Objective: To evaluate clinical, tomographic, and microbiological characteristics of pulmonary disease caused by M. kansasii (MKPD) in patients treated at an outpatient unit from 2006-2016. Methods: We studied thirty eight patients, and analyzed socio demographic, clinical-radiological, laboratory, and therapeutic characteristics. Results: The mean age was 64 years (SD = 10.6; IIQ = 57-72; median = 65.0), and 22 (57.9%) male patients. Pulmonary comorbidity was present in 89.5% of the patients. The most frequent comorbidity was bronchiectasis (78.9%). Previous treatment for pulmonary tuberculosis (PTB) was found in 65.9%. The most used therapeutic regimen was rifampicin, isoniazid and ethambutol (44.7%). Chest tomography (CT) showed bronchiectasis (94.1%), architectural distortion (76.5%), septum thickening (67.6%), and cavities (64.7%). Disease was bilateral in 85.2%. We observed 10.7% resistance to rifampicin, 67.9% resistance to ethambutol, and sensitivity to clarithromycin. Conclusion: In patients with structural lung disease, it is important to search for NTM, the main differential diagnosis with PTB. Chest CT showed different patterns that overlapped with structural disease caused by PTB or other lung diseases. We observed resistance to ethambutol, a drug component of the recommended regimen.

Keywords: Nontuberculous mycobacteria; Mycobacterium kansasii; Epidemiology; Treatment.

Objective: To analyze the epidemiological characteristics of sarcoidosis patients in the city of Rio de Janeiro, Brazil. Methods: A descriptive, case-control study involving 100 sarcoidosis patients under outpatient treatment between 2008 and 2010 at the Pedro Ernesto University Hospital, located in the city of Rio de Janeiro, Brazil. The diagnosis of sarcoidosis was based on clinical, radiological, biochemical, and histopathological criteria. Results: There was a predominance of females in the 35-40 year age bracket (range, 7-69 years), who accounted for 65% of the sample, although there was a second peak at approximately 55 years of age. The most common symptom was dyspnea (in 47%), and the most common radiological findings were pulmonary and lymph node involvement (stage II; in 43%), followed by stage III (in 20%), stage I (in 19%), stage 0 (in 15%), and stage IV (in 3%). No pleural effusion or digital clubbing was observed at diagnosis. The tuberculin skin test was negative in 94 patients. Spirometric findings at diagnosis were normal in 61 patients; indicative of obstructive lung disease in 21; and indicative of restrictive lung disease in 18. The most common biopsy sites were the lungs (principally by bronchoscopy) and the skin, the diagnosis being confirmed by biopsy in 56% and 29% of the cases, respectively. Treatment with prednisone was initiated in 75% of the patients and maintained for more than 2 years in 19.7%. Conclusions: This study corroborates the findings of previous studies regarding the epidemiological characteristics of sarcoidosis patients.

Keywords: Sarcoidosis/epidemiology; Sarcoidosis/diagnosis; Sarcoidosis/therapy.

Objective: To evaluate clinical aspects and the diagnosis of pulmonary tuberculosis (PT) in the aged. Methods: We compared 117 patients over 60 years of age (elderly group) and 464 patients aged 15 to 49 years old (nonelderly group) treated at the Thoracic Diseases Institute of the Federal University of Rio de Janeiro, from 1980 to 1996. Results: Previous history of PT was predominant in the elderly group (OR = 2.09; 95% CI = 1.26-3.45; p = 0.002), whereas household contact with PT was predominant in the nonelderly group (OR = 0.26; 95% CI = 0.10-0.66; p = 0.002). Mean time for diagnosis was 90 days in the elderly group and 60 days in the nonelderly group. In the elderly group, dyspnea (OR = 1.64; 95% CI = 1.06-2.53; p = 0.018) and weight loss (OR = 1.66; 95% CI = 1.01-2.82; p = 0.047) were predominant. In the nonelderly group, hemoptysis (OR = 0.51; 95% CI = 0.32-0.81; p = 0.002), chest pain (OR = 0.62; 95% CI = 0.40-0.97; p = 0.027) and fever (OR = 0.55; 95% CI = 0.35-0.86; p = 0.006) were more common. The most common radiological abnormalities were infiltrates and cavitations. Bilateral involvement was more common in the elderly patients (OR = 1.76; 95% CI = 1.12-2.78; p = 0.009). There were no differences between the two groups regarding positivity for Mycobacterium tuberculosis identified through tuberculin skin testing, sputum smear microscopy and culture. Conclusions: There are few clinical and laboratory differences between the age groups. The delayed diagnosis in the elderly group can be explained by the low clinical suspicion in these patients.

Keywords: Tuberculosis, pulmonary; Aged; Signs and symptoms, respiratory; Diagnosis.

Objective: To evaluate deaths attributed to multiple causes in which tuberculosis was one of the causes listed. Methods: All deaths among residents of the state of Rio de Janeiro, Brazil, occurring between 1999 and 2001 and for which the death certificate mentioned tuberculosis, were investigated. The World Health Organization guidelines were used in characterizing the underlying and associated (non-underlying) causes of death. Results: In deaths from tuberculosis, conditions related to its natural history were the principal associated causes, together with alcoholism and diabetes. In approximately three-fifths of all deaths for which tuberculosis was listed as an associated cause, the underlying cause of death was acquired immunodeficiency syndrome. High proportion of ill-defined causes of death, low values found for the number of causes informed per death certificate and for TB as an associated cause point towards a certain degree of underestimation of the actual number of TB-related deaths in Rio de Janeiro State. Conclusion: The study shows that the rates of tuberculosis-related mortality in the state of Rio de Janeiro, calculated based on the number of times tuberculosis was listed as a cause of death (underlying or associated), are the highest in the country. Epidemiological studies of mortality are recommended as a means of guiding the activities of the tuberculosis control program.

Keywords: Tuberculosis/mortality; Acquired immunodeficiency syndrome; Multipe cause of death; Brazil

In view of the fact that the World Health Organization has recommended the use of the mycobacteria growth indicator tube (MGIT) 960 system for the diagnosis of tuberculosis and that there is as yet no evidence regarding the clinical impact of its use in health care systems, we conducted a pragmatic clinical trial to evaluate the clinical performance and cost-effectiveness of the use of MGIT 960 at two health care facilities in the city of Rio de Janeiro, Brazil, where the incidence of tuberculosis is high. Here, we summarize the methodology and preliminary results of the trial. (ISRCTN.org Identifier: ISRCTN79888843 [http://isrctn.org/])

Keywords: Controlled clinical trial; Tuberculosis; Diagnostic tests, routine.

In 2005 and 2006, 8,121 clinical specimens submitted to the Mycobacteriology Laboratory of the Clementino Fraga Filho University Hospital/Thoracic Diseases Institute, in the city of Rio de Janeiro, Brazil, were inoculated on Löwenstein-Jensen medium containing glycerol and pyruvate. There were 79 mycobacteria isolates that presented growth only on pyruvate-containing medium, and those isolates were selected for the presumptive identification of Mycobacterium bovis. The selected isolates were screened with biochemical tests, PCR amplification (with the specific primers Rv0577 and Rv1510), and pyrazinamide susceptibility tests. All of the strains isolated showed specific phenotypical and genotypical patterns characteristic of M. tuberculosis, and no M. bovis strains were detected.

Keywords: Tuberculosis; Mycobacterium bovis; Polymerase chain reaction.

Background: Tuberculosis in children generally occurs as a direct result of cohabitation with a contagious adult. Objective: To create a profile of a typical adult with contagious tuberculosis (as identified through the public health system) living with a child who has been diagnosed with tuberculosis. Method: Case study. Children younger than 14 years of age who were diagnosed with tuberculosis were included. Parents were interviewed using structured questionnaires. Means and standard deviations were analyzed using the Student's t-test. Fisher's exact test or the Dz test was used for comparisons. Results: Fifty children, representing 96% of those diagnosed with tuberculosis in the Porto Alegre health care system between July 20, 2001 and August 10, 2002, were included. The mean age was 76 months, and 60% were girls. The classic forms of pulmonary presentation (consolidation or cavitation) were seen in 38%. The majority of the children were diagnosed in the hospital and came from homes in which there were (a mean of) 6 cohabitants and a total family income less than 2 times the local minimum wage. Using ELISA, HIV co-infection was identified in 25% (although not all were tested). The children regularly visited places other than their homes. In 78% of cases, the contagious adult was identified. These contagious adults were mostly males (56%), and the mean age was 32. In most cases (79%), the contagious adult was a relative, usually a parent. Within this group of adults with contagious tuberculosis, HIV co-infection was identified in 43% of those tested. Conclusions: Adults with contagious tuberculosis living in the home continue to be the most likely source of tuberculosis infection in children. Co-infection with HIV in these pediatric patients, as well as in the cohabiting adults with contagious tuberculosis, is a significant finding. It must be emphasized that the possibility of contact with contagious individuals in the home should be explored in every diagnosed case of pediatric tuberculosis.

Keywords: Tuberculosis/epidemiology. Children. Communicable diseases/etiology.

Objective: To identify nontuberculous mycobacteria (NTM) isolated from sterile sites in patients hospitalized between 2001 and 2006 at the Clementino Fraga Filho University Hospital, located in the city of Rio de Janeiro, Brazil. Methods: During the study period, 34 NTM isolates from sterile sites of 14 patients, most of whom were HIV-positive, were submitted to phenotypic identification and hsp65 PCR-restriction enzyme analysis (PRA). Results: Most isolates were identified as Mycobacterium avium, followed by M. monacense, M. kansasii, and M. abscessus. Conclusions: The combination of PRA, a relatively simple and inexpensive method, with the evaluation of a few phenotypic characteristics can allow NTM to be accurately identified in the routine of clinical laboratories.

Keywords: Mycobacteria, atypical; Molecular biology; Polymerase chain reaction.

The objective of this study was to compare gender differences among tuberculosis patients in a city with a high incidence of tuberculosis. This was a cross-sectional questionnaire-based study involving 560 tuberculosis patients (373 males and 187 females). Sociodemographic and clinical data, as well as data related to diagnostic criteria and treatment outcome, were collected (from the questionnaires and medical records) and subsequently compared between the genders. The median time from symptom onset to diagnosis was 90 days. There were no differences between the genders regarding the clinical presentation, diagnostic criteria, previous noncompliance with treatment, time from symptom onset, number of medical appointments prior to diagnosis, or treatment outcome. Gender-specific approaches are not a priority in Brazil. However, regardless of patient gender, the delay in diagnosis is a major concern.

Keywords: Poverty; Tuberculosis; Income.

Objective: To examine the trends in overall COPD mortality, as well as trends in in-hospital morbidity and mortality due to COPD, in Brazil, and to validate predictive models. Methods: This was a population-based study with a time-series analysis of cause-specific morbidity and mortality data for individuals ≥ 40 years of age, obtained from national health information systems for the 2000-2016 period. Morbidity and mortality rates, stratified by gender and age group, were calculated for the same period. We used regression analyses to examine the temporal trends and double exponential smoothing in our analysis of the predictive models for 2017. Results: Over the study period, COPD mortality rates trended downward in Brazil. For both genders, there was a downward trend in the southern, southeastern, and central-western regions. In-hospital morbidity rates declined in all regions, more so in the south and southeast. There were significant changes in the number of hospitalizations, length of hospital stay, and hospital expenses. The predictive models for 2017 showed error rates below 9% and were therefore validated. Conclusions: In Brazil, COPD age-adjusted mortality rates have declined in regions with higher socioeconomic indices, where there has been an even sharper decrease in all in-hospital morbidity and mortality variables. In addition to factors such as better treatment adherence and reduced smoking rates, socioeconomic factors appear to be involved in controlling COPD morbidity and mortality. The predictive models estimated here might also facilitate decision making and the planning of health policies aimed at treating COPD.

Keywords: Pulmonary disease, chronic obstructive/mortality; Pulmonary disease, chronic obstructive/epidemiology; Socioeconomic factors.

Objective: To describe the demographic and clinical characteristics of patients with tuberculosis hospitalized in the Nestor Goulart Reis Hospital, located in the city of Américo Brasiliense, Brazil. Methods: Epidemiological investigation by means of an observational, retrospective, descriptive study based on the medical charts of patients diagnosed with tuberculosis and hospitalized between 1994 and 2004. Results: There were 1787 patients diagnosed with tuberculosis during the period evaluated. Of those, 117 (7%) were females, 1670 (93%) were males; 1215 (68%) were single, separated or widowed. Most of the patients (74%) had not completed middle school, and most (63%) were between 30 and 50 years of age. In addition, 61% suffered from alcoholism. The most common occupation was farm worker (25% of the patients), and 70% of the patients were unemployed. The most common clinical form of the disease was the pulmonary form (in 92%). The rate of medical discharge was 60%. The treatment regimen differed from the standard (rifampin, isoniazid and pyrazinamide) in 34% of the cases. Conclusions: The profile of the patients with tuberculosis hospitalized in the hospital studied showed that they had special requirements: they were unable to take care of themselves (social cases) and required alternative treatment regimens, which justified their hospitalization. This hospital played an important social role in the treatment and guidance of these patients.

Keywords: Hospitalization; Tuberculosis; Demography.

Objective: To determine the epidemiological profile of inpatients at a TB referral hospital. Methods: This was a descriptive, retrospective study of the medical charts of patients with TB hospitalized at the Hospital Estadual Santa Maria (HESM), in the city of Rio de Janeiro, Brazil, between January of 2002 and December of 2003. Data were collected using a standardized form. Results: Of the 451 patients included in the study, 313 (69.4%) had been referred to the HESM from health care clinics, and 302 (67.0%) were male. Most of the patients were in the 30-59  year age bracket, 443 (98.2%) lived in the greater metropolitan region of Rio de Janeiro, and 298 (66.1%) lived in the city of Rio de Janeiro itself. The most common reason for hospitalization was poor health status (in 237, 52.5%). The most common comorbidity was AIDS (in 137, 30.4%). The most common signs and symptoms at admission were weight loss, fever and productive cough. Sputum smear microscopy was positive in 122 (71.0%) of the patients presenting with productive cough at admission. Of the 212 patients being retreated, 156 (73.6%) reported noncompliance with previous treatment. Regarding the outcome, 273 (65.8%) of the patients were referred to municipal health care centers, 83 (18.4%) died, 44 (9.8%) were cured, and 27 (6%) were discharged against medical advice. Conclusions: Providing hospitals specializing in TB is relevant for TB control, especially in metropolitan regions. In addition to taking biosafety measures, these hospitals must be prepared to treat patients with TB-related comorbidities and social problems. This study has resulted in improvements at the HESM.

Keywords: Tuberculosis; Epidemiology; Hospitalization.

Background: Asthma is considered the most common chronic childhood disease. However, there have been few studies on the prevalence of asthma in Brazil. Objective: To assess the prevalence and severity of asthma symptoms in school-age children and adolescents living in the city of Duque de Caxias, located in the greater metropolitan area of Rio de Janeiro. Method: Cross-sectional transversal study using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. The sample comprised students of 6, 7, 13 and 14 years of age. Results: One group of 2334 students between the ages of 6 and 7 and another composed of 4040 students between the ages of 13 and 14 were evaluated. The prevalence of wheezing within the last 12 months in the younger children was 27.7%, vs. 19% among the adolescents (p < 0.0001). There was a predominance of males in the 6-7 age group (29.9% vs. 25.6%; p = 0.01) and of females in the 13-14 age group (21.9% vs. 15.8%; p < 0.0001). The proportion of previously diagnosed cases of asthma was similar (approximately 10%) for both age brackets. Wheezing upon physical exertion was more prevalent among the adolescents (21.4% vs. 7.8%; p < 0.0001). Symptom severity was higher among female adolescents (severe asthma: 6.6% vs. 4.4%; p = 0.001), although no differences among genders were seen in the 6-7 age group. Conclusion: Asthma prevalence in Duque de Caxias is high, as it is in other Brazilian and Latin American cities. Values are higher in the 6-7 age group, in which symptoms were seen predominantly in males. Among the adolescents, the prevalence and severity of symptoms were higher in females, a recent observation that seems to be a new epidemiological trend of asthma.

Keywords: Key words: Asthma. Epidemiology. Severity of illness index. Cross-sectional studies.

Objective: To estimate the total time elapsed between symptom onset and diagnosis of pulmonary tuberculosis (patient delay plus health care system delay), analyzing the factors associated with delayed diagnosis in the state of Rio de Janeiro, Brazil. Methods: We conducted a questionnaire-based survey involving 218 pulmonary tuberculosis patients treated for two months at 20 health care clinics and 3 hospitals in eight cities within the state of Rio de Janeiro. We collected socioeconomic and demographic data, as well as data regarding the health care system and the medical history of the patients. Results: The median time elapsed from the onset of symptoms to diagnosis was 68 days (interquartile range [IQR]: 35-119 days). The median patient delay (time from symptom onset to initial medical visit) was 30 days (IQR: 15-60 days), and the median health care system delay (time from initial medical visit to diagnosis) was 21 days (IQR: 8-47 days). A cut-off point of 21 days was adopted. The factors independently associated with patient delay were female gender, cough, and unemployment [adjusted OR (95% CI) = 2.7 (1.3-5.6); 11.6 (2.3-58.8); and 2.0 (1.0-3.8), respectively], whereas only female gender was independently associated with health care system delay (OR= 3.2; 95% CI: 1.7-6.0). Conclusions: Delayed diagnosis of pulmonary tuberculosis remains a problem in Rio de Janeiro, increasing the risk of transmission and mortality, that risk being greater for women and the socioeconomically disadvantaged. Patients might not recognize the significance of chronic cough as a health problem. Tuberculosis education programs targeting women might improve this situation.

Keywords: Lung neoplasms; Neoplasm metastasis; Antineoplastic combined chemotherapy protocols; Radiotherapy, computer-assisted.

Tuberculosis continues to be a public health priority in many countries. In 2015, tuberculosis killed 1.4 million people, including 210,000 children. Despite the recent progress made in the control of tuberculosis in Brazil, it is still one of the countries with the highest tuberculosis burdens. In 2015, there were 69,000 reported cases of tuberculosis in Brazil and tuberculosis was the cause of 4,500 deaths in the country. In 2014, the World Health Organization approved the End TB Strategy, which set a target date of 2035 for meeting its goals of reducing the tuberculosis incidence by 90% and reducing the number of tuberculosis deaths by 95%. However, to achieve those goals in Brazil, there is a need for collaboration among the various sectors involved in tuberculosis control and for the prioritization of activities, including control measures targeting the most vulnerable populations. Children are highly vulnerable to tuberculosis, and there are particularities specific to pediatric patients regarding tuberculosis development (rapid progression from infection to active disease), prevention (low effectiveness of vaccination against the pulmonary forms and limited availability of preventive treatment of latent tuberculosis infection), diagnosis (a low rate of bacteriologically confirmed diagnosis), and treatment (poor availability of child-friendly anti-tuberculosis drugs). In this review, we discuss the epidemiology, clinical manifestations, and prevention of tuberculosis in childhood and adolescence, highlighting the peculiarities of active and latent tuberculosis in those age groups, in order to prompt reflection on new approaches to the management of pediatric tuberculosis within the framework of the End TB Strategy.

Keywords: Tuberculosis, pulmonary/prevention & control; Mycobacterium tuberculosis; Lung diseases/etiology; Child; Adolescent.

Os bacilos que causam a tuberculose estão agrupados no complexo Mycobacterium tuberculosis, composto por: M. tuberculosis, M. bovis subsp. bovis, M. africanum e M. microti, além da cepa vacinal M. bovis BCG. Tem sido proposta a inclusão de novas espécies neste complexo, como M. canettii, uma variante de M. tuberculosis encontrada na região da Somália(1), M. caprae, agente etiológico de tuberculose em caprinos(2), e M. pinnipedii, que causa tuberculose em leões marinhos, mas que também pode infectar o homem(3).

Objective: To estimate the rates of recurrence, cure, and treatment abandonment in patients with pulmonary tuberculosis treated with a four-drug fixed-dose combination (FDC) regimen, as well as to evaluate possible associated factors. Methods: This was a retrospective observational study involving 208 patients with a confirmed diagnosis of pulmonary tuberculosis enrolled in the Hospital Tuberculosis Control Program at the Institute for Thoracic Diseases, located in the city of Rio de Janeiro, Brazil. Between January of 2007 and October of 2010, the patients were treated with the rifampin-isoniazid-pyrazinamide (RHZ) regimen, whereas, between November of 2010 and June of 2013, the patients were treated with the rifampin-isoniazid-pyrazinamide-ethambutol FDC (RHZE/FDC) regimen. Data regarding tuberculosis recurrence and mortality in the patients studied were retrieved from the Brazilian Case Registry Database and the Brazilian Mortality Database, respectively. The follow-up period comprised two years after treatment completion. Results: The rates of cure, treatment abandonment, and death were 90.4%, 4.8%, and 4.8%, respectively. There were 7 cases of recurrence during the follow-up period. No significant differences in the recurrence rate were found between the RHZ and RHZE/FDC regimen groups (p = 0.13). We identified no factors associated with the occurrence of recurrence; nor were there any statistically significant differences between the treatment groups regarding adverse effects or rates of cure, treatment abandonment, or death. Conclusions: The adoption of the RHZE/FDC regimen produced no statistically significant differences in the rates of recurrence, cure, or treatment abandonment; nor did it have any effect on the occurrence of adverse effects, in comparison with the use of the RHZ regimen.

Keywords: Tuberculosis, pulmonary, Drug combinations; Recurrence.

Objective: To determine whether simple diagnostic methods can yield relevant disease information in patients with rheumatoid arthritis (RA). Methods: Patients with RA were randomly selected for inclusion in a cross-sectional study involving clinical evaluation of pulmonary function, including pulse oximetry (determination of SpO2, at rest), chest X-ray, and spirometry. Results: A total of 246 RA patients underwent complete assessments. Half of the patients in our sample reported a history of smoking. Spirometry was abnormal in 30% of the patients; the chest X-ray was abnormal in 45%; and the SpO2 was abnormal in 13%. Normal chest X-ray, spirometry, and SpO2 were observed simultaneously in only 41% of the RA patients. A history of smoking was associated with abnormal spirometry findings, including evidence of obstructive or restrictive lung disease, and with abnormal chest X-ray findings, as well as with an interstitial pattern on the chest X-ray. Comparing the patients in whom all test results were normal (n = 101) with those in whom abnormal test results were obtained (n = 145), we found a statistically significant difference between the two groups, in terms of age and smoking status. Notably, there were signs of airway disease in nearly half of the patients with minimal or no history of tobacco smoke exposure. Conclusions: Pulmonary involvement in RA can be identified through the use of a combination of diagnostic methods that are simple, safe, and inexpensive. Our results lead us to suggest that RA patients with signs of lung involvement should be screened for lung abnormalities, even if presenting with no respiratory symptoms.

Keywords: Arthritis, rheumatoid; Lung diseases, interstitial; Spirometry; Radiography, thoracic; Airway ob-struction.

To describe some aspects of tuberculosis in a low-income community (the Complexo de Manguinhos, in Rio de Janeiro, Brazil), a retrospective study was carried out. Of the 290 cases reported in the 2000-2002 period, 75.8% were new cases. The annual incidence rates were 157/100,000 (2000), 205/100,000 (2001), and 145/100,000 (2002). Although there was a tendency toward a decrease in the number of cases over the period studied, the difference was not significant, suggesting that tuberculosis continues to be endemic in the area. Therefore, despite the existence of local public health care services, more efficient strategies should be implemented in order to increase the effectiveness of tuberculosis control programs in the area.

Keywords: Tuberculosis/epidemiology; Poverty areas; Mycobacterium tuberculosis.

Aim: To evaluated the etiologic percentage of the atypical pneumoniae in outpatients and to identify the epidemiologic, clinical and radiographic features that permit to distinguish between atypical and non-atypical pneumonia. Methods: All patients underwent clinical and radiographic evaluation. Serum and sputum samples were obtained to serological tests including Legionella sp, Chlamydia sp, M. pneumoniae, Influenza A and Influenza B virus, and Gram stain, respectively. These procedures were performed on the first and 21 days after inclusion. Three independent observers reviewed chest X-rays. Results: During 22 months, 129 patients were evaluated. The final population under study comprised 69 patients (46 men - 23 women) with a mean age of 37 years. The etiologic diagnosis was defined in 34 (50%) of the patients. Etiologic agents included Chlamydia sp, 11 (16%) isolated cases; M. pneumoniae 7 (10%) cases. Influenza A was the third more frequent agent in 4 (6%) patients, and Legionella sp in 4 (6%). Mixed infections were observed with association of Chlamydia sp and M. pneumoniae in 5 (7.3%) cases, Chlamydia sp and Influenza B one (1.5%) case, and another of M. pneumoniae and Influenza A. The atypical pneumonia and non-atypical pneumonia groups were compared to respiratory symptoms and signs. There were no differences between them. The three independent observers' radiographic evaluation showed disagreement among them as to the type of pneumonia. Radiographic diagnoses of individual observers were compared to the clinical diagnoses, and no significant association was obtained for any observer. Conclusion: Pneumonia caused by "atypical" agents occurs in 50% of the outpatients with community acquired pneumonia. It is not possible to distinguish atypical pneumonia from non-atypical pneumonia. The clinical and radiographic presentations are similar in both groups.

Keywords: pneumonia; etiology; diagnosis; epidemiology