Factors affecting the bacteriology of deep neck infection: a retrospective study of 128 patients.

CONCLUSIONS: Broad-spectrum antibiotics are advocated for treating deep neck infection. Anaerobic coverage is necessary, especially in odontogenic cases. The presence of diabetes, infection of the parotid space and an obvious odontogenic source of infection can aid in determining the causative organisms.
OBJECTIVES: This study aimed to analyze the bacteriology in deep neck infections and identify the factors that influenced the causative pathogens.
MATERIALS AND METHODS: The records of 212 patients who were diagnosed as having deep neck infections at the National Taiwan University Hospital between 1997 and 2003 were reviewed; 128 patients with bacterial isolation from their pus cultures were enrolled.
RESULTS: The cultures of 46 patients (35.9%) were polymicrobial. Viridans Streptococcus was the most commonly isolated organism (38.3%), followed by Klebsiella pneumoniae (32.0%) and Peptostreptococcus (17.2%). The most common organism in 44 diabetic patients was K. pneumoniae (54.5%), versus viridans streptococcus (48.8%) in 84 nondiabetic patients. In patients with dental sources of infections, the culture rate of anaerobes was 59.3%; in upper airway infections and other sources of infections they were 22.7% and 21.5%, respectively (Chi(2) test, p = 0.0008). The differences in age, sex, and climate did not show any significant changes in the common causative pathogens. Common pathogens in the infection of parapharyngeal, submandibular, and extended spaces were the same as viridans streptococcus, but in the parotid space K. pneumoniae was the most common pathogen.