What complications can occur with norovirus infection, particularly in elderly, very young, immunocompromised, or postoperative patients (e.g., after surgery with cefazolin)?

Norovirus Complications

Norovirus infection, while typically self-limited in healthy adults, can cause severe and life-threatening complications in elderly, immunocompromised, and postoperative patients, including acute renal failure, cardiac arrhythmias, prolonged viral shedding lasting months to years, and mortality rates up to 25% in allogeneic stem cell transplant recipients. 1, 2

High-Risk Populations and Specific Complications

Immunocompromised Patients

Immunocompromised individuals face the most severe complications, including:

• Chronic diarrhea lasting months to years rather than the typical 1-3 day course seen in healthy individuals 2, 3
• Mortality rates up to 25% have been documented specifically in allogeneic stem cell transplant patients 1, 4
• Acute agranulocytosis has been reported in pediatric kidney transplant recipients, presenting as febrile neutropenia that resolves with improvement of gastrointestinal illness 5
• Prolonged viral shedding continuing for extended periods, increasing transmission risk 1, 4
• Signs of acute graft organ rejection in renal transplant patients 6

Elderly Patients

Older adults experience disproportionately severe outcomes:

• Norovirus-associated deaths occur particularly in long-term care facility outbreaks 2, 3
• Prolonged illness duration of 4-6 days compared to 1-3 days in healthy adults 2, 4, 3
• Age >65 years is an independent risk factor for diarrhea lasting >2 days (OR 11.6,95% CI 1.89-224) 6
• Severe dehydration requiring hospitalization and intravenous fluid resuscitation 3, 7

Patients with Cardiovascular Disease

Cardiovascular complications represent a critical but underrecognized risk:

• Cardiovascular disease is a major risk factor for potassium decrease >20% (OR 17.1,95% CI 2.17-403) 6
• Cardiac arrhythmias have been documented during norovirus outbreaks in hospitalized patients 6
• Electrolyte disturbances including severe hypokalemia requiring monitoring and replacement 6

Renal Transplant Recipients

This population faces multiple severe complications:

• Renal transplant status is an independent risk factor for potassium decrease >20% (OR 13.0,95% CI 1.63-281) 6
• Acute renal failure has been observed during norovirus infection 6
• Immunosuppressive therapy increases risk of creatinine elevation >10% (OR 5.7,95% CI 1.78-20.1) 6

Metabolic and Laboratory Complications

Beyond gastrointestinal symptoms, norovirus causes systemic metabolic derangements:

• Decreased potassium levels requiring aggressive monitoring and replacement, particularly in patients with cardiovascular disease or renal transplants 6
• Increased C-reactive protein and creatine phosphokinase levels indicating systemic inflammation 6
• Acute dehydration as the most common serious complication requiring hospitalization 3, 7

Clinical Course in High-Risk Groups

The typical self-limited course does not apply to vulnerable populations:

• While immunocompetent individuals experience symptoms for 12-72 hours, young children, elderly, and hospitalized patients frequently have prolonged courses of 4-6 days 2, 4, 3
• Vomiting or diarrhea persisting >1 week is atypical and requires immediate evaluation for alternative diagnoses 2
• Peak viral shedding occurs 2-5 days after infection with approximately 100 billion viral copies per gram of feces, and shedding can continue for an average of 4 weeks 4, 3

Critical Management Considerations for High-Risk Patients

Patients at risk should be hospitalized early and monitored frequently for the following:

• Electrolyte abnormalities, particularly potassium levels in patients with cardiovascular disease or renal transplants 6
• Renal function through serial creatinine measurements, especially in immunosuppressed patients 6
• Cardiac rhythm monitoring in patients with cardiovascular disease due to arrhythmia risk 6
• Volume status with aggressive oral or intravenous rehydration as needed 3

Postoperative Context

While the evidence does not specifically address norovirus complications in patients receiving cefazolin or other postoperative antibiotics, the general principles for immunocompromised and hospitalized patients apply. Postoperative patients may be at increased risk due to:

• Temporary immunosuppression from surgical stress 8
• Hospitalization in semi-closed environments where norovirus outbreaks frequently occur 8, 9
• Potential for severe dehydration complicating postoperative recovery 3

Strict infection control measures should be implemented immediately when norovirus is suspected in any high-risk patient to prevent nosocomial transmission 6.