Mycoplasma pneumoniae infection in hospitalized patients with acute respiratory illness

Mycoplasma pneumoniae and central nervous system complications: a review

Mycoplasma pneumoniae is a common cause of community-acquired pneumonia. Little is known about the extrapulmonary manifestations of this organism. Numerous central nervous system (CNS) manifestations have been described with M. pneumoniae. CNS involvement is probably the most common site of involvement in addition to the respiratory system. Up to 7% of patients hospitalized with M. pneumoniae may have CNS symptoms. Common CNS presentations include encephalitis, aseptic meningitis, polyradiculitis, cerebellar ataxia, and myelitis. The mechanism behind these CNS manifestations remains unclear. Direct invasion, neurotoxin production, or an immune-mediated mechanism has been proposed. Newer diagnostic techniques for the direct detection of the antigen and the microorganism are proving useful for the detection of extrapulmonary disease. This review comprehensively reviews the CNS complications that have been reported with M. pneumoniae.

Rapid etiological diagnosis of pneumonia in young men

The major findings and conclusions of the present study are: 1. Evidence of the etiology of the pneumonia was established in 86% of 106 young men with pneumonia. Pneumococcus was the most common etiologic agent; it was detected definitely in 30% of the pneumonia patients, and possibly in another 20%, by blood culture, sputum culture, antigen detection, and serological methods. 2. Pneumococcal antigen detection from purulent pretreatment sputum samples was the best rapid diagnostic method for pneumococcus; it was capable of identifying 90% of the pneumococcal pneumonias definite by our criteria, whereas sputum Gram stain was positive in 65% of these. 3. Detection of adenoviral antigens from nasopharyngeal specimens (NPS) by EIA or IF method or adenovirus DNA by HYB method showed good specificity but a somewhat lower sensitivity than did adenovirus isolation from NPS. 4. Adenovirus antigens and DNA can be demonstrated also from sputum specimens. 5. EIA is slightly superior to the CF method in detecting antibody responses to adenovirus, but the detection of different antibody classes offers no additional diagnostic possibilities. 6. Isolation of Mycoplasma pneumoniae from bronchoalveolar fluid in pneumonia patients is a specific and sensitive method in the diagnosis of mycoplasmal pneumonia. 7. It seems possible to differentiate by clinical signs and symptoms and by high CRP (over 85mg/1) and WBC (over 10 x 10(9)/1) values pneumococcal pneumonias from viral, mycoplasmal and mixed pneumonias and from upper respiratory infections. Moderately elevated CRP values were observed in adenoviral (Mean 50 mg/1) and in mycoplasma (mean 59 mg/l) pneumonias, as well as in MRI (mean 44 mg/l).

Antigen detection for the rapid diagnosis of mycoplasma and Legionella pneumonia

Immunologic attempts to detect mycoplasma antigens in fluids of infected patients have been rare and largely unsuccessful. Nucleic acid hybridization procedures appear promising on the basis of successes in detecting mycoplasmal contamination of tissue culture cells; results of attempts to apply these techniques to human infections have not been reported. Antigens can be detected in the urine of about 80% of patients with serogroup 1 Legionella pneumophila pneumonia and of some patients with serogroup 4 Legionella pneumophila and Legionella dumoffii pneumonia. The specificity of these assays is greater than 99%. In a test population in which the prevalence of Legionella pneumophila was 4%, the posterior probabilities of positive and negative results of tests for antigen were 86.5% and 99.3%, respectively. Antigen is detectable within the first 3 days of illness approximately as often as at later periods, and antigen may remain detectable for a few days to 1 yr after successful therapy. Antigen is detectable in serum, but the concentrations are considerably lower than in urine. Combining urinary antigen detection with direct fluorescent antibody examination of secretions increases the rapid diagnostic yield by 10%-20%. Monoclonal antibody studies demonstrate that subgroup specificities are present among the serogroup 1 urinary antigens. Radiometric and enzyme immunoassays detect antigen in equal proportions of patients. Latex agglutination results are positive in about 80% of those cases positive by the other methods.

Age-related prevalence of complement-fixing antibody to Mycoplasma pneumoniae during an 8-year period

We determined the age-related prevalence of complement-fixing antibody to Mycoplasma pneumoniae from the computerized laboratory results of our routine diagnostic department. The material consisted of about 58,000 sera from an 8-year period, 1971 to 1978. Among children less than 1 month old, the frequency of complement-fixing antibody of titers greater than or equal to 8 was low (23%), and no decrease representing loss of maternal antibody was seen thereafter. An unexpectedly early increase in the antibody prevalence up to 62% was seen by 6 months of age. The frequency of antibody was high among young children from the age of 4 months, in whom symptomatic infection due to M. pneumoniae is rare. The frequency of higher titers (greater than or equal to 32) and the geometric mean titer increased more slowly, coinciding with the known age distribution of symptomatic M. pneumoniae disease; the frequency of high titers and the geometric mean titer peaked at the age of 7 to 10 years. Two explanations for the high frequency of complement-fixing antibody to M. pneumoniae in young children are discussed. It may be due to an asymptomatic infection caused by M. pneumoniae or to a nonspecific stimulus by lipids of other organisms, plants, or tissues leading to production of antibodies crossreacting with M. pneumoniae, or it may be due to both of the above. During the study, two extensive epidemics due to M. pneumoniae occurred in Finland, but the prevalence of complement-fixing antibody bore no correlation with these peaks of occurrence.

Central nervous system manifestations associated with serologically verified Mycoplasma pneumoniae infection

Among 560 hospitalized patients with serologically verified Mycoplasma pneumoniae infection (significant titre rise of complement-fixing antibodies in paired sera), 27 (4.8%) had central nervous system (CNS) manifestations for which no evidence incriminating any other causal agent could be found. Of these patients 18 had encephalitis or meningoencephalitis, 8 aseptic meningitis and 1 polyradiculitis. Of the patients with meningoencephalitis 4 died and 3 had permanent sequelae. The cases of aseptic meningitis were benign without any deaths or sequelae. There was a predominance of young age groups, 13 patients (48%) being below 10 years of age. Neither erythromycin nor tetracycline had a beneficial effect on the course of the illness in a few patients treated. Another 15 patients had CNS manifestations for which an alternative aetiology was suspected. The specificity of the M. pneumoniae CF test in the diagnostics of CNS manifestations is discussed, as well as the pathogenesis of the CNS complications associated with M. pneumoniae infection. Some features are summarized from 87 case reports presented earlier in the literature.

Occurrence of serologically verified Mycoplasma pneumoniae infections in Finland and in Scandinavia in 1970--1977

This study analyses the numbers of serologically verified Mycoplasma pneumoniae infections in Finland as a whole and by regions, and in Scandinavia in 1970--77 on the basis of reports collected in the countries concerned. Two peaks of occurrence were found to have extended over most parts of Finland and across Scandinavia; in addition, there were separate local epidemics. Thus, M. pneumoniae infections showed a periodicity of occurrence, but not a regular cyclic pattern. The figures do not necessarily reflect the true incidence of M. pneumoniae infections in the areas investigated.

Clinical and laboratory manifestations in patients with serological evidence of Mycoplasma pneumoniae infection

139 cases of Mycoplasma pneumoniae infection (serological diagnosis) were treated at Aurora Hospital, Helsinki, between January 1975 and August 1977. In 123 patients the main diagnosis was respiratory infection; 114 of these had pneumonia. The frequency of complications was high: 8 patients had neurologic, 6 cardiac and 5 joint symptoms. Although a significant rise in titre of complement-fixing antibodies to M. pneumoniae was required, the low titre level in some patients who had manifestations less frequently associated with M. pneumoniae infection may suggest nonspecific reactions. Nearly half of the patients in this study had plasmocytosis in the peripheral blood suggesting a strong antibody response. This might be connected with some serological reactions detected in association with M. pneumoniae infections.

The incidence and aetiology of respiratory tract infections in general practice--with emphasis on Mycoplasma pneumoniae

The incidence of respiratory tract infections in patients seeking medical advice at a community care centre (Dalby) during 1973 and 1974 was studied. About every third patient seen at this primary health station presented with signs of such infections. In the age groups less than 10, 10-19, 20-39, 40-59 and greater than or equal to 60 years, respiratory tract infections accounted for 65, 45, 32, 18 and 9% of the fotal number of diagnoses made during 1974. The aetiology of acute respiratory tract infections in a series of patients seen at this health station was studied. The series included randomly selected cases, but excluded children under seven years of age and patients presenting with signs of acute otitis media and tonsillitis. Attempts to establish the aetiology were made on the basis of the history, the clinical examination, and cultures for beta-haemolytic streptococci and Mycoplasma pneumoniae, complement foxation tests for influenza A and B, para-influenza 1, 2, and 3, adeno, cytomegalovirus and respiratory syncytial virus, and Chlamydia psittaci. Paul-Bunnell test and tests for cold agglutinins were also performed. With this test battery, an aetiological diagnosis was obtained in only 33% of the 101 patients studied. The findings suggest an infection with M.pneumoniae in 16%, with beta-haemolytic streptococci in 9%, and with viruses (adeno and para-influenza) in 7% of the patients. The present communication highlights the role of M.pneumoniae in upper respiratory infections, as few data have appeared on such infections in patients seen in general practice. The difficulty of establishing the aetiology of respiratory tract infections and the consequent treatment dilemma is discussed.

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.