Montreal Public Health looks to fight back against rise in shigella infections

Montreal Public Health says shigella is being spread locally through sexual contact and the bacteria is evolving to be more drug resistant.

Now the health authority is updating its recommended protocols for combating the potentially dangerous bacterial infection.

Shigella is a bacteria that infects the intestines and usually spreads via the fecal-oral route. That means it can be transmitted when the mouth comes into contact with something like food or a finger that has shigella-contaminated stool on it.

Symptoms of shigellosis include persistent diarrhea, bloody stool, stomach cramps, vomiting and fever. 

For most people, the infection goes away on its own with rest and drinking plenty of water. But infection can lead to hospitalization, as has been seen in Edmonton where there were 172 confirmed cases as of Wednesday and 115 ended up in hospital.

In Edmonton, the outbreak began in August and is having a significant impact on the homeless population, where the bacteria appears to be spreading by contaminated surfaces, food or water.

Bacteria transmitting through sex

Montreal authorities, however, are finding that multi-drug-resistant strains of the bacteria are spreading locally, particularly among men who have sex with men.

As of Sept. 30, 25 out of 56 infections were caused by multi-drug-resistant strains and were spread mainly through sexual transmission. Six of those 25 required hospitalization. 

The cases of multi-drug-resistant infections are almost all found among men who have sex with men, and only six out of the 25 drug-resistant cases were contracted abroad, "which suggests a predominance of local transmission," Montreal Public Health said in a statement.

Slightly more than 40 per cent — or 11 out of 25 — of these drug-resistant cases were reportedly from sexual activity with anonymous partners, the statement said.

One in four infections were in people such as health-care workers or food handlers who have a high risk of spreading it further.

Being multi-drug resistant means the bacterial infection is resistant to at least three classes of clinically useful antibiotics. Montreal Public Health says many strains of shigella have acquired multi-drug resistance.

The health authority says several European countries and the United States have reported large and persistent outbreaks caused by multi-drug-resistant strains, mainly among men who have sex with men.

Montreal health authority makes recommendations

Dr. Christopher Labos, a cardiologist with a degree in epidemiology, says contaminated food used to be the primary mode of transmission and it's only more recently that sexual transmission has become an issue.

A three-day course of an antibiotic like Ciprofloxacin (Cipro) used to be the go-to treatment, Labos said, but now this drugs doesn't always work and that is leading to some worry.

Unless new antibiotics are developed to combat these drug-resistant organisms, "we may start to have a problem," Labos said.

"Diseases that were once easily treatable might start becoming much more complex."

Among its recommendations, which were published Monday, the health authority says doctors should wait for the result of an antibiogram, which reveals the overall susceptibility of bacteria to a variety of antibiotics, before initiating treatment if the patient's condition allows for such a delay.

The health authority says people who work in the sectors of food, daycare and health care should be pulled off the job until they test negative twice 24 hours apart.

Along with good hand hygiene, the health authority suggests using a protective barrier, like a condom or disposable gloves, during sexual activity. 

Wash your hands, genitals and anus before and after sex, the health authority recommends. The bacteria can also be transmitted on sex toys, so Montreal Public Health says those should be kept clean too.

The health authority says people should refrain from having sex if they have diarrhea. Those with a shigellosis infection should refrain from having sex for three to four weeks after symptoms end. 

For those who are prescribed antibiotics, Montreal Public Health says patients must finish the entire course even if symptoms have gone away.