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- Razavi-Shearer, Devin M., et al.
(author)
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Adjusted estimate of the prevalence of hepatitis delta virus in 25 countries and territories
- 2024
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In: JOURNAL OF HEPATOLOGY. - 0168-8278 .- 1600-0641. ; 80:2, s. 232-242
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Journal article (peer-reviewed)abstract
- Background & Aims: Hepatitis delta virus (HDV) is a satellite RNA virus that requires the hepatitis B virus (HBV) for assembly and propagation. Individuals infected with HDV progress to advanced liver disease faster than HBV-monoinfected individuals. Recent studies have estimated the global prevalence of anti-HDV antibodies among the HBV-infected population to be 5-15%. This study aimed to better understand HDV prevalence at the population level in 25 countries/territories. Methods: We conducted a literature review to determine the prevalence of anti-HDV and HDV RNA in hepatitis B surface antigen (HBsAg)-positive individuals in 25 countries/territories. Virtual meetings were held with experts from each setting to discuss the findings and collect unpublished data. Data were weighted for patient segments and regional heterogeneity to estimate the prevalence in the HBV-infected population. The findings were then combined with The Polaris Observatory HBV data to estimate the anti-HDV and HDV RNA prevalence in each country/territory at the population level. Results: After adjusting for geographical distribution, disease stage and special populations, the anti-HDV prevalence among the HBsAg+ population changed from the literature estimate in 19 countries. The highest anti-HDV prevalence was 60.1% in Mongolia. Once adjusted for the size of the HBsAg+ population and HDV RNA positivity rate, China had the highest absolute number of HDV RNA+ cases. Conclusions: We found substantially lower HDV prevalence than previously reported, as prior meta-analyses primarily focused on studies conducted in groups/regions that have a higher probability of HBV infection: tertiary care centers, specific risk groups or geographical regions. There is large uncertainty in HDV prevalence estimates. The implementation of reflex testing would improve estimates, while also allowing earlier linkage to care for HDV RNA+ individuals. The logistical and economic burden of reflex testing on the health system would be limited, as only HBsAg+ cases would be screened.
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- Alanko Blomé, M., et al.
(author)
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Vaccination against hepatitis B virus among people who inject drugs – A 20 year experience from a Swedish needle exchange program
- 2017
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In: Vaccine. - : Elsevier BV. - 0264-410X. ; 35:1, s. 84-90
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Journal article (peer-reviewed)abstract
- Background People who inject drugs (PWID) are at particular risk of hepatitis B virus (HBV) acquisition, but often have poor access or adherence to HBV vaccination. Vaccination against HBV has been offered at a major Swedish needle exchange program (NEP) since 1994. The aim of this study was to evaluate vaccine completion and response rates, and the effect of sequential booster doses to non-responders to the standard vaccination schedule. Methods PWID enrolled in the NEP 1994–2013, without serological markers for HBV at baseline (negative for HBsAg/anti-HBc/anti-HBs), were offered a three-dose standard intramuscular vaccination schedule (Engerix®-B, GSK, 20 μg/mL, intended to be received at months 0, 1 and 6). Vaccination response was defined as protective levels of anti-HBs (⩾10 mIU/mL). Up to three booster doses were then offered for non-responders, each followed by anti-HBs testing. Results HBV data was available for 2352 identifiable individuals at NEP enrolment, of whom 1516 (64.5%) had no markers for previous HBV exposure or vaccination. Vaccination was initiated for 1142 (75.3%) individuals and 898 (59.2%) completed the standard vaccination schedule. Post-vaccination anti-HBs levels were available from 800 individuals, with 598 (74.8%) responding to the basic vaccination schedule. After up to three booster doses a total of 676 (84.5%) individuals achieved protective anti-HBs levels. Non-response to vaccination was associated with higher age and anti-HCV positivity (p < 0.001). Eighteen incident cases of HBV infection were observed among vaccine non-responders, as well as 30 cases among those who had not completed vaccination. Conclusion We demonstrate the feasibility of including HBV vaccination in the services offered by a NEP, with completion of vaccination in a majority of HBV-susceptible PWID. The response to HBV vaccination among PWID was relatively low; however, the addition of up to three booster doses improved the response rate from 74.8 to 84.5%.
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