laboratory, State Key Laboratory for Molecular Virology & Genetic Engineering, Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
Objective:
Analysis of epidemiology of 4 clustered high risk acute flaccid paralysis(AFP) cases reported by Shanxi province in 2006 and VP1 gene characteristic for type III poliovirus isolated from the four AFP cases.
Methods:
Virus isolation and identification were conducted according to the 4th edition of WHO polio laboratory manual. The sequence of VP1 region were amplified and sequenced. The phylogenetic trees based on VP1 region were constructed.
Result:
Three of four high risk AFP cases were suspected as vaccine associated paralysis poliomyelitis (VAPP), the onset date of them were close. VP1 sequencing of the four type III isolates revealed that the identity were 99.7%, 99.9%, 99.4% and 99.9% respectively compared with vaccine reference strain-BJOPV3. According to WHO criteria, the four isolates were identified as type III vaccine-related poliovirus. Phylogenetic analysis based on VP1 coding sequence showed that the four type III poliovirus were not related significantly. The type III poliovirus isolated from 3 suspected VAPP cases shared one nucleotide mutation at 2637 (C-->U), which result in the amino acid mutation from Val into Ala.
Conclusion:
The improvement of laboratory surveillance for clustered high risk AFP cases should be strengthened so as to detect and prevent poliovirus circulation timely.
Insights
Four clustered acute flaccid paralysis (AFP) cases in Shanxi, China, were linked to type III vaccine-related poliovirus. Enhanced laboratory surveillance is crucial for timely poliovirus detection and prevention.
Area of Science:
- Virology
- Epidemiology
- Molecular Biology
Context:
- Analysis of four clustered high-risk acute flaccid paralysis (AFP) cases in Shanxi province, China, reported in 2006.
- Investigation focused on the characteristics of type III poliovirus isolated from these AFP cases.
Purpose:
- To analyze the epidemiology of the clustered AFP cases.
- To characterize the VP1 gene of the type III poliovirus isolates.
- To determine the relationship between the isolates and vaccine strains.
Summary:
- Three of the four high-risk AFP cases were suspected as vaccine-associated paralytic poliomyelitis (VAPP).
- VP1 sequencing identified the four isolates as type III vaccine-related poliovirus, closely matching the vaccine reference strain BJOPV3.
- Phylogenetic analysis indicated the isolates were not significantly related, though three VAPP cases shared a specific nucleotide mutation (2637 C-->U) leading to an amino acid change.
Impact:
- Highlights the need for strengthened laboratory surveillance for clustered high-risk AFP cases.
- Emphasizes the importance of timely detection and prevention of poliovirus circulation.
- Provides insights into the genetic characteristics of vaccine-related poliovirus in the context of AFP outbreaks.
