What is the virus responsible for causing acute herpetic gingivostomatitis?

Acute herpetic gingivostomatitis is primarily caused by the herpes simplex virus type 1, commonly known as HSV-1. This viral infection is most often seen in young children, and it presents as painful sores in the mouth and gums, along with systemic symptoms like fever and irritability.

HSV-1 is well-known for its capability to establish latency in the sensory ganglia and may reactivate in the future, leading to recurrent oral lesions, typically referred to as cold sores or fever blisters. The transmission typically occurs through direct contact with infected saliva or active lesions.

The other viruses listed in the options—HHV-3 (which is responsible for varicella and shingles), HHV-4 (Epstein-Barr virus, associated with infectious mononucleosis), and Influenza A (a respiratory virus)—do not cause acute herpetic gingivostomatitis. Their mechanisms of action and clinical manifestations differ significantly from those of HSV-1, underscoring the specificity of HSV-1 in causing this oral condition.