What is a common viral cause of acute pharyngitis?

Adenovirus is a well-known viral cause of acute pharyngitis, particularly in children. This virus can lead to a variety of respiratory illnesses, including conjunctivitis, fever, and sore throat. Acute pharyngitis caused by adenovirus often presents with symptoms similar to those caused by bacterial infections, making it important to recognize its viral nature in the context of diagnosing and managing throat infections.

In contrast to adenovirus, the other pathogens listed are primarily bacterial and are more commonly associated with other types of infections. Streptococcus pneumoniae is known for causing pneumonia and sinusitis rather than acute pharyngitis as a primary infection. Haemophilus influenzae, while implicated in respiratory infections, is not the primary viral cause of pharyngitis. Staphylococcus aureus can cause skin infections and more serious conditions but is not a typical cause of acute pharyngitis. Therefore, adenovirus stands out as the correct answer in this context.