Effects of influenza vaccination of health-care workers on mortality of elderly people in long-term care: a randomised controlled trial.
ABSTRACT Vaccination of health-care workers has been claimed to prevent nosocomial influenza infection of elderly patients in long-term care. Data are, however, limited on this strategy. We aimed to find out whether vaccination of health-care workers lowers mortality and the frequency of virologically proven influenza in such patients.
In a parallel-group study, health-care workers in 20 long-term elderly-care hospitals (range 44-105 patients) were randomly offered or not offered influenza vaccine (cluster randomisation, stratified for policy for vaccination of patients and hospital size). All deaths among patients were recorded over 6 months in the winter of 1996-97. We selected a random sample of 50% of patients for virological surveillance for influenza, with combined nasal and throat swabs taken every 2 weeks during the epidemic period. Swabs were tested by tissue culture and PCR for influenza viruses A and B.
Influenza vaccine uptake in health-care workers was 50.9% in hospitals in which they were routinely offered vaccine, compared with 4.9% in those in which they were not. The uncorrected rate of mortality in patients was 102 (13.6%) of 749 in vaccine hospitals compared with 154 (22.4%) of 688 in no-vaccine hospitals (odds ratio 0.58 [95% CI 0.40-0.84], p=0.014). The two groups did not differ for proportions of patients positive for influenza infection (5.4% and 6.7%, respectively); at necropsy, PCR was positive in none of 17 patients from vaccine hospitals and six (20%) of 30 from no-vaccine hospitals (p=0.055).
Vaccination of health-care workers was associated with a substantial decrease in mortality among patients. However, virological surveillance showed no associated decrease in non-fatal influenza infection in patients.
Infection Control and Hospital Epidemiology 03/2015; 36(3):363-4. DOI:10.1017/ice.2014.55 · 3.94 Impact Factor
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ABSTRACT: Healthcare personnel influenza immunization rates remain sub-optimal. Following multiple studies and expert consultations, the "Successful Influenza Immunization Programs for Healthcare Personnel: A Guide for Program Planners" was produced. This trial assessed the impact of the Guide with facilitation in improving healthcare personnel influenza immunization rates in Canadian healthcare organizations. A sample of 26 healthcare organizations across six Canadian provinces (ON, MB, NS, BC, SK, NL) was randomized to Intervention (n=13) or Control groups (n=13). Baseline influenza immunization rates were obtained for 2008-2009; the study groups were followed over two subsequent influenza seasons. The Intervention group received the Guide, facilitation support through workshops for managers and ongoing support. The Control groups conducted programs as usual. The Groups were compared using their reported influenza healthcare personnel influenza immunization rates and scores from a program assessment questionnaire. Twenty-six organizations agreed to participate. 35% (9/26) of sites were acute care hospitals, 19% (5/26) continuing care, long-term care organizations or nursing homes, and 46% (12/26) were mixed acute care hospitals and long-term care or regional health authorities. The median rate of influenza immunization among healthcare personnel for the Intervention group was 43%, 44%, and 51% at three points in time respectively, and in the Control group: 62%, 57%, and 55% respectively. No significant differences were observed between the groups at the three points in time. However, there was a 7% increase in the median rates between the Baseline Year and Year Two in the Intervention group, and a 6% decrease in the Control group over the same time period, which was statistically significant (0.071 versus -0.058, p < 0.001). This pragmatic randomized trial of the Guide with facilitation of its implementation improved healthcare personnel immunization rates, but these rates continued to be sub-optimal and below rates achievable in programs requiring personnel to be immunized. ClinicalTrials.gov NCT01207518.PLoS ONE 10(3):e0118368. DOI:10.1371/journal.pone.0118368 · 3.53 Impact Factor
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ABSTRACT: The role of peripheral blood mononuclear cells (PBMCs) in HBV intrauterine infection is not fully defined. Particularly the origin of PBMCs in HBV-infected neonates remains to be addressed. We carried out a population-based nested case-control study by enrolling 312 HBsAg-positive mothers and their babies. PBMC HBV DNA as well as serum HBsAg and HBV DNA was tested in cohort entry samples. Totally, 45.5% (142/312) of the newborns were found to be infected with HBV in perinatal transmission. 119 mother-infant pairs were identified to be different in the genetic profile of maternal and fetal PBMCs by AS-PCR and hemi-nested PCR. Among them, 57.1% (68/119) of the maternal PBMCs in index cases were positive for HBV DNA while 83.8% (57/68) of the HBV DNA positive maternal PBMCs passed the placental barrier and entered the fetus. Furthermore, maternal PBMC HBV infection was significantly associated with newborn infants HBV infection. PBMC traffic from mother to fetus resulted in a 9.5-fold increased risk of HBV infection in PBMC HBV DNA positive newborn infants. These data indicate that maternal PBMCs infected with HBV contribute to HBV intrauterine infection of newborn infants via PBMC traffic from mother to fetus.