Volume 14, Number 1—January 2008
Dispatch
Adamantane-Resistant Influenza Infection During the 2004–05 Season
Table 1
Clinical features of patients with adamantane-resistant or -susceptible influenza A, 2004–05 season
| Clinical feature | Adamantane-resistant influenza, n = 72 | Adamantane-susceptible influenza, n = 80 | p value* |
|---|---|---|---|
| Median duration of illness† | 12 days | 13 days | 0.96 |
| No. (%) hospitalized | 7 (10) | 9 (12) | 0.74 |
| No. (%) fully recovered at time of follow-up interview | 63 (88) | 65 (81) | 0.29 |
| Median no. symptoms‡ | 9 | 8 | 0.59 |
| No. (%) receiving antiviral treatment§ | 15 (21) | 31 (39) | 0.02 |
| Median time from symptom onset to healthcare encounter | 3 days | 2 days | 0.34 |
| Single symptom, no. (%)‡ | |||
| Fever | 34 (69) | 52 (74) | 0.56 |
| Cough | 48 (98) | 68 (97) | 0.78 |
| Headache | 41 (84) | 53 (76) | 0.29 |
| Muscle pain | 37 (76) | 45 (64) | 0.57 |
| Nasal congestion | 40 (82) | 54 (77) | 0.55 |
| Hoarseness | 35 (71) | 55 (79) | 0.37 |
| Fatigue | 45 (92) | 66 (94) | 0.72 |
| Ear pain | 16 (33) | 24 (34) | 0.85 |
| Sore throat | 29 (59) | 40 (57) | 0.82 |
| Difficulty breathing | 28 (57) | 35 (50) | 0.44 |
| Wheezing | 25 (51) | 42 (60) | 0.33 |
| Nausea | 16 (33) | 27 (39) | 0.51 |
| Vomiting | 10 (20) | 9 (13) | 0.27 |
| Diarrhea | 12 (24) | 15 (21) | 0.70 |
| Rash | 2 (4) | 2 (3) | 1.00 |
| Combined symptoms, no. (%)‡ | |||
| Fever and cough | 33 (67) | 52 (74) | 0.41 |
| Fever and headache | 31 (63) | 43 (61) | 0.84 |
| Fever, cough, and headache | 30 (61) | 43 (61) | 0.98 |
| Fever and muscle pain | 29 (59) | 39 (56) | 0.71 |
| Fever, headache, and muscle pain | 27 (55) | 35 (50) | 0.58 |
| Fever, headache, muscle pain, and cough | 26 (53) | 35 (50) | 0.74 |
*χ2, Fisher exact, or Wilcoxon rank sum tests performed as appropriate.
†Based on 128 influenza A patients who had recovered fully at the time of follow-up interview.
‡Children 6 to 23 months of age were excluded from the numerator and denominator for symptoms.
§One patient had received antiviral treatment prior to influenza culture.


