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Sexually transmitted illness grows resistant to drugs

CDC releases report on shigella outbreak in the United States

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An illness that causes thousands of cases of diarrhea a year, and can be sexually transmitted, is being brought to the United States by international travelers — and it’s resistant to antibiotics.

A drug-resistant strain of shigella — a bacteria that can be transmitted orally via fecal matter — caused illness in 243 people in the United States and Puerto Rico between May 2014 and February 2015 according to a recent report from the Centers for Disease Control and Prevention (CDC).

Dr Vanessa Allen, the chief of medical microbiology at Public Health Ontario, says the fact that people get sick from shigella is not uncommon — it causes approximately 500,000 cases of diarrhea a year in the United States, according to the CDC.

What makes the most recent breakout unusual, is that the antibiotics typically used to treat shigella — ciprofloxacin and septra — proved ineffective. Of the cases investigated, almost 90 percent were found to be resistant to ciprofloxacin, and according to Allen, even more patients were resistant to septra.

“Because shigella’s so contagious, if this were to take off it would be extremely problematic because we wouldn’t have any drugs or we would have . . . fewer drugs to be able to treat it effectively,” she says, adding that doctors would have to resort to intravenous therapy.

Shigella can be transmitted sexually, which is why anyone having anal sex needs to take proper preventative measures — namely, proper condom use and handwashing. The risk is also increased because shigella only requires a very small dose to infect another person, compared to similar bacteria like E coli.

Allen says it is very unusual to see a death reported from shigella, and that there were none recorded during the outbreak in the United States. Symptoms of shigella include watery or bloody diarrhea, fever and stomach pain. Potential complications that can arise from it include arthritis, septicemia or bacteremia.

In Canada, the rates of resistance are lower than in the outbreak reported by the CDC — Allen says that they are between 12 and 24 percent. However, she says that the fact that there is any resistance at all is a cause for concern.

“I think this is one example of really the need to focus on how we deal with antibiotics better,” she says. “The resistance probably developed because it was being over used both here and internationally and so it’s really a call to action for how we more aggressively look at anti-microbial resistance.”