Table 6. Late predictors of laboratory-confirmed chikungunya versus all other acute febrile illnesses or laboratory-confirmed dengue for participants of all ages, Acute Febrile Illness Study, May 7, 2012–May 6, 2015, Puerto Rico.
| Predictors | Chikungunya N = 161 |
All Other AFI N = 1,776 |
aRR* (95% CI) | Dengue N = 382 |
aRR* (95% CI) | |||
|---|---|---|---|---|---|---|---|---|
| N | % | N | % | N | % | |||
| Positive Predictors | ||||||||
| Red swollen joints | 76 | 47.2 | 182 | 10.2 | 2.69 (1.89–3.81) | 55 | 14.4 | 1.82 (1.31–2.53) |
| Skin rash | 98 | 60.9 | 475 | 26.7 | 2.40 (1.65–3.50) | - | - | - |
| Pruritic skin | 80 | 49.7 | 290 | 16.3 | 1.69 (1.16–2.46) | 95 | 24.9 | 1.74 (1.25–2.42) |
| Red conjunctiva | 98 | 60.9 | 896 | 50.5 | 1.44 (1.03–2.02) | - | - | - |
| Negative Predictors | ||||||||
| Thrombocytopenia | 7 | 4.3 | 237 | 13.3 | 0.22 (0.11–0.46) | 185 | 48.4 | 0.17 (0.08–0.36) |
| Leukopenia | 69 | 42.9 | - | - | - | 335 | 87.7 | 0.38 (0.27–0.52) |
| Sore throat | 34 | 21.1 | 841 | 47.4 | 0.44 (0.29–0.65) | - | - | - |
| Rhinorrhea | 44 | 27.3 | 986 | 55.5 | 0.52 (0.35–0.75) | - | - | - |
| Sign of poor circulation† | 65 | 40.4 | 835 | 47.0 | 0.64 (0.46–0.89) | - | - | - |
| Nausea | 88 | 54.7 | - | - | - | 277 | 72.5 | 0.65 (0.47–0.91) |
| Cough | 45 | 28.0 | - | - | - | 153 | 40.1 | 0.67 (0.47–0.96) |
* Adjusted relative risk (aRR) based on pooled Poisson regression model.
(-) Indicates no significant predictor between chikungunya and comparator group.
† Signs of poor circulation included report of pale cold skin and/or having cyanosis.