Table 2.
Numerical odds, risk or prevalence ratios for filovirus disease transmission
| Risk factor | Details | Unadjusted effect size (95% CI) | Adjusted effect size (95% CI) |
|---|---|---|---|
| Demographics and personal attributes | |||
| Age | Being > 18 years 24 | PRR* 6.8 | PRR* 3.6 (1.3-10.1) a |
| Being > 30 years old 22 | PPR 1.38 (0.64-2.97) | ||
| Being ≥30 years old 26 | OR 1.32 (0.60-2.92) | ||
| Being ≥34 years old 29 | OR 0.83 (0.35-1.95) | ||
| Being 41–60 years old 27 | OR 2.0 (0.8–4.9) | Not reported b | |
| Being ≥40 years old 26 | OR 0.99 (0.37-2.68) | ||
| Sex | Being female 27 | OR 0.63 (0.28–1.43) | Not reported b |
| Being female 22 | PPR 1.54 (0.7-3.6) | ||
| Being female 24 | PRR* 2.1 | PRR* 1.0 (0.5-2.1) a | |
| Being female 26 | OR 2.46 (1.03 – 5.90) | ||
| Occupation | Working in forest 23 | MOR 1.3 (0.4-6.0) | |
| Fishing 23 | MOR 3.0 (0.04-235) | ||
| Fisherman 29 | OR 3.12 (0.59-16.41) | ||
| Health care worker 23 | MOR 9 . 0 (1 . 6-91 . 2) | ||
| Health care worker 26 | OR 1.52 (0.41-5.64) | ||
| Student 26 | OR 0.81 (0.34-1.94) | ||
| Housewife 26 | OR 1.23 (0.50-3.04) | ||
| Housewife 29 | OR 0.87 (0.24-3.09) | ||
| Farmer 29 | OR 1.27 (0.15 -10.81) | ||
| Trader 29 | OR 0.77 (0.22 -2.75) | ||
| Gold-panner 29 | OR 1.33 (0.56-3.17) | ||
| Setting | Urban or suburban (versus rural) 26 | OR 0.82 (0.23-2.89) | |
| Recent travel | To areas with known cases 27 | OR 1.4 (0.5–3.8) | Not reported b |
| Outside own local area 23 | MOR 3.0 (0.2-41.4) | ||
| Recurring non-intimate contact | |||
| Commerce-related | Frequenting markets 23 | MOR 1.1 (0.3-4.5) | |
| Conversation with case | During incubation period 24 | PRR* 1.5 | PRR* 0.7 (0.2-3.0) a |
| During early illness 24 | PRR* 3.3 | PRR* 0.7 (0.3-2.0) a | |
| During late illness 24 | PRR* 10.6 | PRR* 3.9 (1.2-12.2) a | |
| Washing clothes of a case | (Point of disease onset unclear) 22 | PPR 1.68 (0.78-3.60) | PPR 1.02 (0.47-2.2) d |
| Indirect contact with case | Household or similar contact without direct physical touching 26 | OR 6 . 88 (1 . 35-35 . 1) | |
| Sharing same hut | Without sharing bed/sleeping mat 22 | PPR 2.16 (0.90-5.19) | PPR 2 . 34 (1 . 13-4 . 8)d |
| Entered same room but no physical contact 25 | OR 0.06 (0.00-1.06) | ||
| Slept in same room 11 | OR 1.65 (0.95-2.85) | ||
| Visiting cases | In hospital or their own home, before or after diagnosis 27 | OR 8 . 7 (3 . 0–26 . 3) | Not reported b |
| Visit to ill (with fever and bleeding) friend (in own home) 23 | MOR 10 . 6 (3 . 8-36 . 3) | ||
| Recurring intimate contact | |||
| Shared a meal | During early illness 24 | PRR* 2.5 | PRR* 1.2 (0.5-2.7) a |
| During late illness 24 | PRR* 7.0 | PRR* 2.2 (1.2-4.0) a | |
| With index patient 22 | PPR 1.94 (0.89-4.22) | PPR 1.69 (1.0-2.8) d | |
| Sharing a bed or sleeping mat | During incubation 24 | PRR* 2.9 | PRR* 1.4 (0.8-2.4) a |
| During early illness 24 | PRR* 3.8 | PRR* 1.3 (0.7-2.5) a | |
| During late illness 24 | PRR* 7.4 | PRR* 2.2 (1.2-4.2) a | |
| Point of disease onset unclear 22 | PPR 2.78 (1.15-6.70) | PPR 2 . 93 (1 . 2-7 . 4)d | |
| Direct physical contact – touching | During incubation period 24 | PRR* 2.9 | PRR* 0.8 (0.4-1.8) a |
| During early illness 24 | PRR* 12.5 | ||
| During late illness 24 | PRR* 12.5 | ||
| With person who had fever or bleeding, at work or in the market 23 | MOR 24.0 (3 . 2-1065) | ||
| Contact with body or body fluids of a suspected case 26 | OR 11.0 (2 . 6-46 . 1) | ||
| Touched case 11 | OR 1.45 (0.73-2.87) | ||
| Touching during illness 22 | PPR 3.53 (0.52-24.11) | PPR 1.56 (0.2-13.0) c | |
| Touching but no nursing care 25 | OR 0.40 (0.11-1.45) | ||
| Contact with body fluids | Contact with body fluids 22 | PPR 5.30 (2.14-13.14 ) | PPR 4 . 61 (1 . 7-12 . 3)c |
| Direct contact with individuals potentially infected with MHF or their bodily fluids or direct contact during funeral 26 | OR 12.0 (3 . 6-39 . 6) | ||
| Body fluid contact in early illness 24 | PRR* 6.1 | ||
| Body fluid contact in late illness 24 | PRR* 5.9 | ||
| Likely sexual contact | Being spouse of index case 24 | PRR* 3.8 | PRR* 1.3 (0.7-2.5) a |
| Caring for patient | Nursing a patient 25 | OR 8.9 (3.1-25.4) | |
| Cared for case 11 | OR 0.99 (0.56-1.76) | ||
| Early care at home, not until death 22 | PPR 6 (1 . 3-27 . 1) | P for trend for these 3 < 0.001 | |
| At hospital until death 22 | PPR 8 . 57 (1 . 9-37 . 7) | ||
| In home until death 22 | PPR 13 . 33 (3 . 2-55 . 6) | ||
| Aided patient in childbirth 11 | OR 2.46 (1 . 02-5 . 92) | ||
| Funeral-related activities | |||
| Viewed body | Without touching 24 | PRR* 4.8 | PRR* 1.6 (0.5-4.9) a |
| Attended | Special (pre-funeral) rituals 23 | MOR 0.8 (0.2-3.2) | |
| Funeral itself 23 | MOR 3.0 (1 . 2-7 . 6) | ||
| Funeral itself 11 | OR 0.86 (0.41-1.79) | ||
| Communal meal | As part of funeral event 22 | PPR 2.84 (1.35-5.98) | PPR 1.5 (0.98-2.28) d |
| Touched body | Before or during funeral 22 | PPR 1.95 (0.91-4.17) | PPR 1.84 (0.95-3.55) c |
| Before or during ceremony 24 | PRR* 4.9 | PRR* 2.1 (1.1-4.2) a | |
| Ritual handwashing 22 | PPR 2.25 (1.08-4.72) | PPR 1.16 (0.54-2.49) d | |
| Washing and dressing body 27 | OR 7 . 4 (2 . 9–19 . 3) | OR 3.83 (1.78-8.23) b | |
| Direct contact with corpse, its body fluids or soiled items 26 | OR 38 . 5 (4 . 2-352 . 1) | ||
| Prepared for burial 23 | MOR 13 . 1 (1 . 4-631) | ||
| Prepared cadaver | OR 1.07 (0.63-1.82) | ||
| Previous use of health services (nocosomial indicators) | |||
| Taking regular medication | Kikwit outbreak 1995 23 | MOR 2.0 (0.5-9.8) | |
| Admitted previously to hospital for something else | Before outbreak was recognized, Kikwit outbreak, 1995 23 | MOR 9 . 9 (3 . 1-41.0) | |
| Received injection | Before outbreak was recognized, Kikwit, 1995 23 | MOR 30.0 (4 . 3-1302) | |
| Admission or visit to hospital | For any reason 27 | OR 8 . 7 (3 . 0-26 . 3) | Not reported b |
| Number of types of direct contact (touching ill patient, touching dead body, touching body fluid) | No direct contact 22 | PPR 1.0 | P for trend for these 4 < 0.001 |
| One type of contact 22 | PPR 0.18 (0.01-2.45) | ||
| Two types of contact 22 | PPR 1.94 (0.30-12.44) | ||
| Three types of contact 22 | PPR 4.00 (0.64-25.02) | ||
PRR*, prevalence rate ratio; PPR, prevalence proportion ratio; MOR, matched odds ratio; OR, odds ratio. Bold text indicates a 95% confidence interval that is entirely above 1.0. Otherwise, where figures are missing, figures were not provided or not possible to calculate.
a Adjusted for direct physical contact during illness and contacts with body fluids.
b Dropped from multivariate logistic regression by authors due to lack of significance at P < 0.05.
c Using multivariate log-binomial regression models, factors included touching patient during illness, touching dead body and contact with patient fluids.
d Using multivariate log-binomial regression models, factors included shared meals, washed clothes, slept in same hut or mat, ritual handwashing during funeral and communal meal during funeral, and also controlled for intensity of contacts (two or more indirect contacts versus less).