1. Shigella flexneri enteritis in risk-taking HIV-infected MSM- a single institution experience A diagnosis of Shigella flexneri enteritis is usually associated with a travel history Over the last decade, the number of cases acquired in the UK has increased Most have been reported as serotype 3a Most have occurred in men who have sex with men (MSM), many of whom were also HIV-1 infected 1 Methods We investigated all laboratory confirmed S. flexneri gastrointestinal infections Stool cultures that tested positive for S. flexneri between January 2009 and May 2013 were correlated with clinical presentations from computerized records 1. Health Protection Agency. Outbreak of UK acquired Shigella flexneri in men who have sex with men. Volume 5 No 40; 7 October 2011

2. Results A total of 14,991 stool cultures were performed of which 59 were Shigella species Thirty nine S flexneri cases identified The commonest subtype was 3a (58%) Median age was 40 years (24-55). Thirty six (92%) identified as MSM, 32 of whom were HIV-1 infected (88%) Twenty one MSM (58%) reported at least one casual male partner over the previous month and 7 (25%) recalled engaging in ‘rimming’ (oro-anal contact) Sixteen MSM (44%)had been diagnosed with at least one sexually transmitted infection in the preceding year Eleven MSM (31%) were constitutionally unwell with pyrexia. Of the 7 who were colonoscoped,1 was found to have severe mucosal ulceration, four had varying degrees of colitis and 2 had normal examinations

3. Conclusion Conclusion S. flexneri enteritis is being diagnosed in HIV-infected MSM without a travel history who often have engaged in unprotected oro-anal sex with casual partners. Shigella enteritis in this population should prompt the taking of a thorough sexual history, referral for full STI screening and the provision of safer sex advice.