Walker A M, Jick H, Porter J
JAMA. 1979 Sep 21;242(12):1273-5.
In a series of 14,077 hospitalized medical patients receiving antibiotics, superinfection developed in 95 (0.7%) during drug therapy. The majority were yeast and fungal infections, and serious infections occurred with a frequency of less than one per 1,000 patients treated. Concurrent immunosuppression and impaired renal function increased the risk of new infections.