H.influenzae  is a gram-negative, cocco-bacillary, facultatively anaerobic pathogenic bacterium that can cause infections in people of all ages ranging from mild, such as an ear infection, to severe, such as a bloodstream infection. It is a normal commensal of nose and throat and does not cause any infection under normal situations. But when the host defense mechanisms are weakened it invades the epithelium and disseminates to other parts of the body where it causes infection.
Haemophilus influenzae infection
Streptococcus pneumoniae infection
Pneumococcal infections
COVID-19-associated respiratory failure
Lemierre's syndrome
Pertussis
Middle East respiratory syndrome coronavirus infection
Influenza