Hepatitis A outbreaks mostly affecting men who have sex with men – European Region and the Americas

Between June 2016 and mid-May 2017, an unusual increase in cases of hepatitis A affecting mainly men who have sex with men (MSM) has been reported by low endemicity countries in the European Region, and in the Americas (Chile and the United States of America).

In the European Region, 15 countries (Austria, Belgium, Denmark, Finland, France, Germany, Ireland, Italy, the Netherlands, Norway, Portugal, Slovenia, Spain, Sweden, and the United Kingdom) reported 1173 cases related to the three distinct multi-country hepatitis A outbreaks as of 16 May 2017.

In Chile, 706 hepatitis A cases were reported at national level as of 5 May 2017. In the United States, the New York City Health Department has noted an increase in hepatitis A cases among MSM who did not report international travel.

In low endemicity settings, WHO recommends hepatitis A vaccination for high-risk groups, such as travellers to endemic areas, MSM, people who inject drugs, and chronic liver disease patients.* For MSM the main risk factor is related to sexual transmission, particularly oral-anal sexual contact. Most of the affected countries have routinely recommended hepatitis A vaccine for MSM.

This event is of particular concern from a public health perspective because of the current limited availability of hepatitis A vaccine worldwide. In addition, several national and international lesbian, gay, bisexual, and transgender (LGBT) pride festivals will take place between June and September 2017, including the World Pride Festival in Madrid, Spain between 23 June and 2 July 2017.

In this regard, WHO requests countries to report to WHO Regional IHR Contact points any unusual increase in the number of hepatitis A cases among MSM.

WHO risk assessment

Infection with hepatitis A virus is typically acute and self-limiting. Hepatitis A infection does not cause chronic liver disease and is rarely fatal. Some patients may develop more severe symptoms which may last up to a few months. The virus is primarily spread when an uninfected (and unvaccinated) person ingests food or water that is contaminated with the feces of an infected person. The virus can also be transmitted through close physical contact with an infectious person, through dirty hands and through sexual contact.

In low endemicity countries, reported rates of hepatitis A are low. Disease may occur among adolescents and adults in high-risk groups, such as injecting-drug users, MSM, people travelling to areas of high endemicity, and in isolated populations, such as closed religious communities.

So far, no fatalities have been reported in connection with the ongoing outbreaks. It has the potential to spread further to the general population if control measures (vaccination, hygiene, food safety, and safer sex measures) are not implemented.

WHO advice

Countries with low endemicity profile for hepatitis A should routinely offer vaccination to individuals at increased risk of hepatitis A and of a serious complications following infection. The recommended risk groups, among others, include men who have sex with men. Vaccination against hepatitis A should be included as part of a comprehensive package of services to prevent and control of viral hepatitis, including health education and measures for outbreak control.

Use of hepatitis A vaccine should be preferred for pre- and post-exposure prophylaxis (e.g. for close contacts of acute cases of hepatitis A).

Countries may consider single-dose schedule for hepatitis A vaccination to control outbreaks of hepatitis A, especially when vaccine availability is scarce.

Public health messaging should be directed at groups at increased risk of hepatitis A and of serious complications from the infection.

Information should include advice on prevention - vaccination, hygiene, food safety and safer sex measures.

Madrid LGBT World Pride festival

The Madrid LGBT World Pride festival will be held between 23 June and 2 July 2017 in Spain. Up to two million international guests are expected to attend the event. Although the risk for transmission of hepatitis A by food- and water-related routes in Spain is assessed to be low to moderate, the risk of person-to-person sexual transmission of hepatitis A is moderate to high.

In Spain, hepatitis A cases reported in 2017 are almost eight times higher than the average number of cases reported during the same period between the years 2012 and 2016. Most cases are men with ages between 15 to 45 years old, and MSM are the most affected group.

Specific recommendations for people attending the LGBT World Pride festival are below.

Before the event: Those attending the event should seek advice from healthcare providers on hepatitis A vaccination, HIV, and other STI prevention measures prior to departure.

During the event: Preventive measures should be reinforced to reduce the risk of sexual and / or food and water borne infections.

After the event: Attendants should contact a healthcare provider if experiencing symptoms suggestive of hepatitis A or STI infection.

*In intermediate endemicity setting, hepatitis A vaccination can be considered for the whole population, while in high endemicity, infections are common, but the disease is uncommon, hence, the vaccine is not recommended.