A study on awareness, occupational risk perception & level of vaccination against hepatitis-B among medical & nursing students in tertiary care hospital, Hyderabad.

Background: HBV(Hepatitis B Virus) infection is an occupational hazard for health care workers and the risk of acquiring HBV infections depends on the frequency of percutaneous and permucosal exposure to blood or blood-contaminated body fluids. Avoiding occupational blood exposure is primary preventive means for the transmission of HBV. However, the single most effective measure for the prevention of hepatitis B is active immunisation. Methods: A cross-sectional study was carried among 204 medical and nursing students in second year of their course using pre-designed questionnaire comprised of questions which included age, sex, qualification, awareness, occupational risk perception & vaccination against hepatitis B infection. Results: 69.12% of the respondents knew various modes of transmission of hepatitis B. More than half (56.86%) of the respondents knew that HBV infection causes liver cancer. 79.41% of the respondents knew the correct course of action after a needle stick injury. Only 61.27% of the respondents knew that blood soaked cotton and dressings are discarded in yellow coloured bags and that sharps and needles are disposed in white coloured bags. Only 36.46% of medical students & 57.41% of nursing students were completely vaccinated. Conclusion: Considering the long-term consequences of HBV infection, the health of the study population is at risk. Preventive strategies against the diseases, especially vaccination programmes, should be developed and taken aggressively to improve the vaccination coverage among the study population.

Prevalence of hepatitis-B surface antigen among population of inmates in Tihar Jail, New Delhi.

Background: Hepatitis B Virus (HBV), a DNA virus with a human only reservoir, is a worldwide public health problem. Unlike other countries especially Europe and America, there is scarcity of published data on HBV infection among prison inmates in India despite its tremendous importance in public heath formulation compared to the general population. The present study was designed to investigate the prevalence of Hepatitis B surface antigen among population of Jail inmates (convicts). Methods: The study population comprised of all the 1102 prison inmates who were screened for Hepatitis B surface antigen (HBsAg) status using one step immunochromatographic array [INSTACHK Hepatitis-B]. Seroprevalence rate of seropositive was calculated and stratified by age and sex. The seropositives were further subjected to HBeAg and anti-HBe detection, HIV status, anti HCV status, HBV-DNA levels and Liver function tests (LFTs) and the patients were then classified into three groups based on HBV-DNA levels and alanine amino transferase (ALT) levels. Results: Out of 1102 inmates screened, 30 (2.72%) were HBsAg positive. Slightly higher percentage prevalence of HBsAg was found among males i.e., 3.19% (or 27/844) than females i.e., 1.16% (or 3/258). Out of 30 HBsAg positive cases, 16 were HBeAg negative, 8 were HBeAg positive and 6 refused to get investigated further. Ten of the 16 HBeAg negative cases were further subjected to anti HBe detection. Half of these cases (5) were reactive for anti-HBe. Based on HBV DNA levels and ALT levels, 8 patients were categorized as HBeAg positive chronic hepatitis-B patients, 12 patients were categorized as HBeAg negative chronic Hepatitis-B patients and 4 patients as inactive HBsAg carriers. Conclusion: HBsAg prevalence among Tihar Jail inmates is comparable to that among the non-incarcerated general population in India.

Role of hepatitis B virus genotype D & its mutants in occult hepatitis B infection.

Background & objectives: Non-detection of hepatitis B virus (HBV) envelope protein (hepatitis B surface antigen, HBsAg) in a chronically HBV infected individual has been described as occult infection. One possible reason for this phenotype is alteration in large (L-HBsAg) to small (S-HBsAg) envelope protein ratio associated with reduced or non secretion of HBsAg. This results in quantitative levels of serum HBsAg below the detection limit of enzyme immunoassays. Genotype D of HBV has a characteristic 33 nucleotide (nt) deletion upstream of the pre-S2/S promoter. This deletion may reduce HBsAg secretion in occult infection patients infected with genotype D HBV. Additional deletions in the pre-S2/S promoter may further aggravate reduced HBsAg secretion in patients infected with genotype D HBV. Thus, the aim of the present study was to determine the role of genotype D specific 33nt deletion and additional pre-S2/S promoter deletions in causing reduced or no secretion of HBsAg, in occult infection. Since these deletions overlap virus polymerase, their effect on virus replication was also investigated. Methods: We examined the in vitro expression of HBsAg, ratio of cure and ‘e’ antigen (HBcAg/HBeAg), their secretion and virus replication, using overlength 1.3 mer/1.86 mer genotype A replicons, and genotype D replicons with and without additional pre-S2/S promoter deletions from cases of occult infection. Results: Genotype D replicon showed a decrease in HBsAg secretion compared to the wild-type genotype A. Genotype D replicons carrying additional pre-S2/S promoter deletions, showed further reduction in HBsAg secretion, demonstrated presence of intracellular HBcAg/HBeAg, virus replication intermediates and ‘e’ antigen secretion. Interpretation & conclusions: The characteristic 33 nt deletion of genotype D HBV reduces HBsAg secretion. Additional pre-S2/S promoter deletions may further diminish HBsAg secretion, leading to occult infection. Pre-S2/S promoter deletions do not affect HBV replication.

Pruebas complementarias a la problemática del diagnóstico de la infección por los virus B y C en donantes de sangre / Complementary tests for the problem of B and C virus infection diagnosis in blood donors

El objetivo de este trabajo es determinar si las transaminasas hepáticas tienen valor como pruebas complementarias que orienten el diagnóstico de hepatitis B y C, en donantes de sangre con anticuerpos positivos por el método ELISA a estas infecciones virales; teniendo en cuenta que las pruebas confirmatorias como el inmunoensayo recombinante (RIBA) o la prueba de ácidos nucleicos por técnicas moleculares como PCR (RNA HCV) para hepatitis C y DNA viral (PCR) para hepatitis B no se realizan aún en nuestro país debido a sus elevados costos. Se busca sumar esfuerzos en salud pública desde los bancos de sangre debido a la trascendencia de llegar a un diagnóstico en los donantes seropositivos, que hayan sido captados en el tamizaje, para prevenir la propagación de estas hepatitis. Se realizaron pruebas serológicas para hepatitis C, anticuerpos frente al antígeno del core de la hepatitis B y determinaciones de los niveles de GPT o ALT (Transaminasa Glutámica Pirúvica o Alanina Amino Transferasa), GOT o AST (Transaminasa Glutámico Oxalacética o Aspartato Amino Transferasa) en 236 donantes de sangre seropositivos para hepatitis B y C del Banco de Sangre del Hospital de Clínicas de la Universidad Nacional de Asunción-Paraguay. Las transaminasas elevadas fueron clasificadas de acuerdo a los marcadores serológicos positivos para hepatitis B y C, encontrándose niveles elevados en un 13.9% de individuos con anti-HBc, 40% en individuos con anti HCV y 2 de 7 casos en individuos con serología positiva para ambos marcadores serológicos. Casi la mitad de los donantes con marcador serológico positivo para anti HCV presentan elevación de las transaminasas.

The aim of this study was to determine if liver transaminases had value as complementary tests to orientate the diagnosis of hepatitis B and C in blood donors with positive antibody to these viral infections by the EIA method, considering that confirmatory tests such as the recombinant immunoassay (RIBA) or nucleic acid test by molecular techniques such as PCR (HCV RNA) for hepatitis C and viral DNA (PCR) for hepatitis B are not performed in our country due to their high costs. We are looking for joining efforts in public health from the blood banks due to the importance of reaching a diagnosis of seropositive donors who have been detected in the screening to prevent the spread of hepatitises. Serologic tests for hepatitis C, antibodies against the core antigen of hepatitis B and determinations of the levels of ALT or GPT (Alanine aminotransferase or Glutamic pyruvic transaminase), AST or GOT (Aspartate aminotransferase or Glutamic oxalacetic transaminase) were carried out in 236 blood donors seropositive for hepatitis B and C of the Blood Bank of the Hospital de Clinicas, National University of Asuncion, Paraguay. Elevated transaminases were classified according to the positive serological markers for hepatitis B and C finding high levels in 13.9% in donors with anti-HBc, 40% in donors with anti HCV and two of seven cases in donors with positive serology for both serological markers. Almost half of the donors with positive serologic marker for anti HCV had elevated transaminases.

Preparation of Monoclonal Antibody Against "a" Determinant With Mutation on Site 145 and Rapid Diagnosis Assay for HBV Mutant Strain / 生物化学与生物物理进展

Hepatitis B virus surface antigen with mutation on site 145 may cause omission in detection of hepatitis B virus with HBsAg diagnostic reagent. Monoclonal antibody against this mutation was obtained through hybridoma technique. The sub-class of the monoclonal antibody was determined to be IgG1(? type, the titer is 1∶9?104), and the monoclonal antibody has no cross-reaction to other hepatitis virus. The method of AC-ELISA which was established with monoclonal antibody and polyclonal antibody showed high analysing susceptibility for HBV mutant samples.

Preparation and characterization of monoclonal antibody against S protein of HBV / 重庆医科大学学报

Objective:To prepare anti-HBV S protein hybridoma cell line,this will be helpful to the establishment of rapid HBV infection diagnosis assay.Methods:BALB/c mice were immunized with the recombinant Hepatitis B vaccine.A hybridoma cell line which consistently secreted monoclonal antibody(McAb)against HBsAg was obtained through cell fusion.The specificity of the McAb was analysed by indirect ELISA and Western blot analysis.The immunoglobulin(Ig)subtypethe ascites titers, and the affinity of the obtained mAbs were determined by indirect ELISA.Results:From over hundred positive hybridomas which secreted anti-S protein mAbs,one of hybridomas was screened out,designated 4D2.The subtype of the McAb was lgG_1. The titer of 4D2 mAb produced by ascites fluid was over 1:10~6.The relative affinity constant of 4D2 mAb was determined as 10~5.Conclusion:One of high titer,specific mAb against HBV S protein has been successfully prepared and primarily identified,which may be useful in the development of a rapid and convenient diagnostic kit for detection of HBV infection.