Outbreak of acute hemorrhagic conjunctivitis in Beijing City in 2007 caused by coxsackievirus A24 variant: molecular identification and phylogenetic analysis / 病毒学报

In 2007, an outbreak of acute hemorrhagic conjunctivitis (AHC) occurred in Beijing. In order to identify the etiology of this outbreak, 57 eye conjunctival swabs were collected from 57 outpatient patients, and detected for adenovirus, human enterovirus 70 (HEV70) and Coxsackievirus A24 variant (CVA24v) genes by using RT-PCR or PCR methods. The results showed that 38 were positive for CVA24v, the positive rate was 66.7%, but none was positive for HEV70 and adenovirus, showing that this outbreak was caused by CVA24v. 9 viral isolates were obtained from 57 clinical specimens by using viral isolation method, and all were identified as CVA24v by molecular typing method. All 9 CVA24v isolates were performed by VP1 sequencing, the results showed that except for strain 0744/BJ/CHN/2007, the variability at nucleotide acid level and amino acid level among other 8 CVA24v were relatively low, and the homologies were more than 99.6% and 100.0%, respectively; the homologies of nucleotide acid and amino acid between strain 0744/BJ/CHN/2007 and other 8 CVA24v were 96.8%-97.2% and 99.7%, respectively. Phylogenetic analysis of 9 CVA24v revealed that they represented the Clade 4 and Clade 5 in Group I, showed that this outbreak was caused by at least 2 viral transmission chains. Comparing to 3C region of CVA24v frequently used before, VP1 region was considered as the most rigorous target for molecular epidemiology study of CVA24v. To enhance the research of sero-epidemiology and molecular epidemiology of CVA24v and to know the genetic characterizations and molecular evolution of CVA24v are most important to prevent and control the outbreaks of AHC in China.

Analysis on the epidemiological features and the transmission of an imported severe acute respiratory syndrome case in Beijing / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the characteristics of severe acute respiratory syndrome (SARS) transmission in the population base on analyzing the first imported case and the chains of transmission.</p><p><b>METHODS</b>For the first imported SARS case and cases who were transmitted by the index case, epidemiological investigations were conducted using the guidelines for surveillance and case investigation issued by the Ministry of Health. Data as the date of onset of symptoms, date of hospitalization, contact history etc. for each of the cases and their close contacts were collected and analyzed.</p><p><b>RESULTS</b>The first imported SARS case introduced to Beijing had infected 9 people within the family and at the hospital, with two of whom died of the same disease. The incubation period for that index case was 4 days, and that for the cases considered to be the secondary and tertiary generations were 7 and 8 days, respectively. The shorter the incubation period, the longer the fever would last and clinically more severe.</p><p><b>CONCLUSION</b>One of the epidemiological characteristics of SARS in Beijing was noticed that the disease clustered in families and hospitals. Infection through droplets and close contact has been viewed as the primary mode of transmission.</p>