Hepatitis B infection in households of acute cases

Prevalence of hepatitis B virus infection and associated factors among adults intrafamilial household contacts attending antenatal care clinics in the Central Ethiopian region: from pregnant women index cases

BACKGROUND

In Ethiopia, hepatitis B virus infections are prevalent and highly endemic. Additionally, there has been a significant increase in hospital admissions, morbidity, and mortality associated with hepatitis B virus infections. This study aimed to assess the prevalence of hepatitis B virus infection and associated factors among adult intrafamilial household contacts of pregnant women index cases attending antenatal care clinics in the central Ethiopian region.

METHODS

A community-based cross-sectional study was conducted between October 1, 2023, and March 1, 2024. Three hundred eighty-five adult intrafamilial household contacts were randomly selected via lottery methods. A 3 ml venous blood sample was taken from adult intrafamilial household contacts and checked for hepatitis B virus infection through hepatitis B surface antigen. An interviewer-administered questionnaire was used to collect the data. A logistic regression model predicted the relationship between predictor and outcome variables. A p-value of < 0.05 indicated statistical significance.

RESULTS

The overall response rate was 96.1%. Two-thirds of the adults of intrafamilial household contacts (n = 229; 61.9%) were aged between 18 and 28 years, with a mean age of 28 years. The prevalence rate of hepatitis B virus infection among adults of intrafamilial household contacts with pregnant women as the index case was 11.6% (95% CI, 8.6 to 15.1). Being male (AOR: 0.09; 95% CI: 0.03, 0.37) and a duration of stay with the index case of less than six months (AOR: 0.30; 95% CI: 0.11, 0.81) were associated with a reduced risk of hepatitis B virus infection. Meanwhile, large family sizes (≥ 7) (AOR: 4.32; 95% CI: 1.34, 13.98), genital discharge (AOR: 3.14; 95% CI: 1.60, 6.15), engagement in unsafe sex (AOR: 2.37; 95% CI: 1.13, 4.97), and a history of mortality due to hepatitis in the family (AOR: 3.03; 95% CI: 1.09, 8.42) were associated with an increased risk of hepatitis B virus infection.

CONCLUSION

This study found that hepatitis B surface antigen seropositivity among adult intrafamilial household contacts with pregnant women index cases in the central Ethiopia region was high at 11.6%. These findings suggest that interventions to prevent HBV infection should prioritize educational campaigns targeting adult intrafamilial household contacts of HBV-positive index cases, focusing on risk factors associated with HBV transmission, prevention, counselling, testing, and vaccination.

Is It Time for Treatment as Prevention of Chronic Hepatitis B?

Hepatitis B is a major global health problem with high morbidity and mortality. Approximately 296 million people are living with chronic HBV, and 1.5 million new infections are detected each year, even though a highly effective vaccine has been available for decades and viral replication and transmission can be contained with the use of drugs. Nucleoside therapy, while not curative in most cases, can control viral replication, improve prognosis, and prevent mother-to-child transmission safely. Current treatment guidelines do not include a significant number of chronically infected patients or pregnant women and are often complex to implement. Since these populations continue to have a detectable HVB viral load, they could perpetuate transmission. Expanding and facilitating treatment indications, including treatment as a public health intervention, could help control the spread of the HBV pandemic, thus bringing us closer to the goal of the United Nations General Assembly for the year 2030.

A systematic review and meta-analysis of the prevalence of hepatitis B virus infection among pregnant women in Nigeria

Background

Nigeria has a high burden of hepatitis B virus (HBV) infection, commonly acquired through vertical transmission. However, there is a lack of an efficient surveillance system for monitoring and understanding the epidemiology of HBV among pregnant women. Building on a previous review on the prevalence of HBV in Nigeria (2000–2013), we conducted a systematic review and meta-analysis of HBV prevalence among pregnant women in Nigeria.

Methods

Four electronic databases PubMed, Embase, Global Health, and Scopus were systematically searched from January 2014 to February 2021. We also searched the African Journal Online and manually scanned the reference lists of the identified studies for potentially eligible articles. Observational studies that reported the prevalence of HBsAg and/or HBeAg among pregnant women in peer-reviewed journals were included in the study. We performed a meta-analysis using a random-effects model. We defined HBV infection as a positive test to HBsAg.

Results

From the 158 studies identified, 20 studies with a total sample size of 26, 548 were included in the meta-analysis. The pooled prevalence of HBV infection among pregnant women across the studies was 6.49% (95% confidence interval [CI] = 4.75–8.46%; I² = 96.7%, p = 0.001; n = 20). The prevalence of HBV was significantly lower among pregnant women with at least secondary education compared with those with no education or primary education (prevalence ratio = 0.7, 95% CI = 0.58–0.87; n = 10). However, the prevalence of HBV was not significantly different by age, religion, marital status, or tribe. The prevalence of HBV was not significantly different among pregnant women with previous surgery, blood transfusion, multiple lifetime sex partners, tribal marks, tattoos, scarification, or sexually transmitted infections, compared with those without these risk factors. From a total sample size of 128 (n = 7), the pooled prevalence of HBeAg among HBV-infected pregnant women was 14.59% (95% CI = 4.58–27.99%; I² = 65.5%, p = 0.01). Subgroup analyses of HBV infection by study region and screening method, and meta-regression analysis of the study year, sample size, and quality rating were not statistically significant.

Conclusions

There is an intermediate endemicity of HBV infection among pregnant women in Nigeria. Interventions, such as routine antenatal HBV screening, antiviral prophylaxis for eligible pregnant women, and infant HBV vaccination should be scaled up for the prevention of perinatal transmission of HBV infection in Nigeria.

Together let us confront it: An outbreak investigation of hepatitis B in Pathanamthitta district, Kerala

INTRODUCTION

Hepatitis B is a potentially life-threatening liver infection caused by the Hepatitis B virus (HBV). The established routes of transmission are from mother to infant, sexual contact, and exposure to blood or body fluids. Though HBV is preventable by vaccine and robust infection control practices, outbreaks of HBV infection do occur in India. However, the state of Kerala with its health parameters, one among the best in the country, cannot afford to have continuing outbreaks. An unusual increase in the reported cases of Hepatitis B in a rural area of Pathanamthitta district of Kerala, called for an outbreak investigation.

AIMS

To describe the epidemiological features, to determine the risk factors associated with HBV transmission, and to suggest measures to prevent future transmission.

METHODS

A community-based case-control study (1:2) was undertaken. A total of 162 participants (54 cases and 108 age, gender, and neighborhood matched controls) took part in the study. Focus group discussions were conducted with subject experts to develop an interview schedule assessing 40 risk factors. It was further reviewed by the University of Sydney. Data was collected by trained Junior Health Inspectors and Junior Public Health Nurses of the Primary Health Centers. Data was analyzed using SPSS v. 20. Proportions were compared by Univariate analysis, sub-group analysis, and logistic regression. Population Attributable Risk (PAR) was also calculated.

RESULTS AND CONCLUSION

More than 90% of the infections were IgM anti-HBc positive, suggesting a recent infection. Interventions during hospitalization [OR: 7.98 (95% CI - 2.17--29.4)], family history of Hepatitis B [OR. 4.14 (95%CI - 1.73--9.9)], and laboratory investigations [OR: 3.99 (1.72--9.31)] were found to be significant risk factors. PAR was highest for laboratory interventions (32%). Vaccinating household contacts and strict enforcement of infection control practices could substantially reduce the burden of this fatal disease.

Prevalence of serological markers of hepatitis B in inflammatory bowel disease - Experience from a tertiary care centre in South India

Inflammatory bowel disease patients are at risk of hepatitis B infection. Data on this prevalence from South Asia are limited. We conducted a prospective study comprising of 76 inflammatory bowel disease patients between October 2013 and August 2014. Prevalence of hepatitis B surface antigen in inflammatory bowel disease, ulcerative colitis and Crohn's disease patients were 2.6%, 2.4% and 3% respectively and that of markers of hepatitis B exposure (hepatitis B surface antigen /hepatitis B core antibody) were 11.8%, 14.3% and 9.1% respectively. Risk factors found significantly more common in those positive for viral markers compared to those negative were age, non-inflammatory bowel disease related surgery and hospital admission. Only 7(9.2%) had completed hepatitis B vaccination. There is a need to create awareness among physicians regarding the importance of hepatitis B screening and vaccination in inflammatory bowel disease patients.

Hepatitis B virus detected in paper currencies in a densely populated city of India: A plausible source of horizontal transmission?

BACKGROUND

The recent rise in the incidence of hepatitis B virus (HBV) infections in a densely populated city of eastern India (“mixing vessel” of people of varied socio-economic and immune status) prompted this study. Applying saliva on fingers for enumerating bank notes is a common practice in the Indian subcontinent. Paper notes may be a potential source of “horizontal” transmission of this virus, especially if there are cuts/bruises on the oral mucous membrane or skin.

AIM

To investigate whether paper currencies could be a plausible mode of horizontal transmission of HBV infection.

METHODS

Polymerase chain reactions (PCR) followed by nucleotide sequencing was done for the detection of HBV. Hepatitis B virus surface antigen enzyme-linked immunosorbent assay(HBsAg ELISA) was performed on all HBV deoxyribonucleic acid-positive samples to check the detectability of the virus. Atomic force microscopy (AFM) was carried out for visual confirmation of HBV particles in ultracentrifuged/immunoprecipitated samples from currency paper washings.

RESULTS

HBV-specific PCRs on pellets obtained after ultracentrifugation/ immunoprecipitation of the currency paper washings detected potentially intact/viable HBV (genotype D2) in 7.14% of samples (n = 70). AFM gave the visual confirmation of HBV particles in ultracentrifuged/immunoprecipitated samples from currency paper washings. However, HBV isolates from the currency notes could not be detected by HBsAg ELISA.

CONCLUSION

It is a common practice in the Indian subcontinent to count paper currencies by applying saliva on fingertips. Paper notes may be a potential source of “horizontal” transmission of this virus, especially if there are cuts/bruises on the oral mucous membrane or skin, but it was practically not possible to demonstrate experimentally such transmission. Detection of potentially intact/viable and “occult” HBV from currency poses potential risk of silent transmission of this virus among the general population.

Risk for hepatitis B and C virus transmission in nail salons and barbershops and state regulatory requirements to prevent such transmission in the United States

CONTEXT

The potential for hepatitis B and C virus (HBV/HCV) transmission in nail salons and barbershops has been reported, but a systematic review has not been conducted. These businesses are regulated by state cosmetology or barbering boards, but adequacy of sanitary requirements has not been evaluated.

OBJECTIVES

To conduct literature review to assess risk for HBV/HCV transmission in nail salons and barbershops and to evaluate sanitary requirements in HBV/HCV prevention in these businesses in 50 states and District of Columbia.

DESIGN

Several search engines were used for literature search. Studies that quantified risks associated with manicuring, pedicuring, or barbering were included. State requirements for disinfection and sterilization were reviewed and evaluated.

MAIN OUTCOME MEASURE

For literature review, odds ratios, 95% confidence intervals, and confounding adjustment were extracted and evaluated. For regulation review, requirements for disinfection or sterilization for multiuse items in nail salons and barbershops were assessed according to the US federal guidelines.

RESULTS

Forty-six studies were identified and 36 were included in this study. Overall, the results were not consistent on risk for HBV/HCV transmission in nail salons and barbershops. For sanitary requirements, disinfection with an Environmental Protection Agency-registered disinfectant is required in 39 states for nail salons and in 26 states for barbershops. Sterilization was described in 15 states for nail salons and in 11 states for barbershops, but the majority of these states listed it as an optional approach. Sanitary requirements are consistent in states where 1 board regulates both businesses but are substantially discrepant in states with separate boards.

CONCLUSIONS

Current literature cannot confirm or exclude the risk for HBV/HCV transmission in nail salons and barbershops. Existing sanitary requirements are adequate in the majority of states, but compliance is needed to prevent HBV/HCV transmission in these businesses.

Population-attributable estimates for risk factors associated with hepatitis B and C: policy implications for Pakistan and other South Asian countries

INTRODUCTION

Reuse of contaminated syringes, high frequency of injections, tattooing and skin piercing have repeatedly been shown to be important and independent risk factors for the transmission of hepatitis B (HBV) and C (HCV) infections in South Asian countries. Estimation of population-attributable risks indicates the potential for hepatitis prevention if the exposure to certain modifiable factors can be eliminated.

METHODS

We estimated the population-attributable risks of various risk factors for transmission of HBV and HCV using data from a large, nationally representative survey conducted in 2007 across Pakistan, a country known to have a high prevalence of chronic viral hepatitis. Odds ratio estimates and observed prevalence of the risk factors were used for calculating PAR estimates. We also performed a systematic review of published studies that identify the prevalence of similar modifiable risk factors for HBV and HCV from other South Asian countries in order to define an overall prevention strategy for the region.

RESULTS

For HBV, a high frequency (>10) of therapeutic injections in the past 1 year had an attributable risk of 3.5 % (95 % CI 2.9-3.9), reuse of syringes had a 2.7 % risk (95 % CI 2.2-3.1), the practice of being shaved by a barber 2.1 % (95 % CI 1.7-2.6), sharing of smoking utensils 4.4 % (95 % CI 3.8-4.9) and ear/nose piercing 1.4 % (95 % CI 1.2-1.7). Population-attributable risks for HCV were as follows: high frequency of therapeutic injections in the past 1 year 11.3 % (95 % CI 10.5-11.7), reuse of syringes 6.2 % (95 % CI 6.1-6.9), practice of being shaved by a barber shop 7.9 % (95 % CI 7.1-8.2), sharing of smoking utensils 8.1 % (95 % CI 6.9-8.5), practice of ear/nose piercing among females 5.9 % (95 % CI 5.2-6.1) and tattooing 5 % (95 % CI 4.3-5.6). A systematic review showed that other South Asian countries share a number of common risk factors for the transmission of viral hepatitis.

CONCLUSION

A substantial number of HBV and HCV infections in Pakistan and other South Asian countries can be prevented by key interventions targeted toward a few selected and modifiable risk factors. Hence, policies specifically targeted at key risk factors for HBV and HCV such as safe and rational use of injections prescribed by trained health-care providers are urgently needed for countries like Pakistan.

Deficient knowledge on hepatitis B infection in pregnant women and prevalence of hepatitis B surface antigen carriage in an endemic area: a review

Hepatitis B infection is a major global health problem. Vertical transmission is the commonest route of spreading hepatitis B virus (HBV) in many endemic areas. In order to control such transmission in Hong Kong, neonatal immunization programme was implemented for more than two decades. A declining prevalence of HBV infection was expected. However, the prevalence remained unabated at around 10% in recent studies. We suspect that one of the explanations of this persistent high prevalence is deficient knowledge on infection with the HBV and its prevention. Our paper gives an overview of the knowledge on HBV infection among Chinese population in both high and low endemic areas and discusses the potential factors that influenced the knowledge on as well as the implication of the sources of information for HBV infection, which was not addressed in previous studies.

A case-control study of risk factors for hepatitis B virus infection in North Jordan

Jordan is a country with intermediate endemicity for hepatitis B virus (HBV) infection where risk factors for viral transmission and their relative contributions are not well known. A case-control study of 100 hepatitis B virus seropositive patients and another 100 seronegative controls was conducted. Univariate analysis and logistic regression model were performed to examine probable risk factors for acquisition of hepatitis B virus infections. Logistic-regression analysis showed that significant risk factors for acquisition of hepatitis B virus infection were sharing toothbrushes (odds ratio = 10.167; 95% confidence interval, 1.181-87.509), unhygienic dental care (odds ratio = 2.455; 95% confidence interval, 1.294-4.658), and living abroad for at least 1 year (odds ratio = 20.018; 95% confidence interval, 2.268-176.685). The presence of these risk factors emphasizes the need for both increasing the use of hepatitis B vaccines and risk-targeted public health education. Development and enforcement of appropriate infection control guidelines for dental care services are also necessary to curtail HBV transmission. Further research that controls for confounding factors is needed to assess the relative contribution of the identified risk factors in the Jordanian community.

Blood-borne viruses and their survival in the environment: is public concern about community needlestick exposures justified?

BACKGROUND

More than 30 million needle syringes are distributed per year in Australia as a component of harm-reduction strategies for injecting drug users (IDU). Discarded needle syringes create considerable anxiety within the community, but the extent of needlestick injuries and level of blood-borne virus transmission risk is unclear. We have undertaken a review of studies of blood-borne virus survival as the basis for advice and management of community needlestick injuries.

METHODS

A Medline review of published articles on blood-borne virus survival and outcome from community injuries.

RESULTS

Hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) can all survive outside the human body for several weeks, with virus survival influenced by virus titer, volume of blood, ambient temperature, exposure to sunlight and humidity. HBV has the highest virus titers in untreated individuals and is viable for the most prolonged periods in needle syringes stored at room temperature. However, prevalence of HBV and HIV are only 1-2% within the Australian IDU population. In contrast, prevalence of HCV is 50-60% among Australian IDUs and virus survival in needle syringes has been documented for prolonged periods. There have been no published cases of blood-borne virus transmission following community needlestick injury in Australia.

CONCLUSION

The risk of blood-borne virus transmission from syringes discarded in community settings appears to be very low. Despite this, procedures to systematically follow up individuals following significant needlestick exposures sustained in the community setting should be developed.

The efficacy of a toothbrush disinfectant spray--an in vitro study

OBJECTIVES

Toothbrushes are contaminated by micro-organisms which may be sources of infection, re-infection or cross infection. The object of this research is to test the efficacy of a proprietary toothbrush spray disinfectant (Brushtox) against specific test bacteria and fungi and to consider its potential.

METHODS

Three bacteria and two fungi representing a broad microbial spectrum with relevance to oral bacteria were used in four laboratory tests including an in vitro toothbrush disinfection test.

RESULTS

Brushtox proved to be almost 100% effective in three tests and showed significant inhibitory action in the standard agar diffusion test.

CONCLUSION

Brushtox is an effective disinfectant agent for bacteria and fungi on toothbrushes. The solution may be valuable in the control of a wide variety of oral infections and secondary infections, especially in frail or debilitated individuals or those on immuno-suppressive therapy, and also in healthy individuals.

Risks of hepatitis B in travelers as compared to immunization status

BACKGROUND

Our objective was to determine the risks of infection with hepatitis B among European travelers and to compare this with the immunization status in various risk groups.

METHODS

A cross-sectional telephone questionnaire survey of randomly selected subjects, in nine European study populations was used. A total of 9, 008 individuals were involved, with approximately 1,000 interviews conducted in each country in the native languages. Situations with a high risk of hepatitis B infection, such as invasive medical procedures, attending to a bleeding person, and skin perforating cosmetic practices, particularly when performed in countries with medium/high transmission risk, and vaccination status of travelers, were the main outcome measures.

RESULTS

Depending upon the destination, 6.6-11.2% of travelers were classified as at high risk of hepatitis B, with 24.4% vaccinated; between 60.8-75.8% of travelers at potential risk, with 19.2% vaccinated; and 33.4% of travelers where no hepatitis B risk was identified. Significantly more travelers who only visited medium/high endemicity regions exposed themselves to a high risk of contracting hepatitis B, (40, 10.5%) compared to travelers who only visited low endemicity regions (225, 6.6%; p <.01).

CONCLUSIONS

A significant proportion of travelers surveyed unwittingly exposed themselves to the risk of hepatitis B infection while at medium/high risk destinations. The majority of at-risk travelers had not been vaccinated, regardless of their destination. Improved advice and clear recommendations to avoid transmission are needed.

Prevalence of hepatitis B virus (HBV) infection in Singapore men with sexually transmitted diseases and HIV infection: role of sexual transmission in a city state with intermediate HBV endemicity

STUDY OBJECTIVES

To describe the prevalence of hepatitis B virus (HBV) infection in patients with sexually transmitted diseases (STD) and human immunodeficiency virus (HIV) infection, and to determine the role of sexual transmission of HBV infection in Singapore.

DESIGN

A cross sectional study of all consecutive men presenting with a new episode of STD at a government outpatient clinic and all men with HIV infection on routine follow up at a government hospital. The prevalence of various HBV markers was compared with that of healthy males aged 15 years and above (controls).

SETTING

Singapore, a city state of intermediate HBV endemicity.

SUBJECTS

These comprised 497 STD patients, 47 HIV infected patients, and 418 controls.

MAIN RESULTS

The overall seroprevalences of HBV infection in STD patients, HIV infected patients, and control subjects were 41.2%, 61.7%, and 33.3%, respectively (p < 0.001). The seroprevalences of hepatitis B surface antigen (6.2%, 8.5%, and 4.5%, respectively) were comparable in the three groups. Using stepwise logistic regression analysis, the adjusted seroprevalences of HBV infection in STD and HIV infected patients were respectively 2.4 times (95% confidence interval (CI), 1.7, 3.3) and 3.3 times (95% CI 1.7, 6.3) higher than in controls. HBV infection rates were higher among Chinese (odds ratio (OR), 1.9; 95% CI 1.6, 3.4) than non-Chinese, and among those aged 25-34 years (OR 2.4; 95% CI 1.6, 3.4), 35-44 years (OR 3.9; 95% CI 2.5, 5.9), and 45+ years (OR 6.2; 95% CI 3.8, 10.2) than in those aged 15-24 years. Sex related factors significantly associated with higher infection rates, independent of age and ethnic group, were reactive VDRL test (OR 2.4; 95% CI 1.2, 4.7), participation in anal intercourse (OR 2.3; 95% CI 1.2, 4.3), and having 10 or more lifetime sexual partners (OR 1.5; 95% CI, 1.0, 2.1).

CONCLUSION

The importance of sexual transmission of HBV in an area of intermediate HBV endemicity was confirmed. Patients attending STD clinics should be routinely screened for HBV markers and those found to be seronegative should be strongly advised to be immunised against this virus.

Seroepidemiology of hepatitis A and hepatitis B virus infection in a Gurkha community in Singapore

The overall prevalence of hepatitis A virus (HAV) infection among the Gurkhas and their families stationed in Singapore was 83.2%, with antibody to HAV detected in 67 (38.1%) of 176 children under 5 years of age, 121 (76.6%) of 158 children between 5 and 14 years, and 600 (97.9%) of 613 older children and adults over age 15 years. Children born in Singapore (102/223 or 45.7%) had a significantly lower crude prevalence than those born in Nepal (85/110 or 77.3%) (P < 0.000001). The age-adjusted difference in prevalence was also statistically significant (P < 0.001). Susceptible children had a high risk of acquiring HAV infection when they travelled to Nepal. As for hepatitis B virus (HBV) infection, the prevalence of hepatitis B surface antigen (HBsAg) was 2.8%, with a higher rate in males (20/560 or 3.6%) than in females (6/384 or 1.6%). The highest HBsAg prevalence (4/26 or 15.4%) was in young adult Gurkhas 15-19 years of age. No significant difference in the crude prevalence of HBV markers was noted between children born in Singapore (45/224 or 20.1%) and those born in Nepal (19/107 or 17.8%). Even after age adjustment, the difference remained insignificant. The prevalence of HBV markers of children of seropositive parents (27/156 or 17.3%) was not significantly higher than that of seronegative parents (19/131 or 14.5%). Married men had a significantly higher age-adjusted prevalence of infection than unmarried men (45.4% and 32.4%, respectively; P < 0.05). Seropositivity of one spouse was significantly correlated with the seropositivity of the other (P < 0.05), suggesting a role for heterosexual transmission of HBV infection.

Horizontal or vertical transmission of hepatitis B virus? A serological survey in family members of hepatitis B carriers in Singapore

Hepatitis B serology was performed on 270 family members of 78 hepatitis B carriers and hepatitis B e antigen status determined in those found to be HBsAg positive. The mean age of index patients was 38 years (range 3-74) and that of family members was 28 years (range 1-71). 67 family members (25%) were HBsAg positive. The proportions of family members positive for HBsAg and those negative for HBsAg but positive for anti-HBs and/or anti-HBc were 25% and 20% for children, 10% and 68% for spouses, 36% and 26% for siblings and 29% and 55% for parents. For children of index parents the proportions positive for HBsAg and those negative for HBsAg but positive for anti-HBs and/or anti-HBc were similar whether the index patient was the mother (24% and 24%) or the father (26% and 18%). Our results suggest that horizontal transmission is a significant mode of spread of hepatitis B within the family in Singapore.

The hepatitis B immunization programme in Singapore

A voluntary immunization programme to prevent perinatal transmission of hepatitis B virus (HBV) infection in Singapore was implemented on 1 October 1985 as an integral component of the national childhood immunization programme. Up to April 1988, a total of 68,845 mothers who attended government maternal and child health clinics were screened for the disease. Of these, 2432 (3.5%) were positive for hepatitis B surface antigen (HBsAg) and 904 (1.3%) for hepatitis B e antigen (HBeAg). Virtually all the babies born to carrier mothers completed the full immunization schedule; and in addition, those of HBeAg-positive mothers were given a dose of hepatitis B immunoglobulin at birth. The hepatitis B immunization programme was extended on 1 September 1987 to cover all newborns. About 90% of the 15,943 babies delivered in government institutions from September 1987 to April 1988 were immunized at birth, with the subsequent doses being administered at maternal and child health clinics at 4-6 weeks and 5 months later. More than 85% of the children given the full course of plasma-derived and yeast-derived hepatitis B vaccine from birth continued to have protective antibody to HBV two years after immunization. The programme is being closely monitored to assess the duration of immunity and the need for booster doses, while seronegative adults are also being encouraged to be vaccinated.

The prevalence of hepatitis B virus markers in dental personnel in Singapore

A seroepidemiological survey of the prevalence of hepatitis B virus (HBV) markers was conducted in a group of 693 dental personnel in Singapore where HBV infection is endemic. The overall prevalence of HBsAg (4.5%) and anti-HBc (29%) was no higher than that in the general population. However, dentists had a significantly higher HBsAg prevalence (11.4%) compared with that in the general population (4.2%) (P less than 0.01) and of other categories of dental personnel (3.1%) (P less than 0.001). Similarly, the anti-HBc prevalence of the dentists (45.6%) was significantly higher than that of the general population (29.7%) (P less than 0.01) and of other categories of dental personnel (25.7%) (P less than 0.0001). It appears that dentists in the endemic area have a definite occupational risk of acquiring HBV infection.

History of blood transfusion, tattooing, acupuncture and risk of hepatitis B surface antigenaemia among Chinese men in Singapore

To determine whether a history of blood transfusion, tattooing, and acupuncture is associated with an increased risk of hepatitis B surface antigenaemia, a study of 6,328 Chinese men between 35 and 65 years of age was undertaken in Singapore. The age-adjusted odds ratios were 1.44 (95% CI: 1.14, 1.83) for blood transfusion, 1.14 (95% CI: 0.80, 1.63) for tattooing, and 0.88 (95% CI: 0.71, 1.11) for acupuncture. Using no history of any of the three percutaneous procedures as reference, the age-adjusted odds ratio for blood transfusion only was 1.40, 95% CI: 1.07, 1.84, and for blood transfusion plus tattooing was 2.59, 95% CI: 1.18, 5.70. The proportion of HBsAg positive cases attributable to blood transfusion and tattooing, as measured by the population attributable risk, are 4.1 and 0.7 per cent, respectively.

The hazard of infection from the shared communion cup

Interest and concern that the shared communion cup may act as a vehicle for indirectly transmitting infectious disease was reawakened when the human immunodeficiency virus (HIV) was detected in the saliva of infected persons. Bacteriological experiments have shown that the occasional transmission of micro-organisms is unaffected by the alcoholic content of the wine, the constituent material of the cup or the practice of partially rotating it, but is appreciably reduced when a cloth is used to wipe the lip of the cup between communicants. Nevertheless, transmission does not necessarily imply inoculation or infection. Consideration of the epidemiology of micro-organisms that may be transmitted via saliva, particularly the herpes group of viruses, suggests that indirect transmission of infection is rare and in most instances a much greater opportunity exists for direct transmission by other means. There is substantial evidence that neither infection with hepatitis B virus nor HIV can be transmitted directly via saliva so that indirect transmission via inanimate objects is even less likely. No episode of disease attributable to the shared communion cup has ever been reported. Currently available data do not provide any support for suggesting that the practice of sharing a common communion cup should be abandoned because it might spread infection.

Evaluation of a low dose of hepatitis B vaccine given within a childhood immunisation programme in Singapore

The feasibility of introducing low dose (5 micrograms) hepatitis B (HB) virus vaccination at birth and again 1 and 2 months later as part of an existing primary immunisation programme of childhood, was assessed in 662 healthy newborn Singapore children. The vaccine (B-Hepavac, Menck, Sharp and Dohme) was given to three neonatal groups: those born to HB surface antigen (sAg)-negative mothers, HBsAg-positive/HBeAg-positive mothers and HBsAg-positive/HBeAg-negative mothers. A dose of 5 micrograms was compared in a randomised study with the more usual 10 micrograms dose given at the same intervals. Neonates born to HBsAg-positive/HBeAg-positive mothers were also given hepatitis B immunoglobulin (HBIg) at birth. The 5 microgram dose of vaccine was as immunogenic as the 10 microgram dose in all three groups of children studied. At 1 year, anti-HBsAg seroconversion among infants of antigen-negative mothers was 95.8% for the 5 microgram dose and 91.9% for the 10 microgram dose. Suppression of anti-HBsAg formation was not seen even when maternal anti-HBsAg was present or HBIg given. Among infants born to HBsAg-positive/HBeAg-positive mothers, passive plus active immunisation was 100% protective at doses of 5 micrograms and 10 micrograms vaccine in the newborns who were HBsAg-negative at 24 h. Seroconversion after both the 5 and 10 microgram doses of vaccine was reduced, however, to 88% in each group of infants who were already HBsAg-positive at 24 h of age. Overall, passive plus active immunisation as well as HB vaccine alone (5 micrograms dose), given within the existing but expanded primary immunisation programme of childhood, was effective in preventing infection and the chronic carrier state in newborns exposed to risk of HB virus infection during infancy.