No evidence of transmission from an acute case of hepatitis A in a foodhandler: follow-up of almost 1,000 potentially exposed individuals, London, United Kingdom, April 2012

Identification of acute hepatitis A virus (HAV) infection in a foodhandler in a London hotel led to a large incident response. We identified three potentially exposed groups: hotel staff who had regularly consumed food prepared by the case and shared toilet facilities with the case, patients who shared the same hospital ward as the case and hotel guests who consumed food prepared by the case. We arranged post-exposure HAV vaccination for all 83 potentially exposed hotel staff and all 17 patients. We emailed 887 guests advising them to seek medical care if symptomatic, but did not advise vaccination as it was too late to be effective for most guests. Through the International Health Regulations national focal points and the European Union Early warning and response system (EWRS), we communicated the details of the incident to public health agencies and potential risk of HAV transmission to international guests. Potentially exposed hotel staff and guests were asked to complete an online or telephone-administered questionnaire 50 days following possible exposure, to identify any secondary cases. Survey response was low, with 155 responses from guests and 33 from hotel staff. We identified no secondary cases of HAV infection through follow-up.