Table 2.
Clinical characteristics of patients enrolled with influenza-like illness (ILI) in southern Sri Lanka, March–November 2013*
| Characteristic | Frequency (%) or median (IQR) | OR (95% CI) | P value | |
|---|---|---|---|---|
| Influenza positive | Influenza negative | |||
| Children < 18 years, n | 78 | 89 | − | − |
| Fever (days) | 2 (1–3) | 2 (1–3) | − | 0.62 |
| Cough (days) | 2 (1–3) | 2 (2–3) | − | 0.39 |
| Rhinitis/congestion | 42 (53.9%) | 59 (66.3%) | 0.59 (0.30–1.16) | 0.10 |
| Sore throat | 36 (46.2%) | 38 (42.7%) | 1.15 (0.60–2.22) | 0.65 |
| Shortness of breath | 19 (24.4%) | 17 (19.1%) | 1.36 (0.61–3.06) | 0.41 |
| Pain with breathing | 13 (16.7%) | 1 (1.1%) | 17.6 (2.49–756.1) | < 0.001 |
| Anorexia | 62 (79.5%) | 61 (68.5%) | 1.78 (0.83–3.88) | 0.11 |
| Vomiting | 24 (30.8%) | 25 (28.1%) | 1.14 (0.55–2.34) | 0.70 |
| Abdominal pain | 9 (11.5%) | 8 (9.0%) | 1.32 (0.43–4.16) | 0.59 |
| Headache | 65 (83.3%) | 57 (64.0%) | 2.81 (1.28–6.38) | 0.005 |
| Fatigue | 68 (87.2%) | 63 (70.8%) | 2.81 (1.19–7.03) | 0.01 |
| Arthralgias | 54 (69.2%) | 41 (46.1%) | 2.63 (1.33–5.24) | 0.003 |
| Myalgias | 54 (69.2%) | 43 (48.3%) | 2.41 (1.22–4.79) | 0.006 |
| Prior antibiotic—yes/unsure | 24 (30.8%) | 21 (23.6%) | 1.44 (0.68–3.03) | 0.30 |
| Clinical diagnosis | ||||
| Upper respiratory illness | 18 (23.1%) | 21 (23.6%) | 0.97 (0.44–2.12) | 0.94 |
| Lower respiratory illness | 10 (12.8%) | 14 (15.7%) | 0.79 (0.29–2.05) | 0.59 |
| Unspecified viral fever | 34 (43.6%) | 40 (44.9%) | 0.095 (0.49–1.83) | 0.86 |
| Antibiotic prescribed | 67 (85.9%) | 75 (84.3%) | 1.14 (0.44–2.97) | 0.77 |
| Additional diagnostic test ordered | 17 (21.8%) | 18 (20.2%) | 1.10 (0.49–2.48) | 0.80 |
| Adults ≥ 18 years, n | 69 | 70 | − | − |
| Fever (days) | 2 (1–3) | 2 (1–3) | − | 0.51 |
| Cough (days) | 2 (1–3) | 2 (2–3) | − | 0.10 |
| Rhinitis/ congestion | 42 (60.9%) | 41 (58.6%) | 1.10 (0.53–2.29) | 0.78 |
| Sore throat | 43 (62.3%) | 37 (52.9%) | 1.48 (0.71–3.07) | 0.26 |
| Shortness of breath | 25 (36.2%) | 21 (30.0%) | 1.33 (0.62–2.87) | 0.44 |
| Pain with breathing | 26 (37.7%) | 13 (18.6%) | 2.65 (1.15–6.28) | 0.01 |
| Anorexia | 60 (87.0%) | 54 (77.1%) | 1.98 (0.75–5.49) | 0.13 |
| Vomiting | 12 (17.4%) | 4 (5.7%) | 3.47 (0.97–15.5) | 0.03 |
| Abdominal pain | 3 (4.4%) | 1 (1.4%) | 3.14 (0.24–167.0) | 0.30 |
| Headache | 60 (87.0%) | 60 (85.7%) | 1.11 (0.38–3.33) | 0.83 |
| Fatigue | 61 (88.4%) | 59 (84.3%) | 1.42 (0.48–4.37) | 0.48 |
| Arthralgias | 66 (95.7%) | 59 (84.3%) | 4.10 (1.01–23.8) | 0.03 |
| Myalgias | 66 (95.7%) | 62 (88.6%) | 2.84 (0.64–17.2) | 0.12 |
| Prior antibiotic–y/unsure | 10 (14.5%) | 13 (18.6%) | 0.74 (0.27–2.01) | 0.52 |
| Clinical diagnosis | ||||
| Upper respiratory illness | 12 (17.4%) | 14 (20.0%) | 0.84 (0.32–2.16) | 0.69 |
| Lower respiratory illness | 10 (14.5%) | 10 (14.3%) | 1.02 (0.35–2.95) | 0.97 |
| Unspecified viral fever | 31 (44.9%) | 36 (51.4%) | 0.77 (0.37–1.58) | 0.44 |
| Antibiotic prescribed | 56 (81.2%) | 51 (72.9%) | 1.60 (0.67–3.91) | 0.25 |
| Additional diagnostic test ordered | 14 (20.3%) | 14 (20.0%) | 1.02 (0.41–2.54) | 0.97 |
CI = confidence intervals; IQR = interquartile range; OR = odds ratio.
*
Characteristics of Influenza-positive and influenza-negative patients were compared. Number (%) and odds ratios (OR) with 95% confidence intervals (CI) and P values are listed for categorical variables, and medians with IQR and P values using the Kruskal–Wallis test are listed for continuous variables. P values listed in bold are significant at < 0.05.