Rapid SARS-CoV-2 Seroprevalence Survey in Central and Western Divisions of Fiji, 2021.

During November-December 2021, we performed a SARS-CoV-2 seroprevalence survey in Central and Western Divisions of Fiji. A total of 539 participants 8-70 years of age were 95.5% (95% CI 93.4%-97.1%) seropositive, indicating high community levels of immunity. Seroprevalence studies can inform public health responses to emerging SARS-CoV-2 variants.

Prevalence of hepatitis B virus amongst refugees, asylum seekers and internally displaced persons in low- and middle-income countries: A systematic review.

Hepatitis B, caused by the hepatitis B virus (HBV), is a global public health issue that affects 290 million people worldwide. Most people with hepatitis B are in low- and middle-income countries (LMIC), where health systems and resources are often constrained. Refugees, asylum seekers and internally displaced persons (IDPs) often face barriers in seeking health care and are a priority population at risk of hepatitis B. No systematic review to date has evaluated the prevalence of hepatitis B amongst refugees in in LMIC. We undertook a systematic review of the literature identifying 28 studies addressing this topic. Though few studies on this topic exist, the available evidence suggests a high prevalence amongst refugees in LMIC, with wide variation between and within countries. Possible risk factors contributing to hepatitis B include unsafe injections, low immunization coverage, low awareness, mother-to-child transmission, and limited health services. Further study is needed to better understand the prevalence and risk factors for hepatitis B amongst refugees in LMIC, to inform public health responses. Vulnerable populations such as refugees are an important group to consider in national and global efforts to eliminate hepatitis B.

Genomic Evidence of In-Flight SARS-CoV-2 Transmission, India to Australia, April 2021.

Epidemiologic and genomic investigation of SARS-CoV-2 infections associated with 2 repatriation flights from India to Australia in April 2021 indicated that 4 passengers transmitted SARS-CoV-2 to >11 other passengers. Results suggest transmission despite mandatory mask use and predeparture testing. For subsequent flights, predeparture quarantine and expanded predeparture testing were implemented.

Investment Case for a Comprehensive Package of Interventions Against Hepatitis B in China: Applied Modeling to Help National Strategy Planning.

BACKGROUND: In 2016, the first global viral hepatitis elimination targets were endorsed. An estimated one-third of the world's population of individuals with chronic hepatitis B virus (HBV) infection live in China and liver cancer is the sixth leading cause of mortality, but coverage of first-line antiviral treatment was low. In 2015, China was one of the first countries to initiate a consultative process for a renewed approach to viral hepatitis. We present the investment case for the scale-up of a comprehensive package of HBV interventions. METHODS: A dynamic simulation model of HBV was developed and used to simulate the Chinese HBV epidemic. We evaluated the impact, costs, and return on investment of a comprehensive package of prevention and treatment interventions from a societal perspective, incorporating costs of management of end-stage liver disease and lost productivity costs. RESULTS: Despite the successes of historical vaccination scale-up since 1992, there will be a projected 60 million people still living with HBV in 2030 and 10 million HBV-related deaths, including 5.7 million HBV-related cancer deaths between 2015 and 2030. This could be reduced by 2.1 million by highly active case-finding and optimal antiviral treatment regimens. The package of interventions is likely to have a positive return on investment to society of US$1.57 per US dollar invested. CONCLUSIONS: Increases in HBV-related deaths for the next few decades pose a major public health threat in China. Active case-finding and access to optimal antiviral treatment are required to mitigate this risk. This investment case approach provides a real-world example of how applied modeling can support national dialog and inform policy planning.

Impact of alcohol on the progression of HCV-related liver disease: A systematic review and meta-analysis.

BACKGROUND & AIMS: Despite a marked reduction in new cases of cirrhosis caused by HCV infection, over 500,000 new cirrhosis cases in this category were estimated globally in 2019. This contribution quantifies the relationship between alcohol use and the progression of liver disease in people with HCV infections. METHODS: The causal impact of different levels of alcohol use on cirrhosis has previously been established. The quantification of this relationship was undertaken based on a systematic search of the literature and a meta-analysis. We limited our search to longitudinal and case-control studies with biologically verified outcomes. Different sensitivity analyses were conducted to check on key assumptions and on the generalizability of the relationship. RESULTS: Alcohol use has a dose-dependent relationship with incident cirrhosis, which is linear on the log-linear level, and thus exponential on the level of odds ratios or other risk indicators. Each standard drink of 12 grams of pure alcohol per day increases the risk by about 11%. The results were stable regardless of the statistical model used, level of adjustment, quality of the study, or outcome (i.e., cirrhosis, decompensated cirrhosis, liver-related death). CONCLUSIONS: Alcohol use has a marked impact on the progression of HCV infections to cirrhosis and more severe liver outcomes. LAY SUMMARY: Alcohol consumption has a significant impact on the progression of liver disease in people with HCV infections. Each alcoholic drink per day is associated with an increase in the risk of cirrhosis of 11%.

Survey of programmatic experiences and challenges in delivery of hepatitis B and C testing in low- and middle-income countries.

BACKGROUND: There have been few reports on programmatic experience of viral hepatitis testing and treatment in resource-limited settings. To inform the development of the 2017 World Health Organization (WHO) viral hepatitis testing guidance and in particular the feasibility of proposed recommendations, we undertook a survey across a range of organisations engaged with hepatitis testing in low- and middle-income countries (LMICs). Our objective was to describe current hepatitis B and C testing practices across a range of settings in different countries, as well as key barriers or challenges encountered and proposed solutions to promote testing scale-up. METHODS: Hepatitis testing programmes in predominantly LMICs were identified from the WHO Global Hepatitis Programme contacts database and through WHO regional offices, and invited to participate. The survey comprised a six-part structured questionnaire: general programme information, description of hepatitis testing, treatment and care services, budget and funding, data on programme outcomes, and perceptions on key barriers encountered and strategies to address these. RESULTS: We interviewed 22 viral hepatitis testing programmes from 19 different countries. Nine were from the African region; 6 from the Western Pacific; 4 from South-East Asia; and 3 from Eastern Europe. All but four of the programmes were based in LMICs, and 10 (45.5%) were supported by non-governmental or international organizations. All but two programmes undertook targeted testing of specific affected populations such as people living with HIV, people who inject drugs, sex workers, health care workers, and pregnant women. Only two programmes focussed on routine testing in the general population. The majority of programmes were testing in hospital-based or other health facilities, particularly HIV clinics, and community-based testing was limited. Nucleic acid testing (NAT) for confirmation of HCV and HBV viraemia was available in only 30% and 18% of programmes, respectively. Around a third of programmes required some patient co-payment for diagnosis. The most commonly identified challenges in scale-up of hepatitis testing were: limited community awareness about viral hepatitis; lack of facilities or services for hepatitis testing; no access to low cost treatment, particularly for HCV; absence of national guidance and policies; no dedicated budget for hepatitis; and lack of trained health care and laboratory workers. CONCLUSIONS: At this early stage in the global scale-up of testing for viral hepatitis, there is a wide variation in testing practices and approaches across different programmes. There remains limited access to NAT to confirm viraemia, and patient self-payment for testing and treatment is common. There was consensus from implementing organizations that scale-up of testing will require increased community awareness, health care worker training, development of national strategies and guidelines, and improved access to low cost NAT virological testing.

The HepTestContest: a global innovation contest to identify approaches to hepatitis B and C testing.

BACKGROUND: Innovation contests are a novel approach to elicit good ideas and innovative practices in various areas of public health. There remains limited published literature on approaches to deliver hepatitis testing. The purpose of this innovation contest was to identify examples of different hepatitis B and C approaches to support countries in their scale-up of hepatitis testing and to supplement development of formal recommendations on service delivery in the 2017 World Health Organization hepatitis B and C testing guidelines. METHODS: This contest involved four steps: 1) establishment of a multisectoral steering committee to coordinate a call for contest entries; 2) dissemination of the call for entries through diverse media (Facebook, Twitter, YouTube, email listservs, academic journals); 3) independent ranking of submissions by a panel of judges according to pre-specified criteria (clarity of testing model, innovation, effectiveness, next steps) using a 1-10 scale; 4) recognition of highly ranked entries through presentation at international conferences, commendation certificate, and inclusion as a case study in the WHO 2017 testing guidelines. RESULTS: The innovation contest received 64 entries from 27 countries and took a total of 4 months to complete. Sixteen entries were directly included in the WHO testing guidelines. The entries covered testing in different populations, including primary care patients (n = 5), people who inject drugs (PWID) (n = 4), pregnant women (n = 4), general populations (n = 4), high-risk groups (n = 3), relatives of people living with hepatitis B and C (n = 2), migrants (n = 2), incarcerated individuals (n = 2), workers (n = 2), and emergency department patients (n = 2). A variety of different testing delivery approaches were employed, including integrated HIV-hepatitis testing (n = 12); integrated testing with harm reduction and addiction services (n = 9); use of electronic medical records to support targeted testing (n = 8); decentralization (n = 8); and task shifting (n = 7). CONCLUSION: The global innovation contest identified a range of local hepatitis testing approaches that can be used to inform the development of testing strategies in different settings and populations. Further implementation and evaluation of different testing approaches is needed.

Prevention of infection-related cancers in the WHO Western Pacific Region.

A considerable number of infectious agents have been classified as human carcinogens Group 1 by the International Agency for Research on Cancer. Major infection-related cancers such as cancers of nasopharynx (53%), stomach (60%) and liver (63%) occur in the World Health Organization Western Pacific Region. Many infection-related cancers are preventable, particularly those associated with human papilloma virus, Helicobacter pylori, human immunodeficiency virus-I, hepatitis B virus and hepatitis C virus and liver flukes. Mongolia shows the highest prevalence of hepatitis B virus and hepatitis C virus, and China shows the highest prevalence of Helicobacter pylori. Chronic infection is attributable for 17-28% of overall cancer incidence or mortality in China, Japan and Korea. Through infant immunization for hepatitis B, 30 of 37 countries and areas in the Western Pacific Region have reached the 2012 milestone of chronic hepatitis B virus infection prevalence of <2% in 5-year-old children and countries and areas of the region are now striving toward reaching the regional goal of <1% by 2017. Human papilloma virus immunization program is implemented either by government funding or, in some low-income countries, by public and private sector organizations. Cervical cancer screening via visual inspection with acetic acid or Pap smear is available in many Western Pacific Region Member States. More efforts are needed to implement new World Health Organization guide to vaccinate 9- to 13-year-old girls with two doses of human papilloma virus vaccine, and use human papilloma virus tests to screen women to prevent and control cervical cancer including guaranteed monitoring and appropriate follow-up for abnormal results.

HIV treatment outcomes among people who inject drugs in Victoria, Australia.

BACKGROUND: People who inject drugs (PWID) are a key population affected by HIV. We assessed the effectiveness of HIV treatment among a clinical cohort of people living with HIV (PLHIV) diagnosed and referred for community-based antiretroviral therapy (ART) in Victoria, Australia. METHODS: HIV notification data from a central statewide registry were matched with HIV clinical data from two large HIV treatment centers in Melbourne. We used survival analysis and Cox proportional hazard models to estimate time to AIDS and death for PWID in HIV treatment, compared with non-injectors, in the period 1996-2008. RESULTS: Of the 871 individuals, 93 (10.8%) had injecting as an exposure category and 671 (86%) had ever commenced ART. Adjusted analysis showed younger age, high initial CD4 cell count (>500 cells/mm(3)) or ever having a CD4 cell count >500/mm(3), and more recent calendar year of ART commencement were all associated with reduced hazards for AIDS and death, while older age, low initial CD4 cell count (<200/mm(3)), ever having a CD4 count <200/mm(3) (before or during treatment) and high initial viral load (>5 log10) were associated with increased risk of AIDS and death. PWID were no more likely to experience AIDS (HR 0.98 [0.54-1.80]) or death (HR 0.78 [0.18-3.42]) than non-injectors. CONCLUSION: Survival of HIV-infected PWID on HIV treatment was equivalent to non-injectors. CD4 cell count, initial viral load, calendar year of commencing ART and age are more important determinants of AIDS and mortality than injecting status for in-treatment PLHIV in Victoria, Australia.

Telehealth for Comprehensive Care to Quarantine Residents: A Novel Approach and Lessons Learned.

Proactive engagement and care with regular and timely information are required to manage the health and well-being of people in quarantine. At Australia's Howard Springs International Quarantine Facility, a telehealth model was rapidly established using trained non-clinical Customer Service Officers (CSO's) with the aim to provide comprehensive care to residents, maximize staff safety, and reduce clinical workforce capacity pressures. We describe this model, whereby CSO's provided residents with daily COVID-19 symptom and well-being screening, weekly psychological screening, and ongoing linkage to additional clinical and administrative services. In addition, CSO's went beyond these duties to deliver personalized care through delivery of care packages and attendance of the departure point to farewell residents. From October 2020 to May 2021, across 7105 residents, we estimated that CSO's prevented over 75 000 face-to-face resident visits, which reduced workforce requirements and preserved staff safety through minimizing potential COVID-19 transmission and time spent in personal protective equipment in the challenging ambient environment. We share key lessons learned which may inform future telehealth models and guide a positive experience for quarantine residents.

Building a safety culture for infection prevention and control adherence at Howard Springs: A workplace survey.

BACKGROUND: Building a safety culture is essential to facilitate infection prevention and control (IPC) adherence in workplaces. We aimed to explore perceptions, barriers and facilitators to IPC procedures by the Australian Medical Assistance Team (AUSMAT) at Howard Springs International Quarantine Facility (HSIQF). METHODS: We performed a descriptive analysis of a cross-sectional survey administered to the AUSMAT employed at HSQIF from October 2020 to April 2021. We described motivation, training and compliance to IPC adherence and Likert scales described the level of agreement to the success of IPC procedures across the domains of communication, risk, trust, safety and environment, from the individual, team and organisational perspective. RESULTS: There were 101 participants (response rate 59%, 101/170) and 70% (71/101) were clinical. There was strong agreement to the success of IPC procedures, with a median 4 (agree) or 5 (strongly agree) across each domain and perspective of the 67 Likert items. Clinical staff reported slightly higher agreement than non-clinical staff across Likert items. To improve IPC compliance, most reported that daily training should be provided (77/97, 79%) and daily training was very or extremely effective (91/97, 93%). Participants were motivated by protecting self, friends, family and the community rather than workplace pressures. Barriers to IPC compliance were the ambient environment and fatigue. CONCLUSIONS: A safety culture was successfully built at HSQIF to optimise IPC adherence whilst managing multiple hazards including prevention of COVID-19 transmission. Strategies implemented by AUSMAT at the quarantine facility may inform the development of safety culture in other settings.

Impact and cost-effectiveness of hepatitis B virus prophylaxis in pregnancy: a dynamic simulation modelling study.

BACKGROUND: In 2020, WHO recommended the addition of peripartum antiviral prophylaxis (PAP) to hepatitis B birth dose vaccination (HepB-BD) and hepatitis B infant vaccination (HepB3) to reduce mother-to-child transmission of hepatitis B virus (HBV) infection in pregnant women who have a marker of high infectivity (ie, HBV DNA ≥200 000 international units per mL or HBeAg-positive). We aimed to evaluate the impact and cost-effectiveness of this recommendation and of a theoretical simplified strategy whereby PAP is given to all pregnant women who are HBsAg-positive without risk stratification. METHODS: This modelling study used a dynamic simulation model of the HBV epidemic in 110 countries in all WHO regions, structured by age, sex, and country. We assessed three strategies of scaling up PAP for pregnant women: PAP for those with high viral load (PAP-VL); PAP for those who are HBeAg-positive (PAP-HBeAg); and PAP for all pregnant women who are HBsAg-positive (PAP-universal), in comparison with neonatal vaccination alone (HepB-BD). We investigated how different diagnostic and antiviral drug costs affected the cost-effectiveness of the strategies evaluated. Using a health-care provider perspective, we calculated incremental cost-effectiveness ratios in cost (US$) per disability-adjusted life-year (DALY) averted in each country's population and compared these with country-specific cost-effectiveness thresholds. We also calculated new neonatal infections averted for each of the strategies. FINDINGS: Adding PAP-VL to HepB-BD could avert around 1·1 million (95% uncertainty interval 1·0 million-1·2 million) new neonatal infections by 2030 and around 3·2 million (95% uncertainty interval 3·0 million-3·4 million) new neonatal infections and approximately 8·8 million (7·8 million-9·7 million) DALYs by 2100 across all the countries modelled. This strategy would probably be cost-effective up to 2100 in 28 (26%) of 106 countries analysed (which included some of the countries that have the greatest HBV burden) if costs are as currently expected to be, and in 74 (70%) countries if diagnostic and monitoring costs were lowered (by about 60-75%). The relative cost-effectiveness of PAP-VL and PAP-HBeAg was finely balanced and depended on the respective diagnostic and monitoring costs. The PAP-universal strategy could be more cost-effective than either of these strategies in most countries, but the use of antiviral treatment could be five times as high than with PAP-VL. INTERPRETATION: PAP can provide substantial health benefits, and, although the current approach might already be cost-effective in some high-burden settings, decreased diagnostic costs would probably be needed for PAP to be cost-effective in most countries. Therefore, careful consideration needs to be given about how such a strategy is implemented, and securing reduced costs for diagnostics should be a priority. The theoretical strategy of offering PAP to all women who are HBsAg-positive (eg, if diagnostic tests to identify mothers at risk of transmission are not available) could be a cost-effective alternative, depending on prevailing costs of diagnostics and antiviral therapy. FUNDING: UK Medical Research Council, UK National Institute for Health and Care Research, and the Vaccine Impact Modelling Consortium.

New progress towards elimination of mother-to-child transmission of hepatitis B virus in China.

BACKGROUND: We conducted an evaluation on the potential data resources for the elimination of hepatitis B virus (HBV) mother-to-child transmission in China, so as to provide reference for WHO and other countries in the validation of HBV elimination of mother-to-child transmission (EMTCT) in a real-world large country setting. METHODS: We used the indicators set out in WHO Interim guidance for country validation of viral hepatitis elimination as the benchmark to evaluate the availability of data and progress against indicators for the elimination validation in China. We used descriptive analysis to illustrate the status of all indicators and parameters. RESULTS: According to the indicators which are recommended by WHO for HBV EMTCT validation, the national data in China are attainable, though not for HBV DNA testing for the HBsAg-positive mothers and their subsequent management. The remaining challenges for China are to consider how the national serosurvey might be conducted in future in the context of low HBV prevalence among children under 5 years; to collect systematically the programmatic impact data; to strengthen multi-sectoral collaboration among immunization, maternal and child health, hospital services, as well as other stakeholders. CONCLUSION: The available data on HBV EMTCT are sufficient to support the validation of the elimination of HBV mother-to-child transmission in China.

Acute hepatitis of unknown aetiology among children around the world.

By 26 August 2022, the number of cases of acute hepatitis of unknown etiology (AHUA) has drastically increased to 1115 distributed in 35 countries that fulfill the World Health Organization definition. Several hypotheses on the cause of AHUA have been proposed and are being investigated around the world. In the recent United Kingdom (UK) report, human adenovirus (HAdV) with adeno-associated virus (AAV) co-infection is the leading hypothesis. However, there is still limited evidence in establishing the causal relationship between AHUA and any potential aetiology. The leading aetiology continues to be HAdV infection. It is reported that HAdV genomics is not unusual among the population in the UK, especially among AUHA cases. Expanding the surveillance of HAdV and AAV in the population and the environment in the countries with AUHA cases is suggested to be the primary action. Metagenomics should be used in detecting other infectious pathogens on a larger scale, to supplement the detection of viruses in the blood, stool, and liver specimens from AUHA cases. It is useful to develop a consensus-specific case definition of AHUA to better understand the characteristics of these cases globally based on all the collected cases.

Electronic monitoring of doffing using video surveillance to minimise error rate and increase safety at Howard Springs International Quarantine Facility.

BACKGROUND: Safe donning and doffing of personal protective equipment (PPE) are critical to prevent transmission of infectious diseases. Novel strategies to improve infection prevention and control (IPC) adherence can optimise safety. We describe and quantify video surveillance of doffing at an outdoor hotel quarantine facility led by the Australian Medical Assistance Team in the Northern Territory, Australia. METHODS: Motion-activated video cameras were installed in seven areas where personnel doffed PPE upon exit from an area dedicated to quarantined residents. Video footage was reviewed daily and compliance issues were identified using a standardised checklist and risk graded to initiate feedback. We collated audit data from 1 February to 18 April 2021 to describe trends by month, staff group, doffing component and risk. RESULTS: In 235 h of video footage, 364 compliance issues were identified, of which none were considered high-risk compromising to PPE integrity. Compliance issues were low risk (55/364, 15%) or moderate risk (309/364, 85%) and the most common issue was missed or inadequate hand hygiene (156/364, 43%). Compliance issues per minute of video footage reviewed decreased following introduction of the activity, from 24 per 1000 in February to 7 per 1000 in March and April. CONCLUSION: Video surveillance with feedback supported rapid response to improve IPC adherence in a challenging ambient environment. The activity focused on perfection to identify compliance issues that would go unreported in most healthcare settings and contributed to a suit of activities that prevented any high-risk PPE breaches or compromises to safety.

An outdoor hotel quarantine facility model in Australia: best practice with optimal outcomes.

OBJECTIVE: To describe the operationalisation of a novel outdoor quarantine facility managed by the Australian Medical Assistance Team, the Howard Springs International Quarantine Facility (HSIQF) at the Centre for National Resilience in the Northern Territory, Australia. METHODS: We collated documentation and data from HSIQF to describe policies and procedures implemented and performed a descriptive analysis of key procedures and outcomes. RESULTS: From 23 October 2020 to 31 March 2021, 2.2% (129/5,987) of residents were confirmed COVD-19 cases. On average per day, 82 [Interquartile Range (IQR): 29-95] staff completed personal protective equipment (PPE) training, 94 [IQR: 90-104] staff completed antigen testing and 51 [IQR: 32-136] staff completed polymerase chain reaction testing. The operation focused on building a safe environment with infection prevention and control adherence and workforce sustainability. There was no leakage of SARS-CoV-2 to staff or the community and no PPE compromises requiring staff to quarantine for 14 days. CONCLUSION: HSIQF demonstrates the operationalisation of an effective, safe and replicable quarantine system. IMPLICATIONS FOR PUBLIC HEALTH: Quarantine is a critical public health tool for pandemic control. The HSIQF operations may be useful to inform the establishment and management of quarantine facilities for future and current disease outbreaks.

Methods and indicators to validate country reductions in incidence of hepatitis C virus infection to elimination levels set by WHO.

One of the main goals of the 2016 Global Health Sector Strategy on viral hepatitis is the elimination of hepatitis C virus (HCV) as a public health problem by 2030, defined as an 80% reduction in incidence and 65% reduction in mortality relative to 2015. Although monitoring HCV incidence is key to validating HCV elimination, use of the gold-standard method, which involves prospective HCV retesting of people at risk, can be prohibitively resource-intensive. Additionally, few countries collected quality data in 2015 to enable an 80% decrease by 2030 to be calculated. Here, we first review different methods of monitoring HCV incidence and discuss their resource implications and applicability to various populations. Second, using mathematical models developed for various global settings, we assess whether trends in HCV chronic prevalence or HCV antibody prevalence or scale-up levels for HCV testing, treatment, and preventative interventions can be used as reliable alternative indicators to validate the HCV incidence target. Third, we discuss the advantages and disadvantages of an absolute HCV incidence target and suggest a suitable threshold. Finally, we propose three options that countries can use to validate the HCV incidence target, depending on the available surveillance infrastructure.

Prevalence of hepatitis C virus infection among key populations in China: A systematic review.

BACKGROUND AND AIM: Chronic hepatitis C is a major global health challenge. China has the world's largest burden of hepatitis C and related liver disease, with several groups having an increased risk of acquiring hepatitis C virus (HCV) infection. We undertook a systematic review in Chinese and English literature to determine the seroprevalence of anti-HCV among men who have sex with men (MSM), sex workers, people who use drugs (PWUD) and migrant workers in China. METHODS: We searched three Chinese databases (CNKI, Wanfang and Chongqing VIP Information) and four English databases (Pubmed, EMBASE, Global Health and CINAHL) for studies published between 2010 and 2015. Included were 89 studies for MSM, 112 for sex workers, 11 for migrant workers, 94 for people who inject drugs (PWID) and 67 for non-injectors. Random-effect models pooled estimates of anti-HCV seroprevalence in each population and a meta-regression model examined the relationship between anti-HCV seroprevalence and injecting drug use. RESULTS: The overall pooled seroprevalence of anti-HCV among MSM was 0.67% (CI 95 0.51-0.86); for sex workers 0.65% (CI 95 0.53-0.77); for migrant workers 0.48 (CI 95 0.20-0.85); for IDUs 72.41% (CI 95 68.71-75.97); among non-injectors 25.07% (CI 95 21.51%-28.80%). Our meta-regression model predicted that the seroprevalence of anti-HCV among PWID increased by 8.6% for each 10% increase seroprevalence of reporting ever having injected drugs. CONCLUSIONS: Overall, seroprevalence of HCV infection is high among PWUD, especially those who inject. Lower HCV seroprevalence (<1%) was found among MSM, sex workers and migrant workers. Our estimates for IDU seroprevalence are higher than that from the national surveillance system, though estimates for other at-risk populations are similar.

Hepatitis C virus infection in children and adolescents.

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease and associated morbidity and mortality worldwide. Short-course, oral, curative, direct-acting antiviral regimens have transformed treatment for HCV infection. Since the 2016 launch of the first global strategy towards elimination of viral hepatitis as a public health threat by 2030, the predominant focus of the global response has been on the treatment of adults, who bear the greatest burden of morbidity and mortality of HCV-related chronic liver disease. Compared with adults, there has been little attention paid to addressing the response to HCV in children and adolescents, in part because of the scarcity of data to inform specific paediatric management practices and policy. In this Series paper, we summarise knowledge on the epidemiology, natural history, and treatment of chronic HCV infection in adolescents and children, and we highlight key differences from infection acquired in adulthood. The estimated global prevalence and burden of HCV infection in children aged 1-19 years is 0·15%, corresponding to 3·5 million people (95% CI 3·1-3·9 million). HCV infection is usually asymptomatic during childhood, and cirrhosis and hepatocellular carcinoma are rare. Sofosbuvir with ledipasvir and sofosbuvir with ribavirin have received regulatory approval and guidelines recommend their use in adolescents aged 12 years and older with HCV infection. In April, 2019, glecaprevir with pibrentasvir also received regulatory approval for adolescents aged 12-17 years. Key actions to address the current policy gaps and achieve treatment scale-up that is comparable to that in adults include: establishment of a campaign on access to testing and treatment that is targeted at children and adolescents; fast-track evaluation of pan-genotypic regimens; and accelerated approval of paediatric formulations. Research gaps that need to be addressed include: age-specific prevalence studies of HCV viraemia in priority countries; further validation of non-invasive tests for staging of liver disease in children; and establishment of paediatric treatment registries and international consortia to promote collaborative research agendas.

Hepatitis B virus infection in children and adolescents.

Hepatitis B virus (HBV) infection is a major cause of acute and chronic liver disease and associated morbidity and mortality worldwide. Vertical (mother-to-child) and horizontal early childhood transmission are the main routes of HBV transmission and are responsible for most chronic infections, including among adults who bear the greatest burden of morbidity and mortality. Universal hepatitis B immunisation at birth and in infancy is the key strategy for global elimination of HBV infection, and has been highly effective in reducing new vertical infections. However, global progress in scale-up of HBV testing and treatment has been slow in adults and children. In this Series paper, we summarise knowledge on the epidemiology, natural history, and treatment of chronic HBV infection in adolescents and children, and we highlight key differences from HBV infection in adults. The estimated global prevalence of HBV infection in children aged 5 years or younger is 1·3%. Most children are in the high-replication, low-inflammation phase of infection, with normal or only slightly raised aminotransferases; cirrhosis and hepatocellular carcinoma are rare. Although entecavir is approved and recommended for children aged 2-17 years, and tenofovir for those aged 12-18 years, a conservative approach to treatment initiation in children is recommended. Key actions to address current policy gaps include: validation of non-invasive tests for liver disease staging; additional immunopathogenesis studies in children with HBV infection; long-term follow-up of children on nucleoside or nucleotide analogue regimens to inform guidance on when to start treatment; evaluation of different treatment strategies for children with high rates of HBV replication; and establishment of paediatric treatment registries and international consortia to promote collaborative research.