Bartonella henselae 17 kDa - IgM

What Does a Positive or Elevated IgM Result Mean?

A positive or elevated IgM result for Bartonella henselae 17 kDa suggests:

• A recent or active Bartonella infection

• The immune system is mounting an early-stage response to the bacterium

• You may be currently experiencing symptoms related to Bartonella infection

Because IgM reflects early immune activity, this result is most useful for identifying acute or newly acquired infections.

Common Symptoms of Bartonella henselae Infection

Symptoms may vary depending on the individual and the type of infection. Common presentations include:

• Swollen lymph nodes (especially near the site of a scratch or bite)

• Fever

• Fatigue

• Headache

• Muscle or joint pain

• Eye involvement (neuroretinitis or conjunctivitis)

• Neurologic symptoms in more severe or chronic cases (e.g., confusion, irritability, seizures)

Chronic or systemic Bartonella infections may be more difficult to diagnose and can mimic other conditions.

Next Steps

• Consult your healthcare provider to interpret this result in the context of your symptoms, exposure risks (e.g., recent contact with cats or flea/tick exposure), and overall health.

• Consider additional testing, such as IgG, PCR, or a Bartonella enrichment culture, especially if symptoms are ongoing or unclear.

• Treatment may involve antibiotics such as azithromycin or doxycycline, depending on the severity and type of symptoms.

Summary

The Bartonella henselae 17 kDa – IgM test detects early immune response to a bacterium that can cause cat scratch disease and other systemic infections. A medium or positive result may indicate a recent infection and should be carefully evaluated in combination with symptoms and additional testing. Early diagnosis and treatment can help reduce complications, particularly in people with persistent or atypical symptoms.

Bartonella henselae, a species within the Bartonella genus, is a proteobacterium responsible for bartonellosis, which includes conditions such as Cat Scratch Disease (CSD) and Bacillary Angiomatosis (BA). Human infection is most commonly transmitted through scratches or bites from companion animals, particularly cats and dogs. Symptoms of B. henselae infection typically appear within ten days of exposure, beginning with a papule (a small raised bump) at the site of entry. This is usually followed by swollen lymph nodes, most often in the armpit (axillary) region. About half of infected individuals also experience general symptoms such as body aches, nausea, abdominal pain, and overall malaise.