A 58-year-old woman is dead and a 48-year-old man has lost all four limbs – both of them contracted the bacterium Capnocytophaga canimorsus through contact with the saliva of dogs. Scientists cannot explain why some healthy people are susceptible to C. canimorsus infection. The bacterium can get from the dog’s saliva into the human bloodstream through a bite, and also by licking the dog in the area where the skin is damaged.
Capnocytophaga canimorsus is a gram-negative bacterium found in the throats of most dogs and cats. It is completely harmless to animals, but it can cause disease symptoms in humans. Maybe, however, this is extremely rare and affects people whose immune systems are not working properly. At least so far it has been …
Sharon Larson of Milwaukee, Wisconsin, died in June this year after her own Shih tzu dog lightly bit her hand. A dozen or so days later, Greg Manteufel, who lived in the same area, fell ill. The man had been in contact with several dogs before, but none had bitten him. To save the patient’s life, doctors had to amputate both his arms and legs.
The bacterium C. canimorsus was found in the blood of both patients. Previously, none of them had problems with the immune system or other risk factors for the development of infection, such as lack of spleen or drug use.
When Sharon Larson was bitten in her hand by her Shih Tzu on June 19, it looked completely harmless. The morning was little more than a needle prick. The next day the woman felt a bit weak, and after another day she was unable to hold a glass of water on her own. She complained of severe pain in her stomach and legs. Her husband took her to the hospital, where she was diagnosed with acute renal failure. Although the patient said that she was bitten by a dog, doctors initially did not suspect that it might be related to her symptoms. On June 22, the blood culture showed the presence of C. canimorsus. However, the patient’s condition deteriorated rapidly. Sepsis killed a 58-year-old on June 23, four days after being bitten.
According to prof. William Schaffner of the Vanderbilt University Medical Center in Nashville, scientists at present cannot explain why some, most likely completely healthy people are susceptible to C. canimorsus infection. It is also not always clear how the bacteria got from the dog’s saliva into the human bloodstream. It is known that this can happen through a bite and also when a dog licks someone where the skin is damaged (e.g. in a small wound).
However, in the case of Greg Manteufel, this was not the case. The man remembers that he was just stroking the dogs – they didn’t lick him and they certainly didn’t bite him. Prof. Schaffner suspects that the bacteria were on the animal’s hair, and the man had to touch his conjunctiva or the inside of his mouth with his fingers immediately after stroking the dog.
US regulations do not require reporting of C. canimorsus cases to the CDC. Nevertheless, last year the institution received 12 reports of similar, though not so tragic, cases.
Source: NBC News