Molecular testing for Bartonella henselae is used to confirm the presence of the bacterium in suspected cases of cat-scratch disease and some other related infections.
Bartonella henselae is a gram-negative bacterium that is responsible for causing the infectious disease known as cat-scratch disease (CSD). It is primarily transmitted to humans through scratches or bites from infected cats, particularly kittens, although it can also be transmitted through fleas.
The primary reservoir and carrier of Bartonella henselae are cats. Infected cats can carry the bacterium in their blood for several months to years, and they can shed the bacteria in their saliva and through flea feces. Humans usually acquire the infection when they are scratched or bitten by an infected cat, or when the bacteria-contaminated flea feces enter a wound or the eyes.
The cat-scratch disease typically presents with a small, localized papule or pustule at the site of the scratch or bite. The nearby lymph nodes may become swollen and tender, forming painful regional lymphadenopathy. Other symptoms can include low-grade fever, headache, fatigue, and malaise. In rare cases, complications such as bacillary angiomatosis (characterized by proliferative skin lesions) or Parinaud's oculoglandular syndrome (conjunctivitis with swollen lymph nodes near the ear) may occur.
The diagnosis of cat-scratch disease is often made based on clinical presentation and history of exposure to cats. Laboratory tests, such as serological assays (detection of antibodies against Bartonella henselae) or polymerase chain reaction (PCR) testing, can be used to confirm the diagnosis.
Most cases of cat-scratch disease resolve on their own without specific treatment. Symptomatic management, such as pain relief and warm compresses to reduce lymph node swelling, is usually sufficient. In severe cases or in individuals with weakened immune systems, antibiotics like azithromycin, doxycycline, or ciprofloxacin may be prescribed to shorten the duration of symptoms.
To reduce the risk of cat-scratch disease, it is important to practice good hygiene after handling cats, especially kittens. This includes washing hands thoroughly with soap and water, avoiding close contact with cats that are known to scratch or bite, and keeping cats indoors to limit exposure to fleas.
It's important to note that while the cat-scratch disease is the most well-known manifestation of Bartonella henselae infection, this bacterium has also been associated with other conditions like bacillary angiomatosis, trench fever, and bartonellosis in immunocompromised individuals.