Comment on: A case of intercurrent shigellosis and rectal gonorrhea in an acutely unwell febrile returned traveler by Fuller et al.

Dear Editor,

We congratulate Fuller et al. ¹ who highlight that Shigella in men who have sex with men (MSM) is seen in returning travellers. We would suggest that all MSM presenting with shigellosis, including returning travellers should be managed as having sexually transmitted shigellosis, particularly in those (i) living with human immunodeficiency virus (HIV), (ii) with recent non-regular sexual partners and (iii) with a sexually transmitted co-infection (e.g., Neisseria gonorrhoeae).^2,3 Genomic data demonstrate the global and regional transmission of different Shigella species and lineages among large sexual networks of MSM in Europe, North America and Australia including the emergence and transmission of extensively antimicrobial resistant Shigella.^4–6 Most sexually transmitted Shigella in high-income settings is likely to be resistant to quinolones, macrolides; and more recently cephalosporins.^5,7,8 There are limited guidelines for the clinical management of sexually transmissible shigellosis globally, and those in publication provide conflicting advice. ⁹ We would suggest that the current (2015) Canadian Committee to Advise on Tropical Medicine and Travel guidelines are inadequate for managing shigellosis in MSM as they do not consider the magnitude of antimicrobial resistance (AMR).^5,10 Recent data from the United Kingdom (UK) suggest that following expert microbiological advice, fosfomycin, pivmecillinam or carbapenems could be considered where antimicrobials are indicated.^2,10

In regard to the management of the case, we note that the patient’s travel partners were asymptomatic, and the timing of his sexual contact and onset of symptoms are consistent with an incubation period of up to seven days, so suggest that his infection was acquired through sexual transmission. ² Shigella circulating in sexual networks of MSM in Canada and Europe are likely to be ciprofloxacin resistant; tetracycline resistance among sexually transmissible Shigella is also high, so doxycycline pre-exposure prophylaxis was unlikely to have been effective. ¹⁰ We note that your patient’s symptoms were resolving by the time he was treated with ciprofloxacin, and no antimicrobial sensitivities were reported.

The distinction between managing such cases as sexually transmitted shigellosis rather than travel associated (contaminated food/water) is important, specifically MSM with sexually transmitted Shigella should be offered comprehensive sexually transmitted infection testing (including HIV, Treponema pallidum, hepatitis A and B), partner notification, and be used as an opportunity to ensure other sexual health interventions have been offered such as hepatitis A, B, Human Papilloma Virus and Mpox vaccination, access to HIV pre-exposure prophylaxis in HIV negative MSM, doxycycline post-exposure prophylaxis discussion, condom use and sexual health education. ² Furthermore, we would not advocate for empirical macrolides, quinolones or cephalosporins based on current AMR data in MSM, and treatment decisions, particularly in resolving cases should be informed by antimicrobial susceptibility testing.^4–7,10 More work is needed to inform clinical guidelines, clinicians and communities about sexually transmitted Shigella in MSM, recognising emerging extensively drug-resistant shigella in these networks and the importance of antimicrobial susceptibility testing and future design of infection control strategies.