Table 2. Laboratory-confirmed influenza infection among SARI patients aged <5 years, by demographic and clinical characteristics, at 9 sites in Kenya, July 2007–June 2013.
| Total (N = 22,341) | Influenza positive patients (N = 2,021) | Influenza negative patients (N = 20,320) | Crude OR (95% CI) | p-Value | Adjusteda OR (95% CI) | p-Value | |
| n(%)¥ | n(%)¥ | ||||||
| Sex | |||||||
| Male | 12,644 | 1170(9.3) | 11474(90.7) | Ref | |||
| Female | 9,697 | 851(8.8) | 8846(91.2) | 0.9(0.9–1.0) | 0.218 | - | - |
| Age Group | |||||||
| 0–23 months | 16,709 | 1395(8.3) | 15314(91.7) | Ref | Ref | ||
| 24–59 months | 5,632 | 626(11.1) | 5006(88.9) | 1.4(1.2–1.5) | <0.001 | 1.3(1.2–1.5) | <0.001 |
| Site | |||||||
| Kenyatta NH | 2,084 | 137(6.6) | 1947(93.4) | 121.6b | <0.001 | - | - |
| Coast PGH | 2,020 | 164(8.1) | 1856(91.9) | ||||
| Nakuru PGH | 1,954 | 214(11.0) | 1740(89.0) | ||||
| Nyeri PGH | 2,890 | 325(11.2) | 2565(88.8) | ||||
| Kakamega PGH | 3,655 | 289(7.9) | 3366(92.1) | ||||
| Embu PGH | 405 | 19(4.7) | 386(95.3) | ||||
| Garissa PGH | 733 | 65(8.9) | 668(91.1) | ||||
| Kakuma | 3,206 | 336(10.5) | 2870(89.5) | ||||
| Dadaab | 2,362 | 284(12.0) | 2078(88.0) | ||||
| Siaya DH | 3,032 | 188(6.2) | 2844(93.8) | ||||
| Nyanza PGH | |||||||
| Length of illness before presenting to the hospital | |||||||
| 0–3 days | 12,996 | 1183(9.1) | 11813(90.9) | Ref | Ref | ||
| 4–7 days | 8,031 | 707(8.8) | 7324(91.2) | 1.0(0.9–1.1) | 0.461 | 1.1(0.9–1.2) | 0.259 |
| >7 days | 1,314 | 131(10.0) | 1183(90.0) | 1.1(0.9–1.3) | 0.300 | 1.3(1.0–1.7) | 0.040 |
| Have children or take care of children in the household (Yes vs. No) | 10,900 | 1024(9.4) | 9876(90.6) | 1.1(1.0–1.2) | 0.122 | 1.1(1.0–1.2) | 0.184 |
| Underlying chronic disease c | |||||||
| Any chronic disease (Yes vs. No) | 1,371 | 125(9.1) | 1246(90.9) | 1.0(0.8–1.2) | 0.644 | - | - |
| Heart disease (Yes vs. No) | 95 | 4(4.2) | 91(95.8) | 0.4(0.2–1.2) | 0.096 | 0.7(0.3–2.1) | 0.571 |
| Chronic shortness of breath (Yes vs. No) | 237 | 17(7.2) | 220(92.8) | 0.7(0.5–1.2) | 0.237 | - | |
| Recurrent chest pain (Yes vs. No) | 458 | 71(15.5) | 387(84.5) | 1.8(1.4–2.3) | <0.001 | 1.3(1.0–1.8) | 0.085 |
| Asthma (Yes vs. No) | 309 | 14(4.5) | 295(95.5) | 0.5(0.3–0.8) | 0.004 | 0.5(0.3–0.9) | 0.023 |
| Chronic cough (Yes vs. No) | 102 | 16(15.7) | 86(84.3) | 1.8(1.1–3.1) | 0.032 | 1.7(0.9–3.1) | 0.084 |
| Active Tb (Yes vs. No) | 53 | 1(1.9) | 52(98.1) | 0.2(0.0–1.4) | 0.096 | 0.3(0.0–2.0) | 0.202 |
| Hospitalized in the last 12 months (Yes vs. No) | 3,576 | 341(9.5) | 3235(90.5) | 1.1(0.9–1.2) | 0.356 | - | |
| Had contact with anyone with a similar illness in the last 3 week (Yes vs. No) | 1,839 | 168(9.1) | 1671(90.9) | 1.0(0.8–1.2) | 0.765 | - | |
| Vaccinated against influenza in the past year (Yes vs. No) | 295 | 22(7.5) | 273(92.5) | 0.9(0.6–1.4) | 0.576 | - | |
| Signs and symptoms within the last 14 days * | |||||||
| Reported or Documented Fever (Yes vs. No) | 18,408 | 1770(9.6) | 16638(90.4) | 1.6(1.4–1.8) | <0.001 | 1.4(1.2–1.8) | <0.001 |
| Weight loss (Yes vs. No) | 5,377 | 399(7.4) | 4978(92.6) | 0.8(0.7–0.8) | <0.001 | 0.8(0.7–0.9) | 0.002 |
| Convulsions (Yes vs. No) | 5,242 | 528(10.1) | 4714(89.9) | 1.2(1.0–1.3) | 0.005 | 1.2(1.0–1.3) | 0.032 |
| Stridor (Yes vs. No) | 4,042 | 400(9.9) | 3642(90.1) | 1.1(1.0–1.3) | 0.027 | 1.0(0.9–1.2) | 0.899 |
| Nasal flaring (Yes vs. No) | 9,482 | 880(9.3) | 8602(90.7) | 1.0(0.9–1.1) | 0.369 | - | |
| Tachypnea (Yes vs. No)c | 6,278 | 561(8.9) | 5717(91.1) | 0.9(0.8–1.0) | 0.194 | 0.9(0.8–1.1) | 0.215 |
| Chest in-drawing | 8,234 | 726(8.8) | 7508(91.2) | 1.0(0.9–1.1) | 0.368 | - | |
| Grunting (Yes vs. No)c | 7,353 | 705(9.6) | 6648(90.4) | 1.1(1.0–1.2) | 0.316 | - | |
| Unable to drink or breastfeed at all | 7,234 | 678(9.4) | 6556(90.6) | 1.1(1.0–1.2) | 0.143 | 1.0(0.9–1.2) | 0.966 |
| Lethargic (Yes vs. No) | 6,370 | 624(9.8) | 5746(90.2) | 1.1(1.0–1.3) | 0.014 | 1.1(0.9–1.3) | 0.263 |
| Loss of consciousness (Yes vs. No) | 1,853 | 218(11.8) | 1635(88.2) | 1.4(1.2–1.6) | <0.001 | 1.0(0.8–1.3) | 0.804 |
| Headache (Yes vs. No) | 769 | 103(13.4) | 666(86.6) | 1.6(1.3–1.9) | <0.001 | 1.2(0.9–1.5) | 0.146 |
| Sore throat (Yes vs. No) | 1,977 | 197(10.0) | 1780(90.0) | 1.1(1.0–1.3) | 0.136 | 1.0(0.8–1.2) | 0.958 |
| Nausea (Yes vs. No) | 4,040 | 419(10.4) | 3621(89.6) | 1.2(1.1–1.3) | 0.002 | 1.0(0.9–1.2) | 0.658 |
| Vomiting (Yes vs. No) | 12,270 | 1131(9.2) | 11139(90.8) | 1.0(1.0–1.1) | 0.324 | - |
a
Adjusted for variables that were significant at p<.2 in the bivariate analysis and data collection site;
b
Pearson chi-square;
c
Data not collected in Siaya DH and Tingwangi;
¥
Row percentages shown.
*Signs such as stridor, nasal flaring, tachypnea, chest in-drawing and grunting were evaluated at the time of patient presentation to the hospital.