The first point that should be said is that this is a very rare case but I think it needs to be discussed. In less than 5% of people infected by the bacteria Bartonella henselae the person develops generalised signs such as fever, fatigue, headache and loss of appetite but rarer still internal organs are affected such as spleen, brain, joints, eyes, lungs and other organs. If the individual is immunosuppressed then the disease can be life-threatening.
In this instance a 53-year-old Greek man was left confused. He struggled to speak. He had been bitten by his cat. He displayed signs of a stroke. Medical tests revealed he had been bitten by his cat on his leg.
He was diagnosed with cat scratch disease (CSD) and given antibiotics for 10 days. These did not clear up the disease. He had deficits in five areas of cognitive function. Tests showed that he had high levels of Bartonella henselae.
As a consequence, he was given a second dose of antibiotics in hospital where he remained for five days. This cleared up the condition. There were no long term effects. He recovered completely. He returned to work.
At one time it was thought that cat scratch disease was caused by a virus but now we know that it is caused by the rickettsial organism Bartonella henselae. It is the cat flea which is infected which then feeds on the cat. It does not make the cat sick but this bacteria is then transmitted to people, about 22,000 of them annually, apparently.
The majority of cases occur in September through January in America. We know now that the disease is transmitted to humans indirectly through infected flea faeces under the cat’s nails or in his mouth from grooming. In 90% of cases the disease is transmitted from cat to human through biting, licking or scratching. This suggests that in 10% of cases it is not due to a cat.
In 50% of cases a red sore develops on the human at the site of transmission of the disease. It is common to see a red streak up the arm or leg. Lymph nodes in the armpit neck and groin become tender. Lymph node enlargement may last for 2 to 5 months.
The disease is a reminder, and we have to be realistic and pragmatic, that a cat bite can rarely cause genuine health problems. People should not be concerned but they should be careful and sensible. If it is not cat scratch disease then an ordinary bacterial infection can also generate around the site of the bite and spread. These infected bites need to be treated with antibiotics quickly. The quicker the better because it prevents infection spreading which in the worst cases can require hospitalisation. Elderly people are clearly more at risk and perhaps less likely to deal with the infection. It just requires an observant approach. Of course, the best course of action is to avoid being bitten which will normally take place in play with your cat.
The story comes from the Daily Mail online. The statistics come from the well-respected Cat Owners Home Veterinary Handbook.