Shigella flexneri: A Cause of Significant Morbidity and Associated With Sexually Transmitted Infections in Men Who Have Sex With Men.

Abstract

Sexually transmitted Shigella flexneri has been reported in men who have sex with men (MSM).1–8S flexneri is an infectious enterobacteria causing a self-limited diarrheal illness that has been associated with HIV-infection, unsafe-sexual behavior, sexually transmitted infections (STIs), and more recently recreational drug use.5–7 Brighton & Hove is a city in the United Kingdom with a large population of MSM who have an estimated HIV prevalence of 14%.9 We describe a local analysis of cases of S flexneri in MSM in 2013 using both clinical and laboratory data. Through 2013, 24 cases of S flexneri were identified in MSM with no associated travel history. The median age was 43 years (range, 16–77 years). Cases occurred every month; 5 cases occurred in May and August. Twenty-one of 24 reported condom-less anal sex, and 18 of 24 reported sexualized drug use in the past 3 months. Serotype was identified in 10 cases, 3a being the most common (5 cases). Antibiotic sensitivities were available in 4 cases with no cases of ciprofloxacin resistance. Twelve (50%) of 24 required hospital admission, with an average length of hospital stay of 4.3 days (range, 2–7 days). Four (17%) of 24 had an acute kidney injury requiring renal support, and 1 of 24 required 3 days of treatment in the intensive care unit. C-reactive protein was elevated in all 12 patients tested with a median of 153.1 mg/L (range, 43–287 mg/L). Four of (17%) 24 underwent lower gastrointestinal tract endoscopy as investigation of diarrhea. Thirteen of the (54%) 24 MSM were HIV positive including one who was diagnosed during the episode. Ten (77%) of 13 patients were on antiretroviral therapy at the time of Shigella, all with undetectable HIV viral loads (<40 copies/mL). Median CD4 count was 586 ×106 cells/L (range, 285–964 ×106 cells/L). The HIV-MSM with S flexneri were not more likely to be admitted to hospital or have increased severity of illness. Of the 15 patients tested for STI, 6 (40%) of 15 were found to have a concomitant STI (3, rectal chlamydia; 1, primary HIV infection; 1, acute hepatitis C; 1, rectal gonorrhea). We were not able to identify distinct sexual networks involving S flexneri; however, we have introduced a Shigella partner notification strategy. We describe an outbreak of S flexneri among MSM in 2013. A significant proportion of the MSM required hospitalization and had significant morbidity (high C-reactive protein, 17% had acute kidney injury, 17% patients underwent endoscopy). Fifty-four percent of MSM with S flexneri were HIV positive, but had good CD4 counts and did not experience excess morbidity. Coinfection with other STIs was 40% in those tested including 1 with primary HIV and 1 with acute hepatitis C. Interestingly, reports of S flexneri in MSM are nonexistent after the emergence of HIV infection in 1981: however, outbreaks are being increasingly reported since 1999 (the advent of effective treatment of HIV). It has been suggested that MSM are aware that HIV is a treatable condition and that having an undetectable viral load significantly reduces risk of infection and meeting other MSM for sexual encounters fueled by social media, mobile phones, and recreational drug use has created the “perfect storm” for transmission of Shigella (and other STI).6,10 With local public health teams, both community awareness and enhanced surveillance program for Shigella were initiated locally, and we implemented a stringent partner notification strategy with clear treatment guidelines. S flexneri should not be considered a trivial self-limiting condition, cases should be screened for other STIs, and opportunities for risk reduction should be taken. Fiona Valarie Cresswell, MRCP Sophie Ross, MBBS Tristan Booth, MBBS Nicolas Pinto-Sander, MBBS Eliza Alexander, FRCPath Brighton & Sussex University Hospitals NHS Trust Brighton, UK Jasmine Bradley Brighton & Sussex Medical School Brighton, UK John Paul, FRCPath Brighton Public Health England Collaborating Centre Microbiology Brighton, UK Daniel Richardson, FRCP Brighton & Sussex University Hospitals NHS Trust Brighton, UK [email protected]