Hospitalisation for lower respiratory tract infection in children in the province of Quebec, Canada, before and during the pneumococcal conjugate vaccine era.

Streptococcus pneumoniae is an important cause of community-acquired pneumonia and pneumococcal conjugate vaccines (PCVs) may reduce this burden. This study's goal was to analyse trends in lower respiratory tract infections (LRTI) hospitalisations before and during a routine vaccination programme targeting all newborns with PCV was started in the province of Quebec, Canada in December 2004. The study population included hospital admissions with a main diagnosis of LRTI among 6-59 month-old Quebec residents from April 2000 to December 2014. Trends in proportions and rates were analysed using Cochran-Armitage tests and Poisson regression models. We observed a general downward trend in all LTRI hospitalisations rate: from 11·55/1000 person-years in 2000-2001 to 9·59/1000 in 2013-2014, a 17·0% reduction, which started before the introduction of PCV vaccination. Downward trends in hospitalisation rates were more pronounced for all-cause of pneumonia (minus 17·8%) than for bronchiolitis (minus 15·4%). There was also a decrease in the mean duration of hospital stay. There was little evidence that all-cause pneumonia decreased over the study period due mainly to the introduction of PCVs. Trends may be related to changes in clinical practice. This study casts doubt on the interpretation of ecological analyses of the implementation of PCV vaccination programmes.

Evaluation of the New World Health Organization Case Definition of Severe Acute Respiratory Infection for Influenza Surveillance During the Peak Weeks of Two Influenza Seasons in Quebec, Canada.

During the peak of the 2012-2013 and 2014-2015 influenza seasons in Quebec, Canada, the sensitivity of the new World Health Organization (WHO) case definition of severe acute respiratory infection (SARI) in <5-year-old children was 65% for polymerase chain reaction-confirmed influenza and 79% for other respiratory viruses (ORVs), whereas its specificity and positive predictive value were approximately 2- and 4-fold lower for influenza than ORVs (25% vs 40% and 18% vs 76%, respectively). The use of the WHO SARI definition for influenza surveillance in children should be interpreted with caution according to the specific surveillance goals.

Predictors of hospitalization for lower respiratory tract infection in children aged <2 years in the province of Quebec, Canada.

Young age, adverse environmental conditions and infectious agents are established risk factors of lower respiratory tract infection (LRTI), whereas pneumococcal conjugate vaccines may be protective. To explore their relative role as predictors of hospitalizations under the continental climate prevailing in the province of Quebec, Canada, an ecological study was performed. Records with a main diagnosis of LRTI in children born during 2007-2010 and observed up to their second-year anniversary were extracted from the provincial hospital administrative database. Respiratory virus surveillance data and statistics on ambient air temperature were obtained. Vaccine use in different birth cohorts was derived from the Quebec City Immunization Registry. Additive and multiplicative Poisson regression models were applied to estimate attributable fractions. Age, month of birth, ambient temperature, and respiratory syncytial virus (RSV), human metapneumovirus (hMPV) and influenza-positive test proportions were significant predictors of LRTI hospitalizations. No substantial differences were observed in cohorts exposed to the 7-valent or 10-valent pneumococcal conjugate vaccines. In the additive model, the fraction of hospitalizations explained by temperature variation was 37%, whereas RSV circulation explained 28%, hMPV 4% and influenza 1%. Complex interplay between biological, environmental and social mechanisms may explain the important role of ambient air temperature in predicting LRTI hospitalization risk in young children.

Tuberculosis may be underestimated in Rwandan women.

BACKGROUND AND HYPOTHESIS: The majority of adult tuberculosis (TB) cases reported to the surveillance system in Rwanda are male. If this results from detection mechanisms that are less sensitive to TB in women, notified cases should be more severe in women than in men. METHODS: We analysed the 2006 series of TB cases among persons aged ≥ 15 years in Huye District and Kigali. Severe TB was defined as disease leading to death, or extra-pulmonary or disseminated TB. RESULTS: Of 1673 cases identified, 40% involved women, who were younger than men (65% vs. 54% aged <35 years). Overall severity was similar in both sexes. Considering age <35 years, women were at higher risk of severe TB than men, although the difference was not statistically significant. Smear-negative pulmonary TB (SNPTB), and human immunodeficiency virus (HIV) infection were more frequent in women than in men (59% vs. 42%, P < 0.001). For women with smear-positive pulmonary TB (SPPTB), the risk of death was twice that among men (adjusted hazard ratio 1.8; 95%CI 1.0-3.2). CONCLUSIONS: Among female TB patients, the higher risk of death with SPPTB, the higher frequency of SNPTB and the higher prevalence of HIV infection suggest that the passive system of case detection may underestimate the burden of TB in Rwandan women.

Human metapneumovirus infection in adults with community-acquired pneumonia and exacerbation of chronic obstructive pulmonary disease.

We tested nasopharyngeal aspirate specimens by real-time polymerase chain reaction assays and paired serum samples by enzyme-linked immunosorbent assays. Acute human metapneumovirus infections were identified in 6 (4.1%) of 145 adult patients who presented to the emergency department for pneumonia or acute exacerbation of chronic obstructive pulmonary disease during 2 winter/spring seasons in Quebec, Canada.