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Objective: This study aimed to investigate HBsAg positive rates and risk factors of HBV infection among the children less than 15 years old in Yunnan province, a remote southwest part of mainland China. Methods: Multi-stage sampling was used to randomly select study subjects from 9,360,000 individuals. Hepatitis B vaccine inoculation rate and HBsAg positive rate were investigated, and then propensity score and generalized linear mixed model (GLMMs) were applied to the case-control study. Results: The average HBsAg positive rate was 1.81%, with 1.2% in urban areas and 2.4% in rural areas. Rate of first-dose-in-time in urban areas was 77.7%, obviously higher than 49.5% in rural areas (χ2 = 2811.71, P

The incidence of measles in Yunnan Province among vaccine target-age children has decreased markedly after attaining and sustaining high 2-dose coverage of measles containing vaccine (MCV) through routine immunization services and supplementary immunization activities (SIAs). Most cases of measles now occur among adults. In 2015, we investigated a measles outbreak among adults to determine transmission patterns and the potential role of nosocomial transmission.We enhanced measles surveillance using retrospective active case search. We conducted case investigations to determine sources of infection and routes of transmission; laboratory testing included serologic and molecular diagnostic methods.Twenty-two outbreak-associated cases of measles were identified; most (86.36%) were among individuals 20 to 39 years of age (range, 7 months to 43 years). We interviewed 19 individuals who had acquired measles. The first 3 cases were infected in Tibet; 12 (63%) were hospital-acquired infections; 2 (11%) were community-acquired; and 2 (11%) were family-contact cases. We conducted outbreak response immunization (ORI) that provided MCV without regard to vaccination status; 10,596 residents between 20 and 40 years of age were vaccinated. A serological survey conducted during the ORI showed that 84% of the 20-40 year-olds were immune to measles prior to vaccination. Post-vaccination serological testing showed 100% were immune.Despite high population immunity among children and adolescents, imported measles virus transmission occurred among adults in a provincial cross-border area. Nosocomial transmission and measles immunity gaps among adults poses a threat to measles elimination and highlights the strategy of targeting adults during ORI to outbreaks with adult-to-adult transmission.

Recently, we reported that the frequency of hepatitis C virus (HCV) genotypes and subtypes has rapidly changed among intravenous drug users (IDUs) in Yunnan Province over the last 5 years; this is especially true for subtype 6a which has increased in frequency from 5 to 15%. Here, we assessed 120 HCV-positive plasma samples from the general population (GP). HCV NS5B fragments were amplified and sequenced by PCR. We identified four HCV genotypes (1, 2, 3 and 6) and seven HCV subtypes (1b, 2a, 3a, 3b, 6a, 6n, and 6k) in this population. Genotype 3 was predominant, with a distribution frequency of 0.484, followed by genotype 1 (0.283), genotype 6 (0.133) and genotype 2 (0.100). HCV subtypes 3b (frequency 0.292) and 1b (frequency 0.283) were the most common subtypes. A comparison of the current data with previous results reported for IDUs showed that the distribution frequencies of genotypes 1, 2 and 6 were significantly different between patients in the GP and IDUs (P

Enterovirus B83 (EV-B83) is a recently identified member of enterovirus species B. It is a rarely reported serotype and up to date, only the complete genome sequence of the prototype strain from the United States is available. In this study, we describe the complete genomic characterization of an EV-B83 strain 246/YN/CHN/08HC isolated from a healthy child living in border region of Yunnan Province, China in 2008. Compared with the prototype strain, it had 79.6% similarity in the complete genome and 78.9% similarity in the VP1 coding region, reflecting the great genetic divergence among them. VP1-coding region alignment revealed it had 77.2–91.3% with other EV-B83 sequences available in GenBank. Similarity plot analysis revealed it had higher identity with several other EV-B serotypes than the EV-B83 prototype strain in the P2 and P3 coding region, suggesting multiple recombination events might have occurred. The great genetic divergence with previously isolated strains and the extremely rare isolation suggest this serotype has circulated at a low epidemic strength for many years. This is the first report of complete genome of EV-B83 in China.

SUMMARYEscherichia albertiiis a newly emerging enteric pathogen that has been associated with gastroenteritis in humans. Recently,E. albertiihas also been detected in healthy and sick birds, animals, chicken meat and water. In the present study, the prevalence and characteristics of theeae-positive, lactose non-fermentingE. albertiistrains in retail raw meat in China were evaluated. Thirty isolates of such strains ofE. albertiiwere identified from 446 (6·73%) samples, including duck intestines (21·43%, 6/28), duck meat (9·52%, 2/21), chicken intestines (8·99%, 17/189), chicken meat (5·66%, 3/53), mutton meat (4·55%, 1/22) and pork meat (2·44%, 1/41). None was isolated from 92 samples of raw beef meat. Strains were identified asE. albertiiby phenotypic properties, diagnostic PCR, sequence analysis of the 16S rRNA gene, and housekeeping genes. Five intimin subtypes were harboured by these strains. All strains possessed the II/III/V subtype group of thecdtBgene, with two strains carrying another copy of the I/IV subtype group. Pulsed-field gel electrophoresis showed high genetic diversity ofE. albertiiin raw meats. Our findings indicate thatE. albertiican contaminate various raw meats, posing a potential threat to public health.