Temporal changes of rotavirus strain distribution in a city in the northwest of China, 1996-2005.

BACKGROUND: Very little is known about human rotaviruses in the northwest of China. To investigate the genomic diversity, we evaluated the distribution of rotavirus genotypes in this region covering a 10-year period (1996-2005). METHODS: Rotavirus antigen was detected in stool specimens by enzyme immunoassay (EIA), and G and P genotyping was performed by reverse transcription-polymerase chain reaction and nucleotide sequencing methods. RESULTS: A total of 783 stool specimens collected from children with diarrhea, under 5 years of age, attending an urban hospital in Xinjiang were tested for rotavirus antigen, and 398 (50.8%) were positive. Overall, the most prevalent rotavirus genotype was G1P[8] (40.0%), followed by G3P[8] (17.5%), G2P[4] (8.3%), and G2P[6] (6.5%). G1 rotavirus was the most prevalent genotype until 2004. However, in 2005, G3 rotavirus (51.9%) became a dominating strain. Only one G9 strain was isolated in this region (isolated for the first time in 1999) and it became a more prevalent strain (21.2%) in 2005. CONCLUSIONS: The results of this study are of importance to the decision makers in the evaluation of rotavirus vaccines in China.

[Study on clinical isolates of human cytomegalovirus found in Urumqi by restriction fragment length polymorphism of PCR products].

BACKGROUND: The study was designed to investigate the status of molecular epidemiology of HCMV in Urumqi through genetic comparison of clinical isolates. METHODS: DNA sequences of 2.0-2.6 kb were amplified by polymerase chain reaction from three relatively conservative gene regions (DNA polymerase, glycoproteins H, and major immediate-early antigen) of 28 clinical HCMV strains and then were analysed by restriction enzymes. RESULTS: The restriction patterns of the clinical isolates which did not have relation in epidemiology were greatly different, but the patterns of the clinical isolates related in epidemiology such as strains paired in mother and infant were quite similar. Of eight mother and infant pairs, from whom HCMV were isolated, four pairs showed identity of restriction profiles within each pair for all three amplified regions, four pairs showed differences between mother and infant. CONCLUSION: These results confirm the high degree of genetic variability among cytomegalovirus strains in Urumqi. Analysis of PCR-RFLP can indicate transmission of HCMV infection and facilitate its molecular epidemiologic studies.