Neonates are commonly affected through the vertical, oculogenital transmission of Neisseria gonorrhoeae and Chlamydia trachomatis
In children, Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis are the most common causative agents.
In adults, staphylococcal species with Haemophilus influenzae and Streptococcus pneumoniae as well as Staphylococcus aureus are the common causative agents.
