The bacteriology of acute maxillary sinusitis.

Sinus secretions obtained by antral aspiration from 347 patients with acute maxillary sinusitis were examined bacteriologically. Special attention was paid to the method by which anaerobic bacteria could be recovered. On the total, 485 sinus secretion samples were examined, of these 336 were aspirates, 149 yields of injection-aspirations. Aerobic bacteria were cultured from 263 aspirates and from 100 injection-aspiration samples. Only anaerobes were recovered from 6 sinuses. Bacterial culture was negative in 115 sinuses (24%). The most common pathogens isolated were Haemophilus influenzae (50.5%), Streptococcus pneumoniae (18.5%), Streptococcus pyogenes (5%) and Branhamella catarrhalis (1.5%). A true anaerobic infection was considered to be present in only 7 sinuses (1.5%) indicating that anaerobes are not a significant cause of acute maxillary sinusitis. According to this study the most common pathogen in acute maxillary sinusitis in young adults is H. influenzae. From this follows that in such patients aminopenicillins may be a more appropriate choice than conventional penicillin in the antimicrobial treatment of acute maxillary sinusitis.