Haemophilus Infections (Hemophilus Infections) By Larry M Bush, MD, FACP, Charles E Schmidt College of Medicine, Florida Atlantic University; Maria T Vazquez-Pertejo, MD, FACP, Wellington Regional Medical Center Reviewed / Revised Apr 2022 | Modified Sep 2022 View Patient Education Diagnosis Treatment Prevention Key Points The gram-negative bacteria Haemophilus species cause numerous mild and serious infections, including bacteremia, meningitis, pneumonia, sinusitis, otitis media, cellulitis, and epiglottitis.