Volume 22, Number 8—August 2016
Research
Exposure-Specific and Age-Specific Attack Rates for Ebola Virus Disease in Ebola-Affected Households, Sierra Leone
Hilary Bower, Sembia Johnson, Mohamed S. Bangura, Alie Joshua Kamara, Osman Kamara, Saidu H. Mansaray, Daniel Sesay, Cecilia Turay, Francesco Checchi, and Judith R. Glynn
Table 3
Risk factors associated with being the first EVD case in a household, compared with all other household members in households of Ebola Treatment Centre survivors, Kerry Town, Sierra Leone, 2014–2015*
| Risk factor | Total population | No. primary cases | Risk,% | Adjusted RR* (95% CI) | p value† |
|---|---|---|---|---|---|
| Sex | |||||
| M | 400 | 47 | 11.8 | 1.3 (0.93–1.9) | |
| F |
537 |
50 |
9.3 |
1 |
0.1 |
| Age, y‡ | |||||
| <2 | 54 | 3 | 5.6 | 0.57 (0.17–1.9) | |
| 2–4 | 86 | 2 | 2.3 | 0.24 (0.06–1.0) | |
| 5–9 | 131 | 2 | 1.5 | 0.15 (0.04–0.65) | |
| 10–14 | 121 | 3 | 2.5 | 0.26 (0.08–0.86) | |
| 15–19 | 107 | 7 | 6.5 | 0.69 (0.30–1.6) | |
| 20–29 | 179 | 17 | 9.5 | 1 | |
| 30–39 | 114 | 26 | 22.8 | 2.4 (1.4–4.2) | |
| 40–49 | 63 | 15 | 23.8 | 2.5 (1.3–4.7) | |
| >50 |
78 |
20 |
25.6 |
2.6 (1.5–4.7) |
<0.001 |
| Occupation§ | |||||
| Heathcare worker, formal and informal | 21 | 10 | 47.6 | 3.9 (2.0–7.5) | |
| Ebola front-line worker | 11 | 3 | 27.3 | 2.5 (0.86–7.1) | |
| Driver | 23 | 6 | 26.1 | 1.7 (0.67–4.1) | |
| Religious leader/chief/teacher | 12 | 5 | 41.7 | 2.7 (1.1–6.9) | |
| Farmer/fisherman/unskilled | 54 | 12 | 22.2 | 1.7 (0.83–3.3) | |
| Office/business | 47 | 8 | 17.0 | 1.3 (0.62–2.8) | |
| Child/student | 511 | 15 | 2.9 | 0.41 (0.12–1.4) | |
| Trader/tailor/service |
205 |
25 |
12.2 |
1 |
0.01 |
| Position in household | |||||
| Household head | 87 | 32 | 36.8 | 2.3 (1.5–3.8) | |
| Household member | 850 | 65 | 7.6 | 1 | <0.001 |
*EVD, Ebola virus disease; RR, risk ratio. Adjusted for age, sex, and household clustering.
†p values calculated from likelihood ratio test in logistic regression model.
‡Age missing for 4 persons.
§No occupation recorded for 29 persons, including 28 with no individual-level data.
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Page updated: July 15, 2016
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