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Volume 16, Number 4—April 2010

Household Transmission of Pandemic (H1N1) 2009, San Antonio, Texas, USA, April–May 2009

Oliver W. MorganComments to Author , Sharyn Parks, Trudi Shim, Patricia A. Blevins, Pauline M. Lucas, Roger Sanchez, Nancy Walea, Fleetwood Loustalot, Mark R. Duffy, Matthew J. Shim, Sandra Guerra, Fernando Guerra, Gwen Mills, Jennifer Verani, Bryan Alsip, Stephen Lindstrom, Bo Shu, Shannon L. Emery, Adam L. Cohen, Manoj Menon, Alicia M. Fry, Fatimah Dawood, Vincent P. Fonseca, and Sonja J. Olsen
Author affiliations: Centers for Disease Control and Prevention, Atlanta, Georgia, USA (O.W. Morgan, S. Parks, F. Loustalot, J. Verani, S. Lindstrom, B. Shu, S. Emery, A.L. Cohen, M. Menon, A.M. Fry, F. Dawood, S.J. Olsen); Department of State Health Services, Austin, Texas, USA (S. Parks, T. Shim, N. Walea, S. Guerra, V.P. Fonseca); United States Air Force School of Aerospace Medicine, Brooks City-Base, Texas, USA (P.M. Lucas, M.R. Duffy, M.J. Shim); San Antonio Metropolitan Health District, San Antonio, Texas, USA (P.A. Blevins, R. Sanchez, F. Guerra, B. Alsip); Comal County Health Department, New Braunfels, Texas, USA (G. Mills)

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Table 3

Household secondary attack rates for ARI, ILI, and laboratory-confirmed pandemic (H1N1) 2009, by antiviral medication treatment and prophylaxis, Region 8, Texas, April–May 2009*

Type of contact No. contacts Index case-patient received antiviral treatment (attack rate, %)
Yes No p value†
All contacts of index case-patients 235 22/185 (12) 8/50 (16) 0.64
Contacts who took antiviral prophylaxis 92 12/83 (14) 6/9 (67) 0.003

*ARI, acute respiratory infection; ILI, influenza-like illness (fever measured or subjective and cough or sore throat).
†Fisher exact test comparing the secondary attack rate for any treatment to no antiviral treatment. Data about antiviral medication were missing for 2 index case-patients and 15 contacts.

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