A postal survey of 730 Malaysian dental practitioners was undertaken to assess their awareness and acceptance of the plasma derived hepatitis B vaccine. Only 32% of the 325 practitioners who responded had been vaccinated, 41% intended to be and 15% categorically refused vaccination. The main reservations about vaccine acceptance were fear of side effects including AIDS, cost of the vaccine and lack of information. Vaccine efficacy was not confirmed by serology in two-thirds of the vaccinees and two-fifths of the respondents were unaware that 5% of the vaccinees do not develop a successful antibody response after vaccination. Seventy-eight percent of dentists believed that their risk of contracting hepatitis B was high or very high while 71% recalled having received needle stick injuries in the 3 yr prior to the survey. Only 13% of respondents were aware of delta hepatitis while 63% were aware of non-A non-B hepatitis. The survey has highlighted the need for dissemination of information on hepatitis B vaccine among dentists in Malayasia.
Blood samples from 1,600 persons who sought immunisation against hepatitis B in private clinics in Singapore in 1988-1989 were screened for two viral markers. Of that total, 4.81% were positive for HBsAg and 17.31% had anti-HBs levels greater than 10 mIU/ml, indicating that about 22.12% of the general population would not benefit from immunisation. Preimmunisation screening will identify persons not requiring the hepatitis B vaccine and thus, avoid wastage. When immunisation has already been performed without screening, recall for post-immunisation screening should be considered in order to detect the infectious hepatitis B carriers. Data in this study indicates that at this point in time, it is important to immunise adolescents and adults, in addition to neonates and children.
Matched MeSH terms: Hepatitis B/prevention & control
Fifty medical students were screened for hepatitis B serological markers of whom 42 students entered the study. Those who were found to be negative for all markers were vaccinated with 1.0 ml (20 mcg HBsAg) Engerix-B vaccine intramuscularly in the deltoid region according to the 0, 1, 6 month schedule. Blood samples were taken at 1, 2, 3, 6, 9 months. One month following the first dose, 7% showed detectable AntiHBs with a GMT of 11 IU/I. By the sixth month, just before the third dose was given, 79% seroconverted with a GMT of 2952 IU/I. Three months following the third dose all had seroconverted with a GMT of 18,381 IU/I. No serious adverse reactions were noted and none of the subjects showed evidence of hepatitis B infection during the study. This study thus confirms the high immunogenicity and safety of recombinant yeast-extract hepatitis B vaccine.
A questionnaire was mailed to 1217 dentists whose names appear in the Dentist Register of 1987 in order to assess their awareness and acceptance of hepatitis B vaccine and their pattern of glove usage. Almost all the respondents (99.6%) were aware of the availability of the hepatitis B vaccine yet only 44.8% have received the vaccine. This is in spite of the fact that the majority (61.2%) of the vaccine non-acceptors have no reservations concerning the vaccine. About 71% and 63% of the vaccine-acceptors and non-acceptors respectively believed that the risk of their contracting hepatitis B was high or very high. About 22% of the vaccine non-acceptors never used gloves when treating patients as compared to 9% among vaccine acceptors. Overall, about 78% of the respondents have experienced needleprick injuries in the 3 years preceding the survey.
Asia and Africa have previously been classified as areas of high endemicity for hepatitis B virus (HBV), but in some countries highly effective vaccination programmes have shifted this pattern towards intermediate or low endemicity. Thus, China is now the only country in Asia where HBV endemicity is high. Countries with intermediate endemicity include India, Korea, the Philippines, Taiwan and Thailand, and those with low endemicity include Japan, Pakistan, Bangladesh, Singapore, Sri Lanka and Malaysia. Most countries in Africa have high HBV endemicity, with the exceptions of Tunisia and Morocco, which have intermediate endemicity. Zambia has borderline intermediate/high endemicity. In the Middle East, Bahrain, Iran, Israel and Kuwait are areas of low endemicity, Cyprus, Iraq and the United Arab Emirates have intermediate endemicity, and Egypt, Jordan, Oman, Palestine, Yemen and Saudi Arabia have high endemicity. All of these Middle East countries reach a large proportion of their population with hepatitis B vaccination, which is reducing the infection rate, particularly in Saudi Arabia. The vaccination programme in Taiwan has also greatly reduced the HBV infection rate. Future vaccination programmes must take into account the mode of transmission of HBV, the healthcare infrastructure to deliver vaccination, and the socioeconomic and political factors in each individual country, to determine the most cost-effective way of infection control.
Matched MeSH terms: Hepatitis B/prevention & control
The MLF since its inception in 1996 has endeavored to develop a coordinated approach towards the improved care and treatment of liver diseases in Malaysia. Its close liaison with the Malaysian MOH, local medical associations, and corporate bodies has contributed to the success of its many programs. Educating the public, research, and training have been important elements of successful hepatitis disease control programs. Hepatitis Days have been proven to be very successful in raising the awareness of the general public to hepatitis disease. Rapid screening and vaccination has also helped to remove the social stigma associated with the disease, eliminated the need for numerous clinic appointments, and rendered vaccination more accessible to the public. The MLF perspective emphasizes the need for collaborative effort between Government bodies and other agencies, such as non-governmental organizations, laboratories, and the medical fraternity, to ensure the overall success of hepatitis disease management programs.
"Parenteral" or "serum" hepatitis is known to have afflicted man for centuries. However, it was not until the mid-1960s that the causative agent of this infection, the hepatitis B virus, was discovered. Since then, the biology and the replication strategy of the virus, and the clinical features and the epidemiology of the hepatitis B infection have been determined. Knowledge about the virus and the infection it causes led to the development of firstly, a plasma-derived vaccine and later a recombinant vaccine for the prevention of the infection. Integration of the hepatitis B vaccine into newborn vaccination programmes on a worldwide basis represents a major step in the effort to eliminate this infectious disease and its complications. Laboratory tests are available for the diagnosis and monitoring of the disease. Therapies have been developed to halt the progress of the chronic infection in affected individuals. While these developments have resulted in a decrease of the frequency of infection in many countries, particularly those that have implemented universal immunization of newborns, the chronic infection remains a significant global problem. Worldwide, over 300 million individuals are infected and each year, an estimated 1 million persons die from chronic complications of the disease including hepatocellular carcinoma and hepatic failure. The therapies currently available result in elimination of the virus in only a relatively small proportion of subjects and carry with it serious side effects. Geopolitical, economic and other factors hinder the vision of elimination of the infection through immunization programmes. Nevertheless, work continues to clarify further the underlying pathological mechanism of the infection, the host and viral factors that promote elimination or persistence of the virus in the human host. It is hoped that such investigations will reveal viral targets for the design of newer and potentially more effective drugs to treat the infection.
Matched MeSH terms: Hepatitis B/prevention & control
The Asia-Pacific Expert Committee on Hepatitis B Management recently reviewed the impact of hepatitis B in the region and assessed the differences and similarities observed in the practical management of the disease in individual Asia-Pacific countries. Hepatitis B is a major health concern in the Asia-Pacific region, and of all chronically infected carriers worldwide, approximately 75% are found in Asia. The disease poses a considerable burden on healthcare systems, and is likely to remain a cause of substantial morbidity and mortality for several decades. Disease prevention activities, including screening and vaccination programs, have been implemented successfully in some Asia-Pacific countries and similar measures are being established in other parts of the region. The management of hepatitis B in the Asia-Pacific varies throughout the region, with each country confronting different issues related to treatment options, disease monitoring and duration of therapy. The influence of cost, availability of diagnostic equipment, and patient awareness and compliance are of additional concern. Although guidelines such as those developed by the Asian Pacific Association for the Study of the Liver have been created to address problems encountered in the management of hepatitis B, many physicians in the region still find it difficult to make satisfactory management decisions because of the treatment choices available. This article examines the different approaches to hepatitis B management in a number of Asia-Pacific countries, and highlights the difficulties that can arise when adhering to treatment guidelines and disease prevention solutions that have proved to be successful in the region.
The implementation of the Expanded Program of Immunization (EPI) in 1989 has dramatic impact on hepatitis B virus (HBV) infection in school children in Malaysia. A cross-sectional seroprevalence study of HBV infection in 190,077 school children aged 7-12 years from 1997 to 2003 showed a steady decline of HBV surface antigen (HBsAg) prevalence rate from 2.5% for children born in 1985 to 0.4% among school children born in 1996. The overall prevalence of HBsAg was 0.6%, 0.7% in males and 0.6% in females. Over 92.7% of school children had been vaccinated with HBV vaccine, in which 93.7% were vaccinated under the EPI and 6.3% on voluntary basis. The school children vaccinated under EPI had a 0.4% HBsAg carrier rate, which was significantly lower than school children vaccinated on a voluntary basis (HBsAg carrier rate 1.3%) and non-vaccinated school children (HBsAg carrier rate 2.7%), suggesting that HBV vaccination of infants was the most effective measure in preventing vertical transmission of HBV in the hyperendemic region.
The association of hepatitis B virus (HBV) infection and liver cancer is well documented in epidemiological study. Patients with chronic hepatitis B have increased risk of hepatocelluar carcinoma (HCC), in particular those with active liver disease and cirrhosis. The incidence of HCC increases with age and is more common among male patients. The introduction of universal HBV vaccination program for the newborn in endemic regions has started to show beneficial impact. Taiwan introduced this program two decades ago and the incidence of liver cancer among infants and young children have declined significantly. The carcinogenic events leading to HCC are under intense research. A number of hypotheses have been proposed. HBV is not directly hepatotoxic but its interaction with the host immune system creates opportunity for HBV DNA integration into the host genome. One of the main foci of research is the HBX-encoded X protein. Its integration and protein expression impose alteration in cell proliferation cycle and apoptosis process. Many other factors may be involved including viral-induced alterations in p53 and telemerase, HBV genotypes, co-infection with HCV or delta agents, patient's lifestyle such as smoking, alcohol excesses, and genetic factors of the host patient. The processes of necroinflammation, cell proliferation and fibrosis facilitate the initial carcinogenic development. HCC surveillance with tumor markers such as alpha-foetal protein, decarboxylated prothrombin, in conjunction with imaging techniques has identified early small HCC that is amenable to curative therapy. Viral load has been correlated with increase risk of HCC. The available anti-viral agents have demonstrated clinical benefit among those with maintained and sustained response. Interferon and lamivudine therapy have demonstrated reduction of HCC among responders. However, they only constitute a minority proportion of treated patients. The mainstay of prevention should lie in prevention of HBV infection and early effective therapy of chronic hepatitis B infection.
Matched MeSH terms: Hepatitis B/prevention & control
Health care workers (HCW) are at higher risk of acquiring blood borne infections such as hepatitis B virus, hepatitis C virus and human immunodeficiency virus from patients. To minimise exposure, Universal Precautions Policy guidelines were introduced. This study looked into one of the aspects of hepatitis B prevention among HCW in the Malaysian context. The objective of this study was to assess hepatitis B vaccine coverage among HCW. A cross sectional study involving pre-tested questionnaires was undertaken from February 2001 to August 2001. Hospital staff in Hospital Kuala Lumpur and Hospital Universiti Kebangsaan Malaysia as well as undergraduate students undergoing clinical attachments were randomly chosen. A total of 625 subjects were enrolled. Only 58.4% had taken a complete hepatitis B vaccination. However, 82.2% have taken at least one dose of the hepatitis B vaccine and were supposed to complete the schedule in due course. Not all HCW were protected against hepatitis B. Preventing hepatitis B in HCW should be one of the priorities of the hospital management as it is definitely cheaper than managing chronic hepatitis B cases.
Due to their impaired immune system, patients with renal insufficiency have a suboptimal response to hepatitis B (HB) vaccination and frequent boosters are needed to maintain protection. GlaxoSmithKline Biologicals has developed a HB vaccine containing a new adjuvant system AS04 for use in this immunocompromised patient population.
Prehemodialysis and hemodialysis patients are at an increased risk of hepatitis B infection and have an impaired immune response to hepatitis B vaccines. We evaluated the immune response to the new adjuvant of hepatitis B vaccine AS04 (HBV-AS04) in this population. We measured antibody persistence for up to 42 months, and the anamnestic response and safety of booster doses in patients who were no longer seroprotected. The primary vaccination study showed that HBV-AS04 elicited an earlier antibody response and higher antibody titers than four double doses of standard hepatitis B vaccine. Seroprotection rates were significantly higher in HBV-AS04 recipients throughout the study. The decline in seroprotection over time was significantly less in the HBV-AS04 group with significantly fewer primed patients requiring a booster dose over the follow-up period. Solicited/unsolicited adverse events were rare following booster administration. Fifty-seven patients experienced a serious adverse event during the follow-up; none of which was vaccine related. When HBV-AS04 was used as the priming immunogen, the need for a booster dose occurred at a longer time compared to double doses of standard hepatitis B vaccine. Hence, in this population, the HBV-AS04 was immunogenic, safe, and well-tolerated both as a booster dose after HBV-AS04 or standard hepatitis B vaccine priming.
Health care workers (HCW) are at high risk of acquiring blood-borne diseases. This study compared the risk of infection among HCW in different hospital units and also between HCW and students in medical fields. This cross-sectional study involved pre-tested questionnaires that were completed by 625 HCW and undergraduate students undergoing clinical attachments from February to August 2001. The respondents were separated into two groups: i) HCW from Hospital Kuala Lumpur, HKL (n=241) and Hospital Universiti Kebangsaan Malaysia, HUKM (n=153) ii) Medical students from Universiti Kebangsaan Malaysia, UKM (n=171) and HUKM student nurses (n=60). The results obtained showed that the risk of transmission of blood-borne infections varied significantly according to professional ranks (p<0.05) and to hospital units (p<0.05). The medical intensive care (ICU), haemodialysis, and nephrology and urology units had the highest scores for the risk of infection while the diagnostic laboratory had the lowest risk of infection (p<0.05). Preventive measures taken by the subjects in this study were not satisfactory especially with reference to the use of personal protective equipment and the practice of universal precautions.
Matched MeSH terms: Hepatitis B/prevention & control
INTRODUCTION: This study aimed to assess the immune response in infants who received the three-shot hepatitis B vaccine in Malaysia.
METHODS: Consecutive infants born between March 2002 and April 2010 who received three doses of hepatitis B vaccine at a community clinic in Malaysia were enrolled in the study. Screening for hepatitis B surface antigen (HBsAg) and antibody against HBsAg (anti-HBs) was performed after the completion of primary immunisation, at approximately one year of age.
RESULTS: A total of 572 infants (median age 9.3 ± 2.7 months; range 6.3-48 months) were screened for immune response to hepatitis B vaccination - 553 (96.7%) infants had adequate levels of anti-HBs (≥ 10 IU/L). Of the 440 mothers whose HBsAg status was known, 14 (3.2%) were positive for HBsAg. None of the 14 infants who were born to HBsAg-positive mothers were positive for HBsAg, and all but one infant had anti-HBs level ≥ 10 IU/L. Gender, gestational age and maternal HBsAg status were not found to significantly affect the subsequent immune response in infants following vaccination.
CONCLUSION: The proportion of Malaysian mothers who are positive for HBsAg remains high. The three-shot hepatitis B vaccine, given as part of universal vaccination against hepatitis B, provides adequate anti-HBs in the vast majority of infants in a community setting in Malaysia.
Matched MeSH terms: Hepatitis B/prevention & control
Hepatitis B virus surface mutants are of enormous importance because they are capable of escaping detection by serology and can infect both vaccinated and unvaccinated populations, thus putting the whole population at risk. This study aimed to detect and characterise hepatitis B-escaped mutants among blood donors and vaccinees. One thousand serum samples were collected for this study from blood donors and vaccinees. Hepatitis B surface antigen, antibodies and core antibodies were tested using a commercial enzyme-linked immunosorbent assay (ELISA) kit. DNA detection was performed via nested polymerase chain reaction (PCR), and the S gene was sequenced and analysed using bioinformatics. Of the 1,000 samples that were screened, 5.5% (55/1,000) were found to be HBsAg-negative and anti-HBc- and HBV DNA-positive. All 55 isolates were found to belong to genotype B. Several mutations were found across all the sequences from synonymous and non-synonymous mutations, with the most nucleotide mutations occurring at position 342, where adenine was replaced by guanine, and cytosine at position 46 was replaced by adenine in 96.4% and 98% of the isolates, respectively. Mutation at position 16 of the amino acid sequence was found to be common to all the Malaysian isolates, with 85.7% of the mutations occurring outside the major hydrophilic region. This study revealed a prevalence of 5.5% for hepatitis B-escaped mutations among blood donors and vaccinated undergraduates, with the most common mutation being found at position 16, where glutamine was substituted with lysine.
Matched MeSH terms: Hepatitis B/prevention & control