[Study on the molecular epidemiological characteristics of norovirus in acute gastroenteritis of Beijing].

OBJECTIVE: To study the prevalence, genotypes and molecular characteristics of norovirus (NoV) in acute gastroenteritis. METHODS: RT-PCR was used to determine the molecular epidemiology of NoV. RESULTS: Out of 685 samples, 66 positive specimens were identified and the prevalence was 9.6% (66/685), 9.9% in males and 9.4% in females, respectively, with no significant difference. The prevalence rates showed no differences between age groups or between inpatients and outpatients. NoV gastroenteritis did not present any seasonal distribution. 43 out of the 66 specimens were classified, with 10 (22.7%) belonged to GI including 2 GI.3, 1 GI.4, 4 GI.5 and 3 GI.7. Other 33 (77.3%) belonged to GII genogroup, including GII.4 accounted for 60.6% (20/33) and followed by 7 GII.12, 2 GII.6, 1 GII.2, 1 GII.3, 1 GII.5. Six specimens mixed with GI and GII and 3 specimens were classified as GI.3/GII.7, GI.5/GII.5 and GI.4/GII.4. CONCLUSION: The main symptoms of acute gastroenteritis were abdominal pain, nausea, vomit and fever. There were many genotypes identified in our study and the main genotypes were GII.4/2006a and 2006b. GI and GII could be coinfected with each other.

Consistency of the key genotypes of Orientia tsutsugamushi in scrub typhus patients, rodents, and chiggers from a new endemic focus of northern China.

Scrub typhus is one of the most common infectious diseases of rural south and southeastern Asia and the western Pacific. It emerged in Shandong Province in northern China from autumn to winter of 1986. Since then, the "autumn-winter type scrub typhus" has been found in many areas of northern China. However, the principle genotypes of Orientia tsutsugamushi still remain unknown. This study was undertaken to identify the genotypes of O. tsutsugamushi obtained from scrub typhus patients, chigger mites and rodents from the focal point of the problem in Shandong Province. Forty-four isolates from patients, rodents, and chiggers, 47 blood clots from patients during the acute phase, 10 eschars from patients during the convalescence phase and 16 pools of larval chiggers were tested for the scrub typhus antigen 56-kD protein (Sta56) gene by nested PCR methodology and additional sequence analysis including DNA sequence alignment and phylogenetic analysis. Based on nested PCR, ninety-five initial PCR-positive samples produced amplicons using Kawasaki strain-specific primers, while the other two (the FXS4 and LHGM2 strains) produced amplicons using Karp strain-specific primers. The partial Sta56 gene sequence analysis indicated that the sequence homologies of 3 selected isolates (the B16, FXS2, and XDM2 strains) and 7 eschars out of the 95 samples, which were nested PCR-positive using Kawasaki strain-specific primers, were 94-98% to that of Kawasaki strain. The sequence homology of the FXS4 and LHGM2 strains to that of the Karp strain was respectively 83 and 96%. These findings implied that the key genotypes of O. tsutsugamushi in patients, rodents, and chiggers in Shandong Province were identical and similar to Kawasaki strains.

Perinatal outcomes and congenital abnormalities in the newborns of women affected by the 2009 pandemic influenza A (H1N1) in Beijing, China.

OBJECTIVE: To investigate the pregnancy complications, perinatal outcomes, and congenital abnormalities (CAs) that occurred in Beijing, China, when pregnant women became infected with the 2009 pandemic influenza A (H1N1) (H1N1 pdm). METHODS: Pregnancy complications, perinatal outcomes, and CAs were compared among 3 groups of pregnant women. The 23 women in group 1 were confirmed to harbor viral RNA; the 23 in group 2 had serum levels of virus-specific antibodies against H1N1 pdm, meaning that they were suspected of being infected with the virus; and the 93 in group 3 had no detectable virus-specific antibodies. RESULTS: Perinatal outcomes and pregnancy complications were not significantly different in groups 1 and 3. Higher percentages of stillbirths (12.0%) and placental disorders (13.0%) were observed in group 2 than in group 3. Many women in group 2 (62.5%) experienced symptoms of having a cold during pregnancy and most took no medication. Two cases of CA occurred in group 1, in the offspring of women infected in the second trimester. CONCLUSION: When left untreated, infection with the 2009 H1N1 pdm virus during pregnancy appears to have increased fetal mortality and morbidity. Because CAs are traumatic for all concerned, their possible association with the virus should be further evaluated.