Haemophilus influenzae. Coloured scanning electron micrograph (SEM) of Haemophilus influenzae. H. influenzae a coccobacillus prokaryote (often exhibiting coccoid and bacilli shapes); causes meningitis in children, pneumonia, epiglottitis, laryngitis, conjunctivitis, neonatal infection, otitis media (middle ear infection) and sinusitis in adults. H. influenzae harmlessly colonize the upper respiratory tract in most humans within the first few months of life. Encapsulated strains spread to cause diseases such as bronchitis and pneumonia. Magnification: x 10000 when printed 10 centimetres wide.