Seasonal and Genetic Characteristics of Human Metapneumovirus Circulating - Henan Province, China, 2017-2023.

Introduction: This study examines the seasonal and genetic characteristics of human metapneumovirus (HMPV) in Henan from 2017 to 2023. Methods: Samples from patients with acute respiratory infection (ARI) testing positive for HMPV were subjected to real-time reverse transcription polymerase chain reaction The G gene was amplified and sequenced from these samples for epidemiological and phylogenetic analysis. Results: We enrolled 2,707 ARI patients from October 2017 to March 2023, finding an HMPV positivity rate of 6.17% (167/2,707). Children under five exhibited the highest infection rate at 7.78% (138/1,774). The 2018 and 2019 HMPV outbreaks predominantly occurred in spring (March to May), with peak positivity rates of 31.11% in May 2018 and 19.57% in May 2019. A notable increase occurred in November 2020, when positivity reached a historic high of 42.11%, continuing until January 2021. From February 2021 through March 2023, no significant seasonal peaks were observed, with rates ranging from 0% to 8.70%. Out of 81 G gene sequences analyzed, 46.91% (38/81) were identified as subtype A (A2c: 45.67%, 37/81; A2b: 1.23%, 1/81) and 53.09% (43/81) as subtype B (B1: 9.88%, 8/81; B2: 43.21%, 35/81). Notably, an AAABBA switch pattern was observed in HMPV subtypes. The dominant strains were A2c111nt-dup in subtype A and B2 in subtype B. Conclusions: Six years of surveillance in Henan Province has detailed the seasonal and genetic dynamics of HMPV, contributing valuable insights for the control and prevention of HMPV infections in China. These findings support the development of targeted HMPV vaccines and immunization strategies.

Epidemiological Characteristics of Human Parainfluenza Viruses Infections - China, 2019-2023.

Introduction: A retrospective study based on sentinel surveillance was conducted in 10 provincial-level administrative divisions (PLADs) in China to enhance the understanding of the epidemiological characteristics of human parainfluenza viruses (HPIVs). Methods: From January 2019 to June 2023, respiratory specimens were collected from individuals with acute respiratory infections (ARIs) and screened for four HPIVs serotypes and other common respiratory viruses using multiplex real-time polymerase chain reaction (PCR). This study analyzed the association of HPIVs infections with seasonal patterns, geographical distribution, demographic profiles, clinical features, and co-infection status. Results: During the study period, a total of 12,866 ARIs were included. The overall detection rate of HPIVs was 6.15%, varying from 5.04% in 2022 to 9.70% in 2020. The median age of HPIVs-infected patients was 3 years. HPIV2 was more prevalent among individuals aged 5-17 years (42.57%), while HPIV4 was more common in those over 65 years (12.24%). HPIV3 (54.16%) and HPIV1 (27.18%) were the predominant serotypes, and their prevalence exhibited significant seasonal fluctuations post- coronavirus disease 2019 (COVID-19) pandemic. The peak of HPIV3 shifted three months later in 2020 compared to 2019 and returned to a summer peak thereafter. Two peaks of HPIV1 were observed in 2021 following the peak of HPIV3. Additionally, co-infections were frequent in HPIVs cases (overall rate: 22.12%), with human rhinovirus being the most common co-infecting virus. Conclusions: The prevalence of HPIVs in China was predominantly due to HPIV3 and HPIV1, and their seasonal patterns were altered by pandemic restrictions. Hence, continuous surveillance of HPIVs is essential.

Prevalence and genetic diversity of human rhinovirus among patients with acute respiratory infections in China, 2012-2021.

To understand the prevalence of rhinovirus (RV) among acute respiratory infection (ARI) patients, 10-year ARI surveillance in multiple provinces of China were conducted during 2012-2021. Of 15 645 ARI patients, 1180 (7.54%) were confirmed to have RV infection and 820 (69.49%) were children under 5 years of age. RV typing was performed on the 527 VP1 gene sequences, and species A, B, and C accounted for 73.24%, 4.93%, and 21.82%, respectively. Although no significant difference in the proportions of age groups or disease severity was found between RV species, RV-C was more frequently detected in children under 5 years of age, RV-A was more frequently detected in elderly individuals (≥60), and the proportions of pneumonia in RV-A and RV-C patients were higher than those in RV-B patients. The epidemic peak of RV-A was earlier than that of RV-C. A total of 57 types of RV-A, 13 types of RV-B, and 35 types of RV-C were identified in RV-infected patients, and two uncertain RV types were also detected. The findings showed a few differences in epidemiological and clinical features between RV species in ARI patients, and RV-A and RV-C were more prevalent than RV-B.

Genetic characterization of pediatric SARI-associated human adenoviruses in eight Chinese provinces during 2017-2021.

Human adenovirus (HAdV) is a significant viral pathogen causing severe acute respiratory infections (SARIs) in children. To improve the understanding of type distribution and viral genetic characterization of HAdV in severe cases, this study enrolled 3404 pediatric SARI cases from eight provinces of China spanning 2017-2021, resulting in the acquisition of 112 HAdV strains. HAdV-type identification, based on three target genes (penton base, hexon, and fiber), confirmed the diversity of HAdV types in SARI cases. Twelve types were identified, including species B (HAdV-3, 7, 55), species C (HAdV-1, 2, 6, 89, 108, P89H5F5, Px1/Ps3H1F1, Px1/Ps3H5F5), and E (HAdV-4). Among these, HAdV-3 exhibited the highest detection rate (44.6%), followed by HAdV-7 (19.6%), HAdV-1 (12.5%), and HAdV-108 (9.8%). All HAdV-3, 7, 55, 4 in this study belonged to dominant lineages circulating worldwide, and the sequences of the three genes demonstrated significant conservation and stability. Concerning HAdV-C, excluding the novel type Px1/Ps3H1F1 found in this study, the other seven types were detected both in China and abroad, with HAdV-1 and HAdV-108 considered the two main types of HAdV-C prevalent in China. Two recombinant strains, including P89H5F5 and Px1/Ps3H1F1, could cause SARI as a single pathogen, warranting close monitoring and investigation for potential public health implications. In conclusion, 5 years of SARI surveillance in China provided crucial insights into HAdV-associated respiratory infections among hospitalized pediatric patients.

NCPAD2 is a favorable predictor of prognostic and immunotherapeutic biomarker for multiple cancer types including lung cancer.

BACKGROUND: Non-SMC condensin I complex subunit D2 (NCAPD2) belongs to the chromosomal structural maintenance family. While the different contribution of NCAPD2 to chromosome in mitosis have been thoroughly investigated, much less is known about the expression of NCAPD2 in pan-cancer. Thus, we used a bioinformatics dataset to conduct a pan-cancer analysis of NCAPD2 to determine its regulatory role in tumors. METHODS: Multiple online databases were analyzed NCAPD2 gene expression, protein level, patient survival and functional enrichment in pan-cancer. Genetic alteration and tumor stemness of NCAPD2 were analyzed using cBioPortal and SangerBox. The GSCA and CellMiner were used to explore the relationship between NCAPD2 and drug sensitivity. The diagnostic value of prognosis was evaluated by ROC curve. Subsequently, the immune infiltration level and immune subtype of NCAPD2 in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) were analyzed using TIMER1 and TISIDB. RESULTS: NCAPD2 gene expression was significantly higher in most cancers and associated with clinical stage and poor prognosis. Genomic heterogeneity of NCAPD2 promoted the occurrence and development of tumors. GO enrichment analysis suggested NCAPD2 might be involved in DNA repair and immune response. NCAPD2 was involved in immune infiltration of LUAD and LUSC. ROC curves showed that NCAPD2 has important prognosis diagnostic value in LUAD and LUSC. Moreover, NCAPD2 was drug sensitive to topotecan, which may be an optimize immunotherapy. CONCLUSIONS: It was found that NCAPD2 was overexpressed in pan-cancers, which was associated with poor outcomes. Importantly, NCAPD2 could be a diagnostic marker and an immune related biomarker for LUAD and LUSC.

The epidemiological and genetic characteristics of human parvovirus B19 in patients with febrile rash illnesses in China.

To understand the epidemiological and genetic characteristics of B19V, a multiple-province surveillance of patients with febrile rash illnesses (FRIs) were conducted in China during 2009 ~ 2021. The clinical specimens of 3,820 FRI patients were collected and tested for B19V DNA. A total of 99 (2.59%) patients were positive for B19V, and 49 (49.49%) were children under 5 years old. B19V infections occurred throughout the year without obvious seasonal pattern. Ten NS1-VP1u sequences and seven genome sequences were obtained in this study, identified as subgenotype 1a. Combined with the globally representative genome sequences, no temporal and geographic clustering trends of B19V were observed, and there was no significant correlation between B19V sequences and clinical manifestations. The evolutionary rate of the B19V genome was 2.30 × 10-4 substitutions/site/year. The number of negative selection sites was higher than that of positive selection sites. It was the first to comprehensively describe the prevalence patterns and evolutionary characteristics of B19V in FRI patients in China. B19V played the role in FRI patients. Children under 5 years old were the main population of B19V infection. Subgenotype 1a was prevalent in FRI patients in China. B19V showed a high mutation rate, while negative selection acted on the genome.

Genomic Surveillance for SARS-CoV-2 - China, September 26, 2022 to January 29, 2023.

Introduction: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has generated 2,431 variants over the course of its global transmission over the past 3 years. To better evaluate the genomic variation of SARS-CoV-2 before and after the optimization of coronavirus disease 2019 (COVID-19) prevention and control strategies, we analyzed the genetic evolution branch composition and genomic variation of SARS-CoV-2 in both domestic and imported cases in China (the data from Hong Kong and Macau Special Administrative Regions and Taiwan, China were not included) from September 26, 2022 to January 29, 2023. Methods: Analysis of the number of genome sequences, sampling time, dynamic changes of evolutionary branches, origin, and clinical typing of SARS-CoV-2 variants submitted by 31 provincial-level administrative divisions (PLADs) and Xinjiang Production and Construction Corps (XPCC) was conducted to assess the accuracy and timeliness of SARS-CoV-2 variant surveillance. Results: From September 26, 2022 to January 29, 2023, 20,013 valid genome sequences of domestic cases were reported in China, with 72 evolutionary branches. Additionally, 1,978 valid genome sequences of imported cases were reported, with 169 evolutionary branches. The prevalence of the Omicron variants of SARS-CoV-2 in both domestic and imported cases was consistent with that of international epidemic variants. Conclusions: This study provides an overview of the prevalence of Omicron variants of SARS-CoV-2 in China. After optimizing COVID-19 prevention and control strategies, no novel Omicron variants of SARS-CoV-2 with altered biological characteristics or public health significance have been identified since December 1, 2022.

Circulation pattern and genetic variation of human respiratory syncytial virus in China during 2008-2021.

To better understand the circulation pattern and genetic characterization of human respiratory syncytial virus (HRSV) in China during 2008-2021, a total of 3967 HVR2 sequences were obtained from 20 provinces in China for phylogenetic analysis and sequence variation analysis. The results showed that the HRSV subtype presented the prevalence pattern of "ABBAABAABAAABB." Further genotyping identified seven genotypes for HRSVA and nine genotypes for HRSVB. Multiple genotypes of HRSV were cocirculating during 2008-2015, while ON1 and BA9 became the only predominant genotypes for HRSVA and HRSVB, respectively, since 2015. A genotype switch from NA1 to ON1 for HRSVA occurred in approximately 2014, while genotype BA9 of HRSVB had been the predominant genotype for at least 14 years. ON1 strains could be divided into four lineages with no temporal or geographical distribution tendency. In contrast, BA9 strains could be divided into three lineages with noticeable temporal clustering. Sequence variation analysis showed that two ON1 sequences in 2017 had 10 nucleotide deletion and compensatory extension at the C-terminal; 15 BA9 sequences during 2019-2021 had novel insertions between K225 and E226, along with 6 identical amino acid variant sites. This study further enriched the genetic data of HRSV circulating in China and provided an important basis for the development of HRSV vaccines and drugs as well as the formulation of prevention and control strategies.

Transmission Pattern of Measles Virus Circulating in China During 1993-2021: Genotyping Evidence Supports That China Is Approaching Measles Elimination.

BACKGROUND: To provide useful insights into measles elimination progress in China, measles surveillance data were reviewed, and the transmission patterns of measles viruses circulating in China during 1993-2021 were analyzed. METHODS: Measles incidence data from the National Notifiable Disease Reporting System of the China Center for Disease Control and Prevention were analyzed. A total of 17 570 strains were obtained from 30 of 31 provinces in mainland China during 1993-2021. The recommended genotyping window was amplified. Genotyping analysis was conducted for comparison with the reference strains. Phylogenetic analyses were performed to identify genetic relationships among different lineages within the genotypes. RESULTS: With high coverage of routine immunization and intensive supplementary immunization activities, measles incidence has shown a downward trend since 1993, despite 2 resurgences, reaching a historic low level in 2020-2021 (average 0.5 per million). During 1993-2021, 9 genotypes including domestic genotype H1; imported genotypes B3, D4, D8, D9, D11, G3, and H2; and vaccine-associated genotype A were identified. Among them, the genotype H1 strain circulated endemically in China for more than 25 years; the last strain was detected in Yunnan Province in September 2019. Multiple imported genotypes have been identified since 2009 showing different transmission patterns. Since April 2020, no imported strains have been detected, while vaccine-associated genotype A continues to be detected. CONCLUSIONS: The evidence of low incidence during 2020-2021 and virological surveillance data in this study confirm that China is currently approaching measles elimination.

Importation and circulation of rubella virus lineages 1E-L2 and 2B-L2c between 2018 and 2021 in China: Virus evolution and spatial-temporal transmission characteristics.

To better understand the importation and circulation patterns of rubella virus lineages 1E-L2 and 2B-L2c circulating in China since 2018, 3,312 viral strains collected from 27 out of 31 provinces in China between 2018 and 2021 were sequenced and analyzed with the representative international strains of lineages 1E-L2 and 2B-L2c based on genotyping region. Time-scale phylogenetic analysis revealed that the global lineages 1E-L2 and 2B-L2c presented distinct evolutionary patterns. Lineage 1E-L2 circulated in relatively limited geographical areas (mainly Asia) and showed geographical and temporal clustering, while lineage 2B-L2c strains circulated widely throughout the world and exhibited a complicated topology with several independently evolved branches. Furthermore, both lineages showed extensive international transmission activities, and phylogeographic inference provided evidence that lineage 1E-L2 strains circulating in China possibly originated from Japan, while the source of lineage 2B-L2c isolated since 2018 is still unclear. After importation into China in 2018, the spread of lineage 1E-L2 presented a three-stage transmission pattern from southern to northern China, whereas lineage 2B-L2c spread from a single point in western China to all the other four regions. These two transmission patterns allowed both imported lineages to spread rapidly across China during the 2018-9 rubella epidemic and eventually established endemic circulations. This study provides critical scientific data for rubella control and elimination in China and worldwide.

Comparative analysis of the clinical and epidemiological characteristics of human influenza virus versus human respiratory syncytial virus versus human metapneumovirus infection in nine provinces of China during 2009-2021.

A comparative analysis of confirmed cases of human influenza virus (HIFV), human respiratory syncytial virus (HRSV), and human metapneumovirus (HMPV) was conducted to describe their clinical and epidemiological characteristics. During 2009-2021, active surveillance of acute respiratory infections (ARIs) was performed in nine provinces of China. Clinical and epidemiological information and laboratory testing results of HIFV, HRSV, and HMPV were analyzed. Among 11591 ARI patients, the single-infection rates of HIFV, HRSV, and HMPV were 15.00%, 9.59%, and 2.24%, respectively; the coinfection rate of these three viruses was 0.64%. HIFV infection was mainly in adults aged 15-59 years, accounting for 39.10%. HRSV and HMPV infections were mainly in children under 5 years old, accounting for 87.13% and 83.46%, respectively. Patients with HRSV infection were younger than HMPV. HRSV and HMPV had high similarities in clinical manifestations, presenting with lower respiratory symptoms. HIFV mainly presented with an upper respiratory infection. The epidemic peak of HRSV was earlier than that of HIFV, and that of HMPV was later than those of HRSV and HFIV. A total of 85.14% of coinfection cases were children under 5 years old. Coinfection might increase the risk of pneumonia in HIFV cases. During 2020-2021, the positive rates and seasonal patterns of these three viruses changed due to the impact of the COVID-19 pandemic. Certain clinical and epidemiological features were observed in HIFV, HRSV, and HMPV infections, which could be beneficial for guiding clinical diagnosis, treatment, and prevention of these three viruses in China.

Etiological and epidemiological features of acute meningitis or encephalitis in China: a nationwide active surveillance study.

BACKGROUND: Acute meningitis or encephalitis (AME) results from a neurological infection causing high case fatality and severe sequelae. AME lacked comprehensive surveillance in China. METHODS: Nation-wide surveillance of all-age patients with AME syndromes was conducted in 144 sentinel hospitals of 29 provinces in China. Eleven AME-causative viral and bacterial pathogens were tested with multiple diagnostic methods. FINDINGS: Between 2009 and 2018, 20,454 AME patients were recruited for tests. Based on 9,079 patients with all-four-virus tested, 28.43% (95% CI: 27.50%‒29.36%) of them had at least one virus-positive detection. Enterovirus was the most frequently determined virus in children <18 years, herpes simplex virus and Japanese encephalitis virus were the most frequently determined in 18-59 and ≥60 years age groups, respectively. Based on 6,802 patients with all-seven-bacteria tested, 4.43% (95% CI: 3.94%‒4.91%) had at least one bacteria-positive detection, Streptococcus pneumoniae and Neisseria meningitidis were the leading bacterium in children aged <5 years and 5-17 years, respectively. Staphylococcus aureus was the most frequently detected in adults aged 18-59 and ≥60 years. The pathogen spectrum also differed statistically significantly between northern and southern China. Joinpoint analysis revealed age-specific positive rates, with enterovirus, herpes simplex virus and mumps virus peaking at 3-6 years old, while Japanese encephalitis virus peaked in the ≥60 years old. As age increased, the positive rate for Streptococcus pneumoniae and Escherichia coli statistically significantly decreased, while for Staphylococcus aureus and Streptococcus suis it increased. INTERPRETATION: The current findings allow enhanced identification of the predominant AME-related pathogen candidates for diagnosis in clinical practice and more targeted application of prevention and control measures in China, and a possible reassessment of vaccination strategy. FUNDING: China Mega-Project on Infectious Disease Prevention and the National Natural Science Funds.

Molecular evolution and genomic characteristics of genotype H1 of measles virus.

Measles is one of the most infectious diseases of humans. It is caused by the measles virus (MeV) and can lead to serious illness, lifelong complications, and even death. Whole-genome sequencing (WGS) is now available to study molecular epidemiology and identify MeV transmission pathways. In the present study, WGS of 23 MeV strains of genotype H1, collected in Mainland China between 2006 and 2018, were generated and compared to 31 WGSs from the public domain to analyze genomic characteristics, evolutionary rates and date of emergence of H1 genotype. The noncoding region between M and F protein genes (M/F NCR) was the most variable region throughout the genome. Although the nucleotide substitution rate of H1 WGS was around 0.75 × 10-3 substitution per site per year, the M/F NCR had an evolutionary rate three times higher, with 2.44 × 10-3 substitution per site per year. Phylogenetic analysis identified three distinct genetic groups. The Time of the Most Recent Common Ancestor (TMRCA) of H1 genotype was estimated at approximately 1988, while the first genetic group appeared around 1995 followed by two other genetic groups in 1999-2002. Bayesian skyline plot showed that the genetic diversity of the H1 genotype remained stable even though the number of MeV cases decreased 50 times between 2014 (52 628) and 2020 (993). The current coronavirus disease 2019 (COVID-19) pandemic might have some effect on the measles epidemic and further studies will be necessary to assess the genetic diversity of the H1 genotype in a post-COVID area.

Etiological and epidemiological features of acute respiratory infections in China.

Nationwide prospective surveillance of all-age patients with acute respiratory infections was conducted in China between 2009‒2019. Here we report the etiological and epidemiological features of the 231,107 eligible patients enrolled in this analysis. Children <5 years old and school-age children have the highest viral positivity rate (46.9%) and bacterial positivity rate (30.9%). Influenza virus, respiratory syncytial virus and human rhinovirus are the three leading viral pathogens with proportions of 28.5%, 16.8% and 16.7%, and Streptococcus pneumoniae, Mycoplasma pneumoniae and Klebsiella pneumoniae are the three leading bacterial pathogens (29.9%, 18.6% and 15.8%). Negative interactions between viruses and positive interactions between viral and bacterial pathogens are common. A Join-Point analysis reveals the age-specific positivity rate and how this varied for individual pathogens. These data indicate that differential priorities for diagnosis, prevention and control should be highlighted in terms of acute respiratory tract infection patients' demography, geographic locations and season of illness in China.

Genetic analysis of human parainfluenza virus type 4 associated with severe acute respiratory infection in children in Luohe City, Henan Province, China, during 2017-2018.

During 2017-2018, nasopharyngeal aspirates (NPAs) from 627 hospitalized patients with severe acute respiratory infection at Luohe Center Hospital were tested by RT-PCR for human parainfluenza virus 4 (HPIV-4). Fourteen (2.2%) of the 627 samples were positive for HPIV-4. The complete HN gene was amplified from nine positive samples and sequenced. Sequence comparisons showed that the HPIV-4 strains circulating in the city of Luohe are closely related to HPIV-4A strains. Our study indicated that there were multiple lineages of HPIV-4 circulating in Henan Province in China during the study period. This will improve our understanding of the epidemiological and clinical characteristics of HPIV-4.

Transmission Dynamics of the Rubella Virus Circulating in China During 2010-2019: 2 Lineage Switches Between Genotypes 1E and 2B.

BACKGROUND: To provide a better understanding of the progress on rubella control and elimination in China, a genetic analysis was conducted to examine the transmission pattern of the endemic rubella virus in China during 2010-2019. METHODS: A total of 4895 strains were obtained from 29 of the 31 provinces in mainland China during 2010-2019. The genotyping regions of the strains were amplified, determined, and assembled. Genotyping analysis and lineage division were performed by comparisons with the World Health Organization reference strains and reported lineage reference strains, respectively. Further phylogenetic analyses were performed to compare the genetic relationship. RESULTS: During 2010-2019, the domestic lineage 1E-L1 and multiple imported lineages of rubella viruses including 2B-L1, 1E-L2, and 2B-L2c were identified. Further analysis of the circulation trend of the different lineages indicated that 2 switches occurred among the lineages. The first shift was from lineage 1E-L1 to 2B-L1, which occurred around 2015-2016, followed by the lowest rubella incidence in 2017. The second shift was from lineage 2B-L1 to 1E-L2 and 2B-L2c, which occurred around 2018-2019, coinciding with rubella resurgence and the subsequent nationwide epidemic during 2018-2019. Insufficient genomic information worldwide made it impossible to trace the origin of the imported viruses. CONCLUSIONS: China was moving toward rubella elimination, as evidenced by the fact that previous endemic lineages were not detected. However, rubella reemerged in 2018 2019 due to the newly imported rubella viruses. Therefore, to realize the rubella elimination goal, joint efforts are required for all countries worldwide.

Etiological, epidemiological, and clinical features of acute diarrhea in China.

National-based prospective surveillance of all-age patients with acute diarrhea was conducted in China between 2009‒2018. Here we report the etiological, epidemiological, and clinical features of the 152,792 eligible patients enrolled in this analysis. Rotavirus A and norovirus are the two leading viral pathogens detected in the patients, followed by adenovirus and astrovirus. Diarrheagenic Escherichia coli and nontyphoidal Salmonella are the two leading bacterial pathogens, followed by Shigella and Vibrio parahaemolyticus. Patients aged <5 years had higher overall positive rate of viral pathogens, while bacterial pathogens were more common in patients aged 18‒45 years. A joinpoint analysis revealed the age-specific positivity rate and how this varied for individual pathogens. Our findings fill crucial gaps of how the distributions of enteropathogens change across China in patients with diarrhea. This allows enhanced identification of the predominant diarrheal pathogen candidates for diagnosis in clinical practice and more targeted application of prevention and control measures.

Emerging Human Metapneumovirus Gene Duplication Variants in Patients with Severe Acute Respiratory Infection, China, 2017-2019.

We detected human metapneumovirus (HMPV) in 72 (7.1%) of 1,021 patients hospitalized with severe acute respiratory infection in Luohe, China, during 2017-2019. We detected HMPV most frequently in young children and less often in adults. HMPV genotype A2c variants 111 nt and 180 nt duplications predominated, demonstrating their continuing geographic spread.

Measles Vaccine-Associated Rash Illness in China: an Emerging Issue in the Process of Measles Elimination.

Along with the implementation of measles case-based surveillance, measles vaccine-associated rash illness (VARI) cases were detected in China. To better understand the characteristics of VARI, 101 VARI cases confirmed by measles virus genotyping in 2011 to 2018 were analyzed in this study. With the decrease in measles incidence, the detection rate of VARI cases increased among the cases confirmed by genotyping. Compared with genotype H1 wild-type measles, VARI occurred throughout the year, without obvious seasonal distribution. Infants and children of ages 8 to 23 months were the main population of VARI. VARI mainly occurred within 14 days after measles vaccination. The number of VARI cases peaked on the 8th day after measles vaccination, which was later than that of genotype H1 wild-type measles cases with a measles vaccination history. VARI presents clinical symptoms similar to those of measles. The frequencies of the "3Cs" (cough, coryza, and conjunctivitis), Koplik spots, and complications in VARI cases were significantly lower than those in wild-type measles cases. In total, 94.06% of sequences from VARI cases were identical to measles vaccine strain S191 in the C-terminal 450-nucleotide sequence of the nucleoprotein (N-450) gene. A few substitutions were found in N-450 sequences of the VARI cases. The confirmation of VARI has become an emerging issue in the process of measles elimination. Rapid confirmation of VARI is critical for measles surveillance and will help to determine the response measures for measles, especially in measles preelimination and elimination settings. The suspected measles cases with measles-containing vaccine (MCV) vaccination were recommended to be tested by the laboratory to identify wild-type measles or VARI.