Epidemiological trends and sociodemographic factors associated with acute hemorrhagic conjunctivitis in mainland China from 2004 to 2018.

BACKGROUND: Acute hemorrhagic conjunctivitis (AHC) is classified as a class C notifiable infectious disease in China and poses a great threat to public health. This study aimed to investigate the epidemiological trends and hotspots of AHC in mainland China. Sociodemographic factors that could contribute to early warning of AHC were further explored. METHODS: Yearly and monthly incidences of acute hemorrhagic conjunctivitis by date and region from 2004 to 2018 were extracted from the Data Center of China Public Health Science. Joinpoint regression and spatial autocorrelation analysis were performed to explore the epidemiological trends and hotspots of AHC. A generalized linear model was then applied to explore the relationship between sociodemographic factors and AHC incidence. RESULTS: The average annual AHC incidence was 3.58/100,000 in mainland China. The first-level spatial and temporal aggregation areas were distributed in Guangxi, Hainan, Guangdong, Guizhou, Hunan, Jiangxi, Fujian, Chongqing, Hubei, Anhui, and Zhejiang, with gathering times from 2010/1/1 to 2010/12/31 (RR = 20.13, LLR = 474,522.89, P < 0.01). After 2010, the AHC incidence was stable (APC = - 8.37, 95% CI: - 23.02-9.06). However, it was significantly increased in low- and middle-income provinces (AAPC = 10.65, 95% CI: 0.62-21.68, AAPC = 11.94, 95% CI: 0.62-24.53). The peak of AHC occurred during the August to October period. Children who age 0-3 years are identified as high-risk group with AHC incidence significantly increased (APC = 31.54, 95% CI: 0.27-72.56). Birth rate, population ages 0-14 (% of total population), passenger traffic, and urban population (% of total population) were positively associated with the AHC incidence, while per capita gross domestic product was negatively associated with the AHC incidence. CONCLUSION: Overall, the AHC incidence was stable after 2010 in China, but it was significantly increased in low- and middle-income provinces. Regions with a high birth rate, population ages 0-14 (% of the total population), passenger traffic, urban population (% of the total population) and low per capita gross domestic product are at high risk of incidences of AHC. In the future, public health policy and resource priority for AHC in regions with these characteristics are necessary.

Decreased incidence of acute hemorrhagic conjunctivitis associated with enhanced public health intervention during the COVID-19 epidemic in China, 2020.

Outbreaks of acute hemorrhagic conjunctivitis (AHC) are associated with a high disease burden. In this study, we investigated the association between enhanced public health intervention and the incidence of AHC during the COVID-19 pandemic in China. A total of 212,526 AHC cases were reported in China during 2015-2020. The overall yearly incidence rate and number of AHC cases decreased by 23.08% and 22.15%, respectively, during the COVID-19 epidemic, compared with the previous 5 years (all p < 0.001). Significant reductions in AHC incidence were found both during the emergency period and after the relaxation of emergency measures in 2020 compared to the previous 5 years (22.22% and 28.00% reduction, respectively; p < 0.001). Enhanced public health initiatives during the COVID-19 pandemic in China were therefore associated with lower transmission of pathogens causing AHC.

Long-term effects of weather condition and air pollution on acute hemorrhagic conjunctivitis in China: A nationalwide surveillance study in China.

BACKGROUND: Global climate change could have potential impact on enterovirus (EV)-induced infectious diseases. However, the environmental factors promoting acute hemorrhagic conjunctivitis (AHC) circulation remain inconclusive. This study aimed to quantify the relationship between the environment and AHC. METHODS: We retrieved the monthly counts and incidence of AHC, meteorological variables and air quality in mainland China between 2013 and 2018. Exposure risks were evaluated by multivariate distributed lag nonlinear models. RESULTS: A total of 219,599 AHC cases were reported in 31 provinces of China, predominantly in southern and central China, seasonally increased in summer. AHC incidence increased by 7% between 2013 and 2018, from 2.6873 to 2.7570 per 100,000 people. A moderate positive correlation was seen between AHC and monthly mean temperature, relative humidity (RH) and precipitation. Each unit increment was associated with a relative risk for AHC of 1.058 at 17°-32 °C at lag 0 months, 1.017 at 65-71% RH at lag 1.4 months, and 1.039 at 400-569 mm at lag 2.4 months. By contrast, a negative correlation was seen between monthly ambient NO2 and AHC. CONCLUSION: Long-term exposure to higher mean temperature, RH and precipitation were associated with an increased risk of AHC. The general public, especially susceptible populations, should pay close attention to weather changes and take protective measures in advance to any AHC outbreak as the above situations occur.

Role of enhanced receptor engagement in the evolution of a pandemic acute hemorrhagic conjunctivitis virus.

Acute hemorrhagic conjunctivitis (AHC) is a painful, contagious eye disease, with millions of cases in the last decades. Coxsackievirus A24 (CV-A24) was not originally associated with human disease, but in 1970 a pathogenic "variant" (CV-A24v) emerged, which is now the main cause of AHC. Initially, this variant circulated only in Southeast Asia, but it later spread worldwide, accounting for numerous AHC outbreaks and two pandemics. While both CV-A24 variant and nonvariant strains still circulate in humans, only variant strains cause AHC for reasons that are yet unknown. Since receptors are important determinants of viral tropism, we set out to map the CV-A24 receptor repertoire and establish whether changes in receptor preference have led to the increased pathogenicity and rapid spread of CV-A24v. Here, we identify ICAM-1 as an essential receptor for both AHC-causing and non-AHC strains. We provide a high-resolution cryo-EM structure of a virus-ICAM-1 complex, which revealed critical ICAM-1-binding residues. These data could help identify a possible conserved mode of receptor engagement among ICAM-1-binding enteroviruses and rhinoviruses. Moreover, we identify a single capsid substitution that has been adopted by all pandemic CV-A24v strains and we reveal that this adaptation enhances the capacity of CV-A24v to bind sialic acid. Our data elucidate the CV-A24v receptor repertoire and point to a role of enhanced receptor engagement in the adaptation to the eye, possibly enabling pandemic spread.

Complete genome sequence of a coxsackievirus type A24 variant causing an outbreak of acute haemorrhagic conjunctivitis in southeastern Mexico in 2017.

Cases of acute haemorrhagic conjunctivitis (AHC) caused by a coxsackie virus A24 variant (CV-A24v) in Mexico have been reported since 1987; however, no molecular data on the causative strains have been available. Here, we report the identification of the etiological agent responsible for the most recent AHC outbreak in southeastern Mexico (at the end of 2017) as well as the complete genome sequences of seven isolates, using next-generation sequencing (NGS). Phylogenomic analysis of the CV-A24v sequences reported here showed similarity to contemporary strains causing AHC outbreaks in French Guiana and Uganda, forming a novel clade related to genotype IV. Moreover, a specific mutational pattern in the non-structural proteins was identified in the 2017 isolates. This is the first report of genetic characterization of CV-A24v isolates obtained in Mexico.

Forecasting the incidence of acute haemorrhagic conjunctivitis in Chongqing: a time series analysis.

Acute haemorrhagic conjunctivitis is a highly contagious eye disease, the prediction of acute haemorrhagic conjunctivitis is very important to prevent and grasp its development trend. We use the exponential smoothing model and the seasonal autoregressive integrated moving average (SARIMA) model to analyse and predict. The monthly incidence data from 2004 to 2017 were used to fit two models, the actual incidence of acute haemorrhagic conjunctivitis in 2018 was used to validate the model. Finally, the prediction effect of exponential smoothing is best, the mean square error and the mean absolute percentage error were 0.0152 and 0.1871, respectively. In addition, the incidence of acute haemorrhagic conjunctivitis in Chongqing had a seasonal trend characteristic, with the peak period from June to September each year.

Re-emergence of a coxsackievirus A24 variant causing acute hemorrhagic conjunctivitis in Brazil from 2017 to 2018.

A large outbreak (over 200,000 cases) of acute hemorrhagic conjunctivitis (AHC) took place in Brazil during the summer of 2017/2018, seven years after a nationwide epidemic, which occurred in 2011. To identify the etiological agent, 80 conjunctival swabs from patients with a clinical presentation suggestive of AHC were analyzed at the national enterovirus laboratory. Real-time RT-PCR for human enteroviruses was performed, and enterovirus RNA was detected in 91.25% (73/80) of the specimens. Twenty-nine swab fluids were used to inoculate cell cultures (RD and Hep2C), and 72.4% (21/29) yielded a cytopathic effect. Genotype IV coxsackievirus A24v (CV-A24v) was identified as the causative agent of the outbreak. Phylogenetic analysis based on the VP1 gene revealed that Brazilian isolates were genetically related to strains that caused an outbreak in French Guiana in 2017. Our results show the re-emergence of CV-A24v causing AHC outbreaks in Brazil between the end of 2017 and the beginning of 2018.

Costs of Conjunctivitis Outbreak, Réunion Island, France.

During January-April 2015, a major outbreak of conjunctivitis on Réunion Island caused a large public health impact. On the basis of general practitioner consultations, emergency department visits, and eye medication sales during the 13-week epidemic, we estimated a total healthcare cost of €3,341,191 from the outbreak.

Dynamic modelling of strategies for the control of acute haemorrhagic conjunctivitis outbreaks in schools in Changsha, China (2004-2015).

Outbreaks of acute haemorrhagic conjunctivitis (AHC) - a rapidly progressing and highly contagious infection - often occur in schools during summer and autumn. We used dynamic modelling to evaluate the efficacy of interventions to control AHC outbreaks in schools. A susceptible-infected-recovered (SIR) model was built to simulate AHC outbreaks in Chinese schools, with isolation or school closure added into the model. We used outbreak data from the period 2004-2015 in our models to estimate the effective reproduction number and assess the efficacy of interventions. The median effective reproduction number (uncontrolled) of AHC outbreaks was 7·00 (range 1·77-25·87). The median effective reproduction number (controlled) of AHC outbreaks was 0·16 (range 0·00-2·28). Intervention efficacy is affected by the timing of isolation; earlier isolation is associated with a lower morbidity peak and smaller total attack rate (TAR). School closures were not effective; TARs were almost 100% and did not change even when different school closure durations were adopted. Isolation and school closure as a combined intervention strategy was used to simulate outbreak control, but the efficacy was the same as isolation alone. An isolation programme could be an effective primary intervention during AHC outbreaks in schools. However, school closure is not recommended.

A major outbreak of conjunctivitis caused by coxsackievirus A24, Réunion, January to April 2015.

From January to April 2015, Réunion experienced a major outbreak of acute haemorrhagic conjunctivitis (AHC) caused by coxsackievirus A24, which heavily impacted the healthcare system. According to the general practitioners' (GP) sentinel network, the number of medical consultations due to conjunctivitis during this period was estimated at ca 100,000. This report describes the characteristics of the outbreak, which were obtained through several different yet complementary surveillance systems on the island. These included the network of hospital emergency departments (OSCOUR network), the GPs' sentinel network, an Internet-based population cohort ('Koman i lé') participating in a survey on distinct symptoms including 'red eyes' and the monitoring of eye drop sales. Overall the results of the different surveillance approaches were in good agreement regarding the outbreak dynamic. A peak of patients with conjunctivitis was detected in the first 15 days of March (week 10 and 11), coinciding with increased eye drop sales on the island. Strains recovered from outbreak cases belonged to genotype IV and were most closely related to strains identified in AHC outbreaks in China, Egypt and Japan since 2010. Continued surveillance of AHC in Réunion remains important not only locally, but also because frequent exchanges between the island and mainland France may lead to introduction of this virus in Europe.

Acute hemorrhagic conjunctivitis epidemic in São Paulo State, Brazil, 2011.

Acute hemorrhagic conjunctivitis (AHC) infection is highly contagious and can lead to explosive epidemics. In early February 2011, the Center for Epidemiologic Surveillance of the State of São Paulo Health Secretariat (SES-SP) in Brazil received reports of conjunctivitis outbreaks from rural areas of the state that subsequently spread statewide. This report describes that AHC epidemic and its etiologic agent. Data from the Ministry of Health Information System for Notifiable Diseases (SinanNet) and the SES-SP epidemiologic surveillance system for conjunctivitis, developed to detect outbreaks, confirm the etiologic agent, and carry out control measures, were analyzed. Eye (conjunctival swab) samples were taken from patients with clinical presentation of viral conjunctivitis to perform viral laboratory diagnosis. A total of 1 067 981 conjunctivitis cases were reported to the surveillance system for 2011; there was an increase in the number of cases in epidemiologic weeks 6-26 (summer season) versus previous years. Most cases occurred in the metropolitan region of Greater São Paulo. Of 93 collected samples, 57 tested positive for coxsackievirus-A24 (CV-A24), based on virus isolation in tissue-culture cell lines, reverse transcription polymerase chain reaction (RT-PCR), and enterovirus sequencing of RT-PCR. The data analysis showed that the fast-spreading etiologic agent of the AHC epidemic that occurred in the summer of 2011 was CV-A24. The AHC epidemic was due to an enterovirus that occurred sporadically, spread rapidly and with great magnitude, and had substantial socioeconomic impact due to the high level of absenteeism at work and school.

Epidemic outbreak of acute haemorrhagic conjunctivitis caused by coxsackievirus A24 in Thailand, 2014.

Acute haemorrhagic conjunctivitis outbreaks are often attributed to viral infection. In 2014, an unprecedented nationwide outbreak of infectious conjunctivitis occurred in Thailand, which affected >300 000 individuals over 3 months. To identify and characterize the virus responsible for the epidemic, eye swab specimens from 119 patients were randomly collected from five different provinces. Conserved regions in the enteroviral 5'-UTR and adenovirus hexon gene were analysed. Enterovirus was identified in 71·43% (85/119) of the samples, while no adenovirus was detected. From enterovirus-positive samples, the coxsackievirus A24 variant (70·59%, 84/119) and echovirus (0·84%, 1/119) were identified. Additional sequencing of full-length VP1 and 3C genes and subsequent phylogenetic analysis revealed that these clinical isolates form a new lineage cluster related to genotype IV-C5. In summary, the coxsackievirus A24 variant was identified as an aetiological agent for the recent acute haemorrhagic conjunctivitis outbreak in Thailand.

Molecular evolution of VP3, VP1, 3C(pro) and 3D(pol) coding regions in coxsackievirus group A type 24 variant isolates from acute hemorrhagic conjunctivitis in 2011 in Okinawa, Japan.

A large acute hemorrhagic conjunctivitis (AHC) outbreak occurred in 2011 in Okinawa Prefecture in Japan. Ten strains of coxsackievirus group A type 24 variant (CA24v) were isolated from patients with AHC and full sequence analysis of the VP3, VP1, 3C(pro) and 3D(pol) coding regions performed. To assess time-scale evolution, phylogenetic analysis was performed using the Bayesian Markov chain Monte Carlo method. In addition, similarity plots were constructed and pairwise distance (p-distance) and positive pressure analyses performed. A phylogenetic tree based on the VP1 coding region showed that the present strains belong to genotype 4 (G4). In addition, the present strains could have divided in about 2010 from the same lineages detected in other countries such as China, India and Australia. The mean rates of molecular evolution of four coding regions were estimated at about 6.15 to 7.86 × 10(-3) substitutions/site/year. Similarity plot analyses suggested that nucleotide similarities between the present strains and a prototype strain (EH24/70 strain) were 0.77-0.94. The p-distance of the present strains was relatively short (<0.01). Only one positive selected site (L25H) was identified in the VP1 protein. These findings suggest that the present CA24v strains causing AHC are genetically related to other AHC strains with rapid evolution and emerged in around 2010.

An outbreak of acute hemorrhagic conjunctivitis due to Coxsackievirus A24 in a residential school, Naharlagun, Arunachal Pradesh: July 2023.

PURPOSE: An acute conjunctivitis outbreak was investigated at a residential school in Naharlagun, Arunachal Pradesh, Northeast India, in July 2023. We aimed to identify the etiological agent and assess any complications in follow-up cases. METHODS: We used a structured questionnaire to record clinical findings and followed up with cases one-month post-conjunctivitis. Sixty-one cases were examined and eight conjunctival and oropharyngeal swab samples were collected after obtaining informed consent from guardians/school authorities. We screened for 33 viral and bacterial pathogens using an IVD-approved Real-time PCR assay. Further, the samples were subjected to nucleic acid sequencing. RESULTS: Among 465 screened students and staff, 80 individuals (approximately 17.2%) showed acute hemorrhagic conjunctivitis symptoms among which 61 cases were available for clinical examination. We identified the Enterovirus responsible by targeted sequencing using next-generation sequencing. The etiological agent was found to be Coxsackievirus A24, a member of Enterovirus C, in seven out of eight samples subjected to sequencing. Common symptoms included conjunctival hyperemia and foreign body sensation (100%), bilateral eye involvement (73.8%), eye pain (70%), watery discharge (49.2%), and eyelid swelling (38%). Only 6.5% had purulent discharge. Most cases resolved within 5-6 days, with only 9.8% reporting abdominal symptoms post-conjunctivitis. No serious complications occurred within one month. Throat swabs aided in diagnosing enterovirus infections alongside eye swabs. CONCLUSIONS: The outbreak of acute conjunctivitis was caused by Coxsackievirus A24, a member of Enterovirus C. Cases resolved spontaneously within 6-7 days, with no severe complications. Collecting oropharyngeal swabs alongside conjunctival swabs could improve enteroviral conjunctivitis diagnosis.

Molecular characterization of coxsackievirus A24 variants isolated from an outbreak of acute hemorrhagic conjunctivitis.

PURPOSE: Acute Hemorrhagic conjunctivitis (AHC) is associated with CVA24v. Recently there was a severe outbreak of conjunctivitis in months of July and August 2023 in India. This study emphasizes the identification of the distinct mutations in the CVA24v strains, which were isolated during the AHC outbreak and could have potentially played a role in the high transmission of AHC in India during the 2023 outbreak. METHODS: A total of 71 conjunctivitis patients aged 1-75 years comprising 47 males and 24 females who attended Ophthalmology department of a tertiary care hospital of easternIndia were studied.RNA was extracted from all conjunctival swab samples and converted into cDNA. Subsequently, the viral 5' UTR was amplified and the PCR positive samples were subjected to sequencing. The newly isolated viral 5' UTR sequences were aligned with other worldwide sequences using the Clustal W tool to conduct mutational analysis. A phylogenetic tree was built using the MEGA software for viral genotype identification. RESULTS: All of the current outbreak strains belonged to genotype IV of CVA24v. The present outbreak strains formed a distinct clade in the phylogenetic tree and were different from previously reported Indian strains. Two persistent mutations, specifically in domain IV (T213C) and domain V (C475T), were exclusively detected within the internal ribosome entry site (IRES) of the 5' UTR of the current strains causing the outbreak. These two alterations have previously been shown to impact the virulence of another enterovirus (CV B3), but they have not been described in CVA24v until now. CONCLUSION: Finding of the present study highlights the possibility and the significance of the aforementioned two mutations in enhancing the transmissibility of the newer CVA24v strains. Hence, these two distinct mutations should be investigated further for developing antiviral therapies to combat future AHC outbreaks associated with CVA24v.

A molecular investigative approach to an outbreak of acute hemorrhagic conjunctivitis in Egypt, October 2010.

BACKGROUND: During October 2010, Egypt reported an outbreak of acute hemorrhagic conjunctivitis (AHC). A total of 1831 cases were reported from three governorates; 1703 cases in El Daqahliya, 92 cases in Port Said, and 36 in Damietta. The purpose of this study was to identify and characterize the causative agent associated with this outbreak. METHODS: The U.S. Naval Medical Research Unit No.3 (NAMRU-3) was contacted by the Egyptian Ministry of Health and Population to perform diagnostic laboratory testing on eighteen conjunctival swabs from patients with conjunctivitis from El Daqahliya Governorate. Conjunctival swabs were tested by molecular methods for human adenovirus (HAdV) and enteroviruses (EV). Virus isolation was performed; the isolated virus was further characterized by molecular typing and phylogenetic analysis. RESULTS: The majority of the samples (17/18) were positive for enterovirus and all were negative for HAdV. Molecular typing and sequencing of the isolated virus revealed the presence of coxsackievirus A24 variant. Phylogenetic analysis based on the VP1 and 3C regions demonstrated that the Egyptian viruses belonged to Genotype IV and are closely related to coxsackievirus A24 variant, reported in a similar outbreak in China in August 2010. CONCLUSIONS: This study strongly suggests that coxsackievirus A24 variant was associated with the acute hemorrhagic conjunctivitis outbreak reported in Egypt in October 2010. There is a possibility that the same strain of CV-A24v was implicated in the AHC outbreaks in both China and Egypt in 2010.

Molecular identification and phylogenetic study of coxsackievirus A24 variant isolated from an outbreak of acute hemorrhagic conjunctivitis in India in 2010.

An outbreak of acute hemorrhagic conjunctivitis (AHC) occured in India between August and October 2010. Molecular typing by RT-PCR and sequencing of a partial VP1 region identified coxsackievirus A24 variant (CV A24v) as the serotype involved in this outbreak. Phylogenetic analysis based on the VP1 and 3C genes revealed that CV A24v strains associated with the 2010 AHC outbreak in India were genetically similar to strains from Central and South America that caused outbreaks of AHC in Cuba between 2008 and 2009 and Brazil in 2009. The result shows that the Indian strain of CV A24v may be responsible for the recent AHC outbreak in Marseille, France, in 2012.

Phylogenetic and molecular characterization of coxsackievirus A24 variant isolates from a 2010 acute hemorrhagic conjunctivitis outbreak in Guangdong, China.

BACKGROUND: Acute hemorrhagic conjunctivitis is a common disease in China. As a notifiable disease, cases are registered by ophthalmologists on the AHC surveillance system. An AHC outbreak caused by CA24v was observed in Guangdong Province in 2007 by the National Disease Supervision Information Management System. Three years later, a larger outbreak occurred in Guangdong during the August-October period (2010). To characterize the outbreak and compare the genetic diversity of CA24v, which was determined to be the cause of the outbreak, the epidemiology and the molecular characterization of CA24v were analyzed in this study. RESULTS: A total of 69,635 cases were reported in the outbreak. 73.5% of index cases originated from students, children in kindergarten and factory workers, with the ≦ 9 age group at the highest risk. The male to female ratio was 1.84:1 among 0-19 years. 56 conjunctival swabs were collected to identify the causative agent from five cities with the AHC outbreak. 30 virus strains were isolated, and two of the genomes had the highest identity values (95.8%) with CA24v genomes. Four CA24v genotypes were identified by phylogenetic analysis for the VP1 and 3C regions. CA24v which caused the outbreak belonged to genotype IV. Furthermore, full nucleotide sequences for four representative isolates in 2010 and 2007 were determined and compared. 20 aa mutations, two nt insertions and one nt deletion were observed in the open reading frame, with 5'- and 3'- UTR respectively between them. CONCLUSIONS: CA24v was determined to be the pathogen causing the outbreak and belongs to genotype IV. VP1 is more informative than 3C(Pro) for describing molecular epidemiology and we hypothesize that accumulative mutations may have promoted the outbreak.

2012 outbreak of acute haemorrhagic conjunctivitis in Indian Ocean Islands: identification of Coxsackievirus A24 in a returned traveller.

In May 2012, a Coxsackievirus A24 haemorrhagic conjunctivitis was diagnosed in Marseille, France, in a traveller returning from the Comoros Islands. This case allowed identification of the cause of an ongoing outbreak of haemorrhagic conjunctivitis in Indian Ocean Islands, illustrating that returning travellers may serve as sentinels for infectious diseases outbreaks in tropical areas where laboratory investigation is limited.

Evolutionary phylogeography reveals novel genotypes of coxsackievirus A24 variant and updates the spatiotemporal dynamics in the population with acute hemorrhagic conjunctivitis.

OBJECTIVES: The coxsackievirus A24 variant (CVA24v) has raised a remarkable concern because of its main etiological role in acute hemorrhagic conjunctivitis. METHODS: We conducted a retrospective study to summarize CVA24v isolated from acute hemorrhagic conjunctivitis outbreaks and acute flaccid paralysis surveillance in Shandong province, China during 1988-2020. Phylogenetic and phylogeographic methods based on the VP1 coding region were used to determine the CVA24v origin, spatiotemporal dynamics, and evolution. Also, the positive selection sites in the VP1 gene were identified and exhibited in the tertiary structure. RESULTS: The global CVA24vs were classified into eight genotypes (GⅠ-GⅧ). Here, 12 CVA24v isolates were detected, of which five strains were typed as two novel genotypes (GⅦ and GⅧ) and reported first in the world. The time to the most recent common ancestor of the global CVA24v was estimated around March 1965 and evolved with 5.573 × 10-3 substitutions/site/year. Four residues under positive selection were detected, and residue 146T might be adapted in the CVA24v pandemic. Phylogeographic analysis indicated that China was the main source sink for CVA24v dispersion in a long-lasting global pattern. CONCLUSION: Our study updated the epidemiological characteristics of CVA24v and enabled a better understanding of the molecular mechanism underlying different genotypes. The results provided new insights into the CVA24v origin, spatiotemporal dynamics, and possibly, the determinants of viral tropism and pathogenicity.