An outbreak of E. coli O157 Verotoxin-producing E. coli (VETC) which sickened 22 people at the SSE Hydro concert venue in Glasgow, Scotland, earlier this year was caused by undercooked beef burgers, according to a report from the Public Health Protection Unit, NHS Greater Glasgow and Clyde. The report states that 19 of the 22 confirmed E. coli cases, all male, ate burgers at the Big Grill at the Hydro between Jan. 17-19, 2014. The other three cases, all female, were said to be “household contacts of these primary cases.” Three of the confirmed cases were reportedly hospitalized, nine had to take time off work or school, and one had to take a “prolonged absence from the workplace.” Public health investigators said inconsistent cooking practices, inadequate temperature monitoring and inappropriate cleaning practices, along with a potential for cross-contamination, at the venue’s burger outlet were to blame for the outbreak.

Said Dr. Catriona Milošević, co-author of the report, “The outbreak provides a reminder of the potential for E.coli O157 contamination of beef products and of the need for adequate cooking and cross-contamination measures in the preparation of these products – especially minced meat products such as burgers which should be thoroughly cooked.”

E. coli can be transmitted to humans via contaminated food or water, direct or indirect contact with contaminated livestock, or direct transmission from an infected human to another. VTEC is a highly infectious strain and requires only only a small number of bacteria required to cause infection.