Effect of an infection control program on the frequency of nosocomial viral respiratory infections.

We determined the rate of nosocomial viral respiratory infection in infants and the effect of an infection control program during 4 winter seasons. The rate of nosocomial viral respiratory infection decreased from 6.09 episodes per 100 patients admitted during the first study year to 1.46 episodes per 100 patients admitted during the last study year.

Human metapneumovirus infections in Mexico: epidemiological and clinical characteristics.

The human metapneumovirus (hMPV) is a recently described respiratory RNA virus that mainly affects children. To date there has not been a report that describes the detection of this virus in Mexico. This study was performed to detect hMPV in hospitalized Mexican children with respiratory infections, and describe their epidemiological and clinical characteristics. Nasal wash samples from 558 children younger than 3 years of age with the admission diagnosis of a respiratory tract infection were evaluated. Respiratory viruses were detected in 221 children [respiratory syncytial virus (RSV), 193 (34.6 %); influenza virus, 13 (2.3 %); parainfluenza viruses, 15 (2.7 %)]. Respiratory secretions of 323 children in whom the presence of these viruses was excluded (131 admitted during the 2002-2003 respiratory season and 192 during the 2003-2004 season) were tested for hMPV infection. The hMPV genome was detected in 34 specimens by amplification using real-time RT-PCR. Sequencing of amplicons and phylogenetic analysis indicated the predominance of genotype A hMPV. The months with the highest number of hMPV detections were February and March. During the 2002-2003 season hMPV activity peaked after the RSV season. During the 2003-2004 season hMPV and RSV epidemics occurred simultaneously. The clinical presentation of an hMPV infection was indistinguishable from other respiratory infections. Except for one death, the outcomes of the hMPV infections were good. In this study, among the viruses routinely tested for, hMPV was the second most common agent, after RSV, in children younger than 3 years of age hospitalized with respiratory tract infections.

Viral etiology of lower respiratory tract infections in hospitalized children in Mexico.

BACKGROUND: Respiratory viruses are the main cause of lower respiratory tract infections (LRTI) reported worldwide. The contribution of viral infections to respiratory infections in Mexico has not been fully determined. OBJECTIVE: To determine the contribution of viral infections in hospitalized children with LRTI. METHODS: Children younger than 15 years of age with the admission diagnosis of LRTI were eligible for this study. A nasal wash specimen for virus identification by direct immunofluorescent assay (DFA) was obtained as soon as possible after admission. Clinical and radiographic findings of children with positive and negative detection of viruses were compared. RESULTS: Of 285 subjects admitted to the hospital with LRTI, 265 (93%) had an appropriate specimen for DFA. A viral agent was detected in 125 (47.2%) specimens. Viruses that were identified included respiratory syncytial virus (107), influenza (9) and parainfluenza type 3 (9). Clinical and radiologic diagnoses included bronchiolitis (127), interstitial pneumonia (47) and pneumonia (91). Of the subjects included in the study, 71.3% were younger than 1 year of age. Children with a confirmed viral etiology for their LRTI were younger, had higher respiratory rates on admission and were more likely to present with bronchiolitis than subjects with a negative DFA result. CONCLUSIONS: Respiratory viruses are responsible for at least 47.2% of LRTI requiring hospitalization at our hospital. Respiratory syncytial virus was the most important respiratory agent identified.

Human metapneumovirus and other respiratory viral infections in children attending a day care center.

Human metapneumovirus (hMPV) is an important cause of acute respiratory infections (ARI). We studied 335 ARI episodes in 74 children<5 years of age attending a day care center during a 1-year period to detect the presence of hMPV and other viruses. Seven (9.5%) children were infected by hMPV and this virus accounted for 2.1% of the ARI episodes.