Even small dog bite calls for fast medical attention
Common antibiotic will take care of infection
Jennifer McQuiston isn’t worried about her children getting kisses from the family’s dogs.
The recent reports of death and serious injury to two Wisconsinites tied to bacteria in the saliva of dogs is no reason to panic, McQuiston says.
Why should anyone care what McQuiston thinks?
She’s one of the nation’s leading experts on capnocytophaga, the bacteria at the center of the tragedies.
“I have two dogs and they play and lick my children every day and I am not concerned about capnocytophaga, (pronounced cap-no-sa-TOE-faga)” said McQuiston, deputy director of the Division of High-Consequence Pathogens and Pathology with the U.S. Centers for Disease Control and Prevention.
More important, says McQuiston and other experts, is recognizing the symptoms of sepsis — a potentially lifethreatening complication of an infection — and getting immediate medical attention.
“What’s really happening is a rapidly
overwhelming bacterial infection,” McQuiston said.
And typically, if recognized early and the person has no underlying health problems, capnocytophaga will respond to penicillin or another common antibiotic.
“In the vast majority of cases, people do not get sick from this,” she said.
The bacteria led to the death of a Milwaukee County woman and the amputation of a West Bend man’s hands and parts of his legs in June. In 2015, a 3-year-old Grant County boy had to have his fingers and toes amputated after he developed the same kind of infection.
The CDC does not track the number of cases of illness from capnocytophaga — states have not made it a requirement to report such infections to the CDC — but the agency is confident illness from the bacteria is rare.
The CDC has confirmed nine cases since 2015. At the same time, however, officials with the agency admit they don’t know the full scope because labs across the country are able to test and confirm the bacteria, meaning not all samples are sent to the CDC.
The two recent cases in Wisconsin, for example, were not sent to the CDC. The CDC learned about them from media reports and subsequently reached out to the Wisconsin Health Department.
CDC officials can also get an indication of the prevalence by looking at the agency’s MicrobeNet database that doctors and hospitals use to research rare bacteria. In the past year MicrobeNet has received 12 reports of capnocytophaga infections, McQuiston said.
According to the CDC, 74% of dogs have capnocytophaga detected in their mouths and about 36% of the U.S. population owns at least one dog.
“There are so many dogs and so many people and interactions with dogs, that tells you how rare this is . ... Pets play a really important part of human existence,” she said. “The answer is not to get rid of your pet or test your dog.”
Illness follows puppy bite
It was a normal Tuesday evening and Sharon and Daniel Larson were at their South Milwaukee home visiting with their son and daughter-in-law. It was about 5. p.m. when their Shih Tzu puppy nipped Sharon’s finger. Just a nip. Nothing that seemed serious.
The following evening, Larson felt she was getting the flu. She began throwing up on Thursday morning.
Her husband, Daniel, chided her to go to the doctor when she told him she wasn’t going to work that morning, but Sharon told him she’d sleep it off. By about noon, he noticed his wife was pale — she didn’t look well, according to their son, Steven.
He drove her to Urgent Care at Wheaton Franciscan Healthcare. Taking one look at Sharon Larson, doctors told them to go to the emergency room. They took her vitals, and discovered her blood pressure was extremely low — so low that doctors were surprised she was still alive, her son said.
Doctors recognized the signs of sepsis and administered antibiotics immediately. Family mentioned all the factors they thought might be relevant: the dog bite; that Sharon had been out to visit her daughter in Colorado the week prior; and that she worked at a bank and often handled money.
Doctors weren’t sure what was causing what appeared to be a serious infection. In addition to the antibiotics, they ran ultrasounds, took X-rays, performed an emergency CT scan, took cultures of her blood. Larson continued to worsen.
By 1 a.m. Friday, Larson began showing signs of organ failure. Doctors sedated her and put her on a breathing tube and dialysis. Larson’s condition became grave.
On Saturday, June 23, she died. Doctors did not find out until later that what killed her was capnocytophaga, though they had suspected it.
“My mom was 58 years old and she had dogs all her life. They licked and nibbled her and she was fine,” Steve Larson said Monday, “until the last four days of her life.”
Steven Larson said they will remember their mother as a kind, genuine person who loved her family, her pets, her job at BMO Harris bank and life itself.
“She was a great person,” he said. “I know I can’t change anything; I can’t bring my mom back. But if I can help another family hold onto their loved one by sharing this story, I’ll do that.”
Sneaky bacteria
Capnocytophaga bacteria living in animals’ mouths are common and crafty, according to experts.
The reasons dogs and cats are able to live with the bacteria is because it is part of their microbiome, or community of microbes. Humans have their own, different communities of microbes.
“This organism has developed some tricks to evade immune responses,” said Christopher W. Olsen, a professor emeritus of public health at the University of Wisconsin-Madison School of Veterinary Medicine.
Olsen said the bacteria is able to evade white blood cells called macrophages, and also has the ability to enter the body without triggering the signaling system that normally alerts the body to foreign organisms.
Although people tend to think of large bites or wounds as being a gateway to capnocytophaga, Olsen stressed that the bacteria can enter the body through relatively small cuts or fissures in the skin.
“I dare say the average practicing doctor has never heard of this bacteria,” said William Schaffner, a professor of preventive medicine and infectious disease at Vanderbilt University Medical Center. “It’s not reportable. We, as doctors, just know it is pretty darned unusual.”
Schaffner said the bacteria are often found in dog and cat saliva “and on occasion, you can even find this bug in human saliva.”
It is when the bacteria find its way into unusual niches that it can wreak havoc. When capnocytophaga gets beneath human skin, it finds a rich environment of nutrients in our fatty and fibrous tissue. These nutrients allow the bacteria to multiply rapidly.
The danger increases significantly if the bacteria get into the bloodstream. This can happen in the case of a dog bite or any wound that has damaged blood vessels. Schaffner said it is more likely to result from the bite of a dog than from that of a cat. The reason is that dog bites are crushing injuries that carry a higher probability of damaging blood vessels.
Humans most vulnerable to the bacteria include alcoholics, older adults, people with weakened immune systems and those lacking a spleen. The spleen acts as an effective filter for the blood and fights certain kinds of bacteria.
Alcoholics are at greater risk because they have less efficient infection-fighting white blood cells. Early signs of a human infection from the bacteria include redness, swelling, a discharge, puffiness and pain.
Long recovery road
Greg Manteufel of West Bend is still undergoing treatments at Froedtert Hospital for the infection he contracted in June. Manteufel’s case is atypical: He hadn’t been bitten or scratched by any dogs or cats and didn’t have any of the health conditions that would predispose him to infection.
His wife, Dawn, said that his prior medical history consisted of a sprained ankle and not much more.
Doctors said if Greg had been an alcoholic, he probably wouldn’t be alive today, his wife said.
His flu-like symptoms first appeared the evening of June 25, with a fever and vomiting that worsened over the course of the next day. By the night of the 26th, family members say he was delirious, talking gibberish, and had severe leg pain — but insisted on lying back down instead of going to the hospital.
By the time he got to the hospital at 5:30 the next morning, he was turning black and blue as blood vessels began to burst all over his body.
Doctors started him on antibiotics immediately and initially asked questions about his exposure to ticks and spiders. They sent his blood samples out of state for testing, and the capnocytophaga diagnosis didn’t come for eight days. He’s lost parts of all four limbs to sepsis and will require reconstructive surgery on his nose.
This week he is having his ninth surgery. He is expected to have at least 11 total surgeries before moving to rehab and recovery in the upcoming weeks.