Invasive Pneumococcal Pneumonia and Respiratory Virus Co-infections

Each year, especially in the winter, many get sick and some die of invasive pneumococcal pneumonia. Does this type of pneumonia increase in the winter because people are in closer contact indoors? Or are people more susceptible to this bacterial disease after having had a seasonal respiratory virus infection? A season-by-season analysis found an association between pneumococcal pneumonia and two viruses (influenza and respiratory syncytial virus). The association varied by season and was strongest when the predominant influenza virus subtype was H3N2. Vaccination against influenza and RSV should also help protect against pneumococcal pneumonia.To confirm whether respiratory virus infections increase susceptibility to invasive pneumococcal pneumonia, we examined data from 11 influenza seasons (1994–2005) in the United States. Invasive pneumococcal pneumonia was significantly associated with influenza and respiratory syncytial virus activities in 5 seasons. Association strength was higher when strain H3N2 was the predominant influenza A virus strain