Outbreak Of Conjunctivitis Research Articles

Transmissibility of acute haemorrhagic conjunctivitis in small-scale outbreaks in Hunan Province, China

Acute haemorrhagic conjunctivitis (AHC) outbreaks are reported frequently in China. However, the transmissibility of AHC remains unclear. This study aimed to calculate the transmissibility of the disease with and without interventions. An AHC outbreak dataset from January 2007 to December 2016 in different schools was built in Hunan Province. A Susceptible-Infectious-Recovered (SIR) model was adopted to calculate the effective reproduction number (Reff) of AHC. Reff was divided into two parts (Runc and Rcon) where Runc and Rcon represent the uncontrolled and controlled Reff , respectively. Based on Runc and Rcon, an index of effectiveness of countermeasures (Ieff) was developed to assess the effectiveness of countermeasures in each outbreak. During the study period, 34 AHC outbreaks were reported in 20 counties of 9 cities in Hunan Province, with a mean total attack rate of 7.04% (95% CI: 4.97–9.11%). The mean Runc of AHC outbreaks was 8.28 (95% CI: 6.46–10.11). No significance of Runc was observed between rural and urban areas (t = −1.296, P = 0.205), among college, secondary, and primary schools (F = 0.890, P = 0.459), different levels of school population (F = 0.738, P = 0.538), and different number of index cases (F = 1.749, P = 0.180). The most commonly implemented countermeasures were case isolation, treatment, and health education, followed by environment disinfection, symptom surveillance, and school closure. Social distance, prophylaxis, and stopping eye exercises temporary were implemented occasionally. The mean value of Rcon was 0.16 (range: 0.00–1.50). The mean value of Ieff was 97.16% (range: 71.44–100.00%). The transmissibility of AHC is high in small-scale outbreaks in China. Case isolation, treatment, and health education are the common countermeasures for controlling the disease.

Google Searches and Detection of Conjunctivitis Epidemics Worldwide

Epidemic and seasonal infectious conjunctivitis outbreaks can impact education, workforce, and economy adversely. Yet conjunctivitis typically is not a reportable disease, potentially delaying mitigating intervention. Our study objective was to determine if conjunctivitis epidemics could be identified using Google Trends search data. Search data for conjunctivitis-related and control search terms from 5 years and countries worldwide were obtained. Country and term were masked. Temporal scan statistics were applied to identify candidate epidemics. Candidates then were assessed for geotemporal concordance with an a priori defined collection of known reported conjunctivitis outbreaks, as a measure of sensitivity. Populations by country that searched Google's search engine using our study terms. Percent of known conjunctivitis outbreaks also found in the same country and period by our candidate epidemics, identified from conjunctivitis-related searches. We identified 135 candidate conjunctivitis epidemic periods from 77 countries. Compared with our a priori defined collection of known reported outbreaks, candidate conjunctivitis epidemics identified 18 of 26 (69% sensitivity) of the reported country-wide or island nationwide outbreaks, or both; 9 of 20 (45% sensitivity) of the reported region or district-wide outbreaks, or both; but far fewer nosocomial and reported smaller outbreaks. Similar overall and individual sensitivity, as well as specificity, were found on a country-level basis. We also found that 83% of our candidate epidemics had start dates before (of those, 20% were more than 12 weeks before) their concurrent reported outbreak's report issuance date. Permutation tests provided evidence that on average, conjunctivitis candidate epidemics occurred geotemporally closer to outbreak reports than chance alone suggests (P < 0.001) unlike control term candidates (P= 0.40). Conjunctivitis outbreaks can be detected using temporal scan analysis of Google search data alone, with more than 80% detected before an outbreak report's issuance date, some as early as the reported outbreak's start date. Future approaches using data from smaller regions, social media, and more search terms may improve sensitivity further and cross-validate detected candidates, allowing identification of candidate conjunctivitis epidemics from Internet search data potentially to complementarily benefit traditional reporting and detection systems to improve epidemic awareness.

Mycoplasmosis of House Finches ( Haemorhous mexicanus) and California Scrub-Jays ( Aphelocoma californica) in a Wildlife Rehabilitation Facility with Probable Nosocomial Transmission.

We describe an investigation of an outbreak of conjunctivitis in juvenile House Finches ( Haemorhous mexicanus) and California Scrub-jays ( Aphelocoma californica) at a central California, US wildlife rehabilitation facility. In late May 2015, the facility began admitting juvenile finches, the majority with normal eyes at intake. In June, with juvenile finches already present, the facility admitted juvenile scrub-jays, all with normal eyes at intake. In July, after conjunctivitis was observed in increasing numbers of juvenile finches and scrub-jays, carcasses were submitted for postmortem examination. Histopathology of five finches and three scrub-jays identified lymphocytic infiltrates in the ocular tissues. Conjunctival swabs from 87% (13/15) finches and 33% (4/12) scrub-jays were PCR-positive for Mycoplasma gallisepticum. One finch and two scrub-jays were PCR-positive for Mycoplasma synoviae. Additionally, gene sequencing (16S ribosomal RNA and 16S-23S intergenic spacer region) identified Mycoplasma sturni from 33% (3/9) scrub-jays. This outbreak of conjunctivitis suggested that M. gallisepticum-infected juvenile finches admitted to and maintained in a multispecies nursery likely resulted in transmission within the facility to healthy juvenile finches and scrub-jays. Evidence of other Mycoplasma spp. in finches and scrub-jays indicates that these species are susceptible to infection and may act as carriers. This outbreak highlighted the need for effective triage and biosecurity measures within wildlife rehabilitation facilities.

Clinical and virological analysis of epidemic keratoconjunctivitis caused by adenovirus type 54 in a regional ophthalmic clinic in Kyushu, Japan.

BackgroundHuman adenovirus type 54 (HAdV-54) is a novel type of adenovirus that belongs to species D and has thus far been detected only in Japan in patients with epidemic keratoconjunctivitis (EKC). There was a large nationwide outbreak of HAdV-54 EKC from 2015 to 2016 in Japan. The clinical characteristics of an outbreak of HAdV-54 conjunctivitis treated in a regional ophthalmic clinic in Fukuoka, Japan, in 2016 were analyzed.Patients and methodsA consecutive series of 55 cases diagnosed clinically as EKC confirmed by HAdV-54 detection from conjunctival scrapings by polymerase chain reaction (PCR) method between 17 June 2016 and 29 August 2016 were enrolled. Viral DNA copies were counted by real-time PCR method. The clinical findings were recorded at the first visit to the clinic and evaluated.ResultsIn the analysis of the relationship between mean clinical score groups and several factors, such as days after onset, sex, HAdV DNA number on a logarithmic scale, and age, most factors did not show a significant difference in clinical score between groups. However, mean clinical score of cases aged <23 years was significantly higher than that of cases aged ≥23 years (P<0.01). The correlation coefficient between DNA copies on a logarithmic scale and clinical score was 0.280, and a significant correlation was observed (P<0.05). Multiple subepithelial corneal infiltrates (MSI) were observed in 24 out of 31 cases (77%).ConclusionThese results suggested that the clinical features in the early phase of HAdV-54 keratoconjunctivitis were milder but the rate of MSI observed in the late phase was higher than those in previous epidemics of several HAdV types. The significant difference in clinical severity between age groups might be a virological characteristic of HAdV-54.

\u0391 molecular epidemiological analysis of adenoviruses from excess conjunctivitis cases

BackgroundΤo perform a molecular epidemiological analysis of viral conjunctivitis among excess conjunctivitis cases recorded at the University Hospital of Patras, Greece, for the period March to June 2012.MethodsA structured questionnaire containing demographic and clinical data was developed in order to collect retrospective data on the cases. Eye swab specimens were collected and molecular detection of adenoviruses was performed by nested PCR. Positive results were confirmed by sequencing. To determine the relatedness between the isolated sequences, a phylogenetic analysis was conducted.ResultsThe epidemiological analysis (including retrospective data) included 231 conjunctivitis cases (47.1% male, and 52.8% female). Based on clinical features 205 of the cases were diagnosed of viral origin (46.3% male and 53.7% female), 4 of bacterial origin (50% male and 50% female) while 22 were undefined conjunctivitis. The outbreak excess cases (included 156 cases) affected all age groups regardless gender predilection. For the positive samples indicated that 29 samples (72.5%) were AdV17, and 5 (12.5%) as AdV54.ConclusionsMolecular analysis could define the cause of viral conjunctivitis, while epidemiological data contributed to the assessment of the risk factors and underlined possible preventive measures. This study is one of the very few on viral conjunctivitis in Greece. This outbreak underscores the need for a national surveillance system for acute infectious conjunctivitis outbreaks. The epidemiological as well as molecular investigation on HAdV ocular infections is rather absent in Greece, which has no surveillance system for viral conjunctivitis.

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.

“Koman i lé” : An Online Self-Reported Symptoms Surveillance System in Reunion Island

In Reunion Island, the population is very sensitive to public health concerns. In this context, the health authorities implemented since April 2014 a web-based surveillance system, called “Koman i lé” and based on a volunteers' cohort in general population. This surveillance system allowed to follow the seasonal influenza epidemic in 2014 and the major outbreak of conjunctivitis from January to April 2015. In conclusion, the sentinel population allows the population of Reunion Island to take an active part in the health regional policy. Information reported by individuals can increase traditional public health methods for more timely detection of disease outbreaks.

Interest of Prospective Spatio-Temporal Analysis from ED Data to Detect Unusual Health Events

In Reunion Island, a prospective computer-automated space-time analysis hab been implemented in order to launch daily analyses of ED visits. This tool allowed to the early detection of several infectious diseases outbreak such as a gastroenteritis cluster or a local outbreak of conjunctivitis that spread throughout the island.

Virology and epidemiology analyses of global adenovirus-associated conjunctivitis outbreaks, 1953-2013.

This study aimed to compare the virology and epidemiology of epidemic keratoconjunctivitis (EKC), pharyngoconjunctival fever (PCF) and acute haemorrhagic conjunctivitis (AHC) outbreaks worldwide caused by the human adenovirus (HAdV) from 1953 to 2013. Eighty-three hexon sequences from 76 conjunctivitis outbreaks were analysed and subtyped using Mega 5.05, Clustal X and SimPlot software. Epidemiology was performed for the area, age and seasonal distribution. A phylogenetic analysis indicated that all the isolates could be divided into three subgenetic lineages, without a common ancestor. The major causes of the outbreaks were Ad8, Ad7 and Ad2 co-infection with enterovirus 70 (EV70) in EKC, PCF and AHC, respectively. The epidemiological findings suggested that EKC and AHC were circulating predominantly in Asia during the early winter and spring, whereas PCF was circulating mainly in China, Australia and the United States during the summer. This study suggests that EKC, AHC and PCF outbreaks have different circulating patterns throughout the world and are caused by different adenovirus serotypes. A global surveillance system should be established to monitor conjunctivitis outbreaks in the future.

Attack rate and household secondary attack rate of acute conjunctivitis during an outbreak in South India: A community-based survey.

Introduction:Knowledge on epidemiology of the disease in the contemporary world will help to develop appropriate strategies to curtail the transmission during an outbreak. This study was carried out during an outbreak of conjunctivitis in selected areas of Puducherry, South India, to assess the attack rate of conjunctivitis, identify factors associated with developing conjunctivitis and calculate household secondary attack rate (HSAR) of conjunctivitis and its correlates.Methodology:During December 2014, a community-based survey was conducted in a selected urban and rural area in Puducherry, South India. Simple random sampling was used to select primary sampling units and systematic sampling to select households. All individuals in the selected households were studied. A questionnaire was used to obtain data on sociodemographic characteristics, conjunctivitis during September-November, 2014, and number of household contacts who developed conjunctivitis within 7 days of index case. The attack rate and HSAR of conjunctivitis was expressed as percentage. Multivariate logistic regression was used to find factors independently associated with developing conjunctivitis and also 100% HSAR.Results:Of 3193 study participants from 772 households, 509 (15.9%, 95% confidence interval 14.7-17.2%) had an attack of conjunctivitis during the reference period. Of the 772 households, 218 (28.2%) had at least one case of conjunctivitis. Of 218 households, 33 (15.1%) households had 100% HSAR. Lower age, not being unemployed, low socioeconomic status, and residing in rural area were independently associated with developing conjunctivitis. Index case being male and living in a household with ≥5 members were independently associated with 100% HSAR.Conclusion:In the outbreak under study, more than one-fourth of households had at least one case of conjunctivitis and about one in every six individuals had an attack of conjunctivitis.

A Polymerase Chain Reaction–Based Algorithm to Detect and Prevent Transmission of Adenoviral Conjunctivitis in Hospital Employees

To devise and implement a practice algorithm that would enable rapid detection and appropriate furlough of hospital employees with adenoviral conjunctivitis in order to prevent healthcare-associated epidemic keratoconjunctivitis. Evaluation of an ongoing quality assurance/improvement initiative. Employees of Johns Hopkins Hospital with signs and symptoms of adenoviral conjunctivitis underwent evaluation by nurse practitioners in Occupational Health and rapid diagnostic testing by real-time polymerase chain reaction (PCR). Sequencing was used to determine serotype when adenovirus was detected. Signs, symptoms, diagnosis, and disposition of employees with eye complaints as well as PCR and serotype results were recorded. Over a 36-month period approximately 18% of initial employee visits were due to unique, eye-related complaints. Viral conjunctivitis was suspected in 542 of 858 employees with eye complaints (62%); adenovirus was detected by PCR in 44 of 542 suspected viral conjunctivitis cases (8%) or 44 of 858 employees with any eye concern (5%). Fourteen of the 44 employees had adenoviral serotypes and clinical presentation consistent with epidemic keratoconjunctivitis (type 37 [n = 6], 8 [n = 4], 4 [n = 3], 19 [n = 1]). Other serotypes found in individuals with less severe conjunctivitis were 3 (n = 5), 4 (n = 5), 56 (n = 4), 1 (n = 2), 42 (n = 1), and 7 (n = 1). No healthcare-associated adenoviral conjunctivitis outbreaks occurred after algorithm implementation, and fewer employees required furlough than had clinical diagnosis alone been used. The algorithm is an effective infection prevention tool that minimizes productivity loss compared to clinical diagnosis and allows for determination of prevalence and serotype characterization of adenoviral conjunctivitis in hospital employees.

An Outbreak of Ocular Bacterial Conjunctivitis Due to Unencapsulated Streptococcus Pneumoniae

An Outbreak of Ocular Bacterial Conjunctivitis Due to Unencapsulated Streptococcus Pneumoniae

Molecular identification and phylogenetic analysis of Coxsackievirus A24v causing outbreak of acute hemorrhagic conjunctivitis in Hubei in 2010

Objective To identify the etiology of an outbreak of cute hemorrhagic conjunctivitis (AHC) occurred in Hubei in 2010 and analyze the molecular evolution of these viruses. Methods Conjunctival swabs from 20 eyes were collected from AHC patients, performed virus isolation was performed and then these specimens were tested for human enterovirus 70(EV-D70) and Coxsackievirus A24 variant(CV-A24v) using polymerase chain reaction (PCR) technique. All CV-A24v isolates were subjected to 3C and VP1 coding region sequencing and phylogentic tree were constructed for Hubei CV-A24v and other CV-A24v worldwide based on 3C and VP1 region, respectively. Results The results showed that 11 out of 20 specimens were positive for virus isolation and identified as CV-A24v. The phylogenetic tree based on 3C region showed Hubei CV-A24v belong to Cluster 3 in Genotype Ⅳ(GⅣ-C3)with strains isolated throughout the world after 2010 and further divided into A and B lineages. Conclusions This study suggested that at least two transmission lineages circulated in HuBei province in 2010 causing the AHC outbreak nationwide. Key words: Coxsackievirus infections; Enterovirus B, human; Conjunctivitis, acute hemorrhagic; Phylogeny; Genes

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.

Povidone iodine in the treatment of adenoviral conjunctivitis in infants

Context: Adenoviral conjunctivitis.Objective: To examine the effects of conjunctival irrigation with povidone iodine in infants with adenoviral conjunctivitis. Material and methods: An outbreak of adenovirus conjunctivitis occurred between September and December 2012 at the neonatal intensive care unit of our hospital. Forty-three infants with adenoviral conjunctivitis were examined in this study. Thirty-five eyes of 35 infants who had detailed ophthalmological examination and clinical scoring were included. The conjunctiva of 15 infants (Group 1) were irrigated with povidone iodine 2.5% solution and then treated with preservative-free artificial tears and preservative-free antibiotic drops. Twenty infants (Group 2) were treated only with the same drops with the same posology, without conjunctival irrigation with povidone iodine. Patients were examined two times a week until the complete recovery. Lid edema, conjunctival chemosis, fragility of conjunctival vasculature, pseudomembrane formation, and corneal involvement were scored clinically. Results: Twenty patients (57%) were female and 15 patients (43%) were male and mean age was 3.1 months (ranged from 1 to 4 months). No relation was found between gender and clinical scores. Statistically significant lower clinical scores were obtained from Group 1. The median recovery time was earlier in Group 1 (7 d) than Group 2 (12 d) (p = 0.001). Conclusion: Conjunctival irrigation with 2.5% povidone iodine is effective in the treatment of adenoviral conjunctivitis in infants.

Genetic Characteristics of the Coxsackievirus A24 Variant Causing Outbreaks of Acute Hemorrhagic Conjunctivitis in Jiangsu, China, 2010

During September 2010, an outbreak of acute hemorrhagic conjunctivitis reemerged in Jiangsu, three years after the nationwide epidemic in China in 2007. In total, 2409 cases were reported, 2118 of which were reported in September; 79.8% of those affected were students or teachers, with a median age of 16 years. To identify and demonstrate the genetic characteristics of the etiological agent, 52 conjunctival swabs were randomly collected from four different cities. After detection and isolation, 43 patients were positive for coxsackievirus A24 variant according to PCR and 20 according to culture isolation. Neither adenovirus nor EV70 was detected. A phylogenetic study of the complete 3Cpro and VP1 regions showed that the Jiangsu isolates clustered into a new lineage, GIV-C5, with two uniform amino-acid mutations that distinguished them from all previous strains. Another new cluster, GIV-C4, formed by Indian isolates from 2007 and Brazilian isolates from 2009, was also identified in this study. Interestingly, our isolates shared greatest homology with the GIV-C4 strains, not with the isolates that were responsible for the nationwide acute hemorrhagic conjunctivitis epidemic in China in 2007. Although all our isolates were closely related, they could be differentiated into two subclusters within GIV-C5. In conclusion, our study suggests that a new cluster of coxsackievirus A24 variant that had already evolved into diverse strains was associated with the acute hemorrhagic conjunctivitis outbreaks in Jiangsu in September 2010. These viruses might have originated from the virus isolated in India in 2007, rather than from the epidemic strains isolated in China in 2007.

Deposition of pathogenic Mycoplasma gallisepticum onto bird feeders: host pathology is more important than temperature-driven increases in food intake

Although ambient temperature has diverse effects on disease dynamics, few studies have examined how temperature alters pathogen transmission by changing host physiology or behaviour. Here, we test whether reducing ambient temperature alters host foraging, pathology and the potential for fomite transmission of the bacterial pathogen Mycoplasma gallisepticum (MG), which causes seasonal outbreaks of severe conjunctivitis in house finches (Haemorhous mexicanus). We housed finches at temperatures within or below the thermoneutral zone to manipulate food intake by altering energetic requirements of thermoregulation. We predicted that pathogen deposition on bird feeders would increase with temperature-driven increases in food intake and with conjunctival pathology. As expected, housing birds below the thermoneutral zone increased food consumption. Despite this difference, pathogen deposition on feeders did not vary across temperature treatments. However, pathogen deposition increased with conjunctival pathology, independently of temperature and pathogen load, suggesting that MG could enhance its transmission by increasing virulence. Our results suggest that in this system, host physiological responses are more important for transmission potential than temperature-dependent alterations in feeding. Understanding such behavioural and physiological contributions to disease transmission is critical to linking individual responses to climate with population-level disease dynamics.

THU0485 Muckle Wells Syndrome. A Case Series Characterized Genetically

BackgroundMuckle-Wells Syndrome(MWS) is a rare autosomal dominant disorderincluded inthe groupofhereditaryperiodic feversyndromes1. It is characterized byrecurrentand self-limitedepisodesof fever, rash, joint painand conjunctivitissince childhood. Sensorineural deafnessand amyloidosisappear lateranddetermine the disease prognosis2. It...

Study on the complete sequence of CA24 variant isolated during the acute hemorrhagic conjunctivitis outbreaks in Zhejiang province during 2002 to 2010

To analyze the genetic characteristics of the complete sequence of coxsackievirus A24 variant (CA24v) isolated from acute hemorrhagic conjunctivitis (AHC) outbreaks in Zhejiang province during 2002 to 2010. Complete sequences of CA24v epidemic strains isolated in different years were amplified under the RT-PCR assay, while the sequences of whole genome, VP1, and 3C region of Zhejiang strains were compared with epidemic strains isolated in other areas of China and abroad. The whole genome of Zhejiang CA24v strains isolated in 2002 and 2010 was 7456 - 7458 bp in length, encoding a polyglutamine protein which containing 2214 amino acid residues. There was a insertion with T on site 97 and 119 within 5'non-coding region between epidemic strain Zhejiang/08/10 and strains isolated in 2002. The rates of amino acid homology among Zhejiang/08/10 and other strains isolated since 2002 were between 94.7% and 100.0%. Compared with the representative strains circulated within the recent 60 years, the largest average amino acid variations had been occurred on region 2A and 3A, with the ratios as 8.4% and 7.3% respectively. The smallest variation happened in region 3D, with the ratio only as 1.9%. The rates of stable amino acid variation on the whole genome between strains isolated since 1987 and 2002 were 38 and 20. P-distance within groups appeared that region 3C was more stable than VP1 of strains isolated in 2002 - 2010, and the 3D of early strain Jamaica/10628/87 might have had a nature of recombination but not observed on those epidemic strains in recent years. Within the evolution of CA24v strains, the time course was more significant than the geographical differences. There had been sporadic epidemics of AHC caused by CA24v in Zhejiang province since 2002.