ABSTRACT
<p><b>OBJECTIVE</b>To investigate the prevalence of occult HBV infection in the normal population in Xiamen.</p><p><b>METHODS</b>4 437 registered permanent residents, aged 1-59 years old, were selected in Xiamen using stratified random sampling method from September to October in 2006. Serum samples were obtained, the basic characteristics, inoculation of HBV vaccine, and liver disease were surveyed. The serum samples were tested five HBV seroimmunological markers. The HBsAg-negative specimens were subjected to HBV-DNA detection by nested PCR targeting for multiple gene segments. The amplified products were sequenced and the sequence was used for determination of HBV genotype and mutation analysis of amino acids located in HBsAg "a" epitope. Subjects with serum detectable HBV-DNA and negative result of HBsAg were considered as occult HBV infection.</p><p><b>RESULTS</b>Among the 4 437 subjects, 482 individuals were observed HBsAg positive and 3 944 were observed negative. Of the 3 955 HBsAg- negative specimens, 27 occult HBV infections were determined with the positive rate of 0.68% (27/3 955). There were 16 samples with genotype B and 11 with genotype C. 3 types of amino acid (AA) mutation (M133T, T140I, G145R) that influence "a" epitope conformation were observed in 9 subjects with occult HBV infection. S region was successfully sequenced in 312 of the 482 HBsAg positive samples. In subjects with occult HBV infection, the infection rate of genotype C HBV (40.74%, 11/27), inoculation rate of HBV vaccine (62.96%, 17/27), positive rate of HBsAb (51.85%, 14/27), and mutation rate of critical amino acid of "a" epitope (33.33%, 9/27) were higher than HBsAg positive individuals (22.76% (71/312), 13.78% (43/312),0.32% (1/312),0.99% (31/312), respectively), and all the difference were significant (χ(2) = 4.29, 41.26, 156.00, 13.07, respectively, and P value = 0.038, <0.001, <0.001, <0.001, respectively). While the average age in subjects with occult HBV infection (18.3 ± 16.2) were lower than that in HBsAg positive infection (34.4 ± 11.6), and the difference was significant (t = 6.67, P < 0.001). The reactive rate of HBeAb (11.11%, 3/27) and HBcAb (62.96%, 17/27) in subjects with occult HBV infection were lower than that in HBsAg positive infection (74.36% (232/312), 98.40% (307/312)), and the difference were significant (χ(2) = 46.74, 73.78, respectively, and P value <0.001, <0.001, respectively).</p><p><b>CONCLUSION</b>In normal population in Xiamen, the infection rate of genotype C, the positive rate of HBsAb, the HBV vaccination rate, and the key AA mutation rate in "a" epitope are significantly higher in occult HBV infection than in HBsAg positive infection, and the age, the positive rate of HBeAb and HBcAb are significantly lower.</p>
Subject(s)
Adolescent , Adult , Child , Child, Preschool , Humans , Infant , Middle Aged , DNA Mutational Analysis , Genotype , Hepatitis B , Diagnosis , Hepatitis B Antibodies , Hepatitis B Surface Antigens , Hepatitis B Vaccines , Hepatitis B virus , Mutation , Prevalence , VaccinationABSTRACT
The purpose of the present study was to investigate Norovirus infection status among patients with virus diarrhea in Xiamen city and provide evidence for exploring the prevalence characteristics and constituting appropriate control strategy.From April 2007 to July 2008,323 fecal samples of virus diarrhea cases collected from 3 surveillance hospitals in Xiamen were detected for antigen and RNA by ELISA and Real-Time RT-PCR respectively.The RdPd genes from some samples were furtherly amplified and sequenced for genogroup identification when the Real-Time RT-PCR detection results were positive.In the 323 fecal specimens,68 (21.05%) were positive for Norovirus antigen by ELISA and 107 (31.13%) were positive for Norovirus RNA by Real-Time RT-PCR.The overall positive prevalence rate of Norovirus in Xiamen was 38.08%.107 positive specimens were detected by Real-Time RT-PCR and results showed that 80 strains were Norovirus GGⅡ(74.77%),2 strains were GGⅠ(1.87%) and 25 strains (23.36%)were unidentified.It's indicated that Norovirus infection in Xiamen district was mainly caused by Norovirus GGⅡ,and Norovirus was also the main cause for virus diarrhea.