Evaluation of the immunization effectiveness of bOPV booster immunization and IPV revaccination.

To provide a basis for further optimization of the polio sequential immunization schedule, this study evaluated the effectiveness of booster immunization with one dose of bivalent oral poliovirus vaccine (bOPV) at 48 months of age after different primary polio immunization schedules. At 48 months of age, one dose of bOPV was administered, and their poliovirus types 1-3 (PV1, PV2, and PV3, respectively)-specific neutralizing antibody levels were determined. Participants found to be negative for any type of PV-specific neutralizing antibody at 24, 36, or 48 months of age were re-vaccinated with inactivated polio vaccine (IPV). The 439 subjects who received a bOPV booster immunization at the age of 48 months had lower PV2-specific antibody levels compared with those who received IPV. One dose of IPV during basic polio immunization induced the lowest PV2-specific antibody levels. On the basis of our findings, to ensure that no less than 70% of the vaccinated have protection efficiency, we recommend the following: if basic immunization was conducted with 1IPV + 2bOPV (especially Sabin strain-based IPV), a booster immunization with IPV is recommended at 36 months of age, whereas if basic immunization was conducted with 2IPV + 1bOPV, a booster immunization with IPV is recommended at 48 months of age. A sequential immunization schedule of 2IPV + 1bOPV + 1IPV can not only maintain high levels of antibody against PV1 and PV3 but also increases immunity to PV2 and induces early intestinal mucosal immunity, with relatively good safety. Thus, this may be the best sequential immunization schedule for polio in countries or regions at high risk for polio.

Comparing the antibody titers of sequential program of Sabin strain-based inactivated poliovirus vaccine followed by bivalent types 1 and 3 oral poliovirus vaccine in different dosage forms / 中华疾病控制杂志

Objective To evaluate the antibody titer distributions after primary vaccination by different sequential schedules of Sabin strain-based inactivated poliovirus vaccine(sIPV) and bivalent oral attenuated live poliomyelitis vaccine against types 1 and 3 (bOPV) in Drug Candy(DC) form or liquid dosage form. Methods Eligible infants of 2 months old selected in Liuzhou were assigned randomly in a ratio of 1:1:1:1 to 4 groups as following: sIPV+2bOPV(DC), sIPV+2bOPV(liquid), 2sIPV+bOPV(DC), 2sIPV+bOPV(liquid), and were vaccinated at 0, 28, 56 days. Polio neutralizing antibody titers against poliovirus types 1, 2 and 3 were tested prior to Dose 1 and at 28 days after Dose 3. Results The antibody titer distribution for type 1 was statistically different between sIPV+2bOPV(DC) and sIPV+2bOPV(liquid) (Z=-2.589, P=0.010) while no significant differences were detected between the two groups for type 2(Z=-0.331, P=0.741) and type 3(Z=-1.556, P=0.120). There were no significant differences between 2sIPV +bOPV(DC) and 2sIPV+bOPV(liquid) for the distributions(All P>0.05) (type 1: Z=-1.249, P=0.212; type 2: Z=-1.658, P=0.097; type 3: Z=-1.436, P=0.151). In the same dosage forms with different sequential schedules, the antibody titer distributions were significantly different between 2 doses sIPV and 1 dose sIPV groups(All P<0.05)(sIPV+2bOPV(liquid) vs 2sIPV+bOPV(liquid): type 1: Z=-2.766, P=0.006; type 2: Z=-9.137, P<0.001; type 3: Z=-5.529, P<0.001. sIPV+2bOPV(DC) vs 2sIPV+bOPV(DC): type 1: Z=-3.748, P<0.001; type 2: Z=-7.660, P<0.001; type 3: Z=-6.030, P<0.001). Conclusions Different dosage forms have similar immune effects, so appropriate dosage forms should be selected for vaccination according to the effectiveness, characteristics of subjects and the population density. In the case of sufficient supply of sIPV, 2 doses sIPV sequential program should be the first choice to complete the primary immunization.

Analysis of human rabies high-occurrence factors in Guangxi from 2004 to 2008 / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Analysis the epidemiological characteristics on rabies cases occurred in Guangxi from 2004 to 2008 and summarize the result of healthy-dog infection rabies virus investigation from 2006 to 2008. Exploring the high-occurrence and correlated factors on rabies in Guangxi.</p><p><b>METHODS</b>Data collected from the National Disease Surveillance System and the National Active Surveillance System for Rabies from 2004 to 2008 and Data of healthy-dog infection rabies virus investigation from 2006 to 2008 were analyzed.</p><p><b>RESULTS</b>The total rabies cases were 2463 in Guangxi from 2004-2008 and average incidence rate was 0.98 per 100 thousand per year. There were 95 counties had rabies case reported, anyway more than 10 cases occurred county number was declined while less than 5 cases rose year by year. The rabies case incidence area was expanded and the cases in middle and west area of Guangxi rose significantly. Rabies cases were reported whole year and no seasonal peak. Human rabies cases mainly were farmers, students and children. Yanger than 20 years old and elder 40 years old were the highest age groups in the population of the investigation, 83.79% cases were attacked by dogs. 78.5% cases classification category III. 83.17% cases had exposed on the upper and lower limbs, 10.56% exposed to the head, face or neck. But 67.88% cases did not receive any PEP and only 18.31% cases vaccinated and 3.63% category III exposure cases combined administration of RIG. The incubation median was 60 days. The rabies virus infection rate among randomly collection healthy-dog brain samples from 2006 to 2008 was 1.92%, 0.93% and 0.89%.</p><p><b>CONCLUSION</b>Unsuccessful and inadequate PEP of patients were the main factors leading to the high-occurrence of human rabies in Guangxi. And there are a lot of infection rabies virus healthy-dogs alive in Guangxi also as a high-occurrence factor.</p>

Study on the status of infection and distribution of rabies virus in China / 中华流行病学杂志

Objective To investigate the status of infection and distribution of rabies virus (RV) in different epidemic areas in China. Methods Brain specimens from animals and suspected patients were collected at the districts of high-, medium- and low incidence rates of human rabies and detected by both direct Immunofluorescence assay (DFA) and RT-PCR. Results 254 of 3007 specimens of dog brains showed RV positive by DFA (positive rate of 8.4% ). Among these 254 samples, 78 showed positive (positive rate of 30.7% ) by RT-PCR. 93 specimens from dogs and cats that had attacked human beings, 63 of them showed positive by DFA (positive rate of 67.7%) and all of them were also positive by RT-PCR. In addition, RV could also be detected in Apodemus agrarius,ferret badger, and suspected patients specimens from the districts under survey. There was no statistical difference between the infection rates of RV in different provinces and regions with different incidence of rabies. Conclusion There might be a relatively high infection rate of RV among the domestic dogs/cats in the endemic areas in China. Wild animals might have been infected with RV in the districts under survey.

A research on rotaviral diarrhea outbreak in Guangxi Province / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To analyze epidemiological characters of an outbreak of rotavirus diarrhea in Daxing County, Guangxi Province.</p><p><b>METHODS</b>Rotavirus-positive specimens were identified by ELISA kit. G/P typing assays were confirmed with multiplex seminested RT-PCR. Full-length VP7 genes of 4 positive specimens were amplified and analyzed.</p><p><b>RESULTS</b>30 cases of Rotavirus-positive were identified from 64 specimens. The attack rate was 46.9%, and G/P typing was G1P[8]. A change of VP7 amino acid residue is at positions 68.</p><p><b>CONCLUSION</b>G1P[8] rotavirus is the etiologic agents of this diarrhea outbreak. In addition, adults were included in this outbreak.</p>

Survey and anslysis of infection rate of dog rabies in the regions with high incidence of human rabies / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the situation of dog rabies and analyze it's relationship with human rabies.</p><p><b>METHODS</b>In Guizhou, Guangxi and Hunan provinces which suffered from rabies most heavily, one or two cities were selected respectively from regions with high-, middle-, low-incidence rate of human rabies as investigation spots where Dogs' brain specimens were collected and detected with both direct immunofluorescence assay (IFA) and RT-PCR.</p><p><b>RESULTS</b>A total of 2887 specimens were collected and 66 of these were positive for IFA and RT-PCR. Therefore, the rate of positive specimens was 2.3%. However, there was not a close relationship in the incidence rate of dog rabies and human rabies.</p><p><b>CONCLUSION</b>Dog's infection situation of rabies contributed to the severe epidemic of human rabies.</p>

Characterization of rabies virus phosphoprotein in high prevalence provinces of China / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Characterization of rabies virus phosphoprotein through analyzation of genetic variations about rabies virus phosphoproteins in high-incidence regions in China.</p><p><b>METHODS</b>The nucleotide sequence of the P gene of Guangxi, Guizhou and Hunan provinces positive sample's were sequenced, and the P region's similarity and phylogenetic analyses were completed by using softer wares.</p><p><b>RESULTS</b>The similarity of P region's nucleotide sequence is 82.1%-100%, while, the similarity of amino acid sequence is 87.5%-100%. A little variation in phosphoprotein cannot influence its biological functions.</p><p><b>CONCLUSION</b>All rabies viruses isolated from Guangxi, Guizhou and Hunan provinces belong to genotype 1 and share same phylogenesis and same genome characteristic; Virus distribution presents unique Characterization; Some virus isolates from Hunan province and Thailand may come from the same virus.</p>

Variations of hepatitis B virus infection epidemic pattern after long-term HBV vaccine immunization / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the epidemic pattern and trend of HBV infection in the area where the people had been immunized by HBV vaccine for 20 years.</p><p><b>METHODS</b>The whole sampling method was applied in combination with cross-sectional investigation. Blood samples were taken from every member of families. Markers of HBV infection were determined by using solid-phase radioimmunoassay (SPRIA).</p><p><b>RESULTS</b>(1) The average HBsAg positive rate was 7.5%. The positive rate of markers for HBV infection of 0-19 years old subjects were lower than those of > or = 20 years old subjects. (2) The positive rate of HBsAg of 0-19 years old subjects in 1985 was higher than that in 2005. The anti-HBs positive rate in 1985 stemmed to be higher with age. It was 12.4% in 1- age group to 53.8% in >60 years age group. While the result of 2005 showed that the anti-HBs positive rate of 0-19 years old subjects dropped with age. The anti-HBc positive rate in 1985 also tended to be higher with age. But the result of 2005 showed that the rate of 0-19 years old subjects was just 1.4% to 16.8%.</p><p><b>CONCLUSION</b>The epidemic patterns of HBV infection have had significant variations in the target population. HBV vaccine immunization has obtained excellent efficacy.</p>

Study on the variations of hepatitis B virus status among people having received hepatitis B vaccine / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the epidemiological pattern and trends of hepatitis B virus (HBV) in the area where people had been immunized by HBV vaccine for long time.</p><p><b>METHODS</b>Through cluster sampling and cross-sectional study, relative information and blood samples from people in Long-an county by families were collected. Signals of HBV infection were tested by solid-phase reverse immunosorbent test.</p><p><b>RESULTS</b>(1) The average HBsAg positive rate was 7.5% with anti-HBs as 44.5 %, and anti-HBc as 47.8%. The positive rates of HBsAg and anti-HBc among 0-19 year-olds were lower than those of > or = 20 year-olds. (2) The positive rates of HBsAg, anti-HBc and HBV infection among HBV vaccine immunized group were 2.8%, 12.0% and 12.5% respectively, comparing with which among the un-immunized group as 10.2%, 69.8% and 71.2% respectively. (3) The HBsAg positive rate of male was higher than the female's but with no significant difference of anti-HBs and anti-HBc between different sexes. (4) The average HBsAg positive rate of 0-19 years old group was only 2.4%, while that of 20-30 years old group was 13.6%-17.7% and dropped from 60 years old group and on. The anti-HBs positive rate of 0-19 years old people started to drop significantly by age. The anti-HBs and anti-HBc positive rates of > or = 20 years people were showing a rising trend by ages.</p><p><b>CONCLUSION</b>It seemed obviously that the HBV epidemiological patterns had changed after HBV vaccine had been universally used for long time in newborns. The age peak of infection had been pushed backward for nearly 20 years. It had been proved that the HBV vaccine immunization program had obtained excellent efficacy.</p>

Analysis on the factors related to rabies epidemic in China, in 2005 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To analyse the related epidemic factors of rabies and to provide basic evidence for developing rabies control and prevention programs in China.</p><p><b>METHODS</b>Possible factors that causing rabies epidemics in the southern part of China were obtained through collecting both epidemic and surveillance data of rabies in 2005, and to analyse every factor by software of Excel 2002.</p><p><b>RESULTS</b>The number of rabies cases was 2548 in 2005. Among 885 cases being investigated, 60.56%, 49.04%, 96.16% had not had any chance to receive treatment, vaccine or immunoglobulin. Among the exposed persons, 89.95% received treatment on wounds and 94.93% were immunized, and 8.56% received immunoglobulin. 94.86% of them accomplished the full rabies post-exposure prophylaxis course, but 8.56% of them did not accomplish it. 88.50% of the cases and 92% of the persons under exposure were bitten by dogs. The density of dogs was 3.20-13.37 per 100 persons. The vaccination coverage rates among dogs were 5.31% -75.11% with a positive rate of 2.93 % -6.40%.</p><p><b>CONCLUSION</b>Factors as: low rate of post-exposure prophylaxis and failed to have finished the necessary post-exposure treatment (PET) of the cases, nonstandard PET in hospital or local clinic, low rabies vaccination coverage and high infectivity of rabies virus in animal host (mainly for dog) might be responsible for rabies epidemics in China, in 2005.</p>