How big is the financial burden of hepatitis B to society? A cost-of-illness study of hepatitis B infection in Singapore

Health care resources utilization and costs associated with different clinical stages of chronic hepatitis B in Egypt

Introduction

Chronic hepatitis B (CHB) is associated with many serious clinical and social consequences. Despite Egypt being classified as a country of low endemicity, the infection is associated with a 15–25% risk of premature death from liver cancer or end-stage liver disease. The national committee of treatment and control of viral hepatitis has already offered a high-quality service for the diagnosis and treatment of CHB on a free basis. The current study aims to estimate the health care resources utilization and the annual direct medical cost associated with different clinical stages of CHB-related disease in Egypt.

Methodology

The data was retrieved through record review for three months in the General Administration of Hepatitis Viruses Control, Egypt. Then, the data was extrapolated to the population level by multiplying the prevalence in Egypt with a focus on the productive age groups (25–59 years).

Results

The cost and utilization of different health care resources increase with disease progression. The total annual direct medical costs due to CHB in Egypt is 21.3 L.E. Billion (4.7 Int$ billion/year) for the management of estimated 1,420,700 CHB patients. The direct medical costs among the productive age group (25–59 years) constitute more than half of the total cost (57%). The highest disease burden is encountered among (25–29 years) age group; 2.695 L.E. billion (0.59 Int$ billion/year). Despite liver transplantation phase being associated with the highest annual cost/patient, the number of patients in this stage is the lowest. Then, it only constitutes 0.04% of the disease direct medical cost in the country. The chronic hepatitis clinical stage constitutes 57.26% of the disease direct medical cost in Egypt’s working age group.

Conclusion

Strengthening the preventive and control measures is mandatory to alleviate the disease’s direct medical costs. Close monitoring of the chronic hepatitis stage is mandatory to prevent disease progression. Enhancement of vaccination efforts will lower the disease prevalence and its cost. The universal health insurance system which is gradually implemented in Egypt nowadays will be a cornerstone in relieving the economic stresses by allowing more access to high-quality health care services.

Facilitators and barriers of Hepatitis B screening and vaccination

BACKGROUND

Hepatitis B virus (HBV) infection is the most common cause of liver disease and liver cancer in Singapore, being endemic despite availability of an efficacious vaccine.

OBJECTIVE

To assess the factors associated with HBV screening and vaccination.

METHODS

Using mixed methods analysis, focus group discussions were conducted alongside a cross-sectional study amongst 784 Singapore Citizens and Permanent Residents aged 25-69 residing in Housing and Development Board (HDB) flats.

RESULTS

Amongst the respondents, 50.6% were screened and 37.8% were vaccinated. The self-reported prevalence of HBV infection was 3.4% and that of HBsAg seropositivity among those screened was 4.3%. Routine health screening was the most common reason cited for screening (32.9%) while doctors' recommendation was the most common reason for vaccination (42.7%). For both screening and vaccination, knowledge and cost were the top facilitators and barriers respectively. Multivariable regression models revealed the most significant predictors for not undergoing screening to be poor knowledge (p < 0.001), the presence of stigma (p = 0.040) and not being employed in a healthcare sector (p = 0.022), while factors associated with not undergoing vaccination are that of having not undergone screening (p < 0.001) and the lack of importance placed on the knowledge of the possibility of HBV being a silent killer (p = 0.006).

CONCLUSION

Several facilitators and barriers are seen to regulate health-seeking behaviour towards HBV infection. Public initiatives including education and financial relief targeting specific population groups should be considered to increase the uptake of HBV screening and vaccination.

Estimating the Cost of Illness of Prostate Cancer in Iran

PURPOSE

Prostate cancer is the second most common cancer among men worldwide. In the past 10 years in Iran, prostate cancer has increased and become more common among hormone-related cancers. As the percentage of seniors in the population increases, the economic burden of this cancer will likely increase significantly. This study aims to estimate direct and indirect costs of treatment at different stages of prostate cancer in Iran.

METHODS

This cross-sectional study was conducted on 263 patients diagnosed with prostate cancer who were referred to prostate treatment centers in 2016. Data on direct medical costs were collected by face-to-face interviews with patients and from health care files and medical and financial documents available in the educational or referral centers. Direct nonmedical costs and indirect costs were based on self-reports by patients through face-to-face interview.

FINDINGS

The results indicate that mean (SD) direct medical costs for low-risk metastatic prostate cancer, local nonmetastatic prostate cancer, local regionalized nonmetastatic prostate cancer nonresistant metastatic prostate cancer, and resistant metastatic prostate cancer were $102.79 ($33.03), US$2673.43 ($87.42), $2210.51 ($306.92), $4133.15 ($650.87), and $7747.89 ($455.80), respectively. The results indicate that mean (SD) direct nonmedical costs for low-risk, local, local regionalized, nonresistant, and resistant cancers were $97.06 ($45.00), $339.71 ($58.02), $485.29 ($36.77), $776.47 ($99.25), and $1067.65 ($600.92), respectively, and mean (SD) indirect costs for these categories were $23.85 ($20.44), $83.49 ($65.06), $119.27 ($32.59), $238.54 ($87.35), and $357.81 ($73.00), respectively.

IMPLICATIONS

The findings of this research indicate that patients diagnosed with prostate cancer must bear high costs at advanced stages of the disease, whereas in the early stages of the disease, the medical costs are relatively low. The health system of Iran should work to prevent patients from reaching the metastatic stages of the disease by implementing a suitable screening system for timely diagnosis of the disease and its effective treatment.

Economic evaluation of HBV vaccination: A systematic review of recent publications (2000-2013)

AIM

To conduct a systematic review of the economic evaluations (EE) of HBV vaccination, taking also into account the studies published in the new millennium.

METHODS

An extensive scientific literature review was conducted using two electronic medical journal databases: Scopus and PubMed engines for published studies on EE of HBV vaccination.

RESULTS

22 articles were reviewed, 9, 5 and 8 cost-effectiveness, cost-benefit and cost-utility analysis, respectively. Studies were mainly concerning EE of universal vaccination (UV), mostly with regards to low or low-medium income countries. For high income countries, EE were focused on the possible implementation of HBV vaccination in particular settings, such as diabetic, renal and other chronic conditions care, as well as infectious diseasesUV has usually a very good cost-effectiveness ratio (80%), ranging from cost-saving (China) or few Euro per LY/QALY gained (in Thailand, and Vietnam) to 630.00$/QALY in USA (Asian and Pacific Islands) Moreover, EE of HBV vaccination are favorable in the infectious diseases field as well as for chronic conditions. In relation to diabetes the studies gave controversial results.

CONCLUSION

This systematic review highlighted the importance of introducing HBV vaccination not only for infant UV program but also for other settings in which patients are people affected by communicable and non-communicable diseases.

Economic Burden of Hepatitis C Virus Infection in Different Stages of Disease: A Report From Southern Iran

BACKGROUND

Hepatitis C virus (HCV) infection is a major blood-borne infection which imposes high economic cost on the patients.

OBJECTIVES

The current study aimed to evaluate the total annual cost due to chronic HCV related diseases imposed on each patient and their family in Southern Iran.

PATIENTS AND METHODS

Economic burden of chronic hepatitis C-related liver diseases (chronic hepatitis C, cirrhosis and hepatocellular carcinoma) were examined. The current retrospective study evaluated 200 Iranian patients for their socioeconomic status, utilization (direct and indirect costs) and treatment costs and work days lost due to illness by a structured questionnaire in 2015. Costs of hospital admissions were extracted from databases of Nemazee hospital, Shiraz, Iran. The outpatient expenditure per patient was measured through the rate of outpatient visits and average cost per visit reported by the patients; while the inpatient costs were calculated through annual rate of hospital admissions and average expenditure. Self-medication and direct non-medical costs were also reported. The human capital approach was used to measure the work loss cost.

RESULTS

The total annual cost per patient for chronic hepatitis C, cirrhosis and hepatocellular carcinoma (HCC) based on purchasing power parity (PPP) were USD 1625.50, USD 6117.2, and USD 11047.2 in 2015, respectively.

CONCLUSIONS

Chronic hepatitis C-related liver diseases impose a substantial economic burden on patients, families and the society. The current study provides useful information on cost of treatment and work loss for different disease states, which can be further used in cost-effectiveness evaluations.

Annual economic burden of hepatitis B virus-related diseases among hospitalized patients in twelve cities in China

A nationwide survey of hepatitis B virus (HBV)-associated economic burden has not previously been performed in China. The purpose of this study was to examine the direct, indirect, and intangible costs of HBV-related diseases within the span of one year. A random sample was taken from specialty and general hospitals across 12 cities in six provinces of China. Intangible costs were estimated based on willingness to pay or open-ended answers provided by patients. The results showed that 27 hospitals were enrolled, with a sample population of 4726 patients (77.7% response rate). The average annual costs were $4454.0 (direct), $924.3 (indirect), and $6611.10 (intangible), corresponding to 37.3%, 7.7%, and 55.1% of the total costs, respectively. The direct medical fees were substantially greater than the non-medical fees. Annual indirect costs were divided into outpatient ($112.9) and inpatient ($811.40) loss of income. The intangible costs of chronic HBV were notably higher than either the direct or indirect costs, consistent with the social stigma in China. The comparison amongst individual cities for the average ratio of direct to indirect costs revealed that the sizes of ratios were negatively correlated with the socioeconomic status of the regions. This study suggested that as a whole in China, the HBV-related diseases caused a heavy financial burden which was positively associated with disease severity. Although the intangible costs coincided with a high prevalence of discrimination against CHB patients in Chinese society, our study may serve as future reference for detailed exploration.

Burden of blood transmitted infections in substance users admitted for inpatient treatment in Singapore and the associated factors

INTRODUCTION

There is paucity of local data on the prevalence of blood transmitted infections (BTIs), such as hepatitis B, hepatitis C and human immunodeficiency virus (HIV) infections, among illicit drug users. This study aimed to examine the prevalence of BTIs among substance dependent inpatients and identify the factors associated with BTIs.

METHODS

We conducted a retrospective analysis of clinical notes of 170 inpatients with a diagnosis of substance dependence who were admitted at the National Addictions Management Service, Singapore, between 1 June 2009 and 31 May 2010.

RESULTS

Majority of the 170 inpatients were male (88.2%) and Chinese (58.2%). The mean age of the patients was 43.1 years, and the main drug of abuse was opioids (86.5%). BTIs were found in 70 (41.2%) inpatients; the prevalence of hepatitis B, hepatitis C and HIV infections was 3.7%, 39.6% and 0%, respectively. Lifetime intravenous drug use, but not needle-sharing, was more common among inpatients who were positive for BTIs (p < 0.01). Logistic regression analysis showed that lifetime intravenous drug use (OR 4.3, 95% CI 1.7- 10.8, p < 0.01) was the only significant predictor of BTIs.

CONCLUSION

A large proportion (41.2%) of the substance users seeking help was positive for at least one BTI. Lifetime intravenous drug users were found to be more than four times more likely to have a BTI. Early detection and prevention is essential to improve prognosis.

Disease Burden from Hepatitis B Virus Infection in Guangdong Province, China

Objective: To estimate the disease burden and financial burden attributed to hepatitis B virus (HBV) infection in Guangdong Province. Methods: Based on the data of incidence, mortality and healthcare cost of HBV-related diseases and other socio-economic data in Guangdong Province, we estimated deaths, disability-adjusted life-years (DALYs) and economic cost for the three HBV-related diseases—hepatitis B, liver cirrhosis and liver cancer—in Guangdong following the procedures developed for the global burden of disease study. Then disease burden and economic cost attributed to HBV infection was estimated. Results: HBV infection was estimated to have caused 33,600 (95% confidence interval (CI): 29,300–37,800) premature deaths and the loss of 583,200 (95% CI: 495,200–671,100) DALYs in Guangdong in 2005. The greatest loss of deaths and DALYs were from liver cancer. The 45–59 years age group had the greatest burden attributable to HBV infection. The estimated total annual cost of HBV-related diseases in Guangdong was RMB 10.8 (95% CI: 8.7–13.0) billion，the direct and indirect cost were RMB 2.6 (95% CI: 2.1–3.2) and 8.2 (95% CI: 6.6–9.8) billion. Conclusions: HBV infection is a great medical challenge as well as a significant economic burden to Guangdong Province. The results suggest that substantial health benefits could be gained by extending effective public health and clinical interventions to reduce HBV infection in Guangdong Province.

Rates of cirrhosis and hepatocellular carcinoma in chronic hepatitis B and the role of surveillance: a 10-year follow-up of 673 patients

BACKGROUND AND OBJECTIVES

Development of cirrhosis and hepatocellular carcinoma (HCC) are critical milestones in the natural history of chronic hepatitis B virus (HBV) infection. There are no prospective data on the risk of these critical milestones in HBV patients in Singapore. The efficacy and justification of HCC surveillance is determined by the rate of HCC development. Our study aims to determine the rates of cirrhosis and HCC in HBV patients in Singapore and hence the appropriateness of HCC surveillance.

MATERIALS AND METHODS

A total of 673 HBV patients were enrolled between March 2003 and March 2004 and followed up for 10 years with regular surveillance for HCC using α-fetoprotein and abdominal ultrasound.

RESULTS

Overall, 62.6% of the patients were men, mean age 56.4 years. In all, 31% were hepatitis B e antigen-positive and 14.9% had cirrhosis at baseline. Seventy-four patients developed cirrhosis and 42 patients developed HCC after 10 years. The overall 10-year incidence of cirrhosis and HCC was 16.2% (1.6%/year) and 7.8% (0.8%/year), respectively. The overall incidence of HCC in cirrhotics was 29.7% (3.0%/year), highest within a year of diagnosis of cirrhosis (7.9%). The rate of cirrhosis was significantly higher in those aged more than 55 years (P=0.001). Sex and hepatitis B e antigen status did not affect the rate of cirrhosis. Factors with significantly higher overall rates of HCC were age 55 years or more (P=0.001), male sex (P=0.001), and baseline α-fetoprotein of 4.1 µg/l or more (P<0.0001). However, age more than 55 years was not significant in the development of HCC in cirrhotics.

CONCLUSION

The rate of cirrhosis in HBV patients in Singapore is about 1.6% per year. The rate of HCC is about 0.8% per year overall and 3.0% per year in cirrhotics, which justifies HCC surveillance.

Economic burden of hepatitis B virus-related diseases: evidence from iran

BACKGROUND

Hepatitis B infection is still the main cause of chronic liver disease in Iran, which is associated with significant economic and social costs.

OBJECTIVES

This study aimed to estimate the financial burden caused by CHB infection and its complications in Iran.

PATIENTS AND METHODS

Prevalence-based and bottom-up approaches were used to collect the data. Data on direct medical costs were extracted from outpatient medical records in a referral gastroenterology and hepatology research center, inpatient medical records in several major hospitals in Tehran and Shiraz in 2013, and the self-reports of specialists. Data on direct non-medical and indirect costs were collected based on the patients' self-reports through face-to-face interviews performed in the mentioned centers. To calculate the indirect costs, friction cost approach was used. To calculate the total cost-of-illness in Iran, the total cost per patient at each stage of the disease was estimated and multiplied by the total number of patients.

RESULTS

The total annual cost for the activate population of CHB patients and for those receiving treatment at various disease stages were respectively 450 million and 226 million dollars, with 64% and 70% of which allocated to direct costs respectively, and 36% and 30% to indirect costs respectively. The total direct costs alone for each group were respectively 1.17% and 0.6% of the total health expenditure. Furthermore, the cost spent on drugs encompasses the largest proportion of the direct medical cost for all stages of the disease.

CONCLUSIONS

According to the perspectives of payers, patients, and community, CHB infection can be considered as one of the diseases with a substantial economic burden; the disease, specifically in extreme cases, can be too expensive and costly for patients. Therefore, patients should be protected against more severe stages of the disease through proper treatment and early diagnosis.

The societal burden of chronic liver diseases: results from the COME study

Objective

Chronic liver diseases (CLDs) impose a significant socioeconomic burden on patients and the healthcare system, but to what extent remains underexplored. We estimated costs and health-related-quality-of-life (HRQoL) among patients with CLDs at different stages and with different aetiologies.

Design

A cost-of-illness study was conducted. Direct costs, productivity loss and HRQoL were estimated in patients with chronic hepatitis, cirrhosis hepatocellular carcinoma (HCC) or where orthotopic liver transplantation (OLT) had been performed, for hepatitis C virus (HCV) infection, hepatitis B virus (HBV) infection, or in those with liver disease from other causes. Patients were retrospectively observed for 6 months. The societal perspective was adopted to calculate costs.

Results

In total, 1088 valid patients (median age=59.5 years, 60% men) were enrolled. 61% had chronic hepatitis, 20% cirrhosis, 8% HCC and 12% underwent OLT. HCV infection was identified in 52% and HBV infection in 29% of the patients. Adjusted mean direct costs increased from <€200/patient-month in HCV-infected patients with hepatitis to >€3000/patient-month in HBV infected patients with OLT. Antiviral treatment was the cost driver in patients with hepatitis, while hospital costs were the driver in the other subgroups. Absenteeism increased from HBV-infected patients with hepatitis (0.7 day/patient-month) to patients with OLT with other aetiologies (3.7 days/patient-month). HRQoL was on average more compromised in cirrhosis and patients with HCC, than in hepatitis and patients with OLT. HBV-infected patients generated higher direct costs, patients with other aetiologies generated the highest productivity loss and HCV-infected patients reported the worst HRQoL levels.

Conclusions

The present study can be considered a benchmark for future research and to guide policies aimed at maximising the cost-effective of the interventions.

Direct economic burden and influencing factors in patients with hepatitis B virus related diseases in Jiangsu, China

The purpose of this study was to explore direct economic burden and its influencing factors in patients with hepatitis B virus (HBV) related diseases. Time phasing continuous sampling was used to select patients from August 1, 2012, to December 31, 2012, in 3 county hospitals of 3 model regions in Jiangsu Province, China. A total of 436 outpatients and 196 inpatients were observed. The average direct economic burden of HBV-associated admission was US$107.11 for outpatients, and drug fees accounted for 74%; the burden was US$3193.47 for inpatients, and the direct medical costs accounted for 96%. Multivariate linear regression analysis showed that drug fee, examination fee, and antiviral therapy were influencing factors for outpatients, while hospitalization stay, drug ratio, and patient's age were influencing factors for inpatients. It can be concluded that the direct economic burden of patients with HBV-related diseases was high compared to their household income. Measures should be taken to reduce the economic burden of patients.

Seroepidemiology of hepatitis B virus infection among adults in Singapore: a 12-year review

We undertook a national hepatitis B seroprevalence study to assess the seroprevalence of hepatitis B virus (HBV) markers in the adult population in Singapore in 2010 and make comparisons with the seroprevalence in 1998 and 2004. The study involved residual sera from national health surveys conducted every six years since 1998. The tests for HBV markers were carried out using commercial chemiluminescent microparticle immunoassay. In 2010, the prevalence of hepatitis B surface antigen (HBsAg) among 3293 Singapore residents aged 18-79 years was 3.6% (95% confidence interval [CI] 2.9-4.2%). Hepatitis B e antigen (HBeAg) was detected in 4.2% of those who were HBsAg positive. About 22.5% (95% CI 21.1-23.9%) were positive for antibody to hepatitis B core antigen (anti-HBc). The overall population immunity to HBV, as determined by antibody to hepatitis B surface antigen (anti-HBs)≥ 10 mIU/mL, was 43.9% (95% CI 42.2-45.6%). Among young adults below 30 years of age, HBsAg prevalence (1.1%) was half that in 1998 and 2004, and in those positive for HBsAg, none was positive for HBeAg in 2010, compared to 20.8% in 1998 and 15.8% in 2004. In this age group, anti-HBc prevalence also decreased significantly from 22.1% in 2004 to 4.4% in 2010, while anti-HBs (≥ 10 mIU/mL) prevalence increased significantly from 27.9% in 1998 to 43.3% in 2010 (p<0.001). The national childhood HBV immunisation and catch-up programmes implemented in 1987 and 2001-2004, respectively, had a significant impact in reducing HBV infection and in raising the immunity of the adult population 18-29 years of age.

Risk Factors and Time-Trends of Cytomegalovirus (CMV), Syphilis, Toxoplasmosis and Viral Hepatitis Infection and Seroprevalence in Human Immunodeficiency Virus (HIV) Infected Patients

Introduction: Chronic bacterial, viral and parasitic infections contribute to the morbidity and mortality associated with human immunodeficiency virus (HIV) infection. This study investigated risk factors and time-trends of the seroprevalence of cytomegalovirus (CMV), toxoplasmosis and hepatitis A total antibody; and co-infection with syphilis, hepatitis B and hepatitis C among newly diagnosed HIV individuals in Singapore. Materials and Methods: This was a cross-sectional study. A random sample of 50% of HIV infected patients who visited the Communicable Disease Centre (CDC), Singapore for first-time care from January 2006 to December 2011 were analysed. Results: Among the 793 study subjects, 93.4% were male; 77.9% of them were of Chinese ethnicity; mean age at HIV diagnosis was 41.4 years; and the mean baseline CD4+ T-cell count was 222 cells/mm3. The prevalence of sero-reactivity for CMV was 96.8%; hepatitis A: 40.9%; and toxoplasmosis: 23.7%. Co-infection with syphilis was identified in 12.3%; hepatitis B: 8.1%; and hepatitis C: 2%. Among those co-infected with hepatitis C, 73.3% of them were intravenous drug user (IVDU). Syphilis co-infection was significantly more common among men who have sex with men (MSM) (multivariate OR: 2.53, 95% CI, 1.31 to 4.90, P = 0.006). Conclusion: This study described the baseline rates of HIV co-infection with syphilis, hepatitis B and C in Singapore, and sero-reactivity to CMV, toxoplasmosis and hepatitis A. The increased rates compared to the general population may have important consequences for disease progression, response to antiretroviral treatment and long-term general health. Key words: HIV co-infections, Serology, Sexually Transmitted Infections

Accuracy of routine clinical ultrasound for staging of liver fibrosis

Objective:

To determine the diagnostic accuracy of routine clinical ultrasound in the staging of liver fibrosis in chronic viral hepatitis.

Materials and Methods:

A retrospective evaluation of the ultrasound images of 156 patients with chronic viral hepatitis who underwent liver biopsy was performed. Two radiologists in consensus, blind to the biopsy results and clinical details, evaluated the ultrasound images for liver fibrosis. The readers specifically assessed three features — surface nodularity, liver edge, and parenchymal echotexture — with scores of 0 to 3 (0 = normal, 1 = mild, 2 = moderate, 3 = severe). Accuracies of each sonographic feature for the detection of mild fibrosis and above (≥F1), significant fibrosis (≥F2), severe fibrosis (≥F3), and cirrhosis (F4) were determined with histopathology as the reference standard.

Results:

Fibrosis was present in 99 patients (F1=34, F2=20, F3=22, and F4=23) and absent in 57 patients. The sensitivities for the detection of significant fibrosis with surface nodularity, liver edge, and parenchymal echotexture were 57%, 15%, and 41%, respectively. The accuracies for the detection of ≥F1, ≥F2, ≥F3, and F4 stages were 50.5%, 59%, 59%, and 65% for liver surface, 51%, 53%, 54%, and 55% for liver edge, and 58%, 59%, 63%, and 63% for parenchyma echotexture, respectively. The combined scores from all three features had accuracies of 56%, 59%, 62%, and 66% for the detection of ≥F1, ≥F2, ≥F3, and F4, respectively.

Conclusion:

Routine clinical ultrasound is a not a sensitive predictor of early fibrosis in chronic viral hepatitis. Surface nodularity is the most sensitive sonographic feature for the detection of significant fibrosis and routine clinical ultrasound is the most useful for the detection of cirrhosis.

Trends in prevalence, incidence, and residual risk of major transfusion-transmissible viral infections in United Arab Emirates blood donors: impact of individual-donation nucleic acid testing, 2004 through 2009

BACKGROUND

United Arab Emirates (UAE) has a heterogeneous population consisting of more than 160 nationalities and 85% of the population being non-UAE. In 2007, Dubai Blood Donation Centre (DBDC), the major local supplier of blood in the UAE, introduced six-minipool nucleic acid test (NAT) for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV), which in 2008 upgraded to individual-donation (ID)-NAT. The aim of this study was to analyze the efficacy of the donor screening program in the UAE and evaluate the impact of NAT on the yield and residual risk of transfusion-transmissible viral infections (TTVIs).

STUDY DESIGN AND METHODS

A total of 169,781 blood donations collected at DBDC between 2004 and 2009 were screened for TTVIs. During the period 2008 through 2009, a total of 59,283 donations were tested with both ID-NAT and serologic assays. The incidence, prevalence, and residual risk for each viral agent were estimated and analyzed.

RESULTS

The individual prevalences of HBV, HCV, and HIV per 100,000 donation were 234.4, 110, and 4, respectively. Calculated residual risk per million donations for HBV was decreased from 1.41 in pre-NAT period to 0.92 in post-NAT period. These figures were decreased for HCV and HIV from 1.73 and 0.39 to 0 and 0.32, respectively.

CONCLUSION

Incidence rates and estimated residual risk indicate that the current risk of TTVIs attributable to blood donation is relatively low in the UAE. The study recommends the parallel use of both serology and ID-NAT TTVIs screening in blood donations and suggests the exclusion of antibody to hepatitis B core antigen-positive donations as this can eliminate the potential infectivity of these units with marginal effects on the blood stock in UAE.

Changing Seroprevalence of Hepatitis B Virus Markers of Adults in Singapore

Introduction: We presented the findings from 2 seroprevalence studies conducted 6 years apart, so as to determine changes in the hepatitis B surface antigen (HBsAg) positivity rate and immunity to hepatitis B virus (HBV) among Singapore residents aged 18 to 69 years, and to assess the impact of a 4-year catch-up hepatitis B immunisation programme for adolescents and young adults launched in 2001. Materials and Methods: Two hepatitis B seroprevalence studies (HBSS) were conducted in 1999 and 2005 based on stored blood samples collected from 4698 participants aged 18 to 69 years during the national health survey (NHS) 1998 and from 3460 participants during the NHS 2004, respectively. Serology for HBsAg, hepatitis B e antigen (HBeAg) and antibody to HBsAg (anti-HBs) were tested by enzyme immunoassay in HBSS 1999 and electrochemiluminescence in HBSS 2005. Results: The overall age-standardised prevalence of HBsAg among Singapore residents aged 18 to 69 years decreased significantly from 4.0% in HBSS 1999 to 2.8% in HBSS 2005 (P = 0.002). The age-standardised prevalence of HBsAg in males (4.9% in 1999) and Chinese (4.7% in 1999) both decreased significantly to 2.7% and 2.8%, respectively in 2005. The overall age-standardised population immunity to HBV (anti-HBs >10mIU/ml) increased from 39.7% in 1999 to 42.1% in 2005 (P = 0.019). In particular, the age-specific prevalence of anti-HBs showed a significant increase among those in the age group of 18 to 29 years from 27.9% in 1999 to 41.7% in 2005 (P <0.001) and among those in the age group of 30 to 39 years from 39.9% in 1999 to 44.7% in 2005 (P = 0.021). Conclusion: There was an overall decline in the HBsAg positivity rate as well as an overall increase in population immunity to HBV. Following the 4-year catch-up immunisation programme, there was a significant increase in the immunity to HBV infection in the younger population aged 18 to 29 years. Keywords: Adult infection, Catch-up immunisation, Epidemiological trends