Last update:
28-Jul-2000

Arch Hellen Med, 16(6), November-December 1999, 595�601

ORIGINAL PAPER

Infectious agents causing viral and atypical pneumonia in Northern Greece
during the years 1992�1996

G.N. KONSTANTINOU, G. BOKOLAS, S. ALEXIOU-DANIEL, A. ANTONIADIS
Laboratory of Microbiology, School of Medicine, Aristotle University of Thessaloniki, Greece

OBJECTIVE To investigate the frequency of the infectious agents causing viral and atypical pneumonia in Northe rn Greece.
METHOD Paired blood samples taken in the acute and the convalescent phase from 1013 patients, men and women of all ages, hospitalized in the hospitals of the Thessaloniki area for community acquired pneumonia, were sent to the University Laboratory for serological diagnosis. Sera were tested by the complement fixation test against antigens obtained from influenza A and B, parainfluenza 1 and 3, adenoviruses, respiratory syncytial virus (RSV), Mycoplasma pneumoniae, Coxiella burnetii and Chlamydia sp. All the samples were tested against Legionella pneumophila serogroup 1 by the immunofluorescence test.
RESULTS In 119 of the 1013 patients (11.75%), the serological diagnosis was confirmed by seroconversion or a permanent high titre in both blood samples, obtained in the acute and in the convalescent phase of the disease. The most common causative agents, with the highest rate per year, were found to be influenza A virus (21%), respiratory syncytial virus (17.7%), adenovirus (11.8%), Legionella pneumophila (10.1%) and influenza B virus (10.1%). The annual and seasonal distribution of the infectious agents as well as their total relation to the mean annual atmospheric temperature were studied. Our findings are compared to those of the same laboratory for the previous five years period.
CONCLUSIONS Infectious agents causing viral or atypical pneumonia should be considered in the differential diagnosis of respiratory tract infections.

Key words: Atypical pneumonia, Complement fixation, Immunofluorecence test, Viral pneumonia.