Cat Scratch Disease

choi

Lisa Sanders, At first she would get a fever for a day once a month. Before long the fevers were constant. Then her feet started to swell. Why were all her tests normal?  New York Times Magazine, Sept 10, 2023, at page 16.
https://www.nytimes.com/2023/09/ ... elae-diagnosis.html

Note:
(a) The bacterium causing "cat scratch disease" is Bartonella henselae.
(i) "The genus is named for Alberto Leonardo Barton Thompson (1871–October 26, 1950), a Peruvian scientist [who first described the bacterium in 1905]."  en.wikipedia.org for Bartonella. See also Alberto Barton
https://en.wikipedia.org/wiki/Alberto_Barton
(ii) "The specific name henselae honors Diane Marie Hensel (b. 1953), a clinical microbiology technologist at University of Oklahoma Health Sciences Center, who collected numerous strains and samples of the infective agent during an outbreak in Oklahoma in 1985." en.wikipedia.org for Diane Marie Hensel.
(A) The adjective "specific" means "of species."
(B) Diane Marie Hensel,a technologist or technician, holds a MS, not MD, degree. She did not discover the new species of bacterium, Diane Marie Hensel; Douglas Wear, MD, did, in 1983.

(b) About the bacterium Bartonella henselae. There is non eed to read the rest.
(i) Katherine Baranowski and Ben Huang, Cat Scratch Disease. StatPearls, June 12, 2023.
https://www.ncbi.nlm.nih.gov/books/NBK482139/

Quote:

"Cat scratch disease is an illness caused by an intracellular gram-negative rod known as Bartonella henselae. It affects the lymph nodes draining the area where a cat scratch or bite occurs, causing regional lymphadenopathy [ie, swollen lymph nodes (lymphadenopathy) at the site of inoculation (regional)].

"Cat scratch disease (Cat scratch fever) causes a febrile illness with subacute regional lymphadenopathy. The agent of infection is Bartonella henselae. In most cases [ie, immunocompetent or ordinary persons], there is a spontaneous resolution within 2 to 4 weeks. More severe and disseminated disease can occur in both immunocompetent and immunocompromised hosts. Cat scratch disease was initially described in the 1930s, and the association of the illness with cats was identified in the 1950s pbut identificationof bacterium was not accomplished untl 1983 (by a pathologist), because the bacterium was hard to culture). * * *

(ii) Jane E Sykes and Bruno B Chomel, Bartonellosis. Canine and Feline Infectious Diseases. 2014 : 498–511.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7152345/

Quote:

"Overview of Bartonellosis in Dogs and Cats: First Described: Peru, 1905 (Alberto Barton Thompson) (Bartonella bacilliformis).1 Identification of Bartonella as the cause of cat scratch disease in humans did not occur until 1983.2 [footnote 2 cites Wear DJ etal, Cat Scratch Disease: a Bacterial Infection. Science, 221: 1403 (1983)].  * * * Geographic Distribution: Worldwide, with highest prevalence in subtropical and tropical regions

"Cat fleas (Ctenocephalides felis) play a major role in the transmission of feline Bartonella infections. The presence of cat fleas is essential for maintenance of the infection within the cat population.4  B. henselae can multiply in the digestive system of the flea and survive several days in flea feces.5 The main source of infection appears to be flea feces that are inoculated by contaminated cat claws.6


"The main source of infection appears to be flea feces that are inoculated by contaminated cat claws." This sentence is important, because B henselae must live within cells (intracellular). So for a while I could nto understand cat claws can transmit the disease.

(iii) The cat scratch disease is relatively uncommon in the United States: about 5 infections per 1000,000 persons or a total of 12,000 infections annually.



—------------------------
“Sweetie,” the 59-year-old woman called out to her son. “Can you take a day off from work and take me to the emergency room at Penn?” She had been having fevers off and on for nearly a year, and she was fed up and a little scared. The first one only lasted a day. A month later another fever hit her, but again it was one day of feeling lousy. When it happened a third time, she made an appointment to see her doctor in Bridgeton, N.J., about 10 miles from the small Jersey town she called home for much of her life.

Her doctor was concerned. This was a woman who was never sick, despite the fact that she was born with a bad heart and had a valve donated from a pig for the past 25 years. It had never slowed her down. The doctor sent her to the lab for blood tests. The results were puzzling: Everything was totally normal. Her white-blood-cell count gave no hint of an infection. Her blood cultures grew no organisms. Her doctor wasn’t sure what to make of it. She told the worried patient to let her know if it happened again.

She didn’t have long to wait. A week later, over the Fourth of July weekend, shaking chills racked her body. The thermometer spiked to 103 and just stayed there. Four days in she was scared enough to go to the emergency room. But when she got to the E.R., her temperature was normal. They took some blood for tests, and when those didn’t show anything wrong, she was sent home.

Too Sick to Work
After that, the fevers came faster: from monthly to every two weeks, then every week, and by the time she had to head back to the elementary school where she was a teacher, they came almost every day. Sometimes her temperature was 99 or 100. But soon it regularly got up over 101. Her primary-care physician sent her to see a specialist in infectious diseases. She went to her cardiologist. There were more tests, more blood cultures. She had a chest X-ray and an echocardiogram — an ultrasound of her heart. She knew artificial valves were prone to infection, but all her tests, even the echo, were normal.

By Christmas break, she felt completely worn out. Then her breathing started to get harder. By mid-January she had to stop and catch her breath just walking from her car to her classroom. She went to a pulmonologist. A chest X-ray showed what looked like pneumonia. She took antibiotics for a week, and when that didn’t help, a second week. She still felt awful. She couldn’t walk to the bathroom without gasping for breath. By mid-February she felt too sick to go to work. That was practically a first for her. In her 20 years of teaching, she had banked enough sick days to last an entire school year. She hoped she would not need them all.

The final straw was her feet. They swelled like little balloons, the skin stretched so tight it was shiny. She couldn’t walk. She had to sleep sitting upright, because when she lay down, she could barely breathe at all. That’s when she knew it was time to face the hour drive to the University of Pennsylvania’s Penn Presbyterian Medical Center. She had given the doctors in her small town in New Jersey every chance in the world to help her; she just couldn’t wait any longer to figure this out.

Fluid in the Lung
She and her son set off for the hospital. She was taken into the E.R. immediately. A chest X-ray was hazy, with a small collection of liquid crowding the base of her lung. A CT scan of her chest showed that this wasn’t pneumonia but fluid that had backed up from her heart. That usually happens when the heart’s ability to pump blood out can’t keep up with the amount of blood that flows in. The excess liquid is forced back into the lungs and then the rest of the body. That would explain her shortness of breath and the wildly swollen feet. She had, she was told, what was called congestive heart failure: Her heart just couldn’t get the job of pumping done. But why? Was her pig valve no longer working? The usual life expectancy for these valves is 10 to 20 years — had hers given out? Or had she had a heart attack that weakened the muscle?

The grainy images of the echocardiogram provided an answer: One valve, which is supposed to open and close with every heartbeat to let blood flow into the body, was almost completely closed. Only a trickle was able to get through. But there was more: The valve and the muscle surrounding it appeared to be encircled by strange clumps of alien material.

Dr. Alyssa Ammazzalorso, a physician at the end of her first year of an infectious-disease fellowship at the University of Pennsylvania, was part of the team trying to figure out if the woman had endocarditis, an infection in her heart. After reviewing her chart, Ammazzalorso was pretty certain she did. Endocarditis can progress slowly, the way this woman’s disease had. But by this point she had a half-dozen blood cultures, plus the ones that were done when she arrived at Penn Presbyterian, and none of them showed the presence of bacteria. Ammazzalorso knew that some of the bugs that cause endocarditis don’t show up in blood cultures. Sometimes that’s because the use of antibiotics makes growing the responsible bugs in a petri dish difficult. Other times it’s because the infection is caused by so-called fastidious organisms — bacteria that just don’t like to grow in the lab.

The patient was in bed when Ammazzalorso tapped at the door to her room. Dark skin encircled the woman’s eyes, and her skin had the pallor of someone who had been sick for a long time. As the woman told the doctor her story, she had trouble getting a full sentence out without stopping to catch her breath. Then Ammazzalorso started asking the questions that infectious-disease doctors ask to help get a sense of the patient’s life and possibly reveal clues to what organisms she might have been exposed to. Yes, she recently had dental work done, but she always took antibiotics because of her artificial heart valve. She was a preschool teacher. She lived with one of her two adult sons. She didn’t have a dog, but she did have cats. Lots of cats: seven strays who had somehow adopted her (and vice versa).

When Ammazzalorso finally left the patient’s room, she sat at the computer and considered what tests should be ordered. Certainly, more blood cultures. But she suspected that these, like the others, would be negative. Blood cultures look for organisms in the circulation. That captures most causes of endocarditis but not all. To catch these other organisms, she would need tests that look not for the bugs themselves but instead watch for the body’s immune reaction to specific bacteria. This patient’s biggest risk factor was her exposure to her once-wild cats. Bartonella henselae, which cats catch from fleas and typically transmit to humans through scratches, usually causes a febrile illness called cat-scratch disease, but it can infect the heart. Brucella and Coxiella are less common in cats but can cause endocarditis.

The patient was already on two broad-spectrum antibiotics, but Ammazzalorso and the patient’s attending physician, Dr. Judith O’Donnell, wanted her to start a third that would be needed if this turned out to be Bartonella. The tests were ordered, the additional medication prescribed. And the doctors waited.

Ammazzalorso was ecstatic when the results came back: It was Bartonella henselae. “It was a classic case,” she told me. “It could have been one of those cases you read in the infectious-disease exams.” And there is, she says, a powerful satisfaction when cases come together perfectly like this and provide a definitive treatment.

A few days later, the patient was wheeled into the operating room, where her chest wall was bisected at the sternum and the ribs cranked open. The growths that had invaded her heart muscle were excised along with the infected pig valve. A new “bio-prosthetic” valve, as these porcine implants are called, was put into place, and her chest was wired shut.

The patient felt better the moment she woke up. Sure, her chest felt uncomfortable — it had been through a lot. But she could breathe. Her heart could pump. She could walk. The surgery was six months ago. She is still on antibiotics, but she feels good. She’s looking forward to going back to school, back to her kids. And while she is going to keep her seven strays, she says there won’t be any more, ever.