Participación de los virus respiratorios en la neumonía del adulto inmunocompetente adquirida en la comunidad / Importance of respiratory virus in immunocompetent adult patients hospitalized with community-acquired pneumonia

Background: Community-acquired pneumonia (CAP) is a relevant worldwide cause of morbidity and mortality in adult population, however its etiology is often not identified and therapy is empirical. Aim: To assess the etiology of CAP in immunocompetent adult hospitalized patients using conventional and molecular diagnostic methods. Material and Methods: We prospectively studied 240 adult patients who were hospitalized for CAP to identify the microbial etiology. Sputum and blood cultures were obtained as well as serology testing for Mycoplasma pneumoniae and Chlamydophila pneumoniae, urinary antigen testing for Legionella pneumophila and Streptococcus pneumoniae, and a nasopharyngeal swab for the detection of sixteen respiratory viruses by reverse transcriptase polymerase chain reaction (RT-PCR). Results: In 100 patients (41.7%) a single respiratory pathogen was identified. In 17 (7.1%) cases, a mixed bacterial and viral infection was detected and no pathogen was identified in 123 cases (51%). The most commonly identified pathogens identified were: influenza virus (15.4%), parainfluenza virus (10.8%), rhinovirus (5%), Streptococcus pneumoniae (5%), respiratory syncytial virus (2.9%) and Mycoplasma pneumoniae (2.5%). Infectious agent detection by RT-PCR provided greater sensitivity than conventional techniques. Viral respiratory infections were more prevalent in older patients with comorbidities and high risk patients, according to the Fine index at hospital admission. The clinical severity and outcome were independent of the etiological agents detected. Conclusions: The use of molecular diagnostic techniques expanded the detection of respiratory viruses in immunocompetent adults hospitalized with CAP.

Etiología viral en la neumonía del adulto adquirida en la comunidad en un hospital del sur de Chile / Viral etiology of community acquired pneumonia among adults admitted to a general hospital

Background: There is paucity of information about viral etiology of community acquired pneumonia in adults. Aim: To investigate the viral etiology of pneumonia among hospitalized patients. Material and Methods: All adults with pneumonia that were hospitalized were prospectively enrolled at Puerto Montt hospital. A microbiological and viral assessment was carried out. Viral assessment included direct immunofluorescence of nasopharyngeal aspirates for influenza A and B virus and serum samples obtained during the acute phase of the disease and during convalescence for Hanta virus. Results: Between April 1 2005 and March 31 2006,159 adults aged 62 ± 20 years (58 % males), were admitted to the hospital for pneumonia. Mean hospital stay was 11.9 ± 8.6 days. Four patients had Hantavirus acute infection. Other viruses were identified in twelve patients (7.7%). Nine had influenza A, one syncytial respiratory virus, one syncytial and influenza A virus and one varicella zoster virus. Excluding patients with Hantavirus, no significant differences in age, clinical presentation, chest X ray findings, laboratory results and mortality were observed between patients with bacterial or viral etiology of the pneumonia. Conclusions: Viral etiology was confirmed in 10% of adult patients hospitalized with community acquired pneumonia.

Fatal varicella in a healthy girl.

A fatal case of chickenpox in a healthy 6-year-old girl is reported. She presented with hemorrhagic bullae from thrombocytopenia and then progressed rapidly to disseminated infection involving many systems causing myocarditis, pneumonitis and hepatitis. A peculiar blood picture with marked leukocytosis (leukemoid reaction) is revised and discussed.