Objective: To describe aspects found on HRCT scans of the chest in patients infected with the influenza A (H1N1) virus. Methods: We retrospectively analyzed the HRCT scans of 71 patients (38 females and 33 males) with H1N1 infection, confirmed through laboratory tests, between July and September of 2009. The HRCT scans were interpreted by two thoracic radiologists independently, and in case of disagreement, the decisions were made by consensus. Results: The most common HRCT findings were ground-glass opacities (85%), consolidation (64%), or a combination of ground-glass opacities and consolidation (58%). Other findings were airspace nodules (25%), bronchial wall thickening (25%), interlobular septal thickening (21%), crazy-paving pattern (15%), perilobular pattern (3%), and air trapping (3%). The findings were frequently bilateral (89%), with a random distribution (68%). Pleural effusion, when observed, was typically minimal. No lymphadenopathy was identified. Conclusions: The most common findings were ground-glass opacities and consolidations, or a combination of both. Involvement was commonly bilateral with no axial or craniocaudal predominance in the distribution. Although the major tomographic findings in H1N1 infection are nonspecific, it is important to recognize such findings in order to include infection with the H1N1 virus in the differential diagnosis of respiratory symptoms.

Keywords: Pneumonia, viral; Tomography, X-ray computed; Influenza A virus, H1N1 subtype.

In March of 2009, a flu epidemic began in Mexico. Shortly thereafter, similar cases appeared in other countries, alerting authorities to the risk of a pandemic. This article details the principal signs and symptoms of infection with the swine-origin Influenza A (H1N1) virus. In addition, the measures to be taken in suspected or confirmed cases are addressed, as are the procedures to follow in relation to contacts. Furthermore, the drugs used in the prophylaxis against and the treatment of infection with the H1N1 virus are described.

Keywords: Influenza A virus, H1N1 subtype; Influenza A virus; Disease outbreaks.

In view of the pandemic caused by a new virus, influenza A (H1N1), we report the case of a 56-year-old patient without relevant risk factors and with severe acute respiratory syndrome resulting from infection with this virus. We present the results of laboratory tests and the imaging findings (chest X-ray and CT scans). The evolution was favorable, and the patient was discharged after 14 days.

Keywords: Influenza A virus, H1N1 subtype; Severe acute respiratory syndrome; Patient care.

Objective: To describe the characteristics of patients with influenza A (H1N1)-associated pneumonia treated at two hospitals in the region of Liguria, Italy, as well as to describe their treatment and outcomes. Methods: This was a prospective observational study including all patients older than 16 years of age with a confirmed diagnosis of influenza A (H1N1) who were admitted to Villa Scassi Hospital, in the city of Genoa, Italy, or to the Sestri Levante General Hospital, in the city of Sestri Levante, Italy, between September of 2009 and January of 2010. The primary outcome measure was mortality within 60 days after diagnosis. Secondary outcome measures were the need for mechanical ventilation and the length of hospital stay. Results: Of the 40 patients with a confirmed diagnosis of influenza A (H1N1), 27 presented pneumonia during the study period. The mean age of the 27 patients was 42.8 ± 14.8 years, and the mean length of hospital stay was 11.6 ± 8.2 days. Of the 27 patients, 20 had respiratory failure, 4 underwent invasive mechanical ventilation, and 5 underwent noninvasive ventilation. One patient had comorbidities, developed multiple organ failure, and died. Conclusions: During the influenza A (H1N1) pandemic, the associated mortality rate was lower in Italy than in other countries, and cases reported in the country typically had a milder course than did those reported elsewhere. Nevertheless, 9 of our cases (33%) rapidly evolved to respiratory failure, requiring mechanical ventilation.

Keywords: Pneumonia; Influenza A virus, H1N1 subtype; Respiratory insufficiency.

Objective: To evaluate pandemic influenza A (H1N1) 2009 in hospitalized patients in order to identify risk factors for hospitalization and, consequently, for the worsening of the disease. Methods: This retrospective observational study was conducted between March and December of 2010. The data were collected from the Brazilian Ministry of Health National Case Registry Database. We included only patients (inpatients and outpatients) in whom H1N1 infection was confirmed (via laboratory testing) during the study period. The variables regarding demographic and clinical characteristics were statistically evaluated in order to compare the hospitalization rates in the presence or absence of these factors. Risk factors were identified by logistic regression analysis. Results: We included 4,740 patients with laboratory confirmation of H1N1 infection. Of these, 1,911 individuals were hospitalized, and 258 (13.5%) died. The risk factors for hospitalization were age (20-29 years), African or Indigenous ethnicity, presence of specific comorbidities (heart disease, lung disease, kidney disease, hemoglobinopathy, immunosuppression, diabetes, obesity, puerperium, and smoking), a high number of comorbidities, and specific symptoms (dyspnea, diarrhea, vomiting, chest pain, hemoptysis, pneumonia, and wheezing). Higher levels of education and early use of oseltamivir were found to be protective factors. Hospitalization contributed to an increase in survival. Conclusions: Knowledge of the epidemiological characteristics that can be associated with hospitalization, disease severity, and mortality can be helpful in the adoption of preventive measures, as well as in the early diagnosis and treatment of disease, which might contribute to the reduction in the numbers of hospitalizations and deaths.

Keywords: Influenza A virus, H1N1 subtype; Hospitalization; Risk factors; Oseltamivir.

In 2010, 96 patients suspected of being infected with the influenza A (H1N1) virus were hospitalized at the Hospital São Paulo, located in the city of São Paulo, Brazil. Of those 96 patients, 4 (4.2%) were found to be infected with influenza A virus-3 with influenza A (H1N1) and 1 with seasonal influenza A-and 2 patients (2.1%) were found to be infected with influenza B virus. Most (63.5%) of the suspected cases occurred in children, as did half of the positive cases. The second wave of influenza A (H1N1) infection was weaker in São Paulo. The decrease in the number of hospitalizations for H1N1 infection in 2010 might be attributable to vaccination.

Keywords: Influenza A virus, H1N1 subtype; Influenza, human; Pneumonia; Pandemics.

The objective of this study was to review the literature related to avian influenza A (H5N1). The bibliographic research was conducted using the Medline, MD Consult, HighWire, Medscape and Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS, Latin American and Caribbean Health Sciences Literature) databases, as well as through direct research, limiting the scope to articles published within the past 10 years. We selected 31 original articles addressing the recent outbreaks of infection with the H5N1 subtype of avian influenza A in domesticated birds in Asia, which have resulted in significant economic losses and repercussions for public health, as well as some cases of human infection presenting high lethality. In most cases, infection has been associated with direct exposure to infected birds or contact with surfaces infected with bird excrement. However, cases of human-to-human transmission have been confirmed. In those cases, the incubation period varied from 2 to 4 days. The clinical manifestations range from asymptomatic infection to mild upper airway disease, pneumonia and multiple organ failure. Chest X-rays may reveal bilateral interstitial infiltrate, lobar collapse, focal consolidation and air bronchogram without pleural effusion. Lymphopenia is indicative of a poor prognosis. Supportive care appears to be the only acceptable treatment. Risk factors for poor prognosis include advanced age, delayed hospitalization, lower airway involvement, low white blood cell count or lymphopenia upon admission. Controlling outbreaks in domestic fowl and limiting contact between humans and infected birds must be the priorities in the management of this disease at the public health level. In addition, techniques and knowledge regarding the disease should be widely disseminated.

Keywords: Influenza A virus, avian /pathogenicity; Influenza; Disease outbreaks; Disease vectors; Clinical trials

This study aimed to review the literature on infection with the H5N1 subtype of avian influenza A virus, taking into consideration the fact that, in the event of a pandemic, children might become a major risk group. Searches were limited to the past ten years and were carried out using the following electronic databases: Medline, MD Consult, HighWire and Medscape. Children and young adults account for a significant proportion of the susceptible population. We found that more than half of the individuals infected were under 20 years of age and that one quarter were under the age of 10. The incubation period ranged from 2 to 5 days. Initial clinical manifestations are nonspecific, which hinders the diagnosis. Most of the infected individuals presented severe pneumonia, which evolved to respiratory insufficiency within an average of 4 days. Chest X-rays can reveal diffuse multifocal/interstitial infiltrates or segmental/lobar consolidation with air bronchogram. The pathogenic potential is high, with mortality rates up to 63%, indicating that the pandemic virus might present high pathogenicity and high mortality. Knowledge of the risk of a pandemic and of the measures to be taken in suspect cases constitutes an important step toward controlling a potential pandemic.

Keywords: Influenza A virus; Disease vectors; Disease outbreaks; Influenza A virus, H5N1 subtype.

Leptospirosis is an infectious disease characterized by multisystemic involvement. The lung involvement is common, usually mild and frequently neglected. When respiratory manifestations are prominent in a patient with leptospirosis, there is the potential for diagnostic confusion. The authors report a severe case of leptospiral pneumonia, with the objective of highlighting this etiological possibility of community pneumonia, especially when there is suspicion of epidemic features.

Hepatopulmonary syndrome is characterized by a triad consisting of liver disorder, pulmonary vascular dilatation, and hypoxemia. No case of hepatopulmonary syndrome associated with AIDS has been reported so far. In this study, the authors report the case of a 43-year woman with AIDS and virus C cirrhosis taking prophylactic cotrimoxazole for pneumocystosis and retroviral therapy. Upon admission, the patient presented dyspnea, cyanosis, digital clubbing, vascular spiders, and normal chest examination. Chest X-ray revealed bilateral interstitial infiltration and evidenced increased alveolar-arterial gradient and liver function impairment. Intrapulmonary shunt was evidenced by contrast-enhanced echocardiography and radionuclide perfusion scanning, thus confirming hepatopulmonary syndrome.

Keywords: Hepatopulmonary syndrome. Acquired human immunodeficiency syndrome. Human viral hepatitis. Anoxemia. Liver cirrhosis.

Chronic eosinophilic pneumonia is a rare disease of unknown cause characterized by eosinophilic alveolar and interstitial infiltration. The authors describe the case of a 49-year-old caucasian woman, presenting dyspnea on minimum effort, with insidious beginning and progressive course in the last six months. The main findings were serum eosinophilia and in the sputum, chest radiographs showing multifocal infiltrations of irregular distribution in both lungs and a restrictive functional impairment. The patient was submitted to an open lung biopsy, which demonstrated a chronic eosinophilic pneumonia. There was a dramatic clinical, radiological, and functional response after corticosteroid therapy.

Objective: Staphylococcal pneumonia typically presents high rates of morbidity and mortality. It typically occurs in cases of influenza (airborne transmission) or during episodes of bacteremia (blood-borne transmission). Methods: A retrospective and descriptive study was conducted in patients admitted to our hospital between January of 1992 and December of 2003. All of he patients included had been diagnosed with community-acquired pneumonia caused by Staphylococcus aureus. All were older than 14 years of age, and none were intravenous drug users. Results: Community-acquired pneumonia was identified in 332 cases, of which 24 (7.3%) were identified as cases of staphylococcal pneumonia. Age ranged from 14 to 89 years. Fifteen patients were male, and nine were female. Twelve patients met the criteria for severe pneumonia. Chest X-rays showed unilateral consolidation in 14 cases, bilateral consolidation in 10, pleural effusion in 15, rapid radiological progression of pulmonary lesions in 14, cavitation in 6 and pneumothorax in 1. Most of the patients presented comorbidities, of which diabetes mellitus was the most common. Twelve patients presented complications such as empyema and septic shock. Four patients died, translating to a mortality rate of 16.6% in our sample. Conclusions: The clinical presentation of pneumonia caused by S. aureus is similar to that of pneumonia caused by other etiological agents. Radiological findings, epidemiological data and risk factors provide important clues to the diagnosis. These factors are important for clinical suspicion, since S. aureus is not typically addressed in empirical treatment.

Keywords: Staphylococcal pneumonia; Staphylococcal infections; Community-acquired infections.

48 years-old woman, asymptomatic, presented with radiographic findings of patchy airspace consolidation with nodular opacities in the upper right lobe, middle lobe and lingula. The differential diagnoses of neoplasms, sarcoidosis, granulomatous diseases and tuberculosis were considered. Diagnosis of Bronchiolitis obliterans organizing pneumonia was made by means of videothoracoscopy whereupon treatment with corticosteroids was begun. The patient had a positive evolution with resolution of the radiographic finding.

Keywords: bronchiolitis obliterans organizing pneumonia, bronchiolitis obliterans

Objective: In view of the relevance of co-infection with tuberculosis and human immunodeficiency virus, this study was designed to determine tuberculosis prevalence and identify factors related to tuberculosis in patients residing in a region in which both infections are highly prevalent. Methods: All patients treated during 1999 at the HIV/AIDS Clinic of the Universidade Federal do Rio Grande (Rio Grande Federal University) University Hospital were evaluated retrospectively, from the time of human immunodeficiency virus diagnosis, in terms of the incidence of tuberculosis and its relationship to sociodemographic, behavioral and immunological factors. Results: The sample included 204 patients, and tuberculosis prevalence was found to be 27%. The multivariate analysis showed a significant correlation between the development of tuberculosis and being of African descent (odds ratio: 4.76; 95% confidence interval: 1.93-11.72) and an inverse correlation between the development of tuberculosis and the TCD4+ lymphocyte count at the time of human immunodeficiency virus diagnosis (odds ratio: 0.995; 95% confidence interval: 0.993-0.997). When analyzed separately, other variables were found to be potential risk factors: being of the male gender (odds ratio: 2.49; 95% confidence interval: 1.15-5.39); and using illicit drugs (odds ratio: 2.1; 95% confidence interval: 1.02-4.31). Conclusion: The factors responsible for the development of tuberculosis among patients who are human immunodeficiency virus seropositive include immunological, socioeconomic and demographic factors. The high rate of tuberculosis prevalence among the seropositive patients underscores the urgent need to implement strategies that combine rapid identification and prompt treatment of individuals with active or latent infection, as well as of those with whom they have been in contact.

Keywords: HIV Infections/complications; AIDS-related opportunistic infections/complications; Tuberculosis/etiology; Tuberculosis/epidemiology

A total of 287 bronchoscopies were performed in 267 patients infected with the human immunodeficiency virus (HIV). Bronchoalveolar lavage (BAL) and transbronchial biopsies (TBB) were sequentially performed in the same lung, in all cases. Specimens were examined after routine laboratory procedures for microbiologic and histologic analysis. Age ranged from 16 to 78 (median 37.2); 228 were men (85.4%) and 39 were women. Dyspnea was the main symptom in 198 cases (69.0%) and interstitial infiltrates (diffuse or localized) were the most common findings at chest radiographs (179 patients, 62.4%). Endoscopic view was normal in 246 patients (85.7%). Mucosal lesions suggestive of Kaposi's sarcoma (KS) were visible in 12 cases (4.2%). BAL detected 97 infectious agents, simultaneous co-infection occurred in 3 cases. TBB identified 165 pathogens (9 of them in association), anticipating a better yield than BAL in the diagnosis of P. carinii (84 versus 51, respectively) and cytomegalovirus (35 v. 0). Biopsies were unique in establishing the appropriate diagnosis of extrabronchial cancer and describing inespecific pneumonitis. Altogether, a definite diagnosis was obtained by bronchoscopic examination (including endoscopic view, BAL and TBB) in 271 of 287 cases (94.4%). Infections were caused by P. carinii in 105 patients (36.6%), Mycobacterium sp in 40 (13.9%), cytomegalovirus in 35 (12.2%), C. neoformans in 13 (4.5%) etc. Malignancies (including KS) were found in 16 patients (5.6%). More than one pathologic process was present in 28 (9.8%). Nonspecific pneumonitis was diagnosed in 56 cases (19.5%) and normal lung in 20 (7.0%). Complications related to bronchoscopy were pneumothorax (8 patients, 2.8%), haemorrhage (8), thoracic pain (2) and distal pneumonia (2). Chest tubes were required in 4 patients, including one fatal case (mortality rate of 0.3%). Combining BAL and TBB results increases the diagnostic yield of bronchoscopy in AIDS, with a low complication rate. If both techniques are performed, a higher number of infectious agents and more multiple causes of pulmonary disease may be identified.

Keywords: Bronchoscopy/methods. Acquired Immunodeficiency Syndrome/complications. Opportunistic infections related to AIDS/diagnosis.