International travellers are bringing a multidrug-resistant intestinal illness to the United States and spreading it to others who have not travelled, according to a report released by the Centers for Disease Control and Prevention (CDC). Shigella sonnei bacteria resistant to the antibiotic ciprofloxacin sickened 243 people in 32 states and Puerto Rico between May 2014 and February 2015. Research by the CDC found that the drug-resistant illness was being repeatedly introduced as ill travellers returned and was then infecting other people in a series of outbreaks around the country.

CDC and public health partners investigated several recent clusters of shigellosis in Massachusetts, California and Pennsylvania and found that nearly 90 per cent of the cases tested were resistant to ciprofloxacin (Cipro), the first choice to treat shigellosis among adults in the United States. Shigellosis can spread very quickly in groups like children in childcare facilities, homeless people and gay and bisexual men, as occurred in these outbreaks.

In the United States, most Shigella is already resistant to the antibiotics ampicillin and trimethoprim/sulfamethoxazole. Globally, Shigella resistance to Cipro is increasing. Cipro is often prescribed to people who travel internationally, in case they develop diarrhoea while out of the United States. More study is needed to determine what role, if any, the use of antibiotics during travel may have in increasing the risk of antibiotic-resistant diarrhoea infections among returned travellers.

Click here to read full report on CDC website