BACKGROUND: Influenza transmission in households is a subject of renewed interest, as the vaccination of children is currently under debate and antiviral treatments have been approved for prophylactic use. AIMS: To quantify the risk factors of influenza transmission in households. DESIGN OF STUDY: A prospective study conducted during the 1999 to 2000 winter season in France. SETTING: Nine hundred and forty-six households where a member, the index patient, had visited their general practitioner (GP) because of an influenza-like illness were enrolled in the study. Five hundred and ten of the index patients tested positive for influenza A (subtype H3N2). A standardised daily questionnaire allowed for identification of secondary cases of influenza among their household contacts, who were followed-up for 15 days. Of the 395 (77%) households that completed the questionnaire, we selected 279 where no additional cases had occurred on the day of the index patient's visit to the GP. METHODS: Secondary cases of influenza were those household contacts who had developed clinical influenza within 5 days of the disease onset in the index patient. Hazard ratios for individual clinical and demographic characteristics of the contact and their index patient were derived from a Cox regression model. RESULTS: Overall in the 279 households, 131 (24.1%) secondary cases occurred among the 543 household contacts. There was an increased risk of influenza transmission in preschool contacts (hazard ratio [HR] = 1.85, 95% confidence interval [CI] = 1.09 to 3.26) as compared with school-age and adult contacts. There was also an increased risk in contacts exposed to preschool index patients (HR = 1.93, 95% CI = 1.09 to 3.42) and school-age index patients (HR = 1.68, 95% CI = 1.07 to 2.65), compared with those exposed to adult index cases. No other factor was associated with transmission of the disease. CONCLUSION: Our results support the major role of children in the dissemination of influenza in households. Vaccination of children or prophylaxis with neuraminidase inhibitors would prevent, respectively, 32-38% and 21-41% of secondary cases caused by exposure to a sick child in the household.
BACKGROUND: Influenza transmission in households is a subject of renewed interest, as the vaccination of children is currently under debate and antiviral treatments have been approved for prophylactic use. AIMS: To quantify the risk factors of influenza transmission in households. DESIGN OF STUDY: A prospective study conducted during the 1999 to 2000 winter season in France. SETTING: Nine hundred and forty-six households where a member, the index patient, had visited their general practitioner (GP) because of an influenza-like illness were enrolled in the study. Five hundred and ten of the index patients tested positive for influenza A (subtype H3N2). A standardised daily questionnaire allowed for identification of secondary cases of influenza among their household contacts, who were followed-up for 15 days. Of the 395 (77%) households that completed the questionnaire, we selected 279 where no additional cases had occurred on the day of the index patient's visit to the GP. METHODS: Secondary cases of influenza were those household contacts who had developed clinical influenza within 5 days of the disease onset in the index patient. Hazard ratios for individual clinical and demographic characteristics of the contact and their index patient were derived from a Cox regression model. RESULTS: Overall in the 279 households, 131 (24.1%) secondary cases occurred among the 543 household contacts. There was an increased risk of influenza transmission in preschool contacts (hazard ratio [HR] = 1.85, 95% confidence interval [CI] = 1.09 to 3.26) as compared with school-age and adult contacts. There was also an increased risk in contacts exposed to preschool index patients (HR = 1.93, 95% CI = 1.09 to 3.42) and school-age index patients (HR = 1.68, 95% CI = 1.07 to 2.65), compared with those exposed to adult index cases. No other factor was associated with transmission of the disease. CONCLUSION: Our results support the major role of children in the dissemination of influenza in households. Vaccination of children or prophylaxis with neuraminidase inhibitors would prevent, respectively, 32-38% and 21-41% of secondary cases caused by exposure to a sick child in the household.
Authors: R Welliver; A S Monto; O Carewicz; E Schatteman; M Hassman; J Hedrick; H C Jackson; L Huson; P Ward; J S Oxford Journal: JAMA Date: 2001-02-14 Impact factor: 56.272
Authors: Arnold S Monto; Michael E Pichichero; Steve J Blanckenberg; Olli Ruuskanen; Chris Cooper; Douglas M Fleming; Caron Kerr Journal: J Infect Dis Date: 2002-11-06 Impact factor: 5.226
Authors: Steven A Cohen; Saifuddin Ahmed; Ann C Klassen; Emily M Agree; Thomas A Louis; Elena N Naumova Journal: Vaccine Date: 2010-05-08 Impact factor: 3.641
Authors: Danuta M Skowronski; Travis S Hottes; Naveed Z Janjua; Dale Purych; Suzana Sabaiduc; Tracy Chan; Gaston De Serres; Jennifer Gardy; Janet E McElhaney; David M Patrick; Martin Petric Journal: CMAJ Date: 2010-10-18 Impact factor: 8.262
Authors: Elaine L Larson; Yu-hui Ferng; Jennifer Wong-McLoughlin; Shuang Wang; Michael Haber; Stephen S Morse Journal: Public Health Rep Date: 2010 Mar-Apr Impact factor: 2.792
Authors: Joshua M Wong; Leonard Cosmas; Dhillon Nyachieo; John M Williamson; Beatrice Olack; George Okoth; Henry Njuguna; Daniel R Feikin; Heather Burke; Joel M Montgomery; Robert F Breiman Journal: J Infect Dis Date: 2015-02-25 Impact factor: 5.226
Authors: T H Koep; S Jenkins; M E M Hammerlund; C Clemens; E Fracica; S C Ekker; F T Enders; W C Huskins; C Pierret Journal: J Community Med Health Educ Date: 2016-06-27