Can adenovirus infection cause diarrhea?

Can Adenovirus Cause Diarrhea?

Yes, adenovirus is a well-established cause of acute gastroenteritis and diarrhea, particularly in young children, accounting for 5-20% of hospitalizations for childhood diarrhea in developed countries. 1

Primary Causative Serotypes

Enteric adenovirus serotypes 40 and 41 (previously called fastidious enteric adenoviruses) are the main culprits, primarily affecting the gastrointestinal tract rather than causing respiratory disease. 1 These serotypes contribute to 5-20% of hospitalizations for childhood diarrhea in developed countries and represent a significant proportion of viral gastroenteritis cases. 1, 2

Other adenovirus serotypes, particularly serotype 31, have also been associated with diarrhea, though less commonly. 1

Clinical Presentation

The diarrheal illness caused by adenovirus has distinctive features:

• Diarrhea is more prominent than vomiting or fever, distinguishing it from other viral gastroenteritis patterns. 1
• Duration is notably prolonged: the incubation period is 3-10 days, with illness lasting ≥1 week, which is longer than other enteric viral pathogens. 1
• Watery diarrhea is the predominant stool pattern (87% of cases), though some patients may have mucus (19%) or rarely blood and mucus (3%). 3
• Respiratory symptoms are often present concurrently, occurring in approximately 13-21% of cases. 1, 3, 4
• Associated symptoms include fever (60-80%), vomiting (56%), and mild dehydration (49-80%). 3, 4

The mean duration of diarrhea is 8.6 days for Ad40 and 12.2 days for Ad41, with one-third of Ad41 infections causing prolonged symptoms (≥14 days). 4

Age Distribution and Seasonality

• Peak incidence occurs in children less than 2 years of age, though older children and adults may be infected with or without symptoms. 1
• Infections occur throughout the year with no clear seasonal peaks, unlike rotavirus which has winter predominance. 1
• Most infections occur in children under 3 years of age (85%), with some studies showing peak infection in the 25-36 month age group. 3, 5

Transmission and Outbreak Settings

• Person-to-person transmission is the principal mechanism for spread of infection. 1
• Reported outbreaks have occurred in hospitals and day-care settings, predominantly involving children. 1
• Nosocomial transmission is documented, with adenovirus detected in 6.2% of hospital-acquired diarrhea cases and 13.8% of hospitalized children with diarrhea. 6, 7
• Adult contacts are infrequently affected in outbreak settings. 1

Special Populations at Risk

Immunocompromised patients are at significantly higher risk for severe and chronic adenoviral diarrhea. 1

• In HIV-positive patients with advanced immunocompromise, adenovirus was detected in 24% of specimens from those with diarrhea, more frequently than other microbial agents. 1
• Children with severe combined immunodeficiency syndrome (SCIDS) and bone marrow transplant recipients can develop chronic diarrheal excretion of adenovirus with markedly increased mortality. 1

Diagnostic Considerations

• Commercial antigen-detection kits for enteric adenoviruses are available with 88-89% sensitivity and 91-94% specificity. 1, 2
• Asymptomatic shedding is uncommon (1.3% in controls), making detection in symptomatic patients clinically significant. 6
• The diagnostic value is highest in children less than 2 years of age, as outbreaks involving adults have never been reported. 1

Clinical Significance

Adenovirus ranks as the second or third most common viral cause of acute infantile gastroenteritis, following rotavirus in importance. 3, 4 The illnesses are at least as severe as those caused by rotavirus, with comparable rates of fever, dehydration, and vomiting. 6 Approximately 10% of infected children require hospitalization. 3