สถาบันวิจัยวิทยาศาสตร์สาธารณสุข

NATIONAL INSTITUTE OF HEALTH OF THAILAND

Wild-type Measles Virus Strains Isolated in Thailand during 1998-2004

Authors : Sirima Pattamadilok*, Araya Sungdee*, Sanit Kumperasart*, Patcha Incomserb*, Paul A. Rota** and William J.Bellini**

 

Affiliations:        * National Institute of health, Department of Medical Science,
Ministry of PublicHealth, Nonthaburi 11000 Thailand
                        ** Centers for Disease Control and Prevention, Atlanta, Georgia, USA
 
Source:            Presented at: The 8th International Conference on Emerging Infectious Diseases in the Pacific Rim, 10-13 December 2003, Dhaka, Bangladesh
 
Language:        English
 
Abstract:
 
The Measles Laboratory of the National Institute of Health in Thailand serves as a Regional Reference Laboratory for the Global Measles Laboratory Network of the Southeast Asian Region of the World Health Organization. The laboratory has responsibility for serologic confirmation of suspected measles cases and collection of measles isolates for genetic characterization. Here we describe the genetic analysis of 24 wild-type measles viruses isolated from seven provinces in Thailand during 1998-2004. Sequence analysis of the 456 nucleotide of N gene of all of the isolates and the H gene of representative isolations indicated that at least two genotypes (D5 and G2) have been co-circulating in Thailand during this time. The nucleotide sequences of the N genes of the The Thai wild type measles viruses differed from the reference strains of genotype D5 AND genotype G2 by 0.7-1.1% and 0.2-0.7%, respectively. Therefore, measles viruses in genotype D5 has been circulating continuously in Thailand since at least 1993 and was the only genotype detected in 2002-2004. Genotype D5 is also the endemic genotype in neighboring Cambodia. Genotype G2 viruses were isolated in 1998, 2000, and 2001. Genotype G2 is also one of the endemic genotypes in Indonesia. Thailand is in the enhanced control and mortality reduction phase of measles control and has made very good progress in controlling measles. However, the molecular epidemiologic data suggest that one and possibly 2 endemic genotypes continue to circulate. This report describes baseline genetic data for Thailand which will be used to help measure the continuing successful of Thailand’s measles control program.