This case involves a 47-year-old man who developed sudden confusion and kidney failure after experiencing fatigue and muscle aches. Medical testing revealed severe muscle breakdown, pneumonia, and multiple organ involvement. After thorough evaluation, doctors diagnosed Legionella infection (Legionnaires' disease), likely contracted from his living environment in a converted factory building, highlighting how environmental factors can cause serious illness even in otherwise healthy individuals.
A 47-year-old man with no previous medical problems arrived at Massachusetts General Hospital with severe confusion and acute kidney failure. His symptoms began just six days earlier when he developed fatigue and muscle aches (myalgias). Despite feeling unwell, he continued working at his restaurant job for two more days.
Four days before admission, his coworkers noticed mild confusion. On the day of admission, his confusion worsened significantly, and he developed word-finding difficulties and garbled speech. Emergency services were called, and he was transported to the hospital. In the emergency department, he reported feeling hot and short of breath but couldn't provide a complete medical history due to his confused state.
Additional history from family revealed he took ginseng extract and burdock root supplements but no prescription medications. He lived in a converted factory apartment in New England, smoked marijuana occasionally, had smoked cigarettes as a teenager, and drank alcohol infrequently. His family history included a sister with multiple autoimmune conditions including Sjögren's syndrome and nemaline myopathy.
On examination, the patient had a low body temperature of 35.8°C, elevated blood pressure of 142/78 mm Hg, rapid heart rate of 114 beats per minute, and rapid breathing at 30 breaths per minute. His oxygen saturation was 96% on room air. He appeared anxious and was slow to answer questions, unable to recite days of the week backward, and had difficulty following complex commands.
Notable examination findings included symmetric facial movements, normal cranial nerve function, normal muscle strength and tone, normal sensation and reflexes, and no photophobia (light sensitivity). His mucous membranes were moist, neck was supple, heart sounds were normal, lungs were clear, abdomen was non-tender, and he had no swelling or rash.
The patient's laboratory results revealed multiple abnormalities indicating severe multi-organ involvement:
Urinalysis showed blood (3+), glucose (1+), protein (2+), and elevated red and white blood cells. Toxicology screens were negative for common drugs and substances.
Chest X-ray revealed an opacity in the right lower lobe. CT scan of the head was normal. CT scan of the chest, abdomen, and pelvis showed consolidation in the right lower lobe with minimal adjacent ground-glass opacity but no lymphadenopathy (swollen lymph nodes).
Three hours after arrival, the patient's condition worsened with fever (38.2°C), increased breathing rate (45 breaths/minute), and decreased oxygen saturation (89% on room air), requiring supplemental oxygen at 6 liters/minute.
The medical team identified two main problems: severe muscle breakdown (rhabdomyolysis) without trauma or exertion, and lung consolidation with systemic inflammation. The kidney failure, metabolic acidosis, liver injury, and confusion were considered consequences of these primary issues.
Several possible causes were considered and evaluated:
Among infections, influenza was considered but ruled out by negative testing. HIV and fungal infections like Aspergillus were possible but less likely given the presentation. Bacterial infections, particularly Streptococcus and Legionella, emerged as the most likely causes given the combination of pneumonia, muscle breakdown, and neurological symptoms.
The patient's residence in a converted factory building was particularly relevant, as Legionella bacteria often thrive in complex water systems of large buildings.
The medical team concluded that Legionella infection (Legionnaires' disease) was the most likely diagnosis based on several factors:
The diagnosis was confirmed when a Legionella urinary antigen test returned positive.
Legionella pneumophila is a gram-negative bacterium commonly found in freshwater environments, particularly in warm water systems like cooling towers, plumbing systems, and complex water arrangements often found in large buildings. The bacteria grow best in temperatures between 20-42°C and thrive in biofilms within water systems.
Infection typically occurs when contaminated water is aerosolized and inhaled. The doctors suspected the patient was exposed through the ventilation system in his converted factory apartment. Despite being a generally healthy 47-year-old without typical risk factors (like older age, smoking history, or immunocompromise), he developed severe disease, suggesting he inhaled a large quantity of bacteria.
Diagnostic testing for Legionella includes urinary antigen tests (which detect specific bacterial proteins in urine) and specialized culture techniques. The urinary antigen test is particularly valuable as it provides rapid results and remains positive even after antibiotic treatment has begun.
This case illustrates several important points for patients:
Treatment typically involves specific antibiotics that effectively target Legionella bacteria. In this case, the patient received intravenous ceftriaxone and azithromycin initially, which cover both Legionella and other potential bacterial causes of pneumonia.
Prevention involves proper maintenance of water systems in large buildings, including regular cleaning and temperature control to prevent bacterial growth. Individuals at higher risk (older adults, smokers, those with weakened immune systems) should be particularly aware of these potential exposure risks.
Early symptoms include fatigue, muscle aches, and mild confusion, which can progress to severe confusion, word-finding difficulties, and garbled speech. Patients may also experience fever, shortness of breath, and rapid breathing. These symptoms can appear within six days of exposure to contaminated water aerosols.
Diagnosis is typically made using a urinary antigen test that detects Legionella proteins in urine. This test provides rapid results and remains positive even after antibiotics are started. Doctors may also consider the patient's exposure history, such as living in a building with complex water systems, and laboratory findings like low sodium and high inflammatory markers.
Legionella infection can lead to severe systemic inflammation and multi-organ involvement. The bacteria cause pneumonia, which triggers muscle breakdown (rhabdomyolysis) and releases toxins that affect the brain and kidneys. This results in confusion, acute kidney failure, and other complications, even in previously healthy individuals.
Yes, Legionnaires' disease can affect healthy individuals. In a reported case, a 47-year-old man with no previous medical problems developed severe disease. He had no typical risk factors like older age, smoking history, or weakened immune system. The infection likely occurred because he inhaled a large quantity of Legionella bacteria from a contaminated water system.
Legionella bacteria are commonly found in freshwater environments, especially warm water systems like cooling towers, plumbing systems, and complex water arrangements in large buildings. Infection occurs when contaminated water is aerosolized and inhaled. In one case, a patient lived in a converted factory apartment, and doctors suspected exposure through the ventilation system.
Legionnaires' disease is treated with specific antibiotics that effectively target Legionella bacteria. In a reported case, the patient received intravenous ceftriaxone and azithromycin, which cover both Legionella and other potential bacterial causes of pneumonia. Early recognition and appropriate antibiotic treatment are crucial for recovery.
A positive Legionella urinary antigen test confirms infection with Legionella bacteria. This test detects specific bacterial proteins in urine and provides rapid results. It remains positive even after antibiotic treatment has begun, making it a valuable diagnostic tool. In a reported case, the test confirmed the diagnosis of Legionnaires' disease.
Original Article Title: Case 29-2024: A 47-Year-Old Man with Confusion and Kidney Failure
Authors: Sachin J. Shah, M.D., M.P.H., Melissa C. Price, M.D., and Sanjat Kanjilal, M.D., M.P.H.
Publication: The New England Journal of Medicine, September 19, 2024
DOI: 10.1056/NEJMcpc2402492
This patient-friendly article is based on peer-reviewed research from Massachusetts General Hospital case records.
