National spread of drug-resistant Shigella bacteria prompts San Diego warning

With last summer’s hepatitis A outbreak under control, the county public health department turned its attention last week to another bacterial threat that spreads through the community in much the same way.

The county Health and Human Services Agency reached out to doctors and advocacy groups to share information on Shigellosis, a disease that generated 334 cases in San Diego County last year, the most seen locally since 1997.

Just like the microbe that caused the hepatitis A outbreak, the Shigella bacteria spreads through fecal contamination, and the health department is warning those who work with high-risk groups, including the homeless, those with weakened immune systems and men who have sex with men to be on the alert for signs and symptoms of infection including diarrhea, fever and abdominal pain.

According to the U.S. Centers for Disease Control and Prevention, Shigella samples collected from communities across the nation continue to show signs of antibiotic resistance. Dr. Eric McDonald, chief of the county’s Epidemiology and Immunization Services Branch, said June 29 that his department has not yet received a report of a Shigella infection that could not be treated with first-line antibiotics such as ciprofloxacin, but doctors are counseled to do special antibiotic susceptibility testing before prescribing antibiotics to treat the disease.

Hand washing is the main way to prevent infection.

“The bad news is, unlike hepatitis A, there is no vaccine that works for Shigella. But the good news is that hand sanitizer does work,” McDonald said, referring to the oft-publicized fact that alcohol-based sanitizers are ineffective against hepatitis.

Sanitation efforts are not as robust as they were in the fall of 2017 when the hepatitis outbreak was growing every day. But the City of San Diego has continued some of its efforts, maintaining portable restrooms and hand-washing stations in three different downtown locations, continuing to wash city sidewalks and keeping Balboa Park restrooms open round the clock seven days per week.

A health department survey in April found that Chula Vista, Del Mar, Encinitas, La Mesa, Solana Beach and Vista are using special cleaning products to cleanse their facilities and plan to continue doing so indefinitely. Carlsbad, Chula Vista, Del Mar, La Mesa, San Diego and Vista plan to continue cleaning their streets and sidewalks with bleach solution.

Carlsbad, Encinitas, San Diego and Imperial Beach have added public restroom capacity either by keeping permanent facilities open for additional hours or by using portable units.

Homeless camps look different today than they did last year, according to advocate and regular camp visitor Michael McConnell.

“You see a lot fewer people in tents on the streets downtown living there for multiple days or weeks at a time. I now see smaller encampments popping up in the neighborhoods surrounding downtown,” McConnell said, adding that he wasn’t sure whether that was a good or bad thing for controlling the spread of infectious disease.

Overall, he said, he has not noticed a permanent new culture of sanitation among the homeless despite last year’s outbreak which killed 20 people, most of them homeless.

“If there are hand-washing stations or portable toilets, I do see people using them, and you can even see them migrating to those resources, but I do still see people urinating or defecating on the streets,” McConnell said.

What’s disappointing, the activist added, is that recent homeless counts show little progress in the overall goal of getting people permanently off the streets, the only permanent way to handle the sanitation issue.

“Month over month, quarter over quarter, we’re not seeing a huge improvement in the numbers of people getting out of homelessness, despite the fact that we’re spending a lot of money on this problem,” McConnell said.

Though it can cause severe illness, shigellosis-related deaths are rare. A recent CDC paper that examined foodborne disease reports from 2002 through 2014, estimates that various species of the bacteria cause 500,000 illnesses, 6,000 hospitalizations and 40 deaths per year.

The public health department has recorded eight Shigella-related deaths since 1993 with the two most recent fatalities in 2015 and 2005. The most recent case, McDonald said, was caused by a more virulent species of the bacteria picked up during travel abroad.

The pace of Shigella infection this year appears to be similar to what occurred last year. Both this year and last, records show that there were about 100 cases by mid-June.

“We tend to see more Shigella cases toward the end of the year, sort of late summer, early fall,” McDonald said.

Last year, according to county records, 15 percent of cases were among men who have sex with men, and 12 percent were homeless. So far this year, 25 percent have been MSM and 7 percent have been homeless.

--Paul Sisson is a reporter for The San Diego Union-Tribune