Adenovirus serotypes 40 and 41 cause acute gastroenteritis (inflammation of the stomach and intestines) primarily in children.

Symptoms may include:

• fever
• diarrhea
• vomiting
• abdominal pain

It may last for approximately 10 days. Respiratory symptoms can occur in some individuals. The disease is usually self-limiting in immunocompetent individuals; however rare fatalities can occur in immunocompromised individuals. Asymptomatic infections are common, particularly in children.

Adenovirus 40/41 is also known as Enteric adenovirus. Enteric adenoviruses have been identified in 9% of children with diarrhea. They are the third most common cause of infantile gastroenteritis after rotavirus and norovirus. Sporadic and endemic infections may occur year-round.

Sources:

• Gastroenteritis caused by adenoviruses 40/41: epidemiological and clinical aspects, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4822746/ 
• Seranti H, Johnson G, Brown M, Petric M, Tellier R (2004) Comprehensive detection and serotyping of human adenoviruses by PCR and sequencing. J Clin Microbiol 42: 3963-3969.
• Benko M, Harrach B (2003) Molecular evolution of adenoviruses. Curr Top Microbiol Immunol 272: 3-35.
• Murray PR, Baron EJ, Jorgensen JH, Landry ML, Pfaller MA (2006) Rotaviruses, Caliciviruses, Astroviruses, Enteric adenoviruses and Other Diarrheic Viruses. editor. Washington DC: ASM Press 1453-1469.