[In vitro study on the effect of ribavirin reducing the EV71 replication].

OBJECTIVE: Observe the effect of Ribavirin on reducing the EV71 replication, inactivating EV71 and protecting the RD-A cells against the EV71 infection in vitro. METHODS: Using the EV71 isolated from Anhui Fuyang HFMD outbreak, the effect of Ribavirin on RD-A cells during the EV71 infection was observed. RESULTS: In the experiment of Ribavirin inhibiting the EV71 replication, comparing with the no-Ribavirin-dealed virus control group, the group of 1:640 dilution of Ribavirin delayed the CPE for 2 days, while the normal cell group was growing very well. In the experiment of protecting cell from EV71 infection, comparing with the no-Ribavirin-dealed virus control group, the group of 1:8 dilution of Ribavirin delayed the CPE for 4 days. In the experiment of Ribavirin effect on the inactivation of EV71, the group of 1:40 dilution of Ribavirin delayed the CPE for 2 days comparing with the virus control group. CONCLUSION: Ribavirin could inhibit the replication of the EV71 and inactivate the EV71 in vitro. Additionally, Ribavirin could protect RD-A cells from EV 71 infection. The observation will contribute to EV71 infection control and quick medicine therapy.

[Analysis epidemiological and pathogen characters of mumps in China from 2004 to 2006].

OBJECTIVE: The study was conducted to analyze the epidemiological characteristics of mumps in China (Hong Kong, Macau and Taiwan excluded) from 2004 to 2006 and to provide basic data for mumps control. METHODS: Descriptive epidemiological analysis was conducted based on the data of epidemic parotitis from National Notifiable Disease Reporting System and mumps virus surveillance database from Nation Measles Lab. RESULTS: The annual incidence rates of parotitis cases during 2004-2006 were 17.45/100, 000, 22.40 /100, 000, 20.76 /100, 000 respectively. All the provinces had parotitis cases report. In all parotitis cases during 2004-2006, the percentage of case number of children (< 15 years old) were 89.77%, 87.87%, 85.15% respectively, while the children between 5-9 years old were 49. 16%, 46.90%, 43.26% respectively. The homology based on 316 nucleotides of the Chinese mumps virus isolated during 2004 - 2006 was 95.4%-100%. CONCLUSION: To prevent and control mumps, the mumps surveillance for serology, virology and eoidemiology should be strengthened in China.

[Seroepidemiology investigation of HEV71 in healthy children of 1-6 years old in three counties of China in 2005].

OBJECTIVES: To investigate human enterovirus 71(HEV71) antibody levels among children in China in recent years, to find the epidemic status of hand, foot and mouth diseases (HFMD) in children, and to provide a scientific base for the HFMD prevention and control. METHODS: 371 sera specimens were colleted from 371 children of 1-6 years old in 3 counties of 3 provinces in 2005. All sera proposed to be detected for measles antibodies investigation. HEV71 antibody was detected by using neutralization test, and then the results were analyzed by statistic methods. RESULTS: 164 sera were positive for HEV71 antibody, the positive rate was 44.2%. The distribution of HEV71-positive rate was associated with age of the children, the positive rate was increasing with the age increasing. Children under 3 years old had lower antibody positive rate. The GMT decreased with the increasing of ages. CONCLUSION: HEV71 infections occurred among children in 3 counties of 3 provinces before 2005, and children under 3 years old were main susceptible population due to their low HEV71 antibody level, It is important to take the preventive measures to protect them from HFMD.

[Seroepidemical study of Coxsackievirus A 16, in four provinces, China, 2005].

OBJECTIVE: To study the situation of 1- 5-years-old children's antibody against Coxsackievirus A group 16 strain (CVA16) in Guangdong, Heilongjiang,Yunnan Province and Xinjiang Uygur Autonomous Regions, China, 2005, it can offer scientific evidences for preventing and controlling CVA16 causative hand-food and mouth disease. METHODS: Using microneutrilization test, to study 503 serum samples randomly selected from sera collected in 2005. RESULTS: Positive rate of anti-CVA16 antibody were 41.90%, 9.40%, 40.00% and 34.40% in Guangdong, Heilongjiang,Yunnan and Xinjiang, respectively. Antibody titer was relative low (average, 1: 6.1) and there was no statistical difference of geometry mean of antibody titer (GMT) among Guangdong, Heilongjiang, Yunnan (F = 0.97, 0.40, 1.06, respectively; P > 0.05), while there had statistical difference of GMT between Heilongjiang and other three regions( F = 10.61, P < 0.00). CONCLUSIONS: There had probably existed local epidemic in some regions of Guangdong, Heilongjiang, Yunnan Province and Xinjiang Uygur Autonomous Regions, China, 2005 or even before, but the area and degree of transmission and epidemic had difference. Children aged from 1- 5-years-old were relatively susceptible population of CVA16 infection.

[Analysis of epidemiological and genetic characteristics of rubella viruses in China from 2007 to 2008].

OBJECTIVE: To understand the epidemiological and genetic characteristics of rubella viruses in China (excluded Hongkong, Macao and Taiwan areas, the same below) from 2007 to 2008, and to provide the basis for the development of rubella immunization strategy. METHODS: Both rubella epidemiology data from rubella disease surveillance information management system and rubella virology data from National measles Laboratory surveillance data base were analyzed. RESULTS: The reported rubella incidence rate was 5.70/100,000 in 2007 and 9.11/100,000 in 2008 and the reported cases distributed in the whole country. The predominant proportions of rubella cases were <15-years-old children which accounted for 80.94% and 81.85% of total cases in 2007 and 2008 respectively. And the highest number of cases belong to 6-10 age groups, which accounted for 43.24% and 44.13% of total cases in 2007 and 2008 respectively. 1E genotype was the predominant genotype of rubella viruses in China during 2007-2008, and the nucleotide homology of the rubella isolates was 98.1%-100%. CONCLUSION: The rubella Serology diagnosis, virological and serological surveillance should be strengthened. Practicable vaccine immunization strategy for different age groups should be established to achieve the goal of prevention and control of rubella and congenital rubella syndrome.

[Use of three-dimensional fluorescence deconvolution microscopy for study of spatial distribution of secretory vesicles in living cells].

A three-dimensional image of a living cell is helpful for cell secretion study. In this report, the three-dimensional fluorescence deconvolution microscopy for observing living cells was studied, because this technique can obtain a quick three-dimensional imaging with minimal fluorescence quenching and cytotoxicity for living cell observation. The property of three-dimensional point spread function (PSF) of imaging system was analyzed. The relationship between experimental and theoretical PSF was illustrated, and the theoretical PSF was proved that it could reflect the principle of imaging system with NA 1.65 objective in use. Three-dimensional deconvolution algorithm in this report was proved effective by well-defined three-dimensional specimens. Furthermore, the rat pancreatic beta cell secretory vesicles labeled by acridine orange was observed by using this technique. Results showed that the blurring induced by out-of-focus light was removed by the deconvolution algorithm effectively, under current experiment conditions (with NA 1.65 objective) the experimental PSF approximated the theoretical PSF very well, and deconvolved living cell images exhibited the spatial distribution of the secretory vesicles clearly.