RISK-FACTORS FOR THE DEVELOPMENT OF HAEMOPHILUS-INFLUENZAE PNEUMONIA IN HOSPITALIZED ADULTS

Potential risk factors for developing Haemophilus influenzae nosocomia l pneumonia have not been sufficiently studied. We wanted to investiga te the incidence and risk factors for the development of Haemophilus i nfluenzae pneumonia in the hospital by means of a multivariate analysi s. A total of 468 eases of nosocomial pneumonia were observed during t he study period, 317 (68%) of which were aetiologically diagnosed by m eans of highly reliable methods, and A influenzae was isolated in 57 o f them. Fifty of the 57 episodes of H. influenzae pneumonia occurred i n mechanically-ventilated patients. Underlying diseases were: medical in 12 cases, surgical in 15 eases, and traumatological in 22. Variable s associated with Haemophilus influenzae nosocomial pneumonia in intub ated patients after the univariate analysis were: ''period between adm ission and pneumonia 2-7 days'' and ''no previous antibiotics'', A mul tivariate analysis demonstrated that the variables ''no previous antib iotics'' and ''coma on admission'' were risk factors for 61, influenza e pneumonia. In nonintubated patients, no risk factors were found for H. influenzae pneumonia compared with other nosocomial pneumonia. We c onclude that A influenzae was involved in 57 out of 317 (18%) of nosoc omial pneumonia registered in our institution, and the majority of pat ients (50 out of 57) were mechanically-ventilated. In this particular subgroup, coma of the patient on admission to hospital and absence of antibiotic treatment prior to developing pneumonia constitute two defi nite risk factors for developing Ii. influenzae nosocomial pneumonia.