The aetiology of pneumonia. Application of bacterial serology and basic laboratory methods

Improved diagnostic markers for invasive pulmonary aspergillosis in COPD patients

Background

The prevalence of invasive pulmonary aspergillosis (IPA) among patients with chronic obstructive pulmonary disease (COPD) is steadily increasing, leading to high mortality. Although early diagnosis can significantly reduce mortality, the efficacy of current diagnostic methods is limited. Consequently, there is a need for novel approaches for early IPA detection.

Methods

This retrospective study involved 383 hospitalized COPD patients with GOLD stages III and IV. The IPA group (67 patients) and non-IPA group (316 patients) were identified at the First Affiliated Hospital of Guangzhou Medical University between January 2016 and February 2022. We analyzed common serological indicators in our hospital to identify predictive indicators for the early diagnosis of IPA in COPD patients.

Results

The sensitivity and specificity of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), lactate dehydrogenase (LDH), and ceruloplasmin (CER) for diagnosing IPA in COPD patients were as follows: CRP (91.2%, 57.7%), ESR (77.5%, 73.0%), PCT (60.5%, 71.4%), LDH (50.0%, 88.8%), and CER (60.7%, 74.3%). Combinations of biomarkers, such as CRP-ESR, CRP-LDH, ESR-LDH, ESR-CER, and LDH-CER, showed promising diagnostic potential, with larger area under the curve (AUC) values for IPA diagnosis in COPD patients. However, no statistically significant difference was observed between the diagnostic efficacy of single biomarkers and combined biomarkers. Notably, compared to those in the unassisted ventilation group, the patients in the assisted ventilation group (including noninvasive ventilation and tracheal intubation/incision-assisted ventilation group) exhibited significantly greater PCT and LDH levels, while the CER significantly decreased (p=0.021). There were no significant differences in biomarker levels between the ICU group and the non-ICU group. CRP (p<0.01), ESR (p=0.028), PCT (p<0.01), and CER (p<0.01) were positively correlated with hospitalization duration, whereas LDH was not correlated with hospitalization duration.

Conclusion

Our study highlights the diagnostic potential of CRP, ESR, PCT, LDH, and CER for IPA in COPD patients. CRP and LDH can also initially predict the need for assisted ventilation, while CRP can initially estimate the length of hospitalization. This study represents the first report of the potential of CER for diagnosing IPA, suggesting its significance for further research.

Serological investigation of pneumonia as it presents to the physician's office

PURPOSE

To define the etiology of pneumonia, using a battery of serological tests, among patients presenting to physicians' offices in Cumberland County, Nova Scotia from July 2, 1989 to July 1, 1990.

METHODS

Patients presenting to their physician's office with symptoms suggestive of pneumonia were invited to participate in the study by completing a questionnaire, having a chest radiograph and providing acute and convalescent phase serum samples. These serum samples were tested for antibodies to Mycoplasma pneumoniae, Coxiella burnetii, Legionella pneumophila, adenovirus, and influenza viruses A and B. Some of the samples were tested for antibodies to Chlamydia pneumoniae.

RESULTS

Seventy-five of the inception cohort of 203 patients had a chest radiograph compatible with pneumonia, a completed questionnaire and acute and convalescent phase serum samples. There were 39 females and 36 males with a mean age of 41.7 years. Twenty-six (35%) were admitted to hospital. The mortality rate was 3%. Forty-five per cent had a diagnosis made by serology: M pneumoniae, 22 (29%); influenza A virus, five (7%); C burnetii, L pneumophila, adenovirus, two (3%) each.

CONCLUSIONS

While it is not possible to generalize about these findings because of ascertainment bias, the data suggest that M pneumoniae is a common cause of pneumonia presenting to a physician's office and that mortality is low in this group of patients.

The diagnostic accuracy of high-mobility group box 1 protein and twelve other markers in discriminating bacterial, viral and co-infected bronchial pneumonia in Han children

Pneumonia in children is common and can lead to grave consequences if not addressed in a proper and timely manner. In the management of pneumonia, early identification of the causative infective agent is of obvious importance for treatment, as it allows selection of the appropriate antibiotics. However, such identification requires laboratory test results, which may not be immediately available. The aim of this study was to evaluate the accuracy and usefulness of 13 markers in differentiating between viral and bacterial pneumonia in Han children (34 healthy controls and 78 patients). It was found that WBC counts were more accurate in diagnosis of the type of agent responsible for infection than was the degree of expression of HMGB1. Among the 13 markers investigated, HMGB1 was the best at discriminating between co-infected (bacterium and virus) and single-infected (bacterium or virus) children with bronchial pneumonia. HMGB1 expression of less than 1.0256, excluded most co-infections (the negative predictive value was greater than 89.7%). Diagnosed sole viral pneumonia clinically overlapped with bacterial pneumonia, but bacterial pneumonia was more often associated with higher white blood cell (WBC) counts (WBC ≥ 13,000 cells/mm(3)). When the two marker readouts--HMGB1 < 1.0256 and WBC ≥ 13,000 cells/mm(3)--were combined, the positive predictive value for bacterial pneumonia alone was 92.3%. These findings can help clinicians discriminate between bronchial pneumonia caused by virus, bacterium or both with a high specificity.

C-reactive protein: a tool in the follow-up of nosocomial pneumonia

OBJECTIVES

The aim of this study was to examine the clinical usefulness of serial C-reactive protein (CRP) dosages in patients with nosocomial pneumonia (NP).

METHODS

Prospective and observational study performed in a 24-beds Intensive Care Unit. Sixty four patients with NP, including non-ventilated patients and those with ventilator-associated pneumonia were included. Daily measurements of CRP were performed and CRP ratios were calculated from the day of antibiotic prescription (D0) until day 10. Patients were than classified according to the CRP ratios in 2 groups: 'good' response (CRP ratios lower than 0.67 at day 10) and 'poor' response (non-response or bi-phasic response).

RESULTS

The poor response group (n = 34) had a mortality rate of 53% in comparison to 20% in the good response group (n = 30) (RR = 2.65; 95% CI, 1.21-5.79, p = 0.01). Significant differences between the two groups were found on CRP ratios at Day 4 (p = 0.01). The adequacy of antibiotic therapy was much lower in the group poor response in comparison to the group good response, 14% vs. 67% (p = 0.008), respectively.

CONCLUSIONS

Daily CRP measurements in patients with nosocomial pneumonia may be useful in the identification of patients with poor outcome, as early as day 4, and detect patients with inappropriate antimicrobial therapy.

Role of C-reactive protein and procalcitonin in differentiation of tuberculosis from bacterial community acquired pneumonia

BACKGROUND/AIMS

We investigated the utility of serum C-reactive protein (CRP) and procalcitonin (PCT) for differentiating pulmonary tuberculosis (TB) from bacterial community-acquired pneumonia (CAP) in South Korea, a country with an intermediate TB burden.

METHODS

We conducted a prospective study, enrolling 87 participants with suspected CAP in a community-based referral hospital. A clinical assessment was performed before treatment, and serum CRP and PCT were measured. The test results were compared to the final diagnoses.

RESULTS

Of the 87 patients, 57 had bacterial CAP and 30 had pulmonary TB. The median CRP concentration was 14.58 mg/dL (range, 0.30 to 36.61) in patients with bacterial CAP and 5.27 mg/dL (range, 0.24 to 13.22) in those with pulmonary TB (p<0.001). The median PCT level was 0.514 ng/mL (range, 0.01 to 27.75) with bacterial CAP and 0.029 ng/mL (range, 0.01 to 0.87) with pulmonary TB (p<0.001). No difference was detected in the discriminative values of CRP and PCT (p=0.733).

CONCLUSIONS

The concentrations of CRP and PCT differed significantly in patients with pulmonary TB and bacterial CAP. The high sensitivity and negative predictive value for differentiating pulmonary TB from bacterial CAP suggest a supplementary role of CRP and PCT in the diagnostic exclusion of pulmonary TB from bacterial CAP in areas with an intermediate prevalence of pulmonary TB.

Systemic manifestations in the course of meningococcal disease

BACKGROUND/AIM

Meningococcal disease most often manifests itself as meningitis or sepsis. During the course of these diseases, other clinical events sometimes develop such as pneumonia, pericarditis, arthritis, and they are referred to as extrameningeal or systemic manifestations of the meningococcal disease. The aim of this study was to investigate the type and the incidence of particular extrameningeal/systemic manifestations among patients with meningococcal meningitis and sepsis, including time of their onset and the influence on the disease outcome.

METHODS

The retrospective study of the medical records of 246 patients treated for meningococcal disease over the 25-year period in the Institute for Infectious and Tropical Diseases, Belgrade was conducted. The patients, aged 3 months to 82 years both sexes, were divided into two groups.

RESULTS

Out of 246 patients extrameningeal/systemic manifestations were found in 42 (17.1%) patients: 35 (14.2%) occurred during meningitis, and seven (2.8%) during sepsis. Pulmonary manifestations (mostly pneumonia) were the most prevalent, found in 12 (4.9%) patients, followed by heart involvement in nine (3.6%) patients (mostly pericarditis, in seven or 2.8% patients). Various ophthalmic manifestations occurred in seven (2.8%), arthritis in 4 (1.6%) and sinusitis in six (2.4%) patients. Otitis, multiple renal embolisms with hematuria, osteomyelitis and thrombophlebitis were evidenced in one patient, each. Most of the systemic manifestations (30 patients or 71.4%), developed within the initial three days of the disease (p < 0.01), suggesting direct pathogenic mechanism induced by meningococci per se, while only three (7.1%) developed after seven days, when immune-mediated disease was more likely. Even though these manifestations complicate and prolong treatment of the meningococcal disease, they had no major influence on the disease outcome. Lethal outcome occurred in 2 (4.76%) patients, both with the meningococcal type of the disease.

CONCLUSION

Extrameningeal or systemic manifestations are uncommon complications during the course of both meningococcal meningitis and sepsis. The onset of pneumonia, pericarditis, eye involvement, and arthritis, within the initial seven days of the disease, were most prevalent in the course of meningitis. They had no major influence on the disease outcome.

Use of B-type natriuretic peptide in the risk stratification of community-acquired pneumonia

BACKGROUND

Community-acquired pneumonia (CAP) is the leading infectious cause of death in developed countries. Risk stratification has previously been difficult.

METHODS

Markers of cardiac stress (B-type natriuretic peptide, BNP) and inflammation (C-reactive protein, white blood cell count, procalcitonin) as well as the pneumonia severity index (PSI) were determined in 302 consecutive patients presenting to the emergency department (ED) with CAP. The accuracy of these parameters to predict death was evaluated as the primary endpoint. Prediction of treatment failure was considered as the secondary endpoint.

RESULTS

B-type natriuretic peptide levels increased with rising disease severity as classified by the PSI (P = 0.015). BNP levels were significantly higher in nonsurvivors compared to survivors [median 439.2 (IQR 137.1-1384.6) vs. 114.3 (51.3-359.6) pg mL(-1), P < 0.001]. In a receiver operating characteristic analysis for the prediction of survival the area under the curve (AUC) for BNP was comparable to the AUC of the PSI (0.75 vs. 0.71, P = 0.52). Importantly, the combination of BNP and the PSI significantly improved the prognostic accuracy of the PSI alone (AUC 0.78 vs. 0.71; P = 0.02). The optimal cut-off for BNP was 279 pg mL(-1). The accuracy of BNP to predict treatment failure was identical to the accuracy to predict death (AUC 0.75).

CONCLUSIONS

In patients with CAP, BNP levels are powerful and independent predictors of death and treatment failure. When used in conjunction with the PSI, BNP levels significantly improve the risk prediction when compared with the PSI alone.

The routine use of C-reactive protein in forensic investigations

In clinical medicine, C-reactive protein (CRP) is extensively used as a general marker for immune system activation, and post-mortem applicability has been established [M.Q. Fujita, B.L. Zhu, K. Ishida, L. Quan, S. Oritani, H. Maeda, Serum C-reactive protein levels in postmortem blood-an analysis with special reference to the cause of death and survival time, Forensic Sci. Int. 130 (2002) 160-166; L. Uhlin-Hansen, C-reactive protein (CRP), a comparison of pre- and post-mortem blood levels, Forensic Sci. Int. 124 (2001) 32-35]. We have analysed the routine use of CRP in non-selected cases. Scarcity of blood available for analysis is a common problem in forensic investigation, and in response to this we have developed a method using liver as a source. In 50 consecutive autopsy cases, we have evaluated method, validated results and discussed their interpretation. In three cases the analysis was not possible. For each of the remaining cases (n=47) we have analysed whole blood, serum and/or liver samples. 57% (n=25) had serum CRP > 10 mg/L. Serum levels were higher than in whole blood or liver. CRP levels in serum and whole blood samples were stable in more than one month after death, making storage for later analysis possible. Liver levels peaked at one week, but after one month putrefaction was obvious. CRP levels were independent of the post-mortem interval. The use of liver as a source has not yet been described in literature. Our results in liver samples correlate well with plasma results, and liver is a good post-mortem alternative when blood is not available. We conclude that CRP measurements are easy, viable and inexpensive in a forensic setting, and that the number of cases with CRP elevation is high in a non-selected forensic material. In cases of doubt, marked elevation of CRP is an indicator of natural mode of death, and in cases of trauma, it indicates vital reaction. It can be used as a pre-autopsy screening, leading to a more extensive search for diseases not easily diagnosed, such as sepsis or ketoacidosis.

Diagnostic value of C reactive protein in infections of the lower respiratory tract: systematic review

OBJECTIVES

To evaluate the diagnostic accuracy of C reactive protein in detecting radiologically proved pneumonia and to evaluate how well it can discriminate between bacterial and viral infections of the lower respiratory tract.

DATA SOURCES

Medline and Embase (January 1966 to April 2004), with reference checking.

STUDY SELECTION

We included articles comparing C reactive protein with a chest radiograph or with microbiological work-up as a reference test. Two authors independently assessed methodological items.

RESULTS

None of the studies met all validity criteria. Six studies used an infiltrate on chest radiograph as reference test. Sensitivities ranged from 10% to 98%, specificities from 44% to 99%. For adults, the relation of C reactive protein with an infiltrate (in a subgroup analysis of five studies) showed an area under the curve of 0.80 (95% confidence interval 0.75 to 0.85). In 12 studies, the relation of C reactive protein with a bacterial aetiology of infection of the lower respiratory tract was studied. Sensitivities ranged from 8% to 99%, specificities from 27% to 95%. These data were epidemiologically and statistically heterogeneous, so overall outcomes could not be calculated.

CONCLUSION

Testing for C reactive protein is neither sufficiently sensitive to rule out nor sufficiently specific to rule in an infiltrate on chest radiograph and bacterial aetiology of lower respiratory tract infection. The methodological quality of the diagnostic studies is generally poor. The evidence not consistently and sufficiently supports a wide introduction of C reactive protein as a rapid test to guide antibiotics prescription.

Contribution of C-Reactive Protein to the Diagnosis and Assessment of Severity of Community-Acquired Pneumonia

STUDY OBJECTIVE

To assess the usefulness of serum C-reactive protein (CRP) in the diagnosis and treatment approach of patients with community-acquired pneumonia (CAP).

DESIGN

Population-based case-control study.

SETTING

A mixed residential-industrial urban area of 74,368 adult inhabitants in the Maresme region (Barcelona, Spain).

PATIENTS

From December 1993 to November 1995, all subjects who were > 14 years of age, were living in the area, and had received a diagnosis of CAP, which had been confirmed by chest radiographs and compatible clinical outcome, were registered. Patients from residential care facilities were excluded. Serum samples were assayed for CRP in the acute phase of the disease. Data from 201 patients with CAP were compared with 84 healthy control subjects matched by age, sex, and municipality, as well as with 25 patients with initially suspected pneumonia that was not confirmed at follow-up. Median CRP levels were 110.7, 1.9, and 31.9 mg/L, respectively. The thresholds of the test for discriminating among these three groups of subjects were 11.0 and 33.15 mg/L.

RESULTS

Eighty-nine patients (44.8%) had an identifiable etiology. The most common pathogens were Streptococcus pneumoniae, viruses, and Chlamydia pneumoniae, followed by Mycoplasma pneumoniae, Legionella pneumophila, and Coxiella burnetii. There were statistically significant differences in the median CRP levels in pneumococcal (166.0 mg/L) and L pneumophila (178.0 mg/L) etiologies compared to other causative pathogens. Lower levels of CRP were found in pneumonia caused by viruses and C burnetii as well as in negative microbiological findings. The median CRP levels in hospitalized patients were significantly higher than in outpatients (132.0 vs 76.9 mg/L, respectively; p < 0.001). Considering a cut point of 106 mg/L in men and 110 mg/L in women for deciding about the appropriateness of inpatient care, CRP levels showed a sensitivity of 80.51% and a specificity of 80.72%.

CONCLUSIONS

Serum CRP level is a useful marker for establishing the diagnosis of CAP in adult patients with lower respiratory tract infections. High CRP values are especially high in patients with pneumonias caused by S pneumoniae or L pneumophila. Moreover, high CRP values are suggestive of severity, which may be of value in deciding about the appropriateness of inpatient care.

Connective tissue responses in acute community-acquired pneumonia

Circulating connective tissue components including the aminoterminal propeptides of type III collagen (PIIINP), type I collagen (PINP) and hyaluronan were determined in patients hospitalised for pneumonia of suspected bacterial origin. Ninety patients were included, 64 of these were followed prospectively for up to 21 days after initiation of therapy. Serum PIIINP was determined by RIA, s-PINP by ELISA, and s-hyaluronan by a radiometric assay. S-PIIINP rose significantly above the zero value within 24 h in both pneumococcal pneumonia (T0: 5.3 microg/l, 95% CI: 2.7-8.1 microg/l vs. T1: 6.7 microg/l, 95% CI: 3.8-9.1, P<0.01) and in pneumonia of unknown aetiology (T0: 4.0 microg/l, 95% CI: 3.6-4.8 vs. T1: 4.5 microg/l, 95% CI: 3.8-5.1, P<0.05) followed by a gradual decline. At T1, S-PIIINP was higher in pneumococcal pneumonia compared with pneumonia of unknown aetiology (P<0.05). By contrast, s-PINP tended to decline within 24 h in both pneumococcal pneumonia (T1: 30 microg/l, 95% CI: 23-40, ns) and in pneumonia of unknown aetiology (T1: 32 microg/l, 95% CI: 22-42, ns) followed by a steady increase. The PINP antigen size distribution remained constant throughout the follow-up period. S-hyaluronan in pneumococcal pneumonia paralleled s-PIIINP reaching a peak value on day 1 (121 microg/l, 95% CI: 65-191, P=0.38). There was a positive correlation between s-PIIINP and C-reactive protein (CRP). The study demonstrates, that community-acquired pneumonia elicits a differentiated mesenchymal response, which is turned down in response to successful antibiotic therapy.

Microbial etiology of community-acquired pneumonia in the adult population of 4 municipalities in eastern Finland

To determine the etiology of community-acquired pneumonia in the adult population of a defined area, specific antibody responses in paired serum samples, levels of circulating pneumococcal immune complexes in serum samples, and pneumococcal antigen in urine were measured. Samples (304 paired serum samples and 300 acute urine samples) were obtained from 345 patients > or =15 years old with community-acquired, radiologically confirmed pneumonia, which comprised all cases in the population of 4 municipalities in eastern Finland during 1 year. Specific infecting organisms were identified in 183 patients (including 49 with mixed infection), as follows: Streptococcus pneumoniae, 125 patients; Haemophilus influenzae, 12; Moraxella catarrhalis, 8; chlamydiae, 37 (of which, Chlamydia pneumoniae, 30); Mycoplasma pneumoniae, 30; and virus species, 27. The proportion of patients with pneumococcal infections increased and of those with Mycoplasma infections decreased with age, but for each age group, the etiologic profile was similar among inpatients and among outpatients. S. pneumoniae was the most important etiologic agent. The annual incidence of pneumococcal pneumonia per 1000 inhabitants aged > or =60 years was 8.0.

Pneumonia adquirida na comunidade em pacientes tratados ambulatorialmente: aspectos epidemiológicos, clínicos e radiológicos das pneumonias atípicas e não atípicas

Objetivo: Avaliar o percentual etiológico das pneumonias atípicas tratadas ambulatorialmente. Identificar os fatores epidemiológicos, clínicos e radiológicos que permitam diferenciar pneumonia atípica de não atípica. Métodos: Os pacientes foram submetidos a avaliação clínica, radiológica, coleta de escarro para estudo pelo método de Gram e sangue para testes sorológicos, incluindo Legionella pneumophila, Chlamydia sp, Mycoplasma pneumoniae, vírus Influenza A e Influenza B, no primeiro dia e 21 dias após inclusão. As radiografias de tórax foram revistas por três observadores independentes que desconheciam o quadro clínico. Resultados: Avaliados inicialmente 129 pacientes durante 22 meses. A amostra final para estudo comparativo entre os grupos consistiu de 69 pacientes que tinham em média 37 anos, sendo 46 (67%) homens e 23 (33%) mulheres. O diagnóstico etiológico foi definido em 34 (50%) dos pacientes. Chlamydia sp foi o agente atípico mais freqüente, com 11 (16%) casos, seguido por M. pneumoniae com 7 (10%). Influenza A respondeu por 4 (6%) dos casos e Legionella em 4 (6%) pacientes. Infecções mistas foram evidenciadas, com associação de Chlamydia sp e M. pneumoniae em 5 (7%) casos, Chlamydia sp e Influenza B em um caso e M. pneumoniae e Influenza A em outro. A presença de sintomas respiratórios e achados gerais sugestivos de pneumonia atípica foram comparados entre os grupos e não foram observadas diferenças significantes. A avaliação radiológica realizada por três observadores independentes mostrou discordância entre eles para os tipos de pneumonia. O diagnóstico radiográfico de cada observador comparado com o diagnóstico clínico não mostrou associação significante. Conclusões: A pneumonia causada por agente atípico ocorre em 50% dos pacientes com pneumonia adquirida na comunidade em tratamento ambulatorial. Não é possível distinguir pacientes com pneumonia atípica de pneumonia não atípica. A apresentação clínica e a radiológica são similares nos dois grupos.

Community-acquired pneumonia guidelines--an international comparison: a view from Europe

Following an outline that details the pathogens causing community-acquired pneumonia (CAP) identified in studies from Europe, this article reviews the guidelines for the management of CAP in four European countries--France, Italy, Spain, and the United Kingdom. The method behind the development of each document is described, followed by a comparison of the scope of each document. All four documents provide guidelines for the management of two groups of patients--the severely ill and the nonseverely ill patient. A penicillin or macrolide feature for the nonseverely ill and the combination of a third-generation cephalosporin plus a macrolide for the severely ill patient are described in all four guidelines. Despite their different origins and methods, these four guidelines have more similarities than differences--the latter serving to emphasize some of the areas that require further research in this important condition. An important area for research is the impact that these guidelines have on practice and especially on clinical outcomes.

Influence of age, gender and smoking on Streptococcus pneumoniae, Haemophilus influenzae and Moraxella (Branhamella) catarrhalis antibody titres in an elderly population

The purpose of this study was to investigate the association of serum antibody levels to Streptococcus pneumoniae, Haemophilus influenzae and Moraxella (Branhamella) catarrhalis with age, gender and smoking in an elderly population. The study population comprised all the inhabitants aged 65 years or over in a rural municipality in south-western Finland. Serum samples were obtained from 1,174 out of a total of 1,360 subjects. Bacterial antibodies were measured by enzyme immunoassay (EIA) using pneumolysin and whole bacterial cells of H. influenzae and M. catarrhalis (mixture of 10 different strains for both) as antigens. The main findings were as follows: (i) antibody levels generally decreased with increasing age both in men and in women; (ii) antibody titres against H. influenzae and M. catarrhalis were higher in men than in women; and (iii) antibody titres to H. influenzae and M. catarrhalis, but not to S. pneumoniae, were significantly higher in smokers than in non-smokers. These data suggest that antibody-mediated protection against respiratory pathogens may be impaired in the elderly, leading to a higher susceptibility to respiratory tract infections, that the exposure to H. influenzae and M. catarrhalis may be higher in men than in women, and that smokers have more respiratory infections or colonization due to these 2 bacteria than do non-smokers.

Pneumococcal community-acquired pneumonia in 148 hospitalized adult patients

In a previous prospective study, Streptococcus pneumoniae was identified as the causative agent in 148 (42.8%) of 346 adult patients hospitalized over the course of one year with community-acquired pneumonia (CAP) in the Soroka Medical Center, Beer-Sheva, Israel. The present study characterizes those cases in which Streptococcus pneumoniae was the only pathogen and those in which additional etiological agents were identified. Pneumococcal CAP was diagnosed by standard blood cultures or positive serological tests by one of two laboratory methods. In 100 (67.6%) patients, at least one other etiological agent of CAP was identified in addition to Streptococcus pneumoniae. Compared with patients who were not infected by Streptococcus pneumoniae, patients with Streptococcus pneumoniae CAP were older and had a higher rate of comorbidity (39.5% vs. 29.8%). Streptococcus pneumoniae CAP had a more severe clinical course and a higher mortality rate, especially when Streptococcus pneumoniae was the only pathogen. Community-acquired pneumonia due to Streptococcus pneumoniae only was more similar in its clinical manifestations to classic typical pneumococcal pneumonia. When an additional etiological agent was identified, the clinical characteristics could not be distinguished from those of atypical pneumonia. It is concluded that Streptococcus pneumoniae remains the principal cause of CAP in this region. The frequency of additional etiological agents of CAP and the difficulty in differentiating clinically between cases due to Streptococcus pneumoniae only and those due to Streptococcus pneumoniae plus other organisms necessitates initial empirical treatment that covers Streptococcus pneumoniae as well as other causative agents of atypical pneumonia.

Serum antibody response to outer membrane proteins of Moraxella (Branhamella) catarrhalis in patients with bronchopulmonary infection

A Western blot (immunoblot) method for detecting antibodies against outer membrane protein (OMP) epitopes of Moraxella (Branhamella) catarrhalis was evaluated. Paired serum samples from patients suspected of M. catarrhalis (n = 38) and non-M. catarrhalis (n = 25) bronchopulmonary infection were examined for the presence of antibodies of the immunoglobulin M (IgM), IgG, and IgA classes to OMPs from M. catarrhalis by a gel electrophoresis-immunoperoxidase technique (Western blotting); sera from 40 healthy adult blood donors were also included. A significantly (P = 0.004) more frequent occurrence of IgM-class antibodies and/or an increase in the number of IgG-class antibodies against different M. catarrhalis OMPs from acute- to convalescent-phase serum samples was found for patients with M. catarrhalis (79%) than for patients without M. catarrhalis (40%). IgM-class antibodies against OMPs of M. catarrhalis were found in acute- and/or convalescent-phase serum samples form 58% of patients with M. catarrhalis and 32% of patients without M. catarrhalis. Fifty percent of patients with M. catarrhalis and 16% of patients without M. catarrhalis had, from acute- to convalescent-phase serum samples, an increased number of IgG-class antibodies directed against different OMPs. A total of 34% of patients with M. catarrhalis and 4% of patients without M. catarrhalis had, from acute- to convalescent-phase serum samples, an increased number of IgA-class antibodies directed against different OMPs. The present study indicates that M. catarrhalis is one of the bacteria involved in acute exacerbations of chronic bronchitis.

Diagnosis and treatment of bacterial pneumonia in Korea

Even with advancements in knowledge the problem of pneumonia will not be eliminated. It should be understood who is at risk, why such people develop pneumonia, what causes the pneumonia, and respiratory infection should be managed and prevented. The relative frequency of the isolation of various etiologic agents that cause bacterial pneumonia differ according to age group, geography, socio-economic status, underlying disease, time of year, and possible concomitant viral illnesses. Prompt identification of the causative agent is vital in the management of pneumonia. The present status of elucidating the etiologic agent is far from complete and recently, newer techniques using DNA probes and polymerase chain reactions were used for the identification of microbial pathogens. The timely use of appropriate systemic antibacterial therapy eradicates the pathogens. Considering the alterations of the etiologic agents of bacterial pneumonia and antibiotic susceptibilities, attention should be directed to the usage of antimicrobial agents in order to maximize the efficacy and the therapeutic implications.

Multiple pathogens in adult patients admitted with community-acquired pneumonia: a one year prospective study of 346 consecutive patients

BACKGROUND

The purpose of this study was to assess the causes of community-acquired pneumonia in adult patients admitted to hospital.

METHODS

A prospective study was performed on 346 consecutive adult patients (54% men) of mean (SD) 49.3 (19.5) years (range 17-94) admitted to a university affiliated regional hospital in southern Israel with community-acquired pneumonia over a period of one year. Convalescent serum samples were obtained from 308 patients (89%). The aetiological diagnosis for community-acquired pneumonia was based on positive blood cultures and/or significant changes in antibody titres to Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, respiratory viruses, Coxiella burnetii, Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella sp.

RESULTS

The aetiology of community-acquired pneumonia was identified in 279 patients (80.6%). The distribution of causal agents was as follows: S pneumoniae, 148 patients (42.8%); M pneumoniae, 101 (29.2%); C pneumoniae, 62 (17.9%); Legionella sp, 56 (16.2%); respiratory viruses, 35 (10.1%); C burnetii, 20 (5.8%); H influenzae 19 (5.5%); and other causes, 21 patients (6.0%). In patients above the age of 55 years C pneumoniae was the second most frequent aetiological agent (25.5%). In 133 patients (38.4%) more than one causal agent was found.

CONCLUSIONS

The causal agents for community-acquired pneumonia in Israel are different from those described in other parts of the world. In many of the patients more than one causal agent was found. In all these patients treatment should include a macrolide antibiotic, at least in the first stage of their illness.

C-reactive protein. A clinical marker in community-acquired pneumonia

STUDY OBJECTIVE

To assess the range of plasma C-reactive protein (CRP) in patients presenting with community-acquired pneumonia and to compare the serial changes of this acute-phase protein with clinical outcome.

DESIGN

Prospective hospital-based study, including separate retrospective case series.

PATIENTS

Twenty-eight consecutive patients (mean age, 60 years) admitted to our hospital with community-acquired pneumonia were studied. Serial daily plasma samples were taken and assayed for CRP, tumor necrosis factor-alpha (TNF-alpha), and interleukin 6 (IL-6). Clinical parameters, laboratory data, and response to treatment were recorded. Four other patients considered to be antibiotic failures (three empyemas, one death) were studied separately.

RESULTS

Two patients died. Of those who survived, mean (+/- SD) CRP values for days 1,2,3,4, and 5 were as follows: 136 +/- 43, 96 +/- 44, 53 +/- 36, 54 +/- 43, and 44 +/- 31 mg/L. CRP levels on day 1 in patients who had received antibiotics prior to hospital admission were significantly lower than those who had not, 107 +/- 42 and 152 +/- 44 mg/L (p < 0.05). CRP levels did not correlate with other laboratory parameters or with recognized predictors of mortality. A CRP value that continued to rise despite antibiotic treatment was associated with infective complications or death. Only 52% of patients had detectable TNF-alpha and 24% detectable IL-6 at some point during their hospital stay.

CONCLUSIONS

CRP is a sensitive marker of pneumonia. A persistently high or rising CRP level suggests antibiotic treatment failure or the development of an infective complication. These results suggest that CRP, rather than TNF-alpha or IL-6, may have a role as a clinical marker in pneumonia.

Bacterial colonization of the larynx and trachea in healthy children

Fifty healthy children were included in the study; tracheal and laryngeal aspirations were performed after oral endotracheal intubation during minor surgery. The aspirates were evaluated and examined in the same way as aspirates from children suspected of pneumonia; 31 samples were accepted for the final analysis. After culturing, specimens from 30 children exhibited growth of potential pathogenic bacteria either from the larynx, the trachea or both. Prior to culture, bacteria were seen by microscopy in 24 samples from 30 children. These results indicate that the majority of healthy children carry potential pathogenic bacteria, not only in the larynx but also to a certain extent in the trachea. We conclude that aspirates from the larynx and the trachea are of limited value in the diagnosis of bacterial pneumonia in children.

Diagnostic and prognostic value of interleukin-6 and C-reactive protein in community-acquired pneumonia

The diagnostic and prognostic value of admission serum levels of interleukin-6 (IL-6) and C-reactive protein (CRP) was investigated in 203 hospital-treated patients with community-acquired pneumonia (CAP). In serum samples obtained during the first 24 h after admission, IL-6 was detectable in 198 patients (98%), with a median value of 50 ng/l. Ten % of the patients had IL-6 values of 1000 ng/l. A clear positive correlation between IL-6 and CRP was found (r = 0.29, p < 0.0001). Patients with high IL-6 or CRP levels had longer duration of fever, longer hospital stay, and had less often recovered clinically or radiographically on follow-up weeks after discharge. A high IL-6, but not a high CRP, also seemed to be associated with a higher mortality. Bacteremic pneumococcal pneumonia had the highest levels of IL-6 (mean 2852 and median 420 ng/l) and CRP (mean 292 and median 285 mg/l). High IL-6 values were also seen in patients with non-bacteremic pneumococcal pneumonia, while all patients with pneumonia due to other bacterial, or viral, aetiology had IL-6 levels of < or = 300 ng/l. In conclusion, IL-6 and CRP are promising diagnostic and prognostic tools in the management of CAP. Further studies are needed to establish the usefulness of repeated measurements early in the hospital course of the disease.

Human immune response against outer membrane proteins of Moraxella (Branhamella) catarrhalis determined by immunoblotting and enzyme immunoassay

The role of Moraxella (Branhamella) catarrhalis as a respiratory tract pathogen is increasingly recognized. We looked at the human immune response against individual outer membrane proteins of M. catarrhalis and against the 81-kDa CopB protein, which has previously been shown to be a target for protective antibodies. Paired serum samples from six elderly patients with pneumonia were tested by Western blot (immunoblot) analysis by using outer membrane vesicles of M. catarrhalis 035E as antigen. All of the six convalescent-phase serum samples reacted with a protein which migrated at the position of the CopB protein and with a high-molecular-weight protein of M. catarrhalis; three serum samples also reacted with a 34-kDa outer membrane protein. Paired serum samples from 18 patients, 10 of which had M. catarrhalis infection on the basis of previous serology results, were tested by enzyme immunoassay (EIA) with the CopB protein and whole cells of M. catarrhalis 035E as antigens. Nine patients showed a significant rise in EIA titer between acute- and convalescent-phase sera when whole bacterial cells were used as antigens. Six (67%) patient samples that were positive by the EIA with the whole-cell antigen were also positive by the EIA with the CopB antigen, and six of nine patient samples negative by the EIA with the whole-cell antigen were also negative by the EIA with the CopB antigen. These results suggest that both the CopB and a high-molecular-weight protein are major targets of the immune response against M. catarrhalis, and further studies with greater amounts of patient materials are needed to elucidate the usefulness of CopB as an antigen in etiologic studies.

Evaluation of serological methods in the diagnosis of Chlamydia pneumoniae pneumonia during an epidemic in Finland

A complement fixation (CF) test, a micro-immunofluorescence (micro-IF) test and an enzyme immunoassay (EIA) using Re-lipopolysaccharide as antigen were compared in the diagnosis of chlamydial infection in 136 mainly elderly patients hospitalized with community-acquired pneumonia during a Chlamydia pneumoniae epidemic in Finland in 1986-1987. Chlamydial pneumonia was diagnosed in 58 (42.6%) of the 136 pneumonia patients; 44 (75.9%) of them could be shown by micro-IF to be caused by Chlamydia pneumoniae, three by Chlamydia psittaci and four by Chlamydia spp. Only 5 (11.4%) of 44 patients with Chlamydia pneumoniae pneumonia were IgM-positive, indicating that the majority of cases were reinfections. In this population of mainly elderly patients the CF test was insensitive, being positive in only 6 (10.3%) of 58 cases of chlamydial pneumonia. The EIA detected 72.4% of cases and micro-IF 87.9% of cases (including infections with Chlamydia pneumoniae, Chlamydia psittaci and Chlamydia spp.). In the EIA 77% of positive cases were positive in serum samples taken a week apart, whereas the corresponding figure for micro-IF was 50%. In micro-IF the measurement of IgA antibody levels is recommended and IgM-positive sera should be retested after removal of IgG antibody to avoid false-positive findings due to presence of rheumatoid factor. The collection of a third serum sample, for instance one month after onset, is also recommended, since half of the patients showed a diagnostic response in the micro-IF only in the sera taken one month apart.

Mapping of immunoreactive sites of pneumococcal pneumolysin by use of synthetic peptides

In the search for better diagnostic tools and improved vaccines against pneumococcal diseases, continuous antigenic sites of the pneumococcal pneumolysin molecule were identified with partially overlapping synthetic peptides. Peptides were derived from the predicted amino acid sequence according to the known DNA sequence of pneumolysin. The immunoreactivities of the peptides were studied by enzyme immunoassay with seven human serum samples and three rabbit hyperimmune serum samples. Two immunoreactive sites in the overlapping peptides at the amino-terminal end of the pneumolysin molecule were identified in this study. Two common immunoreactive sites for both human and rabbit sera were demonstrated.

Comparison of radiological findings and microbial aetiology of childhood pneumonia

Sixty-one children were treated in hospital from 1981 to 1982 because of both radiologically and microbiologically verified viral or bacterial pneumonia. The chest radiographs were interpreted by two radiologists, not familiar with the clinical data, on two occasions three years apart, and only those patients with a definite alveolar (n = 27) or interstitial (n = 34) pneumonia at both evaluations were included in the present analysis. In addition, all patients had viral (n = 20), mixed viral-bacterial (n = 21) or bacterial (n = 20) infections diagnosed by viral or bacterial antibody or antigen assays. Viral infection alone was seen in 7 (26%), mixed viral-bacterial infection in 8 (30%) and bacterial infection alone in 12 (44%) of the 27 patients with alveolar pneumonia. The respective figures were 13 (38%), 13 (38%) and 8 (24%) for the 34 patients with interstitial pneumonia. C-reactive protein concentration was greater than 40 mg/l (a screening limit for viral and bacterial infections) in 15 (56%) of the patients with alveolar and in 11 (32%) of the patients with interstitial pneumonia. Thus 74% of the patients with alveolar and 62% with interstitial pneumonia had bacterial infection, either alone or as a mixed viral-bacterial infection. Our results suggest that the presence of an alveolar infiltrate in a chest radiograph is a specific but insensitive indicator of bacterial pneumonia. We conclude that patients with alveolar pneumonia should be treated with antibiotics. In patients with interstitial pneumonia, however, both viral and bacterial aetiology are possible. In those, the decision concerning antibiotic treatment should be based on clinical and laboratory findings.

Fever and neutropenia: bacterial etiology revealed by serological methods

In a prospective study, 91 episodes of fever in neutropenic children with cancer were evaluated. Fifteen episodes were septicemias, verified by a positive blood culture, 62 were fevers of unknown origin, 6 were focal infections and 8 were of other etiologies (i.e. drug fevers and viral infections). Serum antibody responses to bacteria were measured in paired sera by an enzyme immunoassay method. Bacterial infection was demonstrated serologically in 20% of documented septicemias, in 35% of fevers of unknown origin and occasionally in the other groups. Tests were available and found positive in the fever of unknown origin group for Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella (Branhamella) catarrhalis and enterobacteria. Some had multiple etiology. In conclusion, bacterial serology is a promising method of identifying bacterial etiology in fever of otherwise unknown origin in neutropenic children with cancer.

Aetiology of community-acquired pneumonia in children treated in hospital

Viral and bacterial antigen and antibody assays were prospectively applied to study the microbial aetiology of community-acquired pneumonia in 195 hospitalised children during a surveillance period of 12 months. A viral infection alone was indicated in 37 (19%), a bacterial infection alone in 30 (15%) and a mixed viral-bacterial infection in 32 (16%) patients. Thus, 46% of the 69 patients with viral infection and 52% of the 62 patients with bacterial infection had a mixed viral and bacterial aetiology. Respiratory syncytial virus (RSV) was identified in 52 patients and Streptococcus pneumoniae in 41 patients. The next common agents in order were non-classified Haemophilus influenzae (17 cases), adenoviruses (10 cases) and Chlamydia species (8 cases). The diagnosis of an RSV infection was based on detecting viral antigen in nasopharyngeal secretions in 79% of the cases. Pneumococcal infections were in most cases identified by antibody assays; in 39% they were indicated by demonstrating pneumococcal antigen in acute phase serum. An alveolar infiltrate was present in 53 (27%) and an interstitial infiltrate in 108 (55%) of the 195 patients. The remaining 34 patients had probable pneumonia. C-reactive protein (CRP), erythrocyte sedimentation rate and total white blood cell count were elevated in 25%, 40% and 36% of the patients, respectively. CRP was more often elevated in patients with bacterial infection alone than in those with viral or mixed viral-bacterial infections. No other correlation was seen between the radiological or laboratory findings and serologically identified viral, bacterial or mixed viral-bacterial infections.(ABSTRACT TRUNCATED AT 250 WORDS)

The C-reactive protein responses in HIV-infected patients with pneumonia

The acute phase C-reactive protein (CRP) was measured in serum of HIV-infected patients suffering from Pneumocystis carinii pneumonia (PCP) (32 patients), bacterial pneumonia (10 patients), and in 19 immunocompetent patients with bacterial pneumonia. The HIV-infected patients with bacterial pneumonia had a significantly lower CRP level than the immunocompetent patients (50% versus 95% had an s-CRP level > 80 mg/l). No significant difference was found in the CRP response to P. carinii or bacteria in HIV-infected patients with pneumonia due to these microorganisms (20% versus 50% had s-CRP > 80 mg/l). In the group of PCP patients, a significantly lower CRP level was found in those with CD4 positive lymphocyte counts below 50 x 10(6)/l. There was no correlation between the CRP response and the severity of the PCP as estimated by the degree of hypoxia. We conclude that the CRP level cannot be used to discriminate between PCP and bacterial pneumonia in HIV-infected patients.

Role of non-capsulated Haemophilus influenzae as a respiratory pathogen in children

During a 12-month surveillance period from 1981-1982, non-capsulated Haemophilus influenzae was detected in nasopharyngeal aspirates from 64 (14%) of the 449 children hospitalized for middle or lower respiratory infection. An antibody response to H. influenzae was indicated in 15(23%) of the 64 patients with H. influenzae present in nasopharyngeal aspirate and in 10 (3%) of the 385 patients with a negative finding. Thus, serological evidence of H. influenzae infection was demonstrated in 25 (6%) of all the 449 children with respiratory infection. Of 13 patients with cultures positive for H. influenzae acute otitis media, an antibody response was seen in only 4 (30%) patients. H. influenzae infection was associated with infections caused by other microbes in 20 children (80%), with viral infections in 60% and with pneumococcal infections in 24% of cases. An infection focus was present in 15 (79%) of the 25 patients with H. influenzae infection; pneumonia was present in 10 cases and acute otitis media in 9 cases. Non-specific laboratory evidence of bacterial infection was seen in 11 patients (58%); C-reactive protein was increased in 7 and erythrocyte sedimentation rate in 9 patients. It is concluded that non-capsulated H. influenzae is a genuine respiratory pathogen in children. H. influenzae infections appear to be secondary to preceding viral or other bacterial infections in children who are carriers of this strain.

Role of Moraxella (Branhamella) catarrhalis as a respiratory pathogen in children

During a 12-month surveillance period in 1981-1982, Moraxella catarrhalis was detected in cultures from nasopharyngeal aspirates from 76 (17%) of 449 children hospitalized with middle or lower respiratory tract infection. Seroconversion to M. catarrhalis was positive in 4 (5%) of the 76 patients with M. catarrhalis present in nasopharyngeal aspirates and in 4 (1%) of 373 patients with a negative finding. Although children with respiratory tract infections were often colonized by the organism, this was rarely the infective agent of the middle or lower airways. Four of 8 patients with seroconversion to M. catarrhalis exhibited a concomitant RSV infection. The carriage of this species was more closely associated with parainfluenza virus infections. Serological responses to M. catarrhalis were not associated with acute otitis media, and were also rare in children with pneumonia. It is concluded that bronchopulmonary infections caused by M. catarrhalis are rare in children, and that M. catarrhalis aetiology need not be considered in the selection of antibiotics in cases of community-acquired pneumonia or other infections of the middle or lower respiratory tract affecting primarily healthy children.

Pneumococcal finding in a sample from upper airways does not indicate pneumococcal infection of lower airways

The presence of pneumococcus (Pnc) by antigen detection and culture was examined in nasopharyngeal aspirates (NPA) of 315 children hospitalized with middle or lower respiratory tract infection. Pnc was found in NPA from 115 (37%) patients, being demonstrated by antigen detection alone in 34 (30%), by culture alone in 26 (23%) and by both methods in 55 (48%) of Pnc-positive samples. Pnc findings in NPA were most common, 45-46%, in patients aged 1-4 years. Serological evidence of Pnc infection, based either on detection of Pnc antigen in serum or urine, or on demonstration of an antibody response to these antigens, was present in 31 (27%) of the 115 patients with and in 28 (14%) of the 200 patients without Pnc in NPA samples. In the 48 patients positive for Pnc in NPA samples both by antigen detection and culture the isolated Pnc strains were serotyped. In 45 (94%) of these the type/group of Pnc was the same by both methods indicating that the specificity of the antigen detection tests, latex particle agglutination and counterimmunoelectrophoresis, was high. To evaluate the diagnostic significance of Pnc antigen detection and culture in NPA, sensitivity, specificity and likelihood ratios were calculated; serological evidence of Pnc aetiology was used as a reference. For both methods, sensitivity was poor, less than 0.3, but specificity was good, greater than 0.8. It is concluded that the finding of Pnc by culture or antigen detection in NPA is no indication of Pnc respiratory infection. On the other hand, Pnc etiology is unprobable, if Pnc is not present in NPA.(ABSTRACT TRUNCATED AT 250 WORDS)

Cefetamet pivoxil in community-acquired pneumonia: an overview

A total of 305 patients with community-acquired pneumonia have participated in comparative or non-comparative studies involving cefetamet pivoxil. Of these, 211 (55 adults and 156 children) were involved in a series of open, prospective, comparator-controlled, multi-centre studies. Adults were randomized to receive either cefetamet pivoxil 1000 mg twice daily or amoxycillin 750 mg 3-times daily for 10 days. Children received either cefetamet pivoxil 10 mg/kg twice daily, cefetamet pivoxil 20 mg/kg twice daily or cefaclor 10 mg/kg 3-times daily for 7 to 8 days. The remaining 94 patients were treated openly with cefetamet pivoxil, with most patients receiving cefetamet pivoxil 500 mg twice daily for an average of 10 days; an elderly sub-group of these patients aged 70 to 103 years received therapy for an average of 11 days. The main causative organisms isolated were Streptococcus pneumoniae and Haemophilus influenzae. In adult patients, a successful clinical outcome was achieved in 100% of assessable patients receiving cefetamet pivoxil 1000 mg twice daily, and about 90% in those receiving 500 mg twice daily. The success rate in children was 98% for both dose levels of cefetamet pivoxil and 90% for those receiving cefaclor. In elderly patients, the percentage was 78% for the 500 mg twice daily patients. Thus, the standard dose of cefetamet pivoxil (500 mg twice daily in adults, 10 mg/kg twice daily in children) was well tolerated and proved to be at least as effective as the comparator drugs which were given 3-times a day.

Serologically indicated pneumococcal respiratory infection in children

Streptococcus pneumoniae infection was indicated serologically in 84 (19%) of 449 children hospitalized with middle or lower respiratory tract infection. Pneumococcal antigen was detected in acute serum in 28 patients, but in acute urine in only 2. An antibody response to type-specific capsular polysaccharides of S. pneumoniae was indicated in 27 patients and to a protein antigen, pneumolysin, in 25 patients, but to C-polysaccharide in only 10 patients. The observations mentioned above suggest that each serological test for pneumococcal etiology is insensitive, and to get an optimal result, a large panel of pneumococcal antigen and antibody assays must be used. Pneumococcal infection could be indicated serologically although no focus of infection, such as pneumonia or acute otitis media, or no laboratory evidence of bacterial infection as elevated values of C-reactive protein concentration, erythrocyte sedimentation rate or white blood cell count was present. Particularly antibody responses to pneumococcal pneumolysin were present in children without pneumonia or acute otitis media. Our results point out that no nonspecific parameter can be used for the selection of patients with probable pneumococcal etiology among children with respiratory tract infection. Concomitant viral infection, in most cases RSV infection, was present in a third of the children with pneumococcal infection. It is concluded that pneumococcal etiology should be actively sought for also in patients with viral respiratory infection, especially in young children with RSV infection.

Evaluation of a new tube latex agglutination test for detection of type-specific pneumococcal antigens in urine

A modified tube agglutination test using type-specific latex reagents for detection of pneumococcal capsular polysaccharide antigens in alkalinized, unconcentrated urine samples was evaluated in reconstituted urine samples and in groups consisting of 26 children with clinical and roentgenographic evidence of acute lower respiratory tract infection, six patients with blood culture-proven infection of nonpneumococcal etiology, and 30 healthy individuals. The sensitivity of the tube latex agglutination method for pneumococcal polysaccharides was 2 to 10 times higher than that of the slide agglutination method. Positive antigen findings were obtained for 42% of urine samples from patients with acute lower respiratory tract infection but in neither patients with nonpneumococcal septicemia nor healthy controls. Fifty-five percent of the antigen-positive patients also showed evidence of pneumococcal involvement by pneumococcal antibody assay or antigen detection in acute-phase serum.

Aetiology of community acquired pneumonia in Valencia, Spain: a multicentre prospective study

A year long multicentre prospective study was carried out in the Valencia region of Spain, to determine the cause of community acquired pneumonia. The study was based on 510 of 833 patients with pneumonia. Of these, 462 were admitted to hospital, where 31 patients died. A cause was established in only 281 cases--208 of bacterial, 60 of viral, and 13 of mixed infection. The most common microorganisms were Streptococcus pneumoniae (14.5%), Legionella sp (14%), Influenza virus (8%), and Mycoplasma pneumoniae (4%). There was a higher incidence of Legionella sp than in other studies.