They had taken several rounds of drugs, professionally deeply cleaned their home and replaced contaminated toothbrushes, but none of it worked long. Inevitably, the infection came rushing back.
“It seemed like the whole family was on antibiotics, had just stopped taking antibiotics or was going to come down with a stroke again,” recalled Levitis, an evolutionary biologist who was a teacher at the University of Wisconsin at the time.
On New Year̵
Over the next three months, which contained several more strokes, Levitis began to suspect that the cause of the repeated infection was in their home. But finding doctors who took his controversial hypothesis seriously proved to be a challenge.
After a search, Levitis managed to find a receptive audience. And when the possible source of recurrent strep was treated, the round Robin infection ended.
The first case occurred in late October 2017. Levitis was in Massachusetts on a research trip when his wife called to tell him that she and all their three children – Tigerlily, then 6, Kestrel, who was 3 and 14 months old Peregrine – had tested positive for strep and took antibiotics.
Levitis, who had been battling a sore throat since leaving Madison several days earlier, called his doctor and was given a prescription for an antibiotic. Since the rest of his family was infected, he was also believed to have strep.
After a round of antibiotics, everyone seemed to recover.
But five weeks later, his daughters complained of sore throat. This time the whole family was tested. Neck cultures revealed that all five had strep.
Within a few days the infection appeared to have been removed. But success was short-lived; New Year’s Day visit happened three weeks later. This time, the doctor prescribed another antibiotic.
Levitis said he and his wife recalled the need to finish the entire course with antibiotics and sanitation measures they had followed, including replacing the toothbrushes they had used.
But two weeks later, on January 16, Kestrel and Tigerlily had strep again. And at the end of January, all three children tested positive.
“We were so clear about this and painfully aware that something was wrong,” Levitis recalled. No one at school or daycare got a strike, he said, so he suspected something in their house was the source.
Levitis called his mother, a retired pediatrician who had practiced in suburban Maryland, for advice. She told him about a family she had seen who continued to get stroked until they removed their pet tax.
Four months before the first outbreak, the family had adopted Umberto, a 3-year-old gray cat, from a nearby family.
“I started looking at the scientific literature, and everyone said cats can’t transmit strep,” Levitis recalled.
Levitis said his wife asked her doctor about the possibility that cats could be vectors of strep, while asking her cousin, a veterinarian.
“They all pretty much said the same thing: ‘There is no evidence that cats can transmit strep to humans, but if you want to be safe, get rid of the cat,'” Levitis recalled.
It seemed unthinkable; they all loved Umberto. “He is so loving and patient with our children and such a wonderful pet,” Levitis said. “And we didn’t know for sure that he was the culprit.”
Although there are diseases that cats can transmit to humans – including Toxoplasmosis, cat scratch disease and ringworm – Streptococcus A, the bacteria that cause strep throat, is not believed to be among them.
A report from the American Veterinary Medical Association of 2002 found that although doctors sometimes blame pet cats and dogs for recurring strep throats in children, “there is no evidence to do so.”
“There is more evidence that pets carry Group A Strep[tococcus] temporarily and only when in contact with an infected person, “concluded a former association president. “So tell your kids with Strep[tococcus] not to kiss the kitten. “
Cats and dogs can infect humans with a strain called strep canis, which is found in the animal’s saliva and is usually transmitted through a bite.
Iris Levitis asked their vet if she could test Umberto for strep if he was a lead. The vet refused: Umberto seemed healthy and there was no need to swell the throat of a healthy cat, which would require him to be linked to oxygen and administer general anesthesia.
An attractive case
As a researcher, Levitis said he was frustrated that no one seemed prepared to consider the possibility that a cat could in rare cases contain strep that could be transmitted to humans. Some published reports had suggested such a scenario.
Among them is a 2007 letter from the Mayo Clinic Proceedings of a Pennsylvania internist describing an experience similar to the Levitis family. His three young children developed recurrent strokes, which became extinct after they – and their cat – were treated simultaneously with antibiotics.
The Levites called some veterinary methods to see if they tested Umberto; everyone said no.
“We were thinking of dosing him ourselves,” Levitis recalled, but “decided it was a bad idea.”
In early March, 3-year-old Kestrel got throat throat along with respiratory syncytial virus, which led to pneumonia, resulting in a two-day hospital stay. After she returned home, the couple discussed a variety of medical resources available in Madison, which include a large and respected veterinary medical schools.
“Iris had the brilliant idea” to call the university animal hospital and try to talk to an expert there, Levitis recalled. Perhaps, the couple thought, an academic center would be more receptive to the cat hypothesis than society’s veterinarians had been.
She stopped talking to Caitlin Barry-Heffernan, a fourth-year resident of internal medicine. Then she handed the phone over to her husband for his pitch.
“I talked about it as a research case,” Levitis said, “not a guy who got a strep throat from his cat.”
An unusual neck culture
“We were all kind of skeptical,” recalled Barry-Heffernan, who now practices in Southfield, Mich., Outside Detroit. It’s unusual, she said, for cats to carry strep A, for the bacteria “don’t like living on animals.”
But she was fascinated by the opportunity and persuaded by Levitis. He was scientifically knowledgeable and “it was a pretty credible circumstance.”
Barry-Heffernan said she went down the corridor to consult a veteran microbiologist. “She was very skeptical, “Barry-Heffernan recalled, but agreed that” we should be able to cultivate it if it’s there. “
So Barry-Heffernan told Levitis to bring in her cat for a neck culture.
On April 4, while the whole family was taking antibiotics for the seventh stripe in as many months, Umberto was seen by Barry-Heffernan and a veterinary student. They showed Umberto, who Barry-Heffernan said seemed “perfectly healthy”, into a nearby room and quickly swept his throat. Neither anesthesia nor oxygen was required.
“Umberto was a really nice cat,” she recalled, so the procedure was not difficult.
To avoid the Faculty of Veterinary School, Group A strep was found in the cat’s throat. it seemed to match the strain of strep collected during Levi’s latest neck culture.
“Almost certainly Umberto contributed to the family’s infections,” Barry-Heffernan said. She prescribed antibiotics for the cat and a disinfectant spray for his fur. And the Levitis family got another round of antibiotics.
Shortly thereafter, they went on a previously planned two-week trip to Costa Rica. In their absence, Umberto received his medicine, and the house was professionally cleaned a second time.
Since then, Levitis said, no one has had a stroke.
“When we identified Umberto as a carrier, it was really easy to deal with,” Barry-Heffernan said. It seems likely that the infection was transmitted among the asymptomatic cat and various family members; it probably originated in a human being. (Likewise, the small number of cats and dogs that are known to have tested positive for the new coronavirus believed to have been infected by humans; there is no evidence that animals can transmit the virus to humans.)
Barry-Heffernan said she hopes the unusual cases of the Levites will not cause people to get rid of their pets. “It was treated very easily,” she noted.
Levitis, who now lives in Northern California with his family – and Umberto – said he is convinced that treating the cat eradicated the infection that had made his family more difficult.
“We were lucky,” he said, “because Caitlin had an open mind.”