Background:The duration of protection following primary series vaccination against hepatitis B is unknown in children and adolescents. It has been shown that the level of anti-hepatitis B surface antigen antibodies (anti HBs Ab) declines over years after vaccination.Objectives:The aim of this study was to estimate the long-term immunity against hepatitis B virus infection among children and adolescents who had received a complete hepatitis B vaccination series during infancy.Patients and Methods:In a cross-sectional study, the - anti-HBsAb levels of 840 vaccinated children and adolescents were determined by enzyme-linked immunosorbent assay.Results:Hepatitis B seroprotection rates (anti HBsAb ≥ 10 IU/L) among vaccinated children and adolescents aged 1 and 18 years were 90% and 48.9%, respectively. The declining trend of geometric mean titer of anti-HBsAb levels was observed as changed from 272.3 IU/L to 94.1 IU/L in 1 and 18-year-old population, respectively. A significant negative correlation was found between age and anti-HBsAb levels (r = - 0.220, P = 0.0001).Conclusions:The results showed a declining trend in anti-HBsAb titers over the time after vaccination against hepatitis B virus in our region. Further studies are warranted to establish the need for a booster dose in cases that are at risk of hepatitis B virus infection.

Background: Helicobacter pylori, a Gram-negative bacteria, is the most important cause of gastric ulcer, gastric malignancies, and chronic gastritis. Clarithromycin is recognized as the most important antibiotic for the treatment. Clarithromycin resistance is related to point mutations in the 23srRNA, and the most important mutation is A2143G, A2142G. The most common cause of resistance to metronidazole is rdxA gene mutational inactivation. Objectives: This study aimed to evaluate clarithromycin and metronidazole resistance in H. pylori by phenotypic and genotypic methods. Methods: In total, 338 gastric biopsy samples were collected. The samples were cultivated on Colombia agar, consisting of various antibiotics and were incubated at 37°C under microaerophilic conditions. The biochemical tests and PCR assay were applied to identify the strains as H. pylori. The E-test was applied in the antibiogram test based on CLSI standard. The PCR-RFLP assay was performed to identify point mutations and followed by sequencing. The PCR method was done to identify deletion of a 200-bp fragment from the rdxA gene. Results: In total, 131 (38.7%) H. pylori strains were isolated that among them, 70 (53.4%) and 83 (63.4%) showed resistance to clarithromycin and metronidazole, respectively. Prevalence of A2143G, A2142G, A2142C mutations were 71.4%, 7.1% and 4.3%, respectively. Seven (8.4%) strains, included 200-bp deletion. Conclusions: The high prevalence of resistance to clarithromycin and metronidazole in H. pylori is a major concern revealed by this study which should be taken into account by physicians in selecting drug regimens. The results confirmed the necessity of phenotypic and genotypic methods of antibiotic susceptibility.

Background:Rubella is a mild viral infection affecting women of reproductive age, and the fetus in early pregnancy, leading to miscarriage, stillbirth and Congenital Rubella Syndrome.Objectives:The present study aimed to assess serum level of anti-rubella antibodies in women younger than 25 years attending medical centers in Ahvaz city.Patients and Methods:This descriptive cross-sectional study was conducted on 760 women younger than 25 years attending medical centers in Ahvaz. A sample of 3 mL of venous blood was taken from each woman and ELISA method was used to assess anti-rubella IgG levels. Antibody level more than 11 IU/mL was considered safe. Data was analyzed by SPSS software using Chi-square, ANOVA and Pearson Correlation tests.Results:Of total samples, 683 women (88.9%) had immunity against rubella, 80 (10.4%) no immunity and 5 (0.7%) intermediate levels of antibody. Immunity to rubella increased significantly with aging (P = 0.001) and a significant association was found between age and antibody titer (P = 0.001, r = 0.261).Conclusions:More than 95% of 15 to 25 year-old women (main reproductive age in Iran) are within acceptable immunity range. Level of immunity to rubella in women of reproductive age in this region appears satisfactory.

Background and Objectives: Helicobacter pylori is a Gram-negative spiral-shaped bacterium that contaminates more than half of the world's inhabitants, and infection with this bacterium is associated with some gastric disorders. Also, 5% to 10% of H. pylori genes are specific to this bacterium and many bacterial virulence factors fall into this group. The cagA, vacA, sodB and hsp60 are among important virulence factors of H. pylori. Materials and Methods: A gastric biopsy specimen was taken from 341 gastric patients and cultivated on a Colombia agar plate, containing various antibiotics, such as vancomycin, amphotericin B, and trimethoprim & polymyxin B, and incubated for 3 to 10 days under microaerophilic conditions at 37°C. PCR was used to detect the ureC, cagA, vacA, sodB and hsp60 genes. Results: In this study, 131 isolates were identified as H. pylori. The prevalence of cagA, vacA, sodB and hsp60 were 74%, 100%, 92.4% and 96.2%, respectively. The correlation between the clinical forms of the disease and the virulence genes were analyzed by statistical tests and no significant correlation was found. Conclusion: The obtained results are similar to some studies conducted in different parts of the world and is different in other cases. This discrepancy is due to the difference in the type of gastric disorders, sample size and methodology.

Background and Objectives: Nontypeable Haemophilus influenzae (NTHi) are major causes of non-invasive infections, including otitis media and sinusitis and it can also contribute to respiratory infections of all ages. Currently, there is no licensed vaccine against NTHi commercially available. Many studies have been conducted on the use of OMV as a vaccine against NTHi. The purpose of this study is to achieve an immunogenic vaccine against NTHi. Materials and Methods: In this study, standard OMV Haemophilus (ATCC49766) with adjuncts CpG and MPLA was used and after infusion into BALB/c mice, the levels of antibodies and cytokines were measured on serum of immunized mice. Results: The results showed that total IgG antibody and IgG1 and IgG2a isotypes in OMV immunized mice with mixture of CpG-MPLA adjuvant had a significant increase. Also, the results of cytokines (IL-10, IL-4 and IFN-γ) showed that IL-4 had the highest rate. Conclusion: These findings indicate that OMVs derived from NTHi strains have a high potential to act as a vaccine against NTHi infections.