Whipple disease is a rare bacterial infection that affects various body systems. While often associated with the digestive system, it can manifest in diverse ways due to its systemic nature.
Causes
Whipple disease is caused exclusively by the bacterium Tropheryma whipplei. This bacterium is found in the environment, particularly in soil and wastewater, suggesting an environmental source for infection. However, exposure to Tropheryma whipplei does not mean an individual will develop the disease. The exact reasons why some people become ill after exposure while others do not are not fully understood, but it is believed that certain immune system susceptibilities may play a role. The disease is not highly contagious and typically does not spread from person to person.
How It Affects the Body
Whipple disease primarily impacts the small intestine, interfering with its ability to properly absorb nutrients, a condition known as malabsorption. This leads to common gastrointestinal symptoms such as chronic diarrhea, abdominal pain, and significant weight loss. The bacteria damage the finger-like projections, called villi, that line the small intestine, impairing nutrient uptake.
Beyond the digestive tract, the infection can spread to other parts of the body. Joints are frequently affected, with many individuals experiencing arthritis, which can be migratory and nondeforming, appearing years before intestinal issues. The brain and nervous system can also be involved, leading to neurological problems such as confusion, memory loss, difficulty walking, and seizures. Less commonly, the disease may affect the heart, eyes, skin, and lungs.
Diagnosis
Diagnosing Whipple disease often involves a combination of tests due to its varied symptoms and rarity. A key diagnostic procedure is a biopsy, typically taken from the small intestine, often during an endoscopy. These tissue samples are then examined under a microscope for characteristic findings, such as foamy macrophages that stain positive with periodic acid-Schiff (PAS) stain.
Polymerase Chain Reaction (PCR) testing is also crucial, as it can detect the DNA of Tropheryma whipplei in tissue samples or other bodily fluids like cerebrospinal fluid. This molecular test provides high sensitivity and specificity for confirming the presence of the bacterium. While not specific to Whipple disease, blood tests may also be conducted to check for signs of malabsorption, such as anemia or low protein levels, which can support the diagnostic process. An accurate and timely diagnosis is important for effective treatment.
Treatment and Outlook
Treatment for Whipple disease primarily involves long-term antibiotic therapy to eradicate the bacterial infection. The regimen typically begins with an intensive phase of intravenous antibiotics, such as ceftriaxone or penicillin, administered for two to four weeks. Following this initial phase, patients usually transition to an oral antibiotic, commonly trimethoprim-sulfamethoxazole, which is continued for one to two years or even longer.
Strict adherence to the full course of antibiotics is important to prevent relapse, especially if the central nervous system has been affected. In some cases, alternative or lifelong maintenance therapy with antibiotics like doxycycline and hydroxychloroquine may be considered to prevent recurrence. With proper and timely treatment, most individuals experience significant improvement in symptoms and can recover well. However, ongoing medical monitoring is often necessary to ensure the infection does not return and to manage any persistent effects.