Manale Ouakki

An outbreak of severe respiratory tract infection due to human metapneumovirus in a long-term care facility.

BACKGROUND Human metapneumovirus (hMPV) is a newly described paramyxovirus that is mainly associated with bronchiolitis in children. We sought to describe the epidemiological, virological, and histopathological findings associated with a large outbreak of hMPV infection in a long-term care facility. METHODS An investigation of the outbreak was performed by public health authorities, who used standardized questionnaires to collect relevant clinical information from all residents of the facility. Nasopharyngeal samples were obtained from a subset of patients who had influenza-like illnesses for testing by viral culture and reverse-transcriptase polymerase chain reaction. Lung tissue samples from a patient whose case was fatal were available for molecular, histopathological, and immunohistochemical testing. RESULTS A total of 96 (27%) of 364 residents of a long-term care facility presented with respiratory or constitutional symptoms between 1 January 2006 and 15 February 2006. The attack rate in the most affected ward was 72% (31 of 43 patients), which included 4 of the 6 polymerase chain reaction-confirmed cases of hMPV infection. In contrast, viral culture results were positive for hMPV in only 2 of the 5 polymerase chain reaction-positive samples tested. The most reported diagnosis was an upper respiratory tract infection or an influenza-like illness, although 21% of residents in 1 of the 3 wards that had confirmed cases of hMPV infection had lower respiratory tract infections. The fatality rate was 50% (3 of 6 patients) among confirmed cases and 9.4% (9 of 96 patients) among patients with possible cases. A patient with a fatal case had histopathological findings that confirmed the presence of hMPV RNA and proteins in the bronchiolar epithelium of affected lobes. Phylogenetic analysis revealed the presence of 2 distinct strains of hMPV circulating simultaneously on different wards. CONCLUSION hMPV can be associated with important outbreaks of acute respiratory tract infection in elderly institutionalized persons.

Pneumonia after implementation of the pneumococcal conjugate vaccine program in the province of Quebec, Canada.

Background: In Canada, a pneumococcal conjugate vaccine was licensed in 2001, and in the province of Quebec, a publicly-funded program was implemented for high-risk children in 2002, using a 4-dose schedule, and for all children in 2004, using a 3-dose schedule. Objectives: To describe the epidemiology of hospitalized pneumonia in the population aged <5 years. Methodology: Hospital discharge records with a main diagnosis of pneumonia, pleurisy, or empyema were analyzed regarding monthly frequencies by diagnostic categories, duration of stay, proportion of cases admitted to the intensive care unit, and case fatality. Results: Lobar pneumonia represented 32% of 25,319 all-cause pneumonia admissions during the period April 1997 to March 2006. Beginning in the spring of 2004, there was a marked decrease in the frequency of lobar pneumonia, whereas unspecified pneumonia tended to increase to a lesser extent. Compared with the pre-pneumococcal conjugate vaccine period, admissions for all-causes pneumonia decreased by 13% after program implementation and there was no increase in empyema cases. Conclusions: Results are reassuring as to the effectiveness of the pneumococcal vaccination program in Quebec.

Household Transmission of the 2009 Pandemic A/H1N1 Influenza Virus: Elevated Laboratory-Confirmed Secondary Attack Rates and Evidence of Asymptomatic Infections

BACKGROUND Characterizing household transmission of the 2009 pandemic A/H1N1 influenza virus (pH1N1) is critical for the design of effective public health measures to mitigate spread. Our objectives were to estimate the secondary attack rates (SARs), the proportion of asymptomatic infections, and risk factors for pH1N1 transmission within households on the basis of active clinical follow-up and laboratory-confirmed outcomes. METHODS We conducted a prospective observational study during the period May-July 2009 (ie, during the first wave of the pH1N1 pandemic) in Quebec City, Canada. We assessed pH1N1 transmission in 42 households (including 43 primary case patients and 119 contacts). Clinical data were prospectively collected during serial household visits. Secondary case patients were identified by clinical criteria and laboratory diagnostic tests, including serological and molecular methods. RESULTS We identified 53 laboratory-confirmed secondary case patients with pH1N1 virus infection, for an SAR of 45% (95% confidence interval [CI], 35.6%-53.5%). Thirty-four (81%) of the households had ≥1 confirmed secondary case patient. The mean serial interval between onset of primary and confirmed secondary cases was 3.9 days (median interval, 3 days). Influenza-like illness (fever and cough or sore throat) developed in 29% (95% CI, 20.5%-36.7%) of household contacts. Five (9.4%) of secondary case patients were asymptomatic. Young children (<7 years of age) were at highest risk of developing laboratory-confirmed influenza-like illness. Primary case patients with both diarrhea and vomiting were the most likely to transmit pH1N1. CONCLUSION Household transmission of pH1N1 may be substantially greater than previously estimated, especially in association with clinical presentations that include gastrointestinal complaints. Approximately 10% of pH1N1 infections acquired in the household may be asymptomatic.

Human Papilloma Virus vaccine and cervical cancer screening acceptability among adults in Quebec, Canada

BackgroundThe Pap test has been used for cervical cancer screening for more than four decades. A human papillomavirus (HPV) vaccine has been approved for use in Canada and is commercially available now. These two preventive interventions should be considered simultaneously. General population support is an important factor for the successful combination of these interventions. The study had two objectives: 1) To assess practices, beliefs, and attitudes regarding Pap test screening and HPV immunization; 2) To identify socio-demographic factors for Pap screening and vaccine acceptability.MethodsIn 2006, 500 adults were invited to participate in a telephone survey in the region of Quebec City (urban and rural population, 600 000), Canada. Some neutral and standardized information on Pap test and HPV was provided before soliciting opinions.Results471 adults (18–69 year-olds) answered the questionnaire, the mean age was 45 years, 67% were female, and 65% had college or university degree. Eighty-six percent of women had undergone at least one Pap-test in their life, 55% in the last year, and 15% from 1 to 3 years ago. Among screened women, the test had been performed in the last three years in 100% of 18–30 year-olds, but only in 67% of 60–69 year-olds (P < 0.0001). Only 15% of respondents had heard of HPV. Eighty-seven percent agreed that HPV vaccines could prevent cervical cancer, 73% that the vaccine has to be administered before the onset of sexual activity, 89% would recommend vaccination to their daughters and nieces. Among respondents < 25 years, 91% would agree to receive the vaccine if it is publicly funded, but only 72% would agree to pay

Comparison of Risk Factors for Human Metapneumovirus and Respiratory Syncytial Virus Disease Severity in Young Children

100/dose.ConclusionThere is an important heterogeneity in cervical cancer screening frequency and coverage. Despite low awareness of HPV infection, the majority of respondents would recommend or are ready to receive the HPV vaccine, but the cost could prevent its acceptability.

Safe vaccination of patients with egg allergy with an adjuvanted pandemic H1N1 vaccine

Abstract Background. Human metapneumovirus (hMPV) and respiratory syncytial virus (RSV) are leading pediatric pathogens. However, risk factors for severe hMPV disease remain unknown. We comparatively assessed environmental, host, and viral determinants for severe hMPV and RSV infections. Methods. We studied a prospective cohort of >1000 children aged <3 years hospitalized in or presenting to a pediatric clinic for acute respiratory infection. We collected clinical data at enrollment and 1-month follow-up and tested nasopharyngeal secretions for respiratory viruses. Disease severity was defined as hospitalization and was also assessed with a severity score (1 point/variable) calculated on the basis of fraction of inhaled O2 ≥ 30%, hospitalization >5 days, and pediatric intensive care unit admission. Results. hMPV was identified in 58 of 305 outpatient children (19.0%) and 69 of 734 hospitalized children (9.4%), second only to RSV (48.2% and 63.6%, respectively). In multivariate regression analysis of hMPV cases, age <6 months and household crowding were associated with hospitalization. Among hospitalized patients, risk factors for severe hMPV disease were female sex, prematurity, and genotype B infection. Age <6 months, comorbidities, and household crowding were risk factors for RSV hospitalization; breast-feeding and viral coinfection were protective. Age <6 months and prematurity were associated with severe RSV cases among hospitalized children. Conclusions. hMPV and RSV severity risk factors may differ slightly. These findings will inform hMPV prevention strategies.

Reduced Physician Claims for Otitis Media After Implementation of Pneumococcal Conjugate Vaccine Program in the Province of Quebec, Canada

BACKGROUND Because influenza vaccine contains some residual egg protein, there is a theoretic risk of anaphylaxis when vaccinating patients with egg allergy. The objective of this study was to estimate the risk of anaphylaxis in children with egg allergy administered an adjuvanted monovalent 2009 pandemic influenza A/H1N1 influenza vaccine (Arepanrix; GlaxoSmithKline, Mississauga, Ontario, Canada). METHODS Patients with confirmed egg allergy with a history of respiratory or cardiovascular reactions after egg ingestion were vaccinated in 2 divided doses (10% and 90%) administered at a 30-minute interval, whereas children with other types of egg-induced allergic reactions were vaccinated with a single dose. All patients remained under observation for 60 minutes after vaccination. A 24-hour follow-up telephone call was made to detect any delayed reaction. The main outcome was the occurrence of an anaphylactic reaction according to criteria specified by the Brighton Collaboration. RESULTS Among the 830 patients with confirmed egg allergy, only 9% required the vaccine to be administered in divided doses. No patient had an anaphylactic reaction. Nine patients had minor allergic symptoms treated with an antihistamine (1 in the 60 minutes after vaccination and 8 in the following 23 hours), and 3 others received salbutamol (1 in the first 60 minutes after vaccination). Further vaccination of more than 3600 other children with reported egg allergy caused no anaphylaxis based on the criteria of the Brighton Collaboration, although 2 patients received epinephrine for symptoms compatible with allergy. CONCLUSION Although anaphylaxis after influenza immunization is a theoretic risk, vaccination of patients with egg allergy with an adjuvanted monovalent pH1N1 influenza vaccine resulted in no cases of anaphylaxis and on that basis appears safe.

Egg-allergic patients can be safely vaccinated against influenza

Background: In Canada, a 7-valent pneumococcal conjugate vaccine (PCV-7) was licensed in 2001, and free vaccination of children <5 years of age was offered in December 2004 in the province of Quebec. Objectives: To describe the frequency of physician claims for otitis media (OM) in relation to PCV-7 coverage during the period from 1996 to 2007. Methods: The monthly frequency of OM claims in the population aged <10 years was obtained from the provincial health insurance board. Time series in different age categories were analyzed using structural models with unobserved components, including seasonality, linear trends, level changes, and outliers. The candidate explanatory variable was PCV-7 uptake rate as measured in the population <5 years of age in the Quebec City area. Results: Free PCV-7 program implementation was followed by a marked increase in uptake and by the end of 2007, >90% of children had received ≥1 dose. In all models, seasonality was a major determinant of OM frequency rates and there were statistically significant downward trends, as well as downward level breaks and outliers. PCV-7 coverage (≥1 dose) was a significant predictor in children 6 months to 2 years of age. The effect was of lesser magnitude and not significant in the group of children aged 2 to 4 years, and absent in the group 5 to 9 years. Since PCV-7 licensure, an estimated 100,000 visits were averted in children <5 years of age, and OM claim frequency reduction attributable to PCV-7 was 13.2% by the end of the study period. Conclusion: PCV-7 implementation was associated with a significant reduction in the frequency of OM in the target population, and there was no indication of herd protection in older children.

Higher Risk of Measles When the First Dose of a 2-Dose Schedule of Measles Vaccine Is Given at 12–14 Months Versus 15 Months of Age

that additional factors are required. Our study also confirmed the association of FLG mutations and early-onset infantile eczema, which is in line with previous work. Our ability to interrogate the role of sensitization in the relationship between FLG mutations and food allergy in a large population-based, age-matched, challenge-proved food allergy cohort is a major and novel strength of this work. There is some potential participation bias among negative control subjects (higher immediate family history of allergic diseases compared with the general population); however, such a bias would be more likely to create a false-negative than a false-positive association. In conclusion, FLG mutations do not increase the risk of food allergy over and above that of food sensitization among 1-year-old infants. These results confirm the biological plausibility that decreased skin barrier function increases the risk of food sensitization in early life, but other as yet undetermined factors are important in the conversion from food sensitization to allergy.

Risk of narcolepsy associated with inactivated adjuvanted (AS03) A/H1N1 (2009) pandemic influenza vaccine in Quebec.

BACKGROUND In 2011, >750 cases of measles were reported in Quebec, Canada, where a routine 2-dose measles immunization schedule, in which measles vaccine is given at 12 and 18 months of age, had been in effect since 1996. Effectiveness of this schedule was assessed during a high school outbreak. METHODS Cases were identified by passive followed by active surveillance. Classical cases met the national surveillance definition; attenuated cases showed clinical signs and high measles-specific immunoglobulin G but did not fulfill all classical criteria. Immunization status was ascertained from written records, and vaccine effectiveness (VE) was calculated as 1 - [(risk of measles in vaccinated individuals)/(risk in unvaccinated individuals)] × 100%. RESULTS Among 1306 students, 110 measles cases were identified; 98 were classical cases, and 12 were attenuated cases. The attack rates among unvaccinated and fully vaccinated students were 82% and 4.8%, respectively. The VE among 2-dose recipients was 95.5% against classical and 94.2% against all (classical + attenuated) measles. Among 2-dose recipients, attack rates with first immunization at 12 and ≥15 months of age were 5.8% and 2.0%, respectively, with corresponding VE values of 93.0% and 97.5%. The risk of measles in 2-dose recipients was significantly (3-4-fold) higher when vaccine was first administered at 12 months of age, compared with ≥15 months of age (P = .04). CONCLUSIONS Despite compliance with the recommended 2-dose measles immunization schedule, 6% of high school students were susceptible during this outbreak. Residual susceptibility was 2-4-fold higher among 2-dose recipients who had received the first dose of vaccine prior to 15 months of age. If confirmed in other settings, these results suggest that administration of the first dose of measles vaccine before 15 months of age may not be optimal for measles elimination efforts.