Outbreak of hepatitis A in the injecting drug user and homeless populations in Bristol: control by a targeted vaccination programme and possible parenteral transmission

Integration, effectiveness and costs of different models of primary health care provision for people who are homeless: an evaluation study

Background

There is a high prevalence of health problems among single people who are homeless. Specialist primary health care services for this population have been developed in several locations across England; however, there have been very few evaluations of these services.

Objectives

This study evaluated the work of different models of primary health care provision in England to determine their effectiveness in engaging people who are homeless in health care and in providing continuity of care for long-term conditions. It concerned single people (not families or couples with dependent children) staying in hostels, other temporary accommodation or on the streets. The influence on outcomes of contextual factors and mechanisms (service delivery factors), including integration with other services, were examined. Data from medical records were collated on participants' use of health care and social care services over 12 months, and costs were calculated.

Design and setting

The evaluation involved four existing Health Service Models: (1) health centres primarily for people who are homeless (Dedicated Centres), (2) Mobile Teams providing health care in hostels and day centres, (3) Specialist GPs providing some services exclusively for patients who are homeless and (4) Usual Care GPs providing no special services for people who are homeless (as a comparison). Two Case Study Sites were recruited for each of the specialist models, and four for the Usual Care GP model.

Participants

People who had been homeless during the previous 12 months were recruited as 'case study participants'; they were interviewed at baseline and at 4 and 8 months, and information was collected about their circumstances and their health and service use in the preceding 4 months. Overall, 363 participants were recruited; medical records were obtained for 349 participants. Interviews were conducted with 65 Case Study Site staff and sessional workers, and 81 service providers and stakeholders.

Results

The primary outcome was the extent of health screening for body mass index, mental health, alcohol use, tuberculosis, smoking and hepatitis A among participants, and evidence of an intervention if a problem was identified. There were no overall differences in screening between the models apart from Mobile Teams, which scored considerably lower. Dedicated Centres and Specialist GPs were more successful in providing continuity of care for participants with depression and alcohol and drug problems. Service use and costs were significantly higher for Dedicated Centre participants and lower for Usual Care GP participants. Participants and staff welcomed flexible and tailored approaches to care, and related services being available in the same building. Across all models, dental needs were unaddressed and staff reported poor availability of mental health services.

Limitations

There were difficulties recruiting mainstream general practices for the Usual Care GP model. Medical records could not be accessed for 14 participants of this model.

Conclusions

Participant characteristics, contextual factors and mechanisms were influential in determining outcomes. Overall, outcomes for Dedicated Centres and for one of the Specialist GP sites were relatively favourable. They had dedicated staff for patients who were homeless, 'drop-in' services, on-site mental health and substance misuse services, and worked closely with hospitals and homelessness sector services.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (HSDR 13/156/03) and will be published in full in Health and Social Care Delivery Research; Vol. 11, No. 16. See the NIHR Journals Library website for further project information.

Hepatitis A occurrence and outbreaks in Europe over the past two decades: A systematic review

Hepatitis A (HA) is a vaccine-preventable liver disease with >170 million new cases occurring yearly. In recent outbreaks in the USA, hospitalization and case-fatality ratios were >60% and ~1%, respectively. In Europe, endemicity persists and outbreaks continue to occur. We performed a systematic literature review to understand the changes in HA occurrence in Europe over the past two decades. PubMed and Embase were systematically searched for peer-reviewed articles published between 1 January 2001 and 14 April 2021 using terms covering HA, 11 selected European countries, outbreaks, outcomes and HA virus circulation. Here, we focus on HA occurrence and outbreaks in the five countries with the largest population and the most comprehensive vaccination recommendations: France, Germany, Italy, Spain and the UK; 118 reports included data for these five European countries. Notification rates (≤9.7/100,000 population) and percentages of men among cases (≤83.0%) peaked in 2017. The number of person-to-person-transmitted cases and outbreaks decreased in children but increased in other risk groups, such as men who have sex with men (MSM). Sexually transmitted outbreaks in MSM clustered around 2017. Travel-related outbreaks were few; the proportion of travel-related cases decreased during the past two decades, while the number of domestic cases increased. Despite the existing risk-based vaccination recommendations, HA transmission shifted in proportions from travelers and children to other risk groups, such as MSM and older age groups. Because a substantial proportion of the European population is susceptible to HA, adherence to existing recommendations should be monitored more closely, and enhanced vaccination strategies should be considered.

Molecular epidemiology of hepatitis A outbreaks and sporadic cases, Latvia, 2017 to 2019

BackgroundHepatitis A is an acute infection of the liver caused by hepatitis A virus (HAV). Molecular detection and typing of the HAV VP1/P2A genomic region is used for genotyping and outbreak investigations. After a large hepatitis A outbreak in Latvia in 2007-08, only sporadic cases were registered until 2017 when a rise in cases occurred. During 2017-19, 179 laboratory-confirmed hepatitis A cases were notified in Latvia.AimTo investigate the observed increase in hepatitis A cases during 2017 and to determine whether these cases were linked to one another, to risk groups, or to other outbreaks. The majority of HAV samples (69.8%) were typed.MethodsThe VP1/P2A genomic region of HAV was amplified and sequenced for 125 case serum samples. Information about hepatitis-related symptoms, hospitalisation, vaccination, a possible source of infection and suspected countries of origin of the virus were analysed for sequenced cases.ResultsMost HAV strains were subgenotype IA (n = 77), of which 41 were strains circulating among men who have sex with men (MSM) populations in Europe (VRD_521_2016 (n = 32), RIVM-HAV16-090 (n = 7) or V16-25801 (n = 2)). Forty-four cases were subgenotype IB and four cases subgenotype IIIA. However, other clusters and sporadic cases were detected with or without identifying the epidemiological link.ConclusionThis work represents molecular epidemiological data of hepatitis A cases in Latvia from 2017 to 2019. Molecular typing methods allow identification of clusters for public health needs and establishing links with other outbreaks, and to compare Latvian strains with reported strains from other countries.

Vaccine-preventable diseases other than tuberculosis, and homelessness: A scoping review of the published literature, 1980 to 2020

BACKGROUND

Homelessness may result in the breakdown of regular health services, including routine vaccination programmes. A scoping review was conducted to describe vaccine-preventable diseases (VPD) other than tuberculosis in people experiencing homelessness (PEH).

METHODS

We followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). We searched peer-reviewed literature published in English, French, Spanish or Portuguese reporting the outbreak of VPD or VPD prevalence in both infant and adult homeless populations published between 1980 and 2020, using PubMed/Medline, SciELO, Google Scholar, and Web of Science databases. Relevant information from the studies was charted in Microsoft Excel and results were summarised using a descriptive analytical method.

RESULTS

Eighty-one articles were included. A high prevalence of past hepatitis B virus (HBV) and hepatitis A virus (HAV) infections were observed through serosurveys, mostly in high income countries or high-middle income countries (USA, Canada, France, Iran or Brazil). Ten outbreaks of HAV infection were also reported, with lethality rates ranging from 0 to 4.8%. The studies identified numerous risk factors positively associated with HBV infection, including older age, homosexual or bisexual practice, injected drug use (IDU), and, with HAV infection including IDU, having sexual partner(s) with a history of unspecified hepatitis, insertive anal penetration, or originating from a country with a high prevalence of anti-HAV antibody. Eleven outbreaks of pneumococcal infection affecting PEH were reported in Canada and USA, with lethality rates from 0 to 15.6%. Six diphtheria outbreaks were reported. Vaccination status was rarely documented in these studies.

CONCLUSIONS

The literature suggests that homeless populations generally experience a high VPD burden suggesting the need for a national vaccination programme and planning for delivering vaccines in this population.

Homelessness and Hepatitis A-San Diego County, 2016-2018

BACKGROUND

Hepatitis A is a vaccine-preventable viral disease transmitted by the fecal-oral route. During 2016-2018, the County of San Diego investigated an outbreak of hepatitis A infections primarily among people experiencing homelessness (PEH) to identify risk factors and support control measures. At the time of the outbreak, homelessness was not recognized as an independent risk factor for the disease.

METHODS

We tested the association between homelessness and infection with hepatitis A virus (HAV) using a test-negative study design comparing patients with laboratory-confirmed hepatitis A with control subjects who tested negative for HAV infection. We assessed risk factors for severe hepatitis A disease outcomes, including hospitalization and death, using multivariable logistic regression. We measured the frequency of indications for hepatitis A vaccination according to Advisory Committee on Immunization Practices (ACIP) guidelines.

RESULTS

Among 589 outbreak-associated cases reported, 291 (49%) occurred among PEH. Compared with those who were not homeless, PEH had 3.3 (95% confidence interval [CI], 1.5-7.9) times higher odds of HAV infection, 2.5 (95% CI, 1.7-3.9) times higher odds of hospitalization, and 3.9 (95% CI, 1.1-16.9) times higher odds of death associated with hepatitis A. Among PEH, 212 (73%) patients recorded other ACIP indications for hepatitis A vaccination.

CONCLUSIONS

PEH were at higher risk of infection with HAV and of severe hepatitis A disease outcomes compared with those not experiencing homelessness. Approximately one-fourth of PEH had no other ACIP indication for hepatitis A vaccination. These findings support the recent ACIP recommendation to add homelessness as an indication for hepatitis A vaccination.

Outbreaks of Hepatitis A in US Communities, 2017-2018: Firsthand Experiences and Operational Lessons From Public Health Responses

Objectives. To identify and analyze common challenges from multiple US communities affected by the hepatitis A epidemic beginning in March 2017, and to identify operational lessons to support preparedness for similar future public health emergencies.Methods. We conducted semistructured interviews with health officials from 9 city or county health departments to collect the firsthand experience of public health responders. We collected data from January to October 2018 via teleconference. Key informants, whom we purposefully sampled, were senior public health officials who were directly involved in outbreak response or in preparing for potential hepatitis A outbreaks in their communities.Results. Several themes emerged during these discussions, including common challenges and solutions pertaining to sanitation and hygiene infrastructure, hepatitis A vaccination, health workforce availability and surge capacity, communication and stigma, and partnerships and coordination with local law enforcement and other stakeholders.Conclusions. By generating key, evidence-based operational lessons, this study can inform response activities in localities currently experiencing outbreaks as well as community preparedness for possible future outbreaks due to the presence of similar at-risk populations.

Homelessness, Personal Hygiene, and MRSA Nasal Colonization among Persons Who Inject Drugs

Methicillin-resistant Staphylococcus aureus (MRSA) infection is a leading cause of hospitalization and medical visits among individuals experiencing homelessness and also among persons who inject drugs (PWID), populations with significant overlap in urban centers in the USA. While injection drug use is a risk factor for MRSA skin infections, MRSA is also known to transmit easily in crowded, public locations in which individuals have reduced personal hygiene. Individuals in urban centers who experience homelessness or drug addiction may spend significant amounts of time in environments where MRSA can be easily transmitted, and may also experience reduced access to facilities to maintain personal hygiene. We assessed the relationship between homelessness, personal hygiene, and MRSA nasal colonization, a proxy for MRSA infection risk, in a study of PWID in Boston, MA (n = 78). Sleeping in a homeless shelter for at least one night in the last 3 months was significantly associated with MRSA nasal colonization (OR 3.0; p = 0.02; 95% CI 1.2, 7.6). Sleeping at more than one place during the last week (considered a metric of elevated housing instability) was also associated with a threefold increase in odds of MRSA nasal colonization (OR 3.1; p = 0.01; 95% CI 1.3, 7.6). MRSA nasal colonization was strongly associated with use of public showers (OR 13.7; p = 0.02; 95% CI 1.4, 132.8), although few people in this study (4 of 78) reported using these public facilities. Sharing bedding with other people was also associated with increased risk of MRSA colonization (OR 2.2; p = 0.05; 95% CI 1.0-4.7). No associations between hand hygiene, frequency of bathing or clothes laundering, or street sleeping were observed. Use of public facilities supporting persons experiencing homelessness and housing instability, including shelters and public showers, is associated with an increased risk of MRSA nasal colonization in this study. Personal hygiene behaviors appear less associated with MRSA nasal colonization. Environmental assessments of MRSA contamination in homeless shelters and public sanitation facilities are warranted so as to inform appropriate intervention activities.

Hepatitis A-2017 an unusual year in Scotland

BACKGROUND

The number of cases of acute hepatitis A reported in Scotland each year is small, and the majority of cases have been associated with travel to endemic regions. However, in early 2017, in the midst of ongoing outbreaks of hepatitis A among MSM in Europe, there was a sharp rise in the number of cases reported to Health Protection Scotland.

OBJECTIVES

The initial aim of this study was to investigate the reason for the observed increase in cases of hepatitis A at the start of 2017. As cases continued for the remainder of the year, these cases were typed to determine whether these cases were linked to each other, or other outbreaks.

STUDY DESIGN

The study population consisted of 42 hepatitis A infected patients with no obvious source of infection. The patient samples were collected between January and December 2017. The VP1/2 A region was amplified and sequenced.

RESULTS

The majority of samples typed as genotype 1 A (n = 17) or genotype 1B (n = 15). Within genotype 1 A, fifteen samples had strains (VRD_521_2016 or RIVM_HAV16_090) associated with ongoing outbreaks of hepatitis A in MSM in Europe. Within genotype 1B, there were four clusters of infections, with identical cases in geographically distinct regions with no identified epidemiological link.

CONCLUSIONS

Molecular typing proved useful, as it allowed public health to identify clusters, establish links with other outbreaks and compare Scottish strains with those reported elsewhere.

A Description of a Health System's Emergency Department Patients Who Were Part of a Large Hepatitis A Outbreak

BACKGROUND

A recent hepatitis A virus (HAV) outbreak in San Diego, California represents one of the largest HAV outbreaks in the United States. The County of San Diego Health and Human Services Agency identified homelessness and illicit or injection drug use as risk factors for contracting HAV during this outbreak.

OBJECTIVE

We describe those patients who presented to our Emergency Department (ED) and were identified as HAV positive.

METHODS

This was a retrospective descriptive study conducted at a tertiary care university health system's EDs from November 2016 to February 2018. Included were those of all ages who tested positive for HAV immunoglobulin M antibody. Outcome measures included: 1) demographic data; 2) number of patients testing positive for HAV by week and month of the outbreak; 3) homeless status, illicit and injection drug use, and alcohol use; 4) ED chief complaint; 5) initial liver function and coagulopathy test results, hepatitis B and C test results, and initial vital signs; 6) admission status; 7) death; and 8) the 7-day ED revisit rate for nonadmitted patients and the 30-day all-cause readmission rate for admitted patients.

RESULTS

We identified 57,721 patients with at least one ED visit, and 1,453 of these were tested for HAV; 133 patients (9.2%) tested positive. Average age was 45.1 years, and 91 (68.4%) were male. Eighty-six patients (64.7%) were homeless and 53 patients (39.8%) reported illicit or injection drug use; 64 patients (48.1%) had chief complaints consistent with typical HAV symptoms. Most patients (112 or 84.2%) were admitted. Nine patients (6.8%) were admitted to a critical care setting; 8 patients (6%) died.

CONCLUSIONS

During this large HAV outbreak, 9% of those screened for HAV tested positive. The majority were homeless, and 40% reported illicit or injection drug use. Most required hospitalization, and 6% of patients died.

Use of gender distribution in routine surveillance data to detect potential transmission of gastrointestinal infections among men who have sex with men in England

Detecting gastrointestinal (GI) infection transmission among men who have sex with men (MSM) in England is complicated by a lack of routine sexual behavioural data. We investigated whether gender distributions might generate signals for increased transmission of GI pathogens among MSM. We examined the percentage male of laboratory-confirmed patient-episodes for patients with no known travel history for 10 GI infections of public health interest in England between 2003 and 2013, stratified by age and region. An adult male excess was observed for Shigella spp. (annual maximum 71% male); most pronounced for those aged 25-49 years and living in London, Brighton and Manchester. An adult male excess was observed every year for Entamoeba histolytica (range 59.8-76.1% male), Giardia (53.1-57.6%) and Campylobacter (52.1-53.5%) and for a minority of years for hepatitis A (max. 69.8%) and typhoidal salmonella (max. 65.7%). This approach generated a signal for excess male episodes for six GI pathogens, including a characterised outbreak of Shigella among MSM. Stratified analyses by geography and age group were consistent with MSM transmission for Shigella. Optimisation and routine application of this technique by public health authorities elsewhere might help identify potential GI infection outbreaks due to sexual transmission among MSM, for further investigation.

Evolution of hepatitis A virus seroprevalence among HIV-positive adults in Taiwan

OBJECTIVES

The study aimed to describe the seroprevalence of hepatitis A virus (HAV) in HIV-positive adult patients in Taiwan between 2012 and 2016 and to examine the evolution of HAV seroprevalence between 2004-2007 and 2012-2016.

METHODS

Clinical information and data of anti-HAV antibody results were collected from 2,860 antiretroviral-naïve HIV-positive Taiwanese aged 18 years or older who initiated combination antiretroviral therapy at 11 hospitals around Taiwan between 2012 and 2016 (2012-2016 cohort). A multivariate logistic regression model was applied to identify independent variables associated with HAV seropositivity. Comparisons of HAV seroprevalences and associated clinical characteristics were made between this 2012-2016 cohort and a previous cohort of 1580 HIV-positive patients in 2004-2007 (2004-2007 cohort).

RESULTS

Of the 2,860 HIV-positive patients between 2012 and 2016, the overall HAV seropositivity rate was 21.2% (605/2860), which was independently associated with an older age (adjusted odds ratio [AOR], per 1-year increase, 1.13; 95% confidence interval [95% CI], 1.11-1.15) and co-infection with hepatitis B virus (AOR 1.44; 95% CI, 1.08-1.93). Residence in southern Taiwan (AOR 0.49; 95% CI, 0.34-0.72) was inversely associated with HAV seropositivity. The overall HAV seroprevalence in the 2012-2016 cohort was significantly lower than that in the 2004-2007 cohort (21.2% vs 60.9%, p<0.01). The decreases of HAV seropositivity rate were observed in nearly every age-matched group, which suggested the cohort effect on HAV seroepidemiology. However, among individuals aged 25 years or younger, the HAV seropositivity rate increased from 3.8% (2/52) in the 2004-2007 cohort to 8.5% (50/587) in the 2012-2016 cohort, with 95.4% (560/587) being MSM in this age group of the latter cohort.

CONCLUSIONS

HAV seroprevalence has decreased with time among HIV-positive adults in Taiwan. The cohort effect has increased the number of young HIV-positive patients that are susceptible to HAV infection in a country without nationwide childhood vaccination program against HAV.

The financial crisis and the expected effects on vaccinations in Europe: a literature review

Starting in 2008 several European countries experienced a financial crisis. Historically, diseases whose prevention and treatment depend highly on the continuity of healthcare re-emerge during political and financial crises. Evidence suggests that the current financial crisis has had an impact on the health and welfare of Europeans and that population health status and morbidity as well as mortality patterns may change in the coming years. At the same time decisions about expenditure for health services may impact the ability of public health providers to respond. It is expected that the current crisis will further exacerbate socioeconomic and health inequalities and novel vulnerable groups will emerge in addition to existing ones. We review the available evidence and discuss how the current crisis may have an impact on vaccine-preventable diseases and influence vaccination coverage rates in Europe.

Hepatitis A virus: host interactions, molecular epidemiology and evolution

Infection with hepatitis A virus (HAV) is the commonest viral cause of liver disease and presents an important public health problem worldwide. Several unique HAV properties and molecular mechanisms of its interaction with host were recently discovered and should aid in clarifying the pathogenesis of hepatitis A. Genetic characterization of HAV strains have resulted in the identification of different genotypes and subtypes, which exhibit a characteristic worldwide distribution. Shifts in HAV endemicity occurring in different parts of the world, introduction of genetically diverse strains from geographically distant regions, genotype displacement observed in some countries and population expansion detected in the last decades of the 20th century using phylogenetic analysis are important factors contributing to the complex dynamics of HAV infections worldwide. Strong selection pressures, some of which, like usage of deoptimized codons, are unique to HAV, limit genetic variability of the virus. Analysis of subgenomic regions has been proven useful for outbreak investigations. However, sharing short sequences among epidemiologically unrelated strains indicates that specific identification of HAV strains for molecular surveillance can be achieved only using whole-genome sequences. Here, we present up-to-date information on the HAV molecular epidemiology and evolution, and highlight the most relevant features of the HAV-host interactions.

Trends in the population prevalence of people who inject drugs in US metropolitan areas 1992-2007

BACKGROUND

People who inject drugs (PWID) have increased risk of morbidity and mortality. We update and present estimates and trends of the prevalence of current PWID and PWID subpopulations in 96 US metropolitan statistical areas (MSAs) for 1992-2007. Current estimates of PWID and PWID subpopulations will help target services and help to understand long-term health trends among PWID populations.

METHODOLOGY

We calculated the number of PWID in the US annually from 1992-2007 and apportioned estimates to MSAs using multiplier methods. We used four types of data indicating drug injection to allocate national annual totals to MSAs, creating four distinct series of component estimates of PWID in each MSA and year. The four component estimates are averaged to create the best estimate of PWID for each MSA and year. We estimated PWID prevalence rates for three subpopulations defined by gender, age, and race/ethnicity. We evaluated trends using multi-level polynomial models.

RESULTS

PWID per 10,000 persons aged 15-64 years varied across MSAs from 31 to 345 in 1992 (median 104.4) to 34 to 324 in 2007 (median 91.5). Trend analysis indicates that this rate declined during the early period and then was relatively stable in 2002-2007. Overall prevalence rates for non-Hispanic black PWID increased in 2005 as compared to other racial/ethnic groups. Hispanic prevalence, in contrast, declined across time. Importantly, results show a worrisome trend in young PWID prevalence since HAART was initiated--the mean prevalence was 90 to 100 per 10,000 youth in 1992-1996, but increased to >120 PWID per 10,000 youth in 2006-2007.

CONCLUSIONS

Overall, PWID rates remained constant since 2002, but increased for two subpopulations: non-Hispanic black PWID and young PWID. Estimates of PWID are important for planning and evaluating public health programs to reduce harm among PWID and for understanding related trends in social and health outcomes.

Identification of acute vaccine-preventable hepatitis in individuals with chronic hepatitis in British Columbia between 1991 and 2007

BACKGROUND

In British Columbia (BC), hepatitis A virus (HAV) and hepatitis B virus (HBV) vaccines are provincially funded for persons with chronic hepatitis infections.

PURPOSE

To assess the effectiveness of BC public health follow-up of HBV and hepatitis C virus (HCV) cases and immunization policy by determining the number of vaccine-preventable acute hepatitis infections reported following a chronic HBV or HCV diagnosis, by examining demographic characteristics and by observing temporal trends.

METHODS

All newly identified cases of HAV, HBV and HCV between 1991 and October 2007 were extracted from the BC integrated Public Health Information System and linked to ascertain cases of hepatitis suprainfection.

RESULTS

Between 1991 and October 2007, 30 BC residents with chronic HBV and 104 with HCV were subsequently diagnosed with HAV. Acute HBV was identified in 162 persons previously diagnosed with HCV. Significantly more men than women developed hepatitis suprainfection (P<0.0001), but women were of a younger age when they were diagnosed with HAV (P=0.02) and acute HBV (P=0.0002). HAV suprainfection cases among those with HCV peaked in 1998 at 33 cases and declined to zero cases in 2007. In comparison, HBV suprainfection among individuals with chronic HCV peaked in 1996 at 26 cases and declined to two cases in 2007.

DISCUSSION

Cases of HAV and acute HBV have declined among HCV-infected individuals. However, despite the availability of publicly funded vaccines for high-risk groups, a substantial number of acute HBV infections post-HCV identification are still identified, indicating that follow-up and vaccination coverage should be improved in these populations.

Hepatitis A Virus among Drug Users and the Role of Vaccination: A Review

In countries with advanced economies better health and hygiene conditions, along with the introduction, in some cases, of global vaccination, have relegated most viral hepatitis to marginal social groups and, in particular, drug users (DUs). The availability of safe and effective vaccines for hepatitis A virus (HAV) and B (HBV) may play a major role in combating this phenomenon. Despite the availability of a safe and effective vaccine for over a decade and the recommendations of international health organizations, vaccinations against HAV among DUs are not as widely known and available as are HBV vaccinations. The purpose of this review article is to present the most significant data in the literature on the prevalence of HAV among DUs and the role of targeted vaccination. To our knowledge, the present article is the first to solely deal with vaccination against HAV in DUs. Immunization after the administration of anti-HAV vaccine has been demonstrated in DUs even if they have responded significantly less than either the general population or carriers of chronic liver disease. All the vaccines were well tolerated and adherence to the vaccine schedule was good. Further studies are needed to optimize the timing and doses of vaccine to be administered to DUs, especially to assess adherence and antibody persistence. Vaccination campaigns are feasible among DUs and have proven to be highly cost-effective.

An outbreak of hepatitis A affecting a nursery school and a primary school

Between March and June 2008, 12 cases of hepatitis A were notified in Winchester. Cases were from a primary school and a nursery school with no direct linkage. Hepatitis A virus (HAV) RNA sequenced from nine cases confirmed the strain in both schools to be identical. The outbreak could have affected three other schools and a maternity unit and was controlled by immunization and screening of neonates in the maternity unit by dried blood spots. No neonates were infected and no further cases were reported until 5 months later when the index case's mother became infected with same strain of virus associated with the outbreak despite vaccination. Neither the source of the outbreak or the subsequent infection of the index case's mother was identified; however, with the timing of the cases continued transmission in the community by children with asymptomatic infection or a recurrent source cannot be ruled out.

Hepatitis A seroprevalence and risk factors among homeless adults in San Francisco: should homelessness be included in the risk-based strategy for vaccination?

OBJECTIVES

Homeless adults have an increased risk of infectious diseases due to sexual and drug-related behaviors and substandard living conditions. We investigated the prevalence and risk factors for presence of hepatitis A virus (HAV) antibodies among homeless and marginally housed adults.

METHODS

We analyzed serologic and questionnaire data from a study of marginally housed and homeless adults in San Francisco from April 1999 to March 2000. We tested seroprevalance for total antibodies to HAV (anti-HAV) and analyzed data using Chi-square tests and logistic regression.

RESULTS

Of the 1,138 adults in the study, 52% were anti-HAV positive. The anti-HAV prevalence in this study population was 58% higher than the expected prevalence based on age-specific prevalence rates from the general population. Number of years of homelessness (< or =1, 2-4, and > or =5 years) was associated with anti-HAV prevalence (46%, 50%, and 61%, respectively, p < 0.001). We found other differences in anti-HAV prevalence (p < 0.05) for ever having injected drugs (63% vs. 42% for non-injectors), being foreign-born (75% vs. 51% among U.S.-born), race/ethnicity (72%, 53%, and 45% for Hispanic, white, and black people, respectively), and increasing age (38%, 49%, and 62% among those aged <35, 35-45, and >45 years, respectively). These variables all remained significant in a multivariate model.

CONCLUSIONS

We found overall anti-HAV prevalence elevated in this San Francisco homeless population compared with the general U.S. population. These data show that anti-HAV was associated with homelessness independent of other known risk factors, such as being foreign-born, race/ethnicity, and injection drug use. This increase indicates an excess risk of HAV infection and the potential need to offer hepatitis A vaccination as part of homeless services.

Seroprevalence of hepatitis A virus infection in persons with HIV infection in Taiwan: implications for hepatitis A vaccination

OBJECTIVES

To retrospectively determine the prevalence of anti-hepatitis A virus (HAV) antibody in HIV-positive persons with different routes of HIV exposure and to describe its characteristics in order to guide vaccination policy.

METHODS

The prevalence of anti-HAV antibody was compared between 1580 HIV-positive persons seeking medical attention and 2581 HIV-negative controls seeking health check-ups, who had undergone anti-HAV tests between 2004 and 2007. Comparisons were also made among groups of the HIV-positive patients who had acquired HIV via different routes of transmission. A multivariate logistic regression model was built to identify independent variables associated with anti-HAV seropositivity.

RESULTS

The overall prevalence of anti-HAV antibody was 60.9% in the HIV-positive and 48.0% in the controls (p<0.001). The overall adjusted odds ratio (AOR) for positive anti-HAV antibody was 2.604 (95% confidence interval (CI) 2.106-3.219) in HIV-positive persons compared with HIV-negative persons. In addition, HIV-positive men who have sex with men (MSM), heterosexuals, and injecting drug users (IDU) all had significantly higher AOR for positive anti-HAV antibody than HIV-negative persons. In HIV-positive persons, older age (AOR 1.284, 95% CI 1.246-1.322) and IDU (AOR 5.137, 95% CI 3.499-7.542) were independently associated with an increased prevalence of anti-HAV antibody. Nearly 90% of the IDU had become seropositive for HAV after age 36-40 years, compared with heterosexuals and MSM after age 46-50 years, and controls after age 51-55 years.

CONCLUSION

Our findings suggest that age groups to be targeted for HAV vaccination vary with the different routes of HIV exposure.

Preventing and controlling emerging and reemerging transmissible diseases in the homeless

Homelessness is an increasing public health problem. Because of poor living conditions and limited access to healthcare systems, homeless persons are exposed to many communicable infections. We summarize the intervention measures reported to be efficient for the control and the prevention of common transmissible infections among homeless populations. Evidence suggests that appropriate street- or shelter-based interventions for targeted populations are the most efficient methods. Depending on the populations targeted, these interventions may include education, free condom distribution, syringe and needle prescription programs, chest radiography screening for tuberculosis, directly observed therapy for tuberculosis treatment, improvement of personal clothing and bedding hygiene, and widespread use of ivermectin for scabies and body louse infestation. Systematic vaccination against hepatitis B virus, hepatitis A virus, influenza, Streptococcus pneumoniae, and diphtheria is strongly recommended. National public health programs specific to homeless populations are required.

Outbreaks of hepatitis A in England and Wales associated with two co-circulating hepatitis A virus strains

During 2002, an upsurge in frequency of hepatitis A outbreaks among injecting drug users was observed in England and Wales. As lack of risk factor information and the high mobility of the cases made linkage of outbreaks difficult, the relationship of nucleotide sequences in the VP1/2PA junction of the hepatitis A virus (HAV) genome amplified from serum of case-patients was investigated. A total of 204 HAV RNA positive sera obtained from a network of 23 laboratories were studied. Comparison of the sequences identified two principal strains: ES1 (n=95) belonging to type IB, and ES2 (n=72) to type IIIA. Of the remaining samples, 15 were type IA, 11 were type IB and 11 were type IIIA. ES1 predominated in Doncaster and other towns in Trent and northern England, and ES2 in the Midlands and southern England; the difference in geographical distribution between these two strains was significant (P<0.0001). In comparison to the sporadic cases, cases infected by either ES1 or ES2 tended to be younger, injecting drug users, people in contact with injecting drug users, or those with a history of incarceration in prisons or homelessness (P<0.0001). Cases infected by ES1 tended to be younger than those by ES2 (P<0.0001). The association of the outbreaks to two geographically restricted strains implicates two principal transmission pathways associated with injecting behavior. Identifying these routes may be conducive to preventing further outbreaks.

Estimating the prevalence of injection drug users in the U.S. and in large U.S. metropolitan areas from 1992 to 2002

This paper estimates the prevalence of current injection drug users (IDUs) in 96 large U.S. metropolitan statistical areas (MSAs) annually from 1992 to 2002. Multiplier/allocation methods were used to estimate the prevalence of injectors because confidentiality restrictions precluded the use of other commonly used estimation methods, such as capture-recapture. We first estimated the number of IDUs in the U.S. each year from 1992 to 2002 and then apportioned these estimates to MSAs using multiplier methods. Four different types of data indicating drug injection were used to allocate national annual totals to MSAs, creating four distinct series of estimates of the number of injectors in each MSA. Each series was smoothed over time; and the mean value of the four component estimates was taken as the best estimate of IDUs for that MSA and year (with the range of component estimates indicating the degree of uncertainty in the estimates). Annual cross-sectional correlations of the MSA-level IDU estimates with measures of unemployment, hepatitis C mortality prevalence, and poisoning mortality prevalence were used to validate our estimates. MSA-level IDU estimates correlated moderately well with validators, demonstrating adequate convergence validity. Overall, the number of IDUs per 10,000 persons aged 15-64 years varied from 30 to 348 across MSAs (mean 126.9, standard deviation 65.3, median 106.6, interquartile range 78-162) in 1992 and from 37 to 336 across MSAs (mean 110.6, standard deviation 57.7, median 96.1, interquartile range 67-134) in 2002. A multilevel model showed that overall, across the 96 MSAs, the number of injectors declined each year until 2000, after which the IDU prevalence began to increase. Despite the variation in component estimates and methodological and component data set limitations, these local IDU prevalence estimates may be used to assess: (1) predictors of change in IDU prevalence; (2) differing IDU trends between localities; (3) the adequacy of service delivery to IDUs; and (4) infectious disease dynamics among IDUs across time.

Multiple viral hepatitis in injection drug users and associated risk factors

BACKGROUND

While infections due to hepatitis B virus (HBV) and hepatitis C virus (HCV) have been well-studied in injection drug users (IDUs), hepatitis A virus (HAV) infection and coinfection with multiple hepatitis viruses have received less attention.

METHODS

Hepatitis serology as well as sociodemographic and drug-related parameters were explored in patients (n = 1512) admitted for opiate detoxification.

RESULTS

Antibodies to HAV were positive in 57.7%, to HBV in 53.0%, and to HCV in 75.0% of the sample. Lack of any hepatic marker was reported in 11.2%; one marker was positive in 24.7%; two markers were positive in 31.2%; and all markers were positive in 32.9%. In patients with one positive marker, 58.8% had had exposure to HCV, and 27% had exposure to HAV. In patients with two positive markers, 46.7% were HAV/HCV and 41.8% HBV/HCV antibody positive. Presence of HBV and HCV antibodies was associated with older age, longer duration of (i.v.) heroin use, and a higher number of rehabilitation treatment episodes (anova), current coconsumption of cocaine was associated with presence of antibodies to either HAV, HBV, and HCV.

CONCLUSIONS

Coinfection with hepatic viruses is highly relevant in IDUs, although HAV does not necessarily share the same risk factors relevant for HBV or HCV transmission. The need for outreach vaccination programs is emphasized for HAV and HBV in the target population. Primary prevention should be implemented before initiation or at early stages of a drug career. Epidemiology and transmission of HAV in IDUs requires further research.

Viral interaction and clinical implications of coinfection of hepatitis C virus with other hepatitis viruses

Coinfection with other hepatitis viruses modifies the viral profile in serum and leads to more liver damage and more rapid progression during the course of hepatitis C virus infection. The viral interference is not only carried out by virus-virus or by virus-cell interactions but also by an enhanced immune response. A superinfecting viral infection does not crossactivate protective immune responses to the pre-existing virus albeit the latter can become undetectable. The induced cytokine stimulation might enhance the hepatic inflammation. Moreover, hepatitis B virus coinfection increases the risk of development of hepatocellular carcinoma in hepatitis C virus patients through common necro-inflammatory pathways or by direct oncogenic activity of hepatitis B virus. Viral interaction also complicates the management of the coinfection because hepatitis C virus impairs the humoral response to hepatitis A virus and hepatitis B virus vaccines, and because pharmacological suppression of hepatitis C virus endangers dually infected patients with reactivation of coinfected hepatitis B virus. Optimized strategies and follow-up are thus necessary in the treatment of infection with multiple viruses. It seems thus necessary to look for markers of hepatitis B virus and/or hepatitis D virus infection in chronic hepatitis patients positive for hepatitis C virus antibodies but negative for hepatitis C virus RNA, and equally well to search for hepatitis C virus RNA in HBsAg-negative/anti-HBc-positive patients with a low level of serum hepatitis B virus DNA.

Prevention of hepatitis A by Havrix: a review

Hepatitis A is one of the most common vaccine-preventable infectious diseases in the world. With at least 1.5 million cases of hepatitis A worldwide each year, disease management constitutes a substantial economic burden. The first effective vaccine against hepatitis A, Havrix was introduced in 1992. This review summarizes data accumulated following more than a decade of clinical experience with this vaccine and compares clinical data with other currently available hepatitis A vaccines. Based on this data and on the current immunological knowledge, a recent consensus concluded that hepatitis A vaccines induce lifelong protection, and thus booster vaccinations against hepatitis A are unnecessary in fully immunized, healthy people. In view of this, current regulatory recommendations for the use of hepatitis A vaccines are reviewed and possible future strategies identified.

An outbreak of hepatitis A virus infection with a high case-fatality rate among injecting drug users

BACKGROUND/AIMS

In 2002, the first reported outbreak of hepatitis A virus (HAV) infection involving mostly intravenous drug users (IDU) occurred in Italy. We attempted a thorough evaluation of the outbreak, including epidemiological, clinical and virological analyses.

METHODS

We conducted an epidemiological investigation, including a case-control study, to identify the source and the modes of HAV transmission. Hepatitis B and C (HCV) viruses and human immunodeficiency virus (HIV) coinfections were clinically analysed. Sequence analysis of the VP1/2A junction of the HAV isolates was also performed.

RESULTS

Of the 47 symptomatic cases, 35 were IDUs. The only associated risk factor was contact (not related to injecting practices) with a jaundiced person (odds ratio: 5.8; 95% confidence interval: 1.3-29.9). Of the cases, 58% were anti-HCV positive and 4.7% anti-HIV positive. Three individuals died of acute liver failure: 2 were HCV-coinfected alcohol abusers, with underlying liver cirrhosis; 1 was HCV/HIV-coinfected. HAV-RNA was found in 15 of the 24 tested patients: genotype IB (8 cases) and IIIA (7 cases) were detected.

CONCLUSIONS

HAV was probably transmitted through the fecal-oral route, although parenteral transmission cannot be excluded. The high fatality rate was probably due to severe underlying liver damage. The occurrence of this outbreak highlights the need for routine HAV vaccination for IDUs.

Changing epidemiology of hepatitis A in the Bologna metropolitan area, northern Italy: importance of counselling and prophylactic measures for the male homo/bisexual population

During a 6-year observational study, 122 cases of hepatitis A virus (HAV) infection were detected in Bologna, Italy, with a c. 300% increase in cases between 1999 and 2004. There were 104 cases (85.2%) in male adults, of whom nearly 70% had unprotected sexual contact as the probable risk-factor. There were increasing numbers of cases in immigrants between 1999 and 2004 (p 0.036), and concurrent cases of infection with human immunodeficiency virus, hepatitis B and C viruses and syphilis were also noted in adult males (p 0.0032). There is a need to re-emphasise targeted educational programmes and anti-HAV vaccination for at-risk subjects.

The medical complications of heroin use

PURPOSE OF REVIEW

Heroin use is associated with numerous adverse sequelae. As clinical services develop, addiction psychiatrists will increasingly be called upon to help identify and manage the complications of heroin use. This review focuses on recent research into the medical complications of heroin use and looks at strategies to minimize harm associated with this practice.

RECENT FINDINGS

Mortality associated with heroin overdose has increased substantially in many countries. Parenteral use of opioid drugs is a central factor and other risk factors include polydrug use, particularly benzodiazepines and alcohol, mental health issues and environmental factors not conducive to resuscitation. Unravelling the determinants of blood-borne virus transmission continues, the focus shifting from needle sharing to inadvertent sharing of other injecting equipment. Trials addressing the challenges of antiviral therapy in injecting drug users are emerging. A greater understanding of the effects of opioids on immune functioning complements our knowledge of infection in the heroin-using group as well as possibly explaining the reduced response to vaccination in this group.

SUMMARY

Medical complications of heroin affect a number of different organ systems. The role of the addiction specialist is to be aware of these so that early diagnosis and appropriate management is instituted. The latter will generally be done in collaboration with other specialists. The addictions specialist can play a significant role in the development of clinical systems to minimize these complications.

An outbreak of hepatitis A among homeless drug users in Rotterdam, The Netherlands

From the end of January to mid-June 2004 (weeks 5-24) a hepatitis A virus (HAV) outbreak occurred among a homeless and drug user community in Rotterdam, The Netherlands. To prevent further spread of the virus within this group and to the general population, the Municipal Health Service of Rotterdam organized a mass vaccination campaign during which 83% (1,515/1,800) of the homeless people were vaccinated. As part of a national HAV typing study, blood and/or fecal samples of 30 Rotterdam HAV IgM+ patients who fell ill during the period of 1 September 2003-1 December 2004 were tested. The tests included RT-PCR and sequencing at the VP3-VP1 and VP1-P2a regions of the HAV genome. It was found that 12 homeless people, one family member of a homeless person and two people without a known risk were infected with a unique subtype 3a strain. Four of the homeless patients became ill after vaccination and were probably infected at the time. This study shows that Dutch homeless people and drug users involved in HAV outbreaks should be offered HAV vaccine actively to prevent further spread of the infection. Furthermore, it was shown by molecular techniques that the unique subtype 3a strain was not found before the Rotterdam outbreak or afterwards, indicating that the mass vaccination campaign was successful.