Periodontitis and nosocomial lower respiratory tract infection: preliminary findings

To evaluate the possible association between periodontitis and nosocomial lower respiratory tract infection (LRTI).

A case-control study was conducted at a General Hospital in Feira de Santana, Bahia, Brazil. The sample consisted of 103 individuals: 22 cases (presence of nosocomial LRTI) and 81 controls (absence of nosocomial LRTI). The diagnosis of periodontitis was based on probing depth, gingival recession, clinical attachment loss and bleeding on probing. The diagnosis of nosocomial LRTI was made in accordance with established medical criteria.

Invasive ventilation was much more frequent in cases (95.5%) than in controls (7.4%). An orotracheal tube was used in 81.8% of cases and in 7.4% of controls; bronchoaspiration was suspected in 81.8% of cases and in 6.2% of controls. There was no statistically significant difference in any of the clinical periodontal parameters between cases and controls. The crude odds ratio (OR) value for individuals with periodontitis having LRTI was not statistically significant [OR(crude)=1.70; 95% confidence interval:(0.60-4.87)]. After including age, smoking and duration of hospitalization in the logistic regression, the adjusted OR for individuals with periodontitis having LRTI was statistically significant [OR(adjusted)=3.67 (1.01-13.53); p=0.049].

A marginal association between periodontitis and LRTI was found when smoking, age and length of hospitalization were included as covariates. Patients with LRTI had a high frequency of suspected bronchoaspiration and this could explain the possible association of periodontal disease and LRTI found in this and other studies. Additional studies are needed to further clarify the possible relationship between periodontal disease and LRTI.