CAT SCRATCH DISEASE
What is cat scratch disease and what causes it?
Cat Scratch Disease, or Cat Scratch Fever, is a disease of humans, not of
cats. However, a cat scratch is often associated with the disease, although
this is not believed to be the means by which infection occurs. The disease
is caused by a bacterium-like organism called Bartonella henselae . The
typical symptoms of the disease are mild fever, chills and lethargy accompanied
by enlarged lymph nodes (usually single) and skin or conjunctival lesions. Most
symptoms last for a few days only, but the enlarged lymph nodes may persist
for weeks or months. In a minority of people a more severe disease may develop
with high fever, weight loss, arthritis, enlarged liver or spleen, pneumonia
or nervous signs. These more serious forms of the disease are often associated
with underlying immunodeficiency states, such as HIV infection.
How common is this disease?
It is not possible to give accurate estimates of the prevalence of Cat Scratch
Disease in this country but it is probably a fairly rare disease. Surveys carried
out in the USA indicate that about 5% of the population have been exposed to
infection, but only a small proportion of these reported having the disease.
It is likely that many infections do not give rise to symptoms, or are of a
trivial nature such as a mild 'cold'.
How do humans become infected?
Although many cases of Cat Scratch Disease follow a cat scratch, this is not
universally true and a few cases have occurred in people with no apparent contact
with cats. Recent evidence suggests that the major route of infection is by
flea bite. Infected cats carry the microorganism in their blood, where it can
be present in extremely high numbers. When a flea feeds on an infected cat it
ingests large numbers of Bartonella, some of which may be inoculated
into a human the next time the flea takes a meal. Even cats with extremely high
levels of organism in their blood do not show any signs of disease. It is mainly
younger cats and kittens which carry the organism. They remain infectious for
a few weeks, after which the organism disappears from the blood. It is not clear
whether cats can be reinfected. There are no reported cases of any human being
infected more than once.
Is there a vaccine or treatment for Cat Scratch Disease?
There is no vaccine available against Cat Scratch Disease either for cats
or for man. Bartonella henselae is sensitive to a number of antibiotics,
but not penicillin, ampicillin, erythromycin, tetracycline or some other commonly
prescribed antibiotics. The disease is self-limiting, and mild cases will resolve
without recourse to antibiotics.
Back
to Feline Information Index
|
