Environmental surveillance reveals co-circulation of distinctive lineages of enteroviruses in southwest China's border cities, 2020-2022.

Aims: Enteroviruses are significant human pathogens associated with a range of mild to severe diseases. This study aims to understand the diversity and genetic characterization of enteroviruses circulated in southwest China's border cities by using environmental surveillance.

Methods And Results: A total of 96 sewage samples were collected in three border cities and a port located in Yunnan Province, China from July 2020 to June 2022.

Demographic transition and the dynamics of measles in six provinces in China: A modeling study.

Background: Industrialization and demographic transition generate nonstationary dynamics in human populations that can affect the transmission and persistence of infectious diseases. Decades of increasing vaccination and development have led to dramatic declines in the global burden of measles, but the virus remains persistent in much of the world. Here we show that a combination of demographic transition, as a result of declining birth rates, and reduced measles prevalence, due to improved vaccination, has shifted the age distribution of susceptibility to measles throughout China.

Complete Genome Analysis of an Enterovirus EV-B83 Isolated in China.

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.

[Complete Genome Characterization of Vaccine-derived Polioviruses Isolated in Yunnan,China].

To explore the genomic characterization of 4vaccine-derived poliovirus(VDPV)strains isolated from 2acute flaccid paralysis(AFP)cases in Yunnan Province in 2010 and 2012,respectively,the complete genome sequences of the 4strains were determined. Sequence analysis revealed that the complete genome length of the type Ⅱ and type Ⅰ VDPV was 7439nt and 7441 nt, respectively. Nucleotide and amino acid sequence similarities of type II VDPV were 95.

Effectiveness of prevention of mother-to-child transmission practice in three provinces of Southern China.

Vaccination in prevention mother-to-child transmission (PMTCT) of hepatitis B has been recommended since plasma-derived hepatitis B vaccines became available in China in 1986; however, less study evaluated practice effectiveness of PMTCT systematically. We conducted a prospective survey to evaluate the effectiveness of PMTCT practices in 3 provinces of southern China. We selected prefectures with low timely birth dose coverage in Yunnan, Guangxi, and Hunan provinces.

Cross-border collaboration between China and Myanmar for emergency response to imported vaccine derived poliovirus case.

Background: This report describes emergency response following an imported vaccine derived poliovirus (VDPV) case from Myanmar to Yunnan Province, China and the cross-border collaboration between China and Myanmar. Immediately after confirmation of the VDPV case, China disseminated related information to Myanmar with the assistance of the World Health Organization.

Methods: A series of epidemiological investigations were conducted, both in China and Myanmar, including retrospective searches of acute flaccid paralysis (AFP) cases, oral poliovirus vaccine (OPV) coverage assessment, and investigation of contacts and healthy children.

Molecular epidemiology and recombination of human enteroviruses from AFP surveillance in Yunnan, China from 2006 to 2010.

The study represents the genetic overview of non-polio enteroviruses (NPEV) isolated from acute flaccid paralysis (AFP) cases in Yunnan Province from 2006 to 2010. Molecular typing based on VP1 nucleotide sequence was carried out on 98 NPEV isolates, and 33 serotypes were identified. EV-B was detected most frequently with an overall prevalence of 71.

Risk factors associated with immunoprophylaxis failure against mother to child transmission of hepatitis B virus and hepatitis B vaccination status in Yunnan province, China.

Objective: To explore the risk factors associated with immunoprophylaxis failure against mother to child transmission of hepatitis B virus (HBV) and hepatitis B vaccination status in Yunnan province, China.

Methods: Multicenter cluster sampling was used to select pregnant women who were positive for hepatitis B surface antigen (HBsAg). HBV immunoprophylaxis was carried out for the newborns.

[Molecular epidemiological analysis of ECHO7 virus isolated from sewage water in Yunnan Province, China].

To investigate the epidemic and evolutionary trends of enterovirus (EV) in the external environment of Yunnan Province, China, molecular typing was performed on 4 EV strains that were isolated from environmental sewage in Yunnan. The VP1 region of isolates was amplified by RT-PCR using universal enterovirus primers, and the amplified VP1 region was sequenced for GenBank BLAST search and genotype analysis. The 4 EV strains were identified as ECHO7.

[Evaluation on the efficacy of prevention programs and relevant factors targeting mother-to-infant transmission on hepatitis B virus in Yunnan province].

Objective: To explore the efficacy of prevention programs and relevant factors targeting mother-to-infant transmission of HBV in Yunnan province.

Methods: In Yunnan province, we selected HBsAg positive pregnant women that delivered in hospital from January 1st through June 30th, 2011. Newborns of these pregnant women were under PMTCT (prevention of mother to child treatment) program and followed.

Complete genome characterization of a novel enterovirus type EV-B106 isolated in China, 2012.

Human enterovirus B106 (EV-B106) is a recently identified member of enterovirus species B. In this study, we report the complete genomic characterization of an EV-B106 strain (148/YN/CHN/12) isolated from an acute flaccid paralysis patient in Yunnan Province, China. The new strain had 79.

Epidemiologic and genetic characteristics of mumps viruses isolated in China from 1995 to 2010.

The epidemiologic and genetic characteristics of mumps viruses detected in China from 1995 to 2010 were analyzed in this study. Mumps remains endemic in China with a high overall incidence rate. The incidence of mumps in Western China was higher than that in other regions of the country.

Seroprevalence of antipolio antibodies among children <15 years of age in border provinces in China.

Despite remarkable progression toward polio eradication worldwide, wild poliovirus (WPV) importation has been a great challenge for China, as it shares borders with countries where WPV is endemic. The objective of this study was to estimate poliovirus antibody seroprevalence among children <15 years of age in 3 border provinces (Yunnan Province, Tibet Autonomous Region, and Xinjiang Uygur Autonomous Region) in China. A cross-sectional, hospital-based study was undertaken in 3 border provinces in 2010.

Single endemic genotype of measles virus continuously circulating in China for at least 16 years.

The incidence of measles in China from 1991 to 2008 was reviewed, and the nucleotide sequences from 1507 measles viruses (MeV) isolated during 1993 to 2008 were phylogenetically analyzed. The results showed that measles epidemics peaked approximately every 3 to 5 years with the range of measles cases detected between 56,850 and 140,048 per year. The Chinese MeV strains represented three genotypes; 1501 H1, 1 H2 and 5 A.

[Molecular typing of enteroviruses from healthy children in the border areas of Yunnan Province and Myanmar and the genetic characteristics of ECHO7 and ECHO13 in 2009].

To explore the enteroviruses surveillance among healthy children under 15 years old in the border areas of Yunnan Province and Myanmar in 2009. The stool samples were collected from the healthy children under 15 years old who came from the border areas of Myanmar and Yunnan Province, virus isolation and sequencing were conducted for all the 271 samples. 6 strains of polioviruses (PVs) were detected from 271 stools with an isolation rate of 2.

[Distribution of hepatitis B virus genotypes and serotypes in people who had a physical examination in Yunnan Province].

Objective: To know genotypes and serotypes of hepatitis B virus (HBV) detected from hepatitis B infected people in Yunnan Province.

Methods: Serum samples were collected from HBsAg carriers detected from people who had a physical examination at Yunnan Provincial Center for Disease Control and Prevention. The S genes of HBV were amplified by nested PCR and the PCR products were sequenced.

[Molecular identification of hepatitis B virus genotype I in Yunnan Province, the People's Republic of China].

Molecular typing was conducted according to the reported method for one HBsAg positive carrier who had a physical examination in Yunnan Province. The S gene of this HBV sample was amplified by nested PCR and the PCR products were directly sequenced. Blast searching was done on the Genbank database and the sequence were compared with the HBV reference sequences in database.

[Status of enterovirus infection and molecular identification among healthy children at the areas bordering Myanmar, in Yunnan province, China].

Objective: To explore the enterovirus infection status among healthy children under 15 years old in the border areas of Yunnan province that connecting Myanmar.

Methods: A total of 319 stool samples were collected from healthy children in the 10 entrance ports. Enterovirus was isolated from these stool samples and then poliovirus and adenovirus were serotyped by neutralization test using specific anti-sera.

Type 2 vaccine-derived poliovirus from patients with acute flaccid paralysis in china: current immunization strategy effectively prevented its sustained transmission.

In China, 5 patients with acute flaccid paralysis (AFP) associated with type 2 vaccine-derived poliovirus (VDPV) were identified by an AFP surveillance system from 1996 through 2009. A maximum-likelihood tree shows that all 5 Chinese VDPVs were independent. These 5 VDPVs were 100-216 d old according to the number of synonymous substitutions per synonymous site and 176-292 d old according to the number of substitutions per site.

New measles virus genotype associated with outbreak, China.

To determine the origin of the virus associated with a measles outbreak in Menglian County, Yunnan Province, People's Republic of China, in 2009, we conducted genetic analyses. Phylogenetic analyses based on nucleoprotein (N) and hemagglutinin (H) gene sequences showed that these Menglian viruses were not closely related to sequences of any World Health Organization (WHO) reference strains representing the 23 currently recognized genotypes. The minimum nucleotide divergence between the Menglian viruses and the most closely related reference strain, genotype D7, was 3.