Volume 17, Number 12—December 2011
Research
A Pilot Study of Host Genetic Variants Associated with Influenza-associated Deaths among Children and Young Adults1
, Amy M. Denison, Nicole F. Dowling, Heather A. Jost, Marta L. Gwinn, Lindy Liu, Sherif R. Zaki, and David K. Shay
Table 1
Characteristics of and course of illness for in children and young adults who died of influenza, reported to the Centers for Disease Control and Prevention during influenza seasons 1998–99 through 2007–08, United States*
| Characteristic |
Genotyping status
|
All, n = 442 | |
|---|---|---|---|
| Genotyped, n = 105 | Not genotyped, n = 337 | ||
| Patient demographics | |||
| Median age, y (range)† | 6.0 (0.1–40.0) | 4.0 (0.0–17.3) | 4.3 (0.0–40.0) |
| Female sex | 55 (52) | 158 (47) | 213 (48) |
| Race | |||
| White | 64 (61) | 208 (62) | 272 (62) |
| Black | 18 (17) | 62 (18) | 80 (18) |
| Asian | 7 (7) | 17 (5) | 24 (5) |
| Other | 3 (3) | 9 (3) | 12 (3) |
|
Unknown/missing
|
13 (12)
|
41 (12)
|
54 (12)
|
| Influenza season | |||
| 1998–99 | 1 (1) | 0 | 1 (<1) |
| 1999–00 | 0 | 0 | 0 |
| 2000–01 | 1 (1) | 0 | 1 (<1) |
| 2001–02 | 2 (2) | 0 | 2 (<1) |
| 2002–03 | 10 (10) | 0 | 10 (2) |
| 2003–04 | 33 (31) | 121 (36) | 154 (35) |
| 2004–05 | 7 (7) | 44 (13) | 51 (12) |
| 2005–06 | 6 (6) | 42 (12) | 48 (11) |
| 2006–07 | 22 (21) | 60 (18) | 82 (19) |
|
2007–08
|
23 (22)
|
70 (21)
|
93 (21)
|
| Influenza type | |||
| A | 81 (77) | 233 (69) | 314 (71) |
| B | 24 (23) | 65 (19) | 89 (20) |
| A/B not distinguished | 0 | 36 (11) | 36 (8) |
|
Unknown/missing
|
0
|
3 (<1)
|
3 (<1)
|
| Preexisting medical condition‡ | 29 (28) | 205 (61) | 234 (53) |
| Vaccinated season of death§ | 7 (7) | 54 (16) | 61 (14) |
| Sudden death† | 33 (31) | 74 (22) | 107 (24) |
|
Length of illness, d, median (range)‡
|
3.0 (0–15)
|
5.0 (0–194)
|
5.0 (0–194)
|
| Location of death‡ | |||
| ICU/inpatient | 28 (27) | 216 (64) | 244 (55) |
| Emergency department | 25 (24) | 48 (14) | 73 (17) |
| Outside hospital | 36 (34) | 73 (22) | 109 (25) |
|
Unknown/missing
|
16 (15)
|
0
|
16 (4)
|
| Mechanical ventilation† | 41 (39) | 216 (64) | 257 (58) |
|
ICU admission‡
|
28 (27)
|
165 (49)
|
193 (44)
|
| Invasive bacterial co-infection | 22 (21) | 79 (23) | 101 (23) |
| Invasive MRSA co-infection | 8 (8) | 24 (7) | 32 (7) |
| Pneumonia evident on chest radiograph† | 23 (22) | 154 (46) | 177 (40) |
*Values are no. (%) patients except as indicated. A χ2 test of difference in proportion was used to test differences in proportion between genotyped and ungenotyped cases except for patient age, season, and length of illness, for which the Kruskal-Wallis nonparametric test of difference was used. A total of 442 possible or confirmed influenza-related deaths among children (<18 years old) and young adults (18–40 years old) were reported to the Centers for Disease Control and Prevention (CDC) from 1998–99 through 2007–08. Of these, 105 case-patients had laboratory-confirmed influenza infection and sufficient tissue specimen available at CDC for genotyping. ICU, intensive care unit; MRSA, methicillin-resistant Staphylococcus aureus.
†p<0.05.
‡p<0.001.
§p<0.01.
1Portions of this study were presented at the Options for the Control of Influenza VII meeting, September 3–7, 2010, Hong Kong.