Volume 18, Number 12—December 2012
Research
Outbreak of Influenza A (H3N2) Variant Virus Infection among Attendees of an Agricultural Fair, Pennsylvania, USA, 2011
, Adena Greenbaum, Maria E. Moll, James Lando, Erin L. Moore, Rahul Ganatra, Matthew Biggerstaff, Eugene Lam, Erica E. Smith, Aaron D. Storms, Jeffrey R. Miller, Virginia Dato, Kumar Nalluswami, Atmaram Nambiar, Sharon A. Silvestri, James R. Lute, Stephen Ostroff, Kathy Hancock, Alicia Branch, Susan C. Trock, Alexander Klimov, Bo Shu, Lynnette Brammer, Scott Epperson, Lyn Finelli, and Michael A. Jhung
Table 1
Characteristics of case-patients with suspected, probable, or confirmed A(H3N2)v virus infection after attending agricultural Fair A, Pennsylvania, 2011*
| Characteristic |
A(H3N2)v case status
|
||
|---|---|---|---|
| Suspected, n = 82 | Probable and confirmed, n = 7 | All cases, N = 89 | |
| Sex | |||
|
M |
37 (45) | 2 (29) | 39 (44) |
|
F |
45 (55) | 5 (71) | 50 (56) |
| Age, y | |||
|
Median (range) |
13 (0.5–60) | 3 (1–9) | 12 (0.5–60) |
|
<4 |
9 (11) | 5 (71) | 14 (16) |
|
4–13 |
34 (41) | 2 (29) | 36 (40) |
|
14–18 |
12 (15) | 0 | 12 (13) |
|
19–49 |
17 (21) | 0 | 17 (19) |
|
>50 |
10 (12) | 0 | 10 (11) |
| Underlying medical condition† | 17/80 (21) | 1/7 (14) | 18/87 (21) |
| Reported any prior influenza vaccination | 49/73 (67) | 5/5 (100) | 54/78 (69) |
| No. days spent at fair, median (range) | 7 (1–10) | 4 (1–8) | 6 (1–10) |
| Family owns swine | 27/82 (33) | 2/7 (29) | 29/89 (33) |
| Reported swine exposure‡ | 73/80 (91) | 7/7 (100) | 80/87 (92) |
| Signs/symptoms | |||
|
Fever/feverish |
74/82 (90) | 7/7 (100) | 81/89 (91) |
|
Cough |
58/80 (73) | 6/7 (86) | 64/87 (74) |
|
Runny nose |
38/77 (49) | 3/7 (43) | 41/84 (49) |
|
Headache |
58/72 (81) | 0/4 | 58/76 (76) |
|
Muscle aches |
40/69 (58) | 0/5 | 40/74 (54) |
|
Sore throat |
44/72 (61) | 1/5 (20) | 45/77 (58) |
|
Shortness of breath |
16/69 (23) | 1/7 (14) | 17/76 (22) |
|
Vomiting |
21/82 (26) | 2/7 (29) | 23/89 (26) |
|
Diarrhea |
27/82 (33) | 2/7 (29) | 29/89 (33) |
|
Fatigue |
55/57 (96) | 3/3 (100) | 58/60 (97) |
|
Joint pain |
18/53 (34) | 0/1 | 18/54 (33) |
| Illness duration, median days (range) | 7 (2–18)§ | 6 (3–9)¶ | 6 (2–18)** |
| Received medical attention | 28/81 (35) | 3/7 (43) | 31/88 (35) |
| Hospitalized | 0/81 | 1/7 (14) | 1/88 (1) |
*Data are no. (%) with characteristic or no. with characteristic/total no. case-patients with data (%) unless otherwise specified. A(H3N2)v, influenza A (H3N2) variant virus.
†Includes asthma, chronic lung disease, heart disease, diabetes or metabolic disease, kidney disease, liver disease, immunosuppressive condition, cancer, and neurologic or neurodevelopmental disorders.
‡Includes visiting swine exhibit, walking near swine exhibit, or touching swine at fair.
§Of 60 persons with known dates of illness onset and recovery.
¶Of 5 persons with known date of recovery.
**Of 65 persons with known date of recovery.