Hepatitis A outbreak associated with consumption of dates, England and Wales, January 2021 to April 2021.

We report a national hepatitis A virus (HAV) outbreak linked to the consumption of Medjool dates. Twenty-nine cases of three genetically related sequences have been identified. Epidemiological investigations identified a suspected product (adjusted odds ratio: 47.36; 95% confidence interval: 1.79-1,256.07; p = 0.021). Microbiological testing has confirmed the presence of HAV on dates recovered from two cases and the product has been recalled. Date consumption is currently likely to be increased in connection with Ramadan, with potential ongoing contamination risk.

Hepatitis A outbreak among men who have sex with men (MSM) in England, 2016-2018: The contribution of past and current vaccination policy and practice.

BACKGROUND: We report on an outbreak of hepatitis A among men who have sex with men (MSM) in England and its associated healthcare resource burden, the strategies used to control the outbreak and the role of past and current hepatitis A vaccination policy and practice in England. METHODS: National surveillance of hepatitis A, including reference laboratory confirmation and molecular sequencing, and a case questionnaire, was enhanced in 2017 to collect demographic and risk information, disease severity and healthcare utilisation. National Health Service (NHS) data was used to calculate associated healthcare costs. RESULTS: During the outbreak period (July 2016 to January 2018), 670 confirmed cases were identified in England, caused by three distinct viral strains. The public health response included raising public and professional awareness, reinforcing vaccine recommendations for MSM, contact tracing for post-exposure vaccination, and mass community vaccination where spill-over of infection into the general population occurred. Hepatitis A vaccine was centrally procured to ensure sexual health clinics in England could offer vaccination to MSM. Outbreak associated healthcare costs were estimated to be approximately £1,500,000. CONCLUSIONS: While MSM are at increased risk of hepatitis A infection, inconsistent implementation of MSM vaccination policy in previous years led to an increasingly susceptible MSM population. The large number of cases, hospital admission rate and public health actions contributed to a significant healthcare burden. Recommending hepatitis A vaccination for MSM and clarifying commissioning responsibilities is essential to prevent future outbreaks.

Improving preparedness to respond to cross-border hepatitis A outbreaks in the European Union/European Economic Area: towards comparable sequencing of hepatitis A virus.

IntroductionSequence-based typing of hepatitis A virus (HAV) is important for outbreak detection, investigation and surveillance. In 2013, sequencing was central to resolving a large European Union (EU)-wide outbreak related to frozen berries. However, as the sequenced HAV genome regions were only partly comparable between countries, results were not always conclusive.AimThe objective was to gather information on HAV surveillance and sequencing in EU/European Economic Area (EEA) countries to find ways to harmonise their procedures, for improvement of cross-border outbreak responses.MethodsIn 2014, the European Centre for Disease Prevention and Control (ECDC) conducted a survey on HAV surveillance practices in EU/EEA countries. The survey enquired whether a referral system for confirming primary diagnostics of hepatitis A existed as well as a central collection/storage of hepatitis A cases' samples for typing. Questions on HAV sequencing procedures were also asked. Based on the results, an expert consultation proposed harmonised procedures for cross-border outbreak response, in particular regarding sequencing. In 2016, a follow-up survey assessed uptake of suggested methods.ResultsOf 31 EU/EEA countries, 23 (2014) and 27 (2016) participated. Numbers of countries with central collection and storage of HAV positive samples and of those performing sequencing increased from 12 to 15 and 12 to 14 respectively in 2016, with all countries typing an overlapping fragment of 218 nt. However, variation existed in the sequenced genomic regions and their lengths.ConclusionsWhile HAV sequences in EU/EEA countries are comparable for surveillance, collaboration in sharing and comparing these can be further strengthened.

Oral fluid testing facilitates understanding of hepatitis A virus household transmission.

The public health response to sporadic hepatitis A virus (HAV) infection, hepatitis A, can be complex especially when the index case is a child and no obvious source is identified. Identifying an infection source may avoid mass immunisation within schools when transmission is found to have occurred within the household. Screening of asymptomatic contacts via venepuncture can be challenging and unacceptable, as a result non-invasive methods may facilitate public health intervention. Enzyme-linked immunoassays were developed to detect HAV immunoglobulin M (IgM) and immunoglobulin G (IgG) in oral fluid (ORF). A validation panel of ORF samples from 30 confirmed acute HAV infections were all reactive for HAV IgM and IgG when tested. A panel of 40 ORF samples from persons known to have been uninfected were all unreactive. Two hundred and eighty household contacts of 72 index cases were screened by ORF to identify HAV transmission within the family and factors associated with household transmission. Almost half of households (35/72) revealed evidence of recent infection, which was significantly associated with the presence of children ⩽11 years of age (odds ratio 9.84, 95% confidence interval: 2.74-35.37). These HAV IgM and IgG immunoassays are easy to perform, rapid and sensitive and have been integrated into national guidance on the management of hepatitis A cases.

Vaccination strategies for control of community outbreaks of hepatitis A: A comparison of two outbreaks in England.

In August 2015 two community outbreaks of hepatitis A virus (HAV) occurred in sub-urban communities in Northern England. Each was managed by an independent outbreak control team. In outbreak one, mass vaccination was deployed targeting a residential area and two schools, while in outbreak two, vaccination was reserved for household-type contacts of cases. The highest vaccination uptake was achieved in the school settings (82% and 95%). These case studies illustrate the range of approaches that can be used and the factors that influence decision-making in response to a hepatitis A community outbreak. Both outbreaks likely started from importation(s) of HAV by returning travellers and spread through extended social networks and the local community. Vaccination strategies were selected based on hypotheses about transmission pathways, which were informed by evidence from oral fluid (OF) testing of asymptomatic contacts. More evidence about the effectiveness of mass vaccination in community outbreaks of hepatitis A in low endemicity settings is needed. Hepatitis A guidelines should include recommendations for the use of mass vaccination and OF testing in outbreaks.

Two concurrent outbreaks of hepatitis A highlight the risk of infection for non-immune travellers to Morocco, January to June 2018.

From January to June 2018, two ongoing hepatitis A outbreaks affected travellers returning from Morocco and cases in Europe without travel history, resulting in 163 patients in eight European countries. Most interviewed travel-related cases were unaware of the hepatitis A risk in Morocco. Molecular analysis revealed two distinct hepatitis A virus (HAV) strains (subgenotype IA DK2018_231; subgenotype IB V18-16428). Vaccination recommendations should be emphasised to increase awareness among non-immune travellers to Morocco and HAV-endemic countries.

Outbreak of hepatitis A associated with men who have sex with men (MSM), England, July 2016 to January 2017.

Between July 2016 and January 2017, 37 confirmed cases of hepatitis A with two unique IA genotype strains primarily among men who have sex with men, were reported across eight areas in England and Northern Ireland. Epidemiological and laboratory investigations indicate that these strains may have been imported several times from Spain, with secondary sexual transmission in the United Kingdom. Local and national public health services are collaborating to control this ongoing outbreak.

Acute hepatitis A in an elderly patient after care worker travel to high endemicity country.

Hepatitis A virus (HAV) is considered one of the most important vaccine-preventable diseases in travelers. HAV spreads from person to person via the fecal-oral route and gives rise to an estimated 1.4 million cases worldwide each year. In developing countries with poor sanitary conditions people tend to be infected during childhood and have few symptoms, whereas in developed countries with good sanitary conditions fewer people develop immunity during childhood. This leads to susceptible populations of adults, who are also more prone to severe complications. Here we describe two confirmed cases of hepatitis A associated with a nursing home. The index case was a care worker who had recently traveled to a high-endemicity country, and the second case was a resident at the nursing home where the index case worked. Both cases had an identical genotype IIIA strain, consistent with a transmission event. Current policy does not include a requirement for hepatitis A vaccine in care workers who travel to high endemicity countries despite the fact that infected care workers can potentially spread the disease to elderly patients and other groups at risk of severe complications from HAV infection. We suggest that employers should consider hepatitis A vaccine upon employment; particularly in care workers who plan to visit areas where HAV is known to be endemic.

Hepatitis B transmission event in an English prison and the importance of immunization.

Immunization against hepatitis B virus (HBV) is recommended for all sentenced prisoners and all new entrants to prison in the UK. In November 2008, acute hepatitis B was confirmed serologically in a 27-year-old man (Case 1) who had been incarcerated since February 2007. The cell mate of Case 1, a 26-year-old man was an established HBV carrier. A home-made tattoo gun was confiscated from their prison cell. In the absence of other clearly identifiable risk behaviours, tattooing was deemed to be a possible route of HBV transmission. Transmission of hepatitis B in a prison setting is a real concern and this report highlights the importance of immunizing prisoners against hepatitis B and should encourage health professionals to communicate the benefits of immunization to inmates to increase vaccine uptake.

Incidence and routes of transmission of hepatitis B virus in England and Wales, 1995-2000: implications for immunisation policy.

BACKGROUND: The incidence of hepatitis B virus (HBV) infection in the UK is low. Since the infection can have serious sequelae, there is a continuing need to examine its epidemiology so as to inform control measures. OBJECTIVES: We aimed to describe the current HBV incidence and patterns of transmission in the UK, to estimate the rate of new carrier infections, and to discuss implications for the control of HBV through immunisation. STUDY DESIGN: We analysed routine England and Wales laboratory surveillance data of acute HBV infection (1995-2000) and data on migration and global HBsAg prevalence. RESULTS: The estimated annual incidence of HBV infection in England and Wales was 7.4 per 100,000. Injecting drug use was the most frequently reported route of transmission. The number of cases attributed to heterosexual contact was fairly stable, whereas the number of cases in men having sex with men decreased. These observations continue trends reported for the early 1990s. Transmission during childhood was rarely reported, but was more frequent among South Asians. The incidence in South Asians is relatively high, and their main risk factors are medical treatment overseas and heterosexual contact. For about a third of cases of acute HBV infection no route of transmission is reported, but analysis of secular trends and age distribution suggest that many of these may be related to injecting drug use. Endemic transmission gives rise to only a small proportion of all new chronic infections, with the vast majority arising from immigration of established HBV carriers. CONCLUSIONS: The incidence of acute HBV infection in England and Wales has remained low, with a similar pattern of reported routes of transmission compared to the early 1990s. The UK prevalence of HBV infection is dependant on global rather than national immunisation policy. Endemic transmission may be reduced by improving immunisation coverage among injecting drug users, which is expected to also reduce the number of cases without a risk factor reported. In addition, immunisation options that better suit the needs of ethnic minorities need to be explored.