A serological and molecular survey of hepatitis B in children 15 years after inception of the national hepatitis B vaccination program in eastern China.

The emergence of mutations in the hepatitis B virus (HBV) S gene has threatened the long-term success of vaccination programs since the worldwide introduction of effective vaccines against hepatitis B. This study was conducted on 5,407 children (0-8 years old) in eastern China in 2007. We analyzed the prevalence of HBsAg, anti-HBs, and "a"-determinant mutations in the HBV S gene by microparticle enzyme immunoassays, PCR, and DNASTAR software. The total HBsAg prevalence was 1.52% (82/5,407) in the children and increased with age. In contrast, the positive rate (65.42%, 2,374/3,629) and the titers of anti-HBs decreased with age. The predominant infection was HBV of genotype C and serotype adr (45/51; 88% of cases). Mutations of I126T, amino acid 137 (nt553T deletion mutation), G145A, G145R, and F158S were found in the children; the mutations of amino acid 137 and F158S have not been reported previously. The total prevalence of mutant strains was 14% (7/51). To investigate whether the infection resulted from maternal transmission, we compared the S gene sequences in 16 mother-child pairs. Fourteen mother-child pairs exhibited the same HBV genotype, with 99.5-100% sequence homology in the S gene, while two pairs exhibited different genotypes. This study suggested that the hepatitis B vaccination strategies in eastern China have been successful. Although the emergence of "a"-determinant mutations in the HBV S gene have resulted in HBV infection in immunized children, this does not pose a threat to the vaccination strategies. The HBV-infected children had contracted the infection via vertical transmission.

Epidemiology and Diversity of Rickettsiales Bacteria in Humans and Animals in Jiangsu and Jiangxi provinces, China.

Diseases caused by Rickettsiales bacteria are a global public health problem. To better understand the diversity and origins of Rickettsiales infection in humans and animals, we sampled 134 febrile patients, 173 rodents and 43 shrews, as well as 358 ticks, from two cities in Jiangsu and Jiangxi provinces, China. Our data revealed a relatively high prevalence of scrub typhus cases in both localities. In addition, both serological tests and genetic analysis identified three patients infected with Anaplasma bovis, Rickettsia monacensis, and Orientia tsutsugamushi bacteria. Molecular epidemiological investigation revealed the co-circulation of multiple species of Rickettsiales bacteria in small mammals and ticks in both provinces, potentially including novel bacterial species. In sum, these data demonstrate the ongoing importance of Rickettsiales infection in China and highlight the need for the regular surveillance of local arthropods, mammals and humans.

[An epidemiological investigation of the rabies between 1999 - 2008 in Yancheng city, Jiangsu province.].

OBJECTIVE: To better understand the epidemiology of rabies during the past ten years in Yancheng city, Jiangsu province. METHODS: Data was collected and analyzed on rabies cases in Yancheng. Density and vaccination rate on Canine, Rate of injured people bit by dogs, and the information of post-exposure prophylaxis were studied. Rabies virus in the dog brains, collected around the epidemic areas of Yancheng, were detected and analyzed. RESULTS: A total of 135 human rabies cases occurred from 1999 through 2008, and formed the second epidemic peak since 1958. Of these victims, 84% (114) were farmers. In general, the rate of people having dogs were 3% - 6% per 100 people, and the injured person-times of 100 dogs were 6.37 per year. Notably, the vaccination rate of dogs was only 20%. Of those people injured by dogs and other animals, 77% had received post-exposure treatment, and only 5% - 10% had been administered anti-rabies serum. Rabies virus antigen was found in 4 (3.6%) of 111 brain specimens among dogs collected from epidemic areas. Genetic analysis of N and G genes, which were amplified from brain specimens, indicated that these viruses belong to genotype I rabies and expressing a close relationship with the Chinese vaccine strain CTN. CONCLUSION: The large number of dogs with low vaccination rate among them, together with the incorrect and low post-exposure treatment in rural areas seemed to be responsible for the outbreak of rabies in Yancheng city.

[Study on the efficacy of hepatitis B virus vaccination and its influencing factors among children in rural area of Jiangsu province].

OBJECTIVE: To evaluate the efficacy of hepatitis B viruse (HBV) vaccination and its influencing factors among children in rural area of Jiangsu province. METHODS: Twenty-five hundred and twenty-two children born after 1998 in rural area were selected as the study population using multistage cluster sampling method. HBsAg and anti-HBs were detected by enzyme linked immunoassay (ELISA) and radio-immunoassay (RIA), respectively. Anti-HBs negative children were boosted using different hepatitis B vaccines and the efficacy was compared. Factors causing HBV infection in HBsAg positive children were also investigated. RESULTS: HBsAg positive rates in 1-7 year olds were 0.28%-1.28%, and the anti-HBs positive rates decreased from 76.7% to 45.5%. The HBsAg positive rate in children not timely vaccinated was significantly higher than those with HBV vaccine injection within 24 hours after birth (1.4% vs. 0.5%, P = 0.031). More than 90% of the anti-HBs negative children had protective level of anti-HBs after boosted with HBV vaccine. CONCLUSION: HBsAg positive rate in children born after 1998 in rural area of Jiangsu province decreased significantly, with an average of 0.8%. The reason for HBsAg carriage in children might be attributed to mother-to-infant transmission or not timely HBV vaccination.

Single beam one-way imaging through a thick dynamic turbulent medium.

A new method to record an image through a thick dynamic phase distorting medium by using a photorefractive LiNbO3 crystal is demonstrated. The method uses only one beam of light, the object light. By making use of the photorefractive fanning effect, gratings are formed in the LiNbO3 crystal through the interference between the object light and its own fanning light. Because the time scale of the distorting fluctuation is much shorter than the writing time of the LiNbO3 crystal, the fluctuated light does not induce any fanning. Therefore only the static portion of the image is recorded in the crystal, and the intensity distribution of the image can then be reconstructed at any later time.

One-beam recording in a LiNbO3 crystal.

We propose a new way to record images in a photorefractive LiNbO3 crystal. This method involves only a single object light without any reference light. We believe that the recording is attained by fanning holograms that result from interference between the object light and its scattered light. Although volume gratings are involved, the recorded pattern can be viewed not only with a laser light beam that is incident over a certain angular range but also with white light.

[Sequence analysis of Echovirus type 30 isolated from an aseptic meningitis outbreak in northern Jiangsu province in 2003].

OBJECTIVE: To determine the partial sequence of virus strains causing an aseptic meningitis outbreak in northern part of Jiangsu province in 2003 and to compare them with the same serotype strains isolated in other countries to better understand its genetic characteristics and hereditary trend of development. METHODS: Virus RNA was amplified using two sets of specific enteroviral 3' half of VP1 primers 012/011 and 040/011. Polymerase chain reaction (PCR) products were purified and sequenced. BLAST program was then used to perform on nucleotide and amino acid pairwise-alignment with all available sequences in NCBI database. Phylogenetic trees were drawed to compare with other enteroviral sequences using PHYLIP software. RESULTS: Under BLAST program, three sequences we submitted to GenBank were identically inferred as echovirus type 30, which had been identified by neutralization test in previous study. Phylogenetic analysis demonstrated that strains isolated from this outbreak were aggregated into a cluster, and the closest relationships with them were those isolated in 1999 and 2000. This phenomenon indicated that Echo30 from this outbreak was different from other strains in different epidemic area. CONCLUSION: 3' half of VP1 sequence could be used to quickly identify the serotype of isolated enterovirus. Strains isolated from this outbreak had the similar hereditary developing trend comparing with Echo30 strains isolated from other countries.

[Study on the effects of controlling hepatitis A epidemics by building the colony immune defence].

OBJECTIVE: To build the colony immune defence and to control the periodic epidemics of hepatitis A after a mass vaccination of live attenuated hepatitis A vaccine. METHODS: Through yearly observing the correlation of the accumulative inoculation rates of live attenuated hepatitis A vaccine, the crowd immune standard and the morbidity of hepatitis A after administered live attenuated hepatitis A vaccine among susceptible population and surveilling anti-HAV IgG in the different epidemic areas. RESULTS: (1) The accumulative inoculation rates of live attenuated hepatitis A vaccine was 34.15% in 8 years from 1993 to 2000, among which they were 84.46%, 82.23% and 15.14% in the preschool children, primary and middle school student and 15 - 45 age groups respectively. The morbidity of hepatitis A decreased to 8.26/100,000 in 2000. (2) The crowd positive rates of anti-HAV IgG were 74.24% in 1998 and 83.68% by 2000. Among which they were 74.02%, 68.49%, 79.41%, 85.71% and 90.80% in 2 - 4, 6 - 8, 13 - 15, 20- and 30 - 39 age groups respectively. (3) The accumulative inoculation rates were 37.36%, 51.08% and 28.68% in the inspection areas of Tongtai, Binhai and Yandu respectively. The crowd positive rates of anti-HAV IgG in three inspect area were 85.71%, 85.94% and 78.63% respectively. It was noticed the correlation between the accumulative inoculation rates and the crowd positive rates of anti-HAV IgG was (r(city) = 0.91, F = 15.10, P < 0.03). CONCLUSION: The results showed that the crowd positive rates of anti-HAV IgG had increased to 85% while, the colony immune defence of hepatitis A was effectively built to break the periodic epidemics of hepatitis A. The morbidity of hepatitis A decreased to the lowest level in the history.