Bartonellosis is an infectious disease caused by Bartonella bacteria. It's a zoonotic disease that spreads from animals to humans. Different Bartonella species can enter your body and cause varying bartonellosis symptoms.
What Is Bartonellosis?
Bartonellosis is a group of infectious diseases caused by Bartonella bacteria. There are 22 known species of Bartonella bacteria, of which 15 can cause Bartonellosis. They can spread from animals to humans through carriers like fleas, lice, or sand flies. They can also spread if a pet or wild animal bites or scratches you.
What Are the Causes of Bartonellosis?
Bartonella bacteria are parasites that invade your red blood cells, immune cells like macrophages, and endothelial cells lining your blood vessels. Bartonella species cause different types of bartonellosis. The most common one is cat scratch disease, affecting more than 20,000 Americans per year.
Based on the Bartonella species, bartonellosis is subdivided into:
1. Cat scratch disease. The species Bartonella henselae causes cat scratch disease. The bacteria may be present on a cat or kitten’s claw or mouth and spread through a scratch, bite, or lick. Fleas may transmit the bacteria among cats, and cats can spread it to humans.
If an infected cat without symptoms bites or scratches you, it may not affect you. You may even show mild symptoms, depending on your immunity. But there’s no evidence of the bacteria spreading from human to human.
2. Carrion’s disease. The species B. bacilliformis causes Carrion’s disease. It has two phases of bartonellosis. The sudden or acute phase is called Oroya fever, whereas the chronic or long-term phase is called verruga peruana or Peruvian warts. The bacteria are carried and spread by sand flies, which bite at night.
If an infected sand fly bites you, B. bacilliformis bacteria can enter your body and attach to your red blood cells. The bacteria invade and destroy your blood cells, which can reduce your hemoglobin levels and cause anemia. They may also attack cells lining tiny blood vessels or capillaries, causing blockages or blood clots.
Even if you don’t show symptoms, the bacteria can continue to grow and lead to verruga peruana, which causes nodes or sores on your skin.
3. Trench fever. The species B. quintana causes trench fever, which is transmitted to humans by body lice. This type of bartonellosis is common in poverty-stricken regions with poor hygiene and sanitation.
Bartonellosis is common in people with weakened immunity — including those with HIV/AIDS, cancer treatment, or organ transplants. They are at a higher risk of severe B. henselae and B. quintana infection.
What Are Bartonellosis Symptoms?
Common bartonellosis symptoms include fever, chills, weakness, and headache. Other symptoms vary based on the infection-causing Bartonella species.
Cat scratch disease. Cat scratch disease symptoms may appear days or weeks after exposure. Mild infection may go away in two to four months without treatment. But severe infection or a weakened immune system can cause serious symptoms.
At the infection site, you’ll notice a red spot that becomes a bump after a week. It is painless and does not itch. It may get filled with fluid, dry up, and heal after one to three weeks, leaving a scar.
After one to three weeks, you may have lymph node swelling or lymphadenopathy near the infection site. It can occur in your underarms, neck, or groin area. You’ll feel tenderness, warmth, or redness around the lymph nodes. It may also lead to pus formation. Lymphadenopathy goes away within two to 12 months.
Other symptoms of cat scratch disease include:
- Body ache and discomfort
- Tiredness and weakness
- Headache
- Fever and chills
- Loss of appetite
- Sore throat
- Weight loss
In severe cases, B. henselae may also cause infection and swelling or inflammation in your eyes, liver, heart, brain, spleen, or bones.
Carrion’s disease. Carrion’s disease is rare. The acute phase or Oroya fever presents with high fever, chills, continuous sweating, severe headache, weakness, and skin paleness. It can also cause muscle, abdominal, and joint pain.
B. bacilliformis can cause inflammation in the brain and swollen lymph nodes. The bacteria destroy blood cells and decrease hemoglobin and oxygen in the blood. This can lead to severe symptoms like chest pain or angina, seizures, blood clots, liver and gut problems, and breathing problems. Some people may develop mental changes like confusion, disorientation, or a coma due to anemia.
During the chronic phase called verruga peruana, you’ll notice an outbreak of raised, reddish-purple nodules or Peruvian warts on your skin. They appear three to 12 weeks after B. bacilliformis exposure. Over time, they may form blisters or ulcers and cause bleeding. Left untreated, verruga peruana can last for months or years.
Trench fever. Trench fever symptoms occur up to five weeks after bacterial exposure. You’ll have a sudden fever, headache, dizziness, chills, weakness, and body pain. Fever may come and go many times, lasting five days each time. You may also develop a temporary skin rash and liver or spleen enlargement.
How Is Bartonellosis Diagnosed?
Doctors may confuse bartonellosis symptoms with other conditions caused by bacterial infection. So, diagnosis requires confirmation through blood tests and antibody assays. Your doctor may take blood samples and confirm Bartonella infection using polymerase chain reaction (PCR), DNA sequencing, and the Western blot test.
The doctor may conduct a biopsy to remove infected tissue in severe cases. They’ll use microscopic examination, cell culture, and molecular techniques like PCR to study the tissue and confirm Bartonella infection.
What Does Bartonellosis Treatment Involve?
Mild bartonellosis may resolve within a few months without taking antibiotics. If you have serious symptoms, your doctor will prescribe antibiotic bartonellosis treatment for four to six weeks. They may also prescribe pain relief and fever-reducing medication.
If you have lymph node swelling, your doctor will prescribe a five-day azithromycin course. B. henselae is resistant to antibiotics like penicillin and amoxicillin. So, your doctor will give you antibiotics like rifampin, ciprofloxacin, or gentamicin to treat cat scratch disease. They may also give you other medication to treat severe symptoms and complications like inflammation.
If you have Carrion’s disease, your doctor will prescribe the antibiotics ciprofloxacin or chloramphenicol. B. bacilliformis infection can cause severe anemia. You may require a blood transfusion to restore your hemoglobin levels. For verruga peruana, you’ll have to take the antibiotics rifampin and streptomycin.
For trench fever, you’ll be given doxycycline, tetracycline, and gentamicin for two to four weeks.
How Can You Prevent Bartonellosis?
You can prevent bartonellosis through the following measures:
- Take care of your pets and ensure they receive treatment for fleas and other parasites.
- Avoid getting scratched or bitten by cats, and wash your hands after playing with them.
- Avoid exposure to lice. Seek immediate lice treatment if you find them on your body.
- Avoid contact with sand flies. Use insecticides or insect repellents and bed nets to keep sand flies away.
- If you’re immune compromised, consult your doctor for safety measures.