This article reviews the effects of aging, tobacco-smoking, chronic bronchitis and emphysema, heart failure, oropharyngeal colonization, aspiration (micro and macro), alcoholism, hepatic cirrhosis, nutritional deficiency, immunosuppression, and environmental factors on the risk of community-acquired pneumonia and its severity. In the second part, the authors review the prophylactic action of anti-influenza and anti-pneumococcus vaccines as well as the role of prevention and treatment of antiviral agents in community-acquired pneumonia.

Keywords: Pneumococcal pneumonia. Influenza. Influenza vaccine. Viral vaccines. Risk factors.

Objective: To identify and classify risk factors for venous thromboembolism (VTE) in hospitalized patients, as well as to evaluate medical practices regarding prophylaxis for the disease. Methods: An observational cross-sectional study, carried out between January and March of 2006, involving inpatients at three hospitals in the city of Manaus, Brazil. Risk stratification for VTE was based on the criteria established by the Brazilian Society of Angiology and Vascular Surgery and by the International Union of Angiology. Clinical, surgical and medication-related risk factors were analyzed. The statistical analysis of the data obtained was conducted, adopting an alpha error of 5% and 95% CI. Qualitative data were analyzed using the chi-square test, whereas quantitative data were analyzed using Student's t-test. Results: Of the 1,036 patients included (total number of admissions, 1,051), 515 (49.7%) were male, and 521 (50.3%) were female. A total of 23 risk factors for VTE were identified (total number of occurrences, 2,319). The stratified risk for VTE was 50.6%, 16.6% and 30.8% among the admissions of high-, moderate- and low-risk cases, respectively. In 73.3% of the admissions, nonpharmacological prophylaxis was not employed at any point during the study period. In 74% of those classified as high- or moderate-risk cases, no prophylactic medications were administered. Conclusions: This study showed that, in the population studied, risk factors were common and that prophylactic measures were not employed in patients prone to developing VTE and its complications.

Keywords: Venous thromboembolism; Risk factors; Venous thrombosis/prevention & control.

Objectives: To identify the frequency of risk factors, classification of degree of risk and the practice of prophylaxis to venous thromboembolism (VTE) in a general hospital. Methods: Randomly selected cases were included. Patients were excluded if they were on anticoagulant treatment. Determination of risk factors and classification of degree of risk were done according to international consensus. Results: Most patients (96%) had at least one recognized risk factor, 81% of them fulfilled the criteria to be classified as moderate/high risk. Prophylactic measures were prescribed to 221 (63%) patients. There was a significant association between the higher risk level for VTE and increased use of heparin (p < 0.001). Contraindications to the use of heparin were noticed in 7% of the cases. Conclusion: Risk factors for VTE are usually seen and prophylaxis is unsatisfactory. Contraindications to the use of heparin are uncommon; prophylaxis should be considered for a higher number of patients.

Keywords: Pulmonary embolism. Deep venous thrombosis. Prevention.

Objective: To determine the prevalence of recurrent wheezing (RW) in preterm infants who received prophylaxis against severe infection with respiratory syncytial virus (RSV) and to identify genetic susceptibility (atopy or asthma) and risk factors for RW. Methods: This was a cross-sectional study involving preterm infants who received prophylaxis with palivizumab at a referral center in Brazil during the first two years of age. A structured questionnaire was administered in a face-to-face interview with parents or legal guardians. Results: The study included 410 preterm infants (median age = 9 months [0-24 months]). In the sample as a whole, 111 children (27.1%; [95% CI, 22.9-31.5]) had RW. The univariate analysis between the groups with and without RW showed no differences regarding the following variables: sex, ethnicity, maternal level of education, gestational age, birth weight, breastfeeding, number of children in the household, day care center attendance, pets in the household, and smoking caregiver. The prevalence of RW was twice as high among children with bronchopulmonary dysplasia (adjusted OR = 2.08; 95% CI, 1.11-3.89; p = 0.022) and almost five times as high among those with a personal/family history of atopy (adjusted OR = 4.96; 95% CI, 2.62-9.39; p < 0.001) as among those without these conditions. Conclusions: Preterm infants who received prophylaxis with palivizumab but have a personal/family history of atopy or bronchopulmonary dysplasia are more likely to have RW than do those without these conditions.

Keywords: Infant, premature; Respiratory sounds; Asthma; Palivizumab; respiratory syncytial viruses; Respiratory hypersensitivity.

Objective: To identify risk factors for recurrence of tuberculosis. Methods: We studied a cohort of 610 patients with active pulmonary tuberculosis who were enrolled for treatment between 1989 and 1994 and cured using a three-drug treatment regimen of rifampin, isoniazid and pyrazinamide (RHZ). The risk factors studied were age, gender, race, duration of symptoms, lesion cavitation, extent of disease, diabetes mellitus, alcoholism, HIV infection, delayed negative sputum conversion, treatment compliance, and medication doses. In order to detect recurrence, the patients were monitored through the Rio Grande do Sul State Healt Department Information System for 7.7 ± 2.0 years after cure. Data were analyzed using the Student's t-test, the chi-square test or Fisher's exact test, and Cox regression models. Results: There were 26 cases of recurrence (4.3%), which corresponds to 0.55/100 patients-year. The recurrence rate was 5.95 and 0.48/100 patients-year in HIV-positive and HIV-negative patients, respectively (p < 0.0001). In the multivariate analysis, HIV infection [RR = 8.04 (95% CI: 2.35-27.50); p = 0.001] and noncompliance [RR = 6.43 (95% CI: 2.02-20.44); p = 0.002] proved to be independently associated with recurrence of tuberculosis. Conclusions: Recurrence of tuberculosis was more common in HIV-positive patients and in patients who did not comply with the self-administered treatment (RHZ regimen). Patients presenting at least one of these risk factors can benefit from the implementation of a post-treatment surveillance system for early detection of recurrence. An alternative to prevent noncompliance with tuberculosis treatment would be the use of supervised treatment.

Keywords: Tuberculosis; Recurrence; Risk factors.

Objective: To determine the prevalence of and the risk factors for wheezing in infants under one year of age and residing in the city of Porto Alegre, Brazil. Methods: This was a cross-sectional study and is part of a multicenter, multinational project. The parents or legal guardians of the infants were interviewed at primary health care clinics or during home visits. We used a standardized questionnaire, validated for use in Brazil. Potential risk factors were assessed by means of a Poisson regression model with robust variance estimation, using the Wald test to determine the significance of each variable in the model. Results: The sample comprised 1,013 infants. The majority of those were male (53%), and the mean age was 13.5 ± 1.2 months. In 61% of the infants, there had been at least one episode of wheezing, which had recurred at least three times in one third of those infants. The mean age at the first episode of wheezing was 5.16 months (median, 5 months). Over 40% of the infants with wheezing visited emergency rooms due to wheezing, and 17% of those were hospitalized at least once in the first year of life because of this symptom. In the multivariate analysis, the risk factors for wheezing were as follows: male gender; history of pneumonia; maternal smoking during pregnancy; day care center attendance; low maternal level of education; early weaning; multiple episodes of cold; first viral infection prior to 3 months of age; existence of siblings; and history of asthma in the nuclear family. Conclusions: The prevalence of wheezing is high among infants in the city of Porto Alegre. We identified various risk factors for wheezing in infants.

Keywords: Respiratory sounds/epidemiology; Asthma; Infant; Risk factors.

Objective: To determine, in a sample of infants, the prevalence of and risk factors for occasional wheezing (OW) and recurrent wheezing-wheezy baby syndrome (WBS). Methods: Parents of infants (12-15 months of age) completed the International Study of Wheezing in Infants questionnaire. Results: We included 1,269 infants residing in the city of Blumenau, Brazil. Of those, 715 (56.34%) had a history of wheezing, which was more common among boys. The prevalences of OW and WBS were 27.03% (n = 343) and 29.31% (n = 372), respectively. On average, the first wheezing episode occurred at 5.55 ± 2.87 months of age. Among the 715 infants with a history of wheezing, the first episode occurred within the first six months of life in 479 (66.99%), and 372 (52.03%) had had three or more episodes. Factors associated with wheezing in general were pneumonia; oral corticosteroid use; a cold; attending daycare; having a parent with asthma or allergies; mother working outside the home; male gender; no breastfeeding; and mold. Factors associated with WBS were a cold; physician-diagnosed asthma; ER visits; corticosteroid use; pneumonia; bronchitis; dyspnea; attending daycare; bronchodilator use; having a parent with asthma; no breastfeeding; mother working outside the home; and a dog in the household. Conclusions: The prevalence of wheezing in the studied population was high (56.34%). The etiology was multifactorial, and the risk factors were intrinsic and extrinsic (respiratory tract infections, allergies, attending daycare, and early wheezing). The high prevalence and the intrinsic risk factors indicate the need and the opportunity for epidemiological and genetic studies in this population. In addition, mothers should be encouraged to prolong breastfeeding and to keep infants under six months of age out of daycare.

Keywords: Asthma; Prevalence; Risk factors.

Tuberculosis continues to be a major public health problem. Although efforts to control the epidemic have reduced mortality and incidence, there are several predisposing factors that should be modified in order to reduce the burden of the disease. This review article will address some of the risk factors associated with tuberculosis infection and active tuberculosis, including diabetes, smoking, alcohol use, and the use of other drugs, all of which can also contribute to poor tuberculosis treatment results. Tuberculosis can also lead to complications in the course and management of other diseases, such as diabetes. It is therefore important to identify these comorbidities in tuberculosis patients in order to ensure adequate management of both conditions.

Keywords: Tuberculosis/epidemiology; Tuberculosis/prevention & control; Diabetes mellitus/prevention & control; Smoking/adverse effects; Alcohol drinking/adverse effects; Street drugs/adverse effects.

Objective: Ventilator-associated pneumonia (VAP) is a serious complication of mechanical ventilation (MV). However, data on VAP in patients on prolonged MV (PMV) are scarce. We aimed to describe the characteristics of VAP patients on PMV and to identify factors associated with mortality. Methods: This was a retrospective cohort study including VAP patients on PMV. We recorded baseline characteristics, as well as 30-day and 90-day mortality rates. Variables associated with mortality were determined by Kaplan-Meier survival analysis and Cox regression model. Results: We identified 80 episodes of VAP in 62 subjects on PMV. The medians for age, Charlson Comorbidity Index, SOFA score, and days on MV were, respectively, 69.5 years, 5, 4, and 56 days. Episodes of VAP occurred between days 21 and 50 of MV in 28 patients (45.2%) and, by day 90 of MV, in 48 patients (77.4%). The 30-day and 90-day mortality rates were 30.0% and 63.7%, respectively. There were associations of 30-day mortality with the SOFA score (hazard ratio [HR] = 1.30; 95% CI: 1.12-1.52; p < 0.001) and use of vasoactive agents (HR = 4.0; 95% CI: 1.2-12.9; p = 0.02), whereas 90-day mortality was associated with age (HR = 1.03; 95% CI: 1.00-1.05; p = 0.003), SOFA score (HR = 1.20; 95% CI: 1.07-1.34; p = 0.001), use of vasoactive agents (HR = 4.07; 95% CI: 1.93-8.55; p < 0.001), and COPD (HR = 3.35; 95% CI: 1.71-6.60; p < 0.001). Conclusions: Mortality rates in VAP patients on PMV are considerably high. The onset of VAP can occur various days after MV initiation. The SOFA score is useful for predicting fatal outcomes. The factors associated with mortality could help guide therapeutic decisions and determine prognosis.

Keywords: Pneumonia, ventilator-associated; Critical care; Ventilators, mechanical.

Objective: To identify microorganisms in sputum samples of patients with stable non-cystic fibrosis bronchiectasis and to determine risk factors related to the isolation of Pseudomonas aeruginosa (PA) in those patients. Methods: Consecutive patients were recruited from a tertiary hospital outpatient clinic in the city of Fortaleza, Brazil. The patients were submitted to spirometry, six-minute walk test, HRCT, and sputum collection. Data on serum fibrinogen levels, disease severity, sputum color, and history of azithromycin treatment were collected. Results: The study included 112 patients, and females predominated (68%). The mean age was 51.6 ± 17.4 years. Most patients presented with mild-to-moderate disease (83%). The mean six-minute walk distance was 468.8 ± 87.9 m. Mean FEV1 and FVC, in % of predicted values, were 60.4 ± 21.8% and 69.9 ± 18.5%, respectively. The mean serum fibrinogen level was 396.1 ± 76.3 mg/dL. PA was isolated in 47 patients, other potentially pathogenic microorganisms (PPMs) were isolated in 31 patients, and non-PPMs were isolated in 34 patients. Purulent sputum was identified in 77 patients (68%). The patients with PA, when compared with those without it, presented with more severe disease, higher serum fibrinogen levels, and lower FVC%. In addition, purulent sputum and long-term azithromycin treatment were more common in those with PA. The multivariate regression analysis showed that the independent factors associated with PA were serum fibrinogen level > 400 mg/dL (OR = 3.0; 95% CI: 1.1-7.7) and purulent sputum (OR = 4.3; 95% CI: 1.6-11.3). Conclusions: In our sample, the prevalence of PA in sputum was 42%. Sputum color and inflammatory markers were able to predict the isolation of PA, emphasizing the importance of routine sputum monitoring.

Keywords: Bronchiectasis; Pseudomonas aeruginosa; Sputum/microbiology.

The authors report the case of a 7-year-old girl, with a history of recurrent respiratory infections since five months of age. Immunological evaluation at four years of age revealed a normal level of total serum immunoglobulins, but a deficient humoral response to Streptococcus pneumoniae. Although having all normal IgG subclasses, the patient had inadequate antibody levels to all serotypes tested (1, 3, 5, 6, 9, and 14). Concurrent radiological evaluation showed diffuse atelectasis and bronchiectasis. Patient was started on IVIG, and subsequent chest CT scan revealed resolution of the above-mentioned lesions. To prevent irreversible damage to lung parenchyma, due to recurrent lower respiratory infections, it is important to identify immunocompromised individuals and treat them accordingly.

Keywords: Immunologic deficiency syndromes. Streptococcus pneumoniae.

Objective: To investigate the clinical characteristics of preterm infants with different severities of bronchopulmonary dysplasia (BPD) and disclose the high-risk factors of exacerbating BPD. Methods: Collection of clinical data of 91 preterm infants admitted to the NICU and diagnosed with BPD, categorized in groups according to the disease severity: 41 mild cases,, 24 moderate cases, and 26 severe cases. Comparison and analysis of perinatal risk factors, treatment, complications and prognosis of the infants with different severity degrees. Results: The severe group had a higher proportion of infants with congenital heart disease (CHD) higher than the moderate group (P < 0.05), and a higher ratio of pneumonia and mechanical ventilation (MV) = seven days than the mild group (P < 0.05). The severe group also presented higher reintubation incidence than both the mild and moderate groups (P < 0.05). The groups presented different (P < 0.05) incidence rates of hemodynamically significant patent ductus arteriosus (hsPDA) . Ridit analysis suggested that the premature infants (PIs) with hsPDA, multiple microbial pulmonary infections, or Klebsiella pneumoniae pneumonia had more severe illness. Conclusion: CHD, hsPDA, MV = seven days, reintubation, pneumonia, especially multiple microbial pulmonary infections, and Klebsiella pneumoniae pneumonia are correlated with the severity of BPD and can be used as BPD progression predictor.

Keywords: BPD; Preterm infant; CHD; hsPDA;, Pneumonia; Mechanical ventilation

Objective: The identification of persistent airway obstruction is key to making a diagnosis of COPD. The GOLD guidelines suggest a fixed criterion-a post-bronchodilator FEV1/FVC ratio < 70%-to define obstruction, although other guidelines suggest that a post-bronchodilator FEV1/FVC ratio < the lower limit of normal (LLN) is the most accurate criterion. Methods: This was an observational study of individuals = 40 years of age with risk factors for COPD who were referred to our pulmonary function laboratory for spirometry. Respiratory symptoms were also recorded. We calculated the prevalence of airway obstruction and of no airway obstruction, according to the GOLD criterion (GOLD+ and GOLD-, respectively) and according to the LLN criterion (LLN+ and LLN-, respectively). We also evaluated the level of agreement between the two criteria. Results: A total of 241 individuals were included. Airway obstruction was identified according to the GOLD criterion in 42 individuals (17.4%) and according to the LLN criterion in 23 (9.5%). The overall level of agreement between the two criteria was good (? = 0.67; 95% CI: 0.52-0.81), although it was lower among the individuals = 70 years of age (? = 0.42; 95% CI: 0.12-0.72). The proportion of obese individuals was lower in the GOLD+/LLN+ category than in the GOLD+/LLN- category (p = 0.03), as was the median DLCO (p = 0.04). Conclusions: The use of the GOLD criterion appears to be associated with a higher prevalence of COPD. The agreement between the GOLD and LLN criteria also appears to be good, albeit weaker in older individuals. The use of different criteria to define airway obstruction seems to identify individuals with different characteristics. It is essential to understand the clinical meaning of discordance between such criteria. Until more data are available, we recommend a holistic, individualized approach to, as well as close follow-up of, patients with discordant results for airway obstruction.

Keywords: Pulmonary disease, chronic obstructive; Airway obstruction; Spirometry.

Objective: To determine the risk factors for ER visits due to asthma exacerbations in patients monitored at a referral center. Methods: Prospective cohort study of 253 outpatients (children and adults) with asthma who were monitored for 12 months at the Referral Center of the Program for the Control of Asthma and Allergic Rhinitis in the city of Feira de Santana, Brazil. Results: Exacerbations were common, and 36.5% of the patients sought ER treatment within the twelve-month period. The risk factors for asthma exacerbations were being over 20 years of age (OR = 1.34: (95% CI: 1.06-1.70), residing in an urban area (OR = 1.19; 95% CI: 1.06-1.33); having a low level of education (OR = 1.53: 95% CI: 1.00-2.39); having severe asthma (OR = 1.65; 95% CI: 1.24-2.18); and having chronic rhinitis (OR = 2.20; 95% CI: 1.00-4.80). Conclusions: In this cohort, having chronic rhinitis, having asthma that is more severe and having a low level of education were the main risk factors for ER visits due to asthma exacerbations. These results are similar to those reported for asthma patients who are receiving no regular treatment.

Keywords: Asthma/etiology; Health services; Program evaluation.

Objective: To assess the determining factors for Mycobacterium tuberculosis multidrug resistance at a referral center for infectious diseases in the state of Minas Gerais, Brazil. Methods: A retrospective case-control study was conducted using data collected from September of 2000 to January of 2004. During this period, 473 cultures presenting growth of M. tuberculosis, corresponding to 313 patients, were submitted to susceptibility tests at the Central Laboratory of Minas Gerais. Cases presenting resistance to at least rifampin and isoniazid were classified as cases of multidrug resistance and were selected for study. These cases were paired to control group cases of drug-susceptible tuberculosis at a ratio of 1:3. Clinical and demographic data were analyzed using univariate and multivariate analyses. Results: During the study period, 12 (3.83%) cases of multidrug-resistant tuberculosis were identified. In the univariate analysis, multidrug-resistant tuberculosis was found to be more common among male patients, as well as among those testing positive in the sputum smear microscopy, those with cavitations larger than 4 cm in diameter and those having been previously treated for tuberculosis (p = 0.10 for all). After the multivariate analysis, only previous treatment for tuberculosis remained statistically significant (p = 0.0374), with an odds ratio of 14.36 (1.96-176.46). Conclusion: In the present study, previous treatment for tuberculosis was found to be an independent risk factor for multidrug-resistant tuberculosis.

Keywords: Mycobacterium tuberculosis; Tuberculosis, multidrug-resistant; Tuberculosis; Microbial sensitivity tests; Risk factors

Objective: To determine the influence that hospital admission of suckling infants with asthma has on their risk for future admissions for the same cause. Methods: A retrospective study was conducted, in which the charts of 202 patients, all less than fifteen years of age, were evaluated. All of the patients had been treated as outpatients in a pediatric pulmonology clinic and had been admitted to the hospital on one or more occasions. A multivariate analysis was conducted in order to evaluate the risk factors associated with multiple hospitalizations. Results: Virtually all of the patients evaluated were hospitalized a second time within 18 months of the first hospitalization. Among the patients first hospitalized at = 12 months of age, the second admission occurred sooner than did that recorded for those first hospitalized at > 12 months of age (p = 0.001). The risk factors found to be associated with multiple hospital admissions were as follows: age at first admission = 12 months (odds ratio: 2.55; 95% confidence interval: 1.18-5.48); age at first admission between 13 and 24 months (odds ratio: 3.54; 95% confidence interval: 1.31-9.63); and severity of asthma symptoms (odds ratio: 3.86; 95% confidence interval: 2.02-7.40). Conclusion: After the first hospitalization, children with asthma should be closely monitored, since the risk of subsequent admissions is elevated in the first months following discharge, especially among those of less than two years of age. Health care facilities should be organized to confront this problem appropriately and should dispense prophylactic medication more freely.

Keywords: Asthma; Child, hospitalized; Patient readmission; Risk factors

Coronavirus disease 2019 (COVID-19), caused by the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is probably systemic, has a major respiratory component, and is transmitted by person-to-person contact, via airborne droplets or aerosols. In the respiratory tract, the virus begins to replicate within cells, after which the host starts shedding the virus. The individuals recognized as being at risk for an unfavorable COVID-19 outcome are those > 60 years of age, those with chronic diseases such as diabetes mellitus, those with hypertension, and those with chronic lung diseases, as well as those using chemotherapy, corticosteroids, or biological agents. Some studies have suggested that infection with SARS-CoV-2 is associated with other risk factors, such as smoking, external environmental pollution, and certain climatic conditions. The purpose of this narrative review was to perform a critical assessment of the relationship between COVID-19 and these potential risk factors.

Keywords: Coronavirus infections; COVID-19; Air pollution; Smoking; Tobacco use disorder.

The authors conducted a cross-sectional survey to estimate the prevalence of tuberculosis infection in employees at the Uberlândia University Hospital, Minas Gerais. The participants (167) were classified according to exposure to tuberculosis into three groups: A) clinical medicine ward, frequent; B) admission unit, limited; and C) administration area, none, and underwent a two-step tuberculin testing. Factors associated with positive results were: level of exposure (44.70%; OR, 1.45; IC, 1.13-2.15; p = 0.013), age over 40 years (52.60%; OR, 1.66; IC, 1.20-2.30; p = 0.004) and employed for more than 10 years (59.30%; OR, 1.63; IC, 1.13-2.22; p = 0.011). Among clinical personnel at the Uberlândia University Hospital the prevalence of significant tuberculin reaction was high.

Keywords: Tuberculosis. Tuberculin skin test. Health care personnel.

Objective: To determine the prevalence of risk factors for obstructive sleep apnea syndrome in interstate bus drivers. Methods: This study involved 262 professional interstate bus drivers employed by a Brazilian company headquartered in the Federal District. The drivers were evaluated using a questionnaire designed to assess respiratory sleep disorders, the Epworth Sleepiness Scale, test of sustained attention, test of divided attention and anthropometric measurements. Results: Body weight was found to be above the ideal in 68% of the drivers evaluated, 34% of which had a neck circumference = 42 cm. During the study period, the drivers reported using tobacco (27%), cola-based soft drinks (55%), alcohol (65%) and coffee (88%). The Epworth Sleepiness Scale score was = 10 points in 28%. Snoring was reported by 36%, sleep apnea by 5%, a sensation of suffocation during sleep by 12%, restless sleep by 29% and drowsiness while driving by 48%. There were 42% who had been involved in transit accidents, 7.6% of which were attributed to hypersomnolence. Those scoring higher than 10 of the Epworth Sleepiness Scale presented lower levels of sustained attention. In addition, a reduction in divided attention was found to correlate with greater daytime sleepiness and larger neck circumference. Conclusion: The rate of stimulant use found in the group of drivers evaluated is alarming. The high prevalence of daytime sleepiness indicates that attentiveness is reduced in this population.

Keywords: Automobile driving; Sleep apnea, obstructive; Work schedule tolerance; Psychometrics; Risk factors; Attention; Questionnaires