Emerging Infectious Diseases (Apr 2010)

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

  • Oliver W. Morgan,
  • 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,
  • Sonja J. Olsen

DOI
https://doi.org/10.3201/eid1604.091658
Journal volume & issue
Vol. 16, no. 4
pp. 631 – 637

Abstract

Read online

To assess household transmission of pandemic (H1N1) 2009 in San Antonio, Texas, USA, during April 15–May 8, 2009, we investigated 77 households. The index case-patient was defined as the household member with the earliest onset date of symptoms of acute respiratory infection (ARI), influenza-like illness (ILI), or laboratory-confirmed pandemic (H1N1) 2009. Median interval between illness onset in index and secondary case-patients was 4 days (range 1–9 days); the index case-patient was likely to be 50 years of age (4%–12%). Early in the outbreak, household transmission primarily occurred from children to other household members and was lower than the transmission rate for seasonal influenza.

Keywords