Infections with Eaton agent in pneumonia

Bacteremic pneumococcal pneumonia in Sweden: clinical course and outcome and comparison with non-bacteremic pneumococcal and mycoplasmal pneumonias

279 patients with 285 episodes of bacteremic pneumococcal pneumonia (Pnb), treated at the 2 departments for infectious diseases in Stockholm, Sweden, were reviewed retrospectively. Almost half of all episodes were caused by serotypes 3, 9 and 4 (in that order). The overall mortality rate was 7% and as low as 5% if patients with extrapulmonary complications were excluded. As in other studies male sex, alcoholism and absence of leukocytosis on admission to hospital were all associated with a higher mortality rate. However, the prognosis for old patients was much better than in most other studies. This was true also when the infecting strain was of serotype 3. For 89 consecutive patients out of the 279 ones with Pnb the clinical, laboratory and chest X-ray data were compared with those of 44 patients with non-bacteremic pneumococcal pneumonia (Pn) and 27 patients with Mycoplasma pneumoniae pneumonia (MP). Within the pneumococcal group almost all non-bacteremic patients had respiratory tract symptoms compared to less than half of the patients with bacteremic disease. High age, alcoholism, chills, pleuritic chest pain, a leukocyte count of greater than 15 x 10(9)l and an elevated CRP were factors significantly more common among those with pneumococcal pneumonia than among the MP patients. On chest X-ray an alveolar pattern was seen in all but 2 of the totally 133 patients with a pneumococcal pneumonia, but also in half the patients with MP.

Antibody response against the type specific capsular polysaccharide in pneumococcal pneumonia measured by enzyme linked immunosorbent assay

The enzyme linked immunosorbent assay (ELISA) was used for estimation of the IgG and IgM antibody responses against 13 type specific pneumococcal capsular polysaccharides, individually and in a pool, in 52 patients with pneumococcal pneumonia and in 20 control patients with non-pneumococcal pneumonia or enterobacterial septicemia. By use of the isolated type 3 polysaccharide as antigen a greater than or equal to 50% increase in absorbance from acute to convalescence phase serum, equivalent to a doubling in antibody titer, was seen significantly more often in 22 patients with type 3 pneumococcal pneumonia than in the 20 control patients (for IgG 14 vs. 3, p less than 0.01; for IgM 14 vs. 4, p less than 0.01). However, for an acceptable degree of specificity to be obtained (less than or equal to 10% control patients positive) a doubling of the IgG or IgM absorbance values had to be demanded. With this criterium only half of the patients infected with pneumococcal types included in the antigen set up used, showed a type specific antibody response and only one third of all patients with pneumococcal pneumonia could be diagnosed by use of the 13 polysaccharides as a pool antigen.

Etiological diagnosis of bacterial pneumonia by gram stain and quantitative culture of expectorates. Leukocytes or alveolar macrophages as indicators of sample representativity

Sputum samples from 151 patients admitted to Roslagstull Hospital for Infectious Diseases, Stockholm, from Sept. 1978 through May 1979 with acute community-acquired lower respiratory tract disease and roentgenological evidence of acute pneumonia were examined by direct microscopy of gram-stained smears and semiquantitative culture. It was carefully noted if the specimen was collected before or after initiation of antibiotic therapy. For an estimate of the suitability of the samples for bacteriological examination 2 criteria were applied: (i) presence of alveolar macrophages, and (ii) purulence, i.e. a ratio leukocytes/squamous epithelial cells of greater than 5. The latter was found to be a good indicator of sample suitability, while the presence of macrophages was not. Of the 266 samples examined 76% were deemed purulent. Potentially pathogenic bacteria in numbers of greater than or equal to 10(5) colony forming units/ml were found in 67% of the purulent sputum samples obtained before antibiotic therapy but in only 36% if such treatment had already been started. Pneumococci were isolated from 52% of pre-treatment samples but from only 8% after treatment. H. influenzae was found as often in post-treatment samples (17%) as in pre-treatment ones (15%) and enteric gram-negative rods twice as often in post-treatment samples (11 vs. 6%). The use of gram-stained smears was a valuable aid in the interpretation of the culture results and the results could be made available to the clinician within minutes after receipt of the specimen. The results were in agreement with those of the cultures for about 75% of the purulent samples.

The protean manifestations of Mycoplasma pneumoniae infection in adults

Mycoplasma pneumoniae is a well recognized respiratory pathogen in children and young adults. In addition, M. pneumoniae infections may also involve other organ systems. Reviewed here are the various clinical syndromes in adults caused by this infectious agent, with emphasis on those which have recently been seen at The New York Hospital. Two previously unreported manifestations of M. pneumoniae infection, cranial nerve mononeuropathy and hepatitis, are described, and the laboratory methods for diagnosis are discussed.