Volume 16, Number 4—April 2010
Research
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 Emery, Adam L. Cohen, Manoj Menon, Alicia M. Fry, Fatimah Dawood, Vincent P. Fonseca, and Sonja J. Olsen
, 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 Emery, Adam L. Cohen, Manoj Menon, Alicia M. Fry, Fatimah Dawood, Vincent P. Fonseca, and Sonja J. OlsenTable 1
Index and secondary household case-patients with ARI, ILI, or laboratory-confirmed pandemic (H1N1) 2009, Region 8, Texas, April–May, 2009*
| Household | Index case-patients |
Secondary case-patients |
Serial interval, d† | |||||
|---|---|---|---|---|---|---|---|---|
| Date of onset | Age, y | Case definition | Date of onset | Age, y | Case definition | |||
| A | Apr 18 | 14‡ | A, no subtype | Apr 25 | 21 | Pandemic (H1N1) 2009 | 7 | |
| B | Apr 19 | 5 | Pandemic (H1N1) 2009 | Apr 21 | 9 | Pandemic (H1N1) 2009 | 2 | |
| C | Apr 22 | 18 | Pandemic (H1N1) 2009 | Apr 25 | <1 | Pandemic (H1N1) 2009 | 3 | |
| D | Apr 26 | 1 | Pandemic (H1N1) 2009 | May 4 | 27 | Pandemic (H1N1) 2009 | 2 | |
| E | Apr 26 | 16 | Pandemic (H1N1) 2009 | Apr 27 | 51 | Pandemic (H1N1) 2009 | 1 | |
| Apr 27 | 8 | ILI | 1 | |||||
| F | Apr 27 | <1 | Pandemic (H1N1) 2009 | Apr 29 | 22 | Pandemic (H1N1) 2009 | 2 | |
| May 6 | 47 | ARI | 9 | |||||
| G | Apr 27 | 16 | Pandemic (H1N1) 2009 | May 1 | 16 | Pandemic (H1N1) 2009 | 4 | |
| May 1 | 14 | Pandemic (H1N1) 2009 | 4 | |||||
| H | Apr 29 | 6 | Pandemic (H1N1) 2009 | Apr 3 | <1 | Pandemic (H1N1) 2009 | 1 | |
| I | May 3 | 33 | Pandemic (H1N1) 2009 | May 7 | 15 | Pandemic (H1N1) 2009 | 4 | |
| May 8 |
14 |
Pandemic (H1N1) 2009 |
5 |
|||||
| Subtotal no. case-patients | 9 | 13 | 3 (1–9) | |||||
| J | Apr 20 | 17 | Pandemic (H1N1) 2009 | Apr 26 | 14 | ARI | 6 | |
| K | Apr 24 | 71 | Pandemic (H1N1) 2009 | Apr 27 | 65 | ILI | 3 | |
| L | Apr 25 | 16 | Pandemic (H1N1) 2009 | Apr 27 | 16 | ILI | 2 | |
| M | Apr 25 | 12 | Pandemic (H1N1) 2009 | Apr 28 | 30 | ARI | 3 | |
| Apr 28 | 33 | ARI | 3 | |||||
| Apr 30 | 6 | ARI | 5 | |||||
| N | Apr 26 | 30 | Pandemic (H1N1) 2009 | May 1 | 28 | ARI | 5 | |
| O | Apr 27 | 33 | Pandemic (H1N1) 2009 | May 5 | 53 | ARI | 8 | |
| P | Apr 28 | 25 | Pandemic (H1N1) 2009 | May 4 | 14 | ILI | 6 | |
| Q | Apr 29 | 1 | Pandemic (H1N1) 2009 | May 1 | 21 | ILI | 2 | |
| May 2 | 2 | ILI | 3 | |||||
| R | Apr 29 | 8 | Pandemic (H1N1) 2009 | May 3 | 44 | ARI | 4 | |
| S |
May 1 |
6 |
Pandemic (H1N1) 2009 |
May 3 |
45 |
ILI |
2 |
|
| Subtotal no. case-patients | 10 | 13 | 3 (1–8) | |||||
| T | Apr 17 | 11 | ILI | Apr 21 | 18 | Pandemic (H1N1) 2009 | 4 | |
| U | Apr 18 | 48 | ILI | Apr 26 | 10 | Pandemic (H1N1) 2009 | 8 | |
| V | Apr 23 | 53 | ILI | Apr 26 | 42 | Pandemic (H1N1) 2009 | 3 | |
| W | Apr 24 | 5 | ILI | Apr 29 | <1 | Pandemic (H1N1) 2009 | 5 | |
| X | Apr 28 | 26 | ILI | May 2 | 7 | Pandemic (H1N1) 2009 | 4 | |
| May 3 |
4 |
ILI |
5 |
|||||
| Subtotal no. case-patients |
5 |
6 |
4.5 (3–8) |
|||||
| Total no. case-patients | 24 | 32 | 4 (1–9) | |||||
*ARI, acute respiratory infection; ILI, influenza-like illness (fever measured or subjective and cough or sore throat).
†Median (range) number of days between symptom onset of the index and secondary case-patients.
‡The influenza virus from this person could not be subtyped, possibly because of the quality of the sample or the length of time from symptom onset to sample collection. We considered this case-patient to have been infected with pandemic (H1N1) 2009.
