Understanding Bartonella: A Hidden Epidemic
Bartonella is a genus of gram-negative, intracellular bacteria responsible for a spectrum of human disease that ranges from mild, self-limiting illness to severe, chronic multi-system infection. Despite being one of the most common vector-borne pathogens worldwide, bartonella remains dramatically underdiagnosed — and its symptoms are frequently misattributed to other conditions.
At St. George Hospital (Klinik St. Georg) in Bad Aibling, Germany, our physicians have treated thousands of patients with complex tick-borne and vector-borne infections over more than 35 years. Dr. Julian Douwes, Chief Medical Officer, considers bartonella one of the most clinically important yet overlooked infections in modern medicine. “The symptom profile of bartonella is remarkably broad,” he notes. “It can mimic autoimmune disease, psychiatric illness, rheumatological conditions, and neurological disorders. Without a high index of suspicion, it is easily missed.”
What Is Bartonella?
The Bartonella genus includes more than 40 identified species, of which at least 15 are known to cause disease in humans. The most clinically relevant species include:
- Bartonella henselae — the agent of cat scratch disease, also associated with chronic multi-system illness
- Bartonella quintana — historically known as the agent of trench fever
- Bartonella bacilliformis — causes Carrion’s disease (Oroya fever) in South America
- Bartonella vinsonii — increasingly recognized in human infection, particularly in co-infection with Lyme disease
These bacteria are transmitted through bites or scratches from infected animals (particularly cats), and through the bites of fleas, lice, sand flies, and ticks. Transmission via Ixodes ticks — the same ticks that carry Lyme disease — is of particular importance, as it explains the high rate of bartonella-Lyme co-infection seen in clinical practice.
Acute Bartonella Symptoms
Acute bartonella infection typically develops days to weeks after exposure. The presentation varies depending on the species and the patient’s immune status.
Cat Scratch Disease (Classic Presentation)
The most recognized form of acute bartonella infection includes:
- A papule or pustule at the site of the scratch or bite, appearing 3-10 days after exposure
- Regional lymphadenopathy (swollen lymph nodes near the site of inoculation), developing 1-3 weeks later
- Low-grade fever
- Malaise and fatigue
- Headache
- Loss of appetite
In most immunocompetent patients, cat scratch disease resolves spontaneously within 2-4 months. However, this does not mean the infection has been fully cleared — subclinical persistence is increasingly recognized.
Acute Systemic Bartonellosis
Some patients develop more severe acute illness, characterized by:
- High or relapsing fever
- Severe fatigue and prostration
- Night sweats
- Hepatosplenomegaly (enlarged liver and spleen)
- Severe headache
- Myalgia (muscle pain) and arthralgia (joint pain)
Chronic Bartonella Symptoms: The Full Spectrum
Chronic bartonella infection is where the diagnostic challenge intensifies. The bacteria’s ability to invade endothelial cells, red blood cells, and bone marrow progenitor cells allows it to establish persistent infection that can affect virtually every organ system.
Neuropsychiatric Symptoms
Bartonella has a pronounced tropism for the central nervous system, producing some of the most debilitating symptoms of chronic infection:
- Anxiety: Often severe, disproportionate to circumstances, and resistant to conventional treatment
- Depression: Persistent depressive episodes that do not respond to standard antidepressants
- Irritability and rage: Episodes of intense agitation that may be uncharacteristic for the patient
- Cognitive impairment: Brain fog, difficulty concentrating, word-finding problems, and short-term memory loss
- Seizures: In severe cases, particularly with CNS involvement
- Insomnia: Difficulty falling or staying asleep, often with a wired-but-tired quality
- Visual disturbances: Blurred vision, floaters, photophobia
- Hallucinations: In severe neurological involvement
A landmark study published in Pathogens (2019) documented the neurological manifestations of bartonellosis, confirming the organism’s capacity for significant CNS involvement.
Musculoskeletal Symptoms
- Migratory joint pain (arthralgia) — often affecting different joints on different days
- Morning stiffness
- Plantar fasciitis and heel pain — an underrecognized but characteristic finding
- Shin splints without athletic activity
- Bone pain
- Muscle twitching and fasciculations
Dermatological Symptoms
- Bartonella stretch marks (striae): Reddish-purple marks appearing without mechanical cause — see our detailed guide on bartonella stretch marks
- Subcutaneous nodules
- Papular eruptions
- Livedo reticularis (mottled, purplish skin discoloration)
- Erythema nodosum
Cardiovascular Symptoms
- Endocarditis (infection of heart valves) — bartonella is a leading cause of culture-negative endocarditis
- Myocarditis (inflammation of the heart muscle)
- Palpitations and tachycardia
- Vasculitis (inflammation of blood vessels)
Gastrointestinal Symptoms
- Abdominal pain
- Nausea
- Hepatitis and elevated liver enzymes
- Splenomegaly
- Mesenteric lymphadenitis
General Systemic Symptoms
- Chronic fatigue — often profound and unrelieved by rest
- Relapsing low-grade fevers
- Night sweats
- Unexplained weight loss
- Lymphadenopathy (generalized swollen lymph nodes)
Bartonella as a Lyme Disease Co-Infection
One of the most important clinical contexts for bartonella is its role as a co-infection with Lyme disease. Ticks in the Ixodes genus can carry multiple pathogens simultaneously, and patients bitten by an infected tick may acquire Lyme disease, bartonella, babesia, anaplasma, and other organisms in a single exposure.
At St. George Hospital’s Lyme disease program, we routinely test for the full spectrum of co-infections because:
- Co-infected patients tend to have more severe and treatment-resistant symptoms
- The neuropsychiatric symptoms of bartonella can dominate the clinical picture, leading to misdiagnosis
- Treatment strategies differ — what works for Lyme may not adequately address bartonella
- Missing a co-infection is one of the most common reasons patients fail to recover
Why Bartonella Is So Difficult to Diagnose
Several factors contribute to the diagnostic challenge:
- Serological insensitivity: Standard antibody tests (IFA) miss a significant percentage of infections due to bartonella’s intracellular lifestyle and low circulating bacterial load
- Symptom overlap: Bartonella symptoms overlap with fibromyalgia, chronic fatigue syndrome, autoimmune disease, and psychiatric disorders
- Physician unfamiliarity: Many clinicians are not aware of chronic bartonella infection as a clinical entity
- Intermittent bacteremia: The organism circulates in the blood intermittently, making single-draw blood tests unreliable
Advanced testing methods, including PCR, ePCR (enrichment culture PCR), and FISH (Fluorescence In Situ Hybridization), offer improved sensitivity. The CDC’s bartonella resource page provides additional information on recognized diagnostic approaches.
Treatment of Bartonella at St. George Hospital
Our approach to bartonella treatment is integrative and multimodal, addressing the infection, the immune dysregulation, and the systemic inflammation it produces:
- Targeted antibiotic therapy: Species-specific combinations, often including intracellular-penetrating agents
- Whole-body hyperthermia: Fever-range temperatures create conditions hostile to intracellular bacteria. Our hospital is a European leader in medical hyperthermia with over 35 years of clinical experience
- Therapeutic apheresis: Blood filtration to reduce immune complexes and manage the inflammatory burden of treatment
- Ozone therapy: Immune modulation and antimicrobial support
- Detoxification and nutritional support: Comprehensive protocols to support the body through treatment
Dr. Julian Douwes notes: “Bartonella is not an infection that responds well to a single antibiotic given for a few weeks. It requires a sophisticated, layered approach — and that is exactly what we provide in our inpatient setting.”
Frequently Asked Questions
Can bartonella infection be cured?
Acute bartonella infection is generally treatable with appropriate antibiotic therapy. Chronic bartonella can be significantly more challenging, particularly when biofilm formation and co-infections are present. However, with a comprehensive multimodal approach — combining targeted antibiotics, hyperthermia, immune support, and detoxification — most patients experience substantial improvement. Full eradication may require extended treatment.
How is bartonella different from Lyme disease?
Both are vector-borne infections, but they are caused by entirely different organisms. Lyme disease is caused by Borrelia burgdorferi, while bartonella is caused by various Bartonella species. Their symptom profiles overlap significantly, particularly regarding fatigue, joint pain, and neurological symptoms. However, bartonella tends to produce more prominent neuropsychiatric symptoms (anxiety, rage, cognitive impairment) and distinctive skin findings (stretch marks). The two infections frequently co-occur.
Can you have bartonella without knowing it?
Absolutely. Many patients with chronic bartonella infection are unaware they carry the organism. Their symptoms — fatigue, anxiety, brain fog, pain — are often attributed to stress, depression, fibromyalgia, or “unknown cause.” This is particularly true when there is no remembered cat scratch or tick bite. If you have persistent unexplained symptoms affecting multiple organ systems, bartonella should be considered.
What doctor should I see for suspected bartonella?
Bartonella is best evaluated by physicians experienced in vector-borne and tick-borne infections. Infectious disease specialists with expertise in chronic intracellular infections, or integrative medicine physicians with specific training in tick-borne disease, are most likely to provide accurate diagnosis and effective treatment. At St. George Hospital, our medical team includes physicians with decades of experience in this field.
Schedule Your Consultation
If you recognize yourself in the symptoms described above, comprehensive evaluation may be the first step toward answers and recovery. St. George Hospital welcomes patients from around the world for individualized diagnostic and treatment programs.
Contact us:
- Phone: +49 (0)8061 398-0
- Email: info@clinicum-stgeorg.de
- Visit: Contact page
St. George Hospital (Klinik St. Georg) — Rosenheimer Str. 6-8, 83043 Bad Aibling, Germany