ABSTRACT
Objective@#To identify the epidemiological characteristics of the common diarrhea-related virusesof children under 5 years of age in Chengdu area, and provide the objective evidences for prevention and control of diarrhea.@*Methods@#Fecal specimens collected from children with acute gastroenteritis between March 2006 and June 2015 were sent to Center for Disease Control and Prevention(CDC) of Sichuan province for detection of viral RNA. Clinical data were also documented. Enzyme-linked immunosorbent assay(ELISA) and/or Reverse transcriptase-polymerase chain reaction(RT-PCR) were used to detect and classify rotavirus, human calicivirus, adenovirus and astrovirus.@*Results@#A total of 2 331 fecal specimens from children (1 446 male and 885 female) under 5 were collected. 1 351 were identified as having viral gastroenteritis with the overall positive rate of 58.0%. Children at the age from 7 to 12 months were the susceptible population. Rotavirus was detected in 659 specimens (28.3%) with epidemic time from November to December. Human calicivirus was detected in 542 specimens (23.3%) and September was its epidemic time. Norovirus GII was the main strain of the virus, but no outbreak was observed in our study. Prevalence of rotavirus declined after 2007, while the detection rate of calicivirus was increasing, which led it to be one of the primary pathogens related to viral gastroenteritis in children under 5. Astrovirus was detected in only 35 patients (1.5%) mainly identified from January to March. Adenovirus was detected in 118 patients (5.1%) mainly from May to August with limited epidemic in 2011. Most patients had acute progress(91.2%), none have chronic progress. Mild dehydration was the most common symptom among all the children, followed by moderate dehydration, while none of the patient had severe symptom. Digestive symptoms are usually accompanied by extra-intestinal symptoms in both virus infection. However, extra-intestinal symptoms had higher incidences in rotavirus infection than in calicivirus infection, while the patients with these symptoms recovered during the follow-up period.@*Conclusions@#Virus infection is the common cause of acute gastroenteritis in children under 5. Rotavirus and human calicivirus were the leading pathogens in Chengdu area.
ABSTRACT
Objective To compare four PCR genotyping method for Clostridium botulinum,and provide the reliable method for detection and identification of Clostridium botulinum from surveillance and foodborn poisoning in Sichuan Province.Methods Six strains of C.botulinum types A,B and E were used to compare four PCR genotyping method-one muhiplex PCR method was from US FDA,two multiplex PCR method and one real-time PCR method were from ISO,and the differences were preliminarily analyzed.Results Three multiplex PCR method could detect C.botulinum types A,B and E in a single reaction.The expected bands for type A were vague using ISO multiplex PCR method 1,whereas bright expected bands could be obtained in the identification of C.botulinum by the other two multiplex PCR method.Real-time multiplex PCR method could detect different types of C.botulinum simultaneously;however,classification should be carried out separately because fluorescent labels were the same.Conclusion Multiplex PCR method from FDA and multiplex PCR method 2 from ISO were relatively simple and could be recommended for C.botulinum surveillance in Sichuan Province.