An 83-year-old who still lives in her own home has developed pneumonia following influenza. The Gram stain of her sputa is shown. What is the most likely agent?

Question

Quizplus · Accepted Answer

The most common cause of pneumonia in people over 65 years of age has generally been S. pneumoniae. Although the other agents also cause pneumonia, S. pneumoniae is the only organism that fits the descriptions of Gram-positive cocci in chains. It is also quite common following influenza. If the woman had not been vaccinated for influenza, then she also may not have been vaccinated for pneumococcus.

An 83-Year-Old Who Still Lives in Her Own Home Has