Final answer:
Acute Otitis Media and sinusitis are infections that occur in the middle ear and the sinuses, caused by bacteria such as Streptococcus pneumoniae and Haemophilus influenzae, often following a viral infection that compromises immune defenses.
Step-by-step explanation:
Otitis media and sinusitis both initiate infection in the middle ear and the sinuses, respectively. Acute Otitis Media (AOM) is a common infection in young children, with usual causative agents including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Factors that facilitate AOM with effusion include blockage of the eustachian tubes, which may be caused by anatomic differences in children, such as shorter and more horizontally positioned eustachian tubes, leading to easier fluid transfer from the nasopharynx to the middle ear. Bacterial rhinosinusitis, often triggered by a prior viral infection compromising the immune defenses, can lead to secondary bacterial infection caused by similar pathogens as AOM.