SAN DIEGO -- Sitting at a table in the doctor's lounge on Nov. 22 at Sharp Chula Vista Medical Center, Dr. Hai Shao listened as a colleague described a puzzling situation.
Two patients, he learned, came in with apparent infections under their skin after using black tar heroin, but neither responded to the standard one-two punch of antibiotics and surgery that usually resolves such situations in just a few days. One patient had already died and the second looked to be headed in the same direction.
Overhearing the conversation, a surgeon who was also in the room at the time chimed in.
"He was like, I had another patient fitting your description at Scripps just a week ago," Shao said.
Three cases all lining up right there over lunch. It was too much for an expert in all things infectious to ignore.
"It really got me thinking because most of the black tar heroin patients that I have treated in my career, they don't come to the hospital and die the next day," Shao said.
The hunch turned out to be quite correct. Further sleuthing at Sharp Chula Vista and Scripps Mercy Hospital Chula Vista ultimately turned up nine cases, including seven who died after using black tar heroin. Working through the weekend to prove that the cases were connected by more than illicit drugs, Shao notified the county health department on the Monday before Thanksgiving, a move that generated flesh-eating bacteria headlines nationwide when a public notice went out on Dec. 4.
Though the use of the flesh-eating moniker was technically inaccurate, patients most likely suffered from toxin poisoning rather than tissue digestion, it quickly became clear that half of those affected were homeless. That bit of news carried particular weight in San Diego County, which saw 20 die in 2016 and 2017 in a hepatitis A outbreak that was linked to poor sanitation, and a lack of public sanitation resources, among those experiencing homelessness.
Notifying the public last week has already paid off. Dr. Eric McDonald, medical director of the county's epidemiology and immunization services branch, said that a 10th case, this one a 44-year-old man from East County, was recently identified by a local physician who heard about the nine previously identified cases.
At the moment, the exact cause of the case cluster is still under investigation. Two bacteria, clostridium sordellii and clostridium tertium, were discovered in tissue samples from just one of the patients. Lab workers were unable to culture any bacteria at all from nine of the samples collected, and it will take high-powered analysis from toxicologists at the U.S. Centers for Disease Control and Prevention to confirm that toxins were ultimately the cause of rapid illness that, in one case, killed a young man one day after his 20th birthday.