Volume 22, Number 1—January 2016
Research
Risk Factors for Primary Middle East Respiratory Syndrome Coronavirus Illness in Humans, Saudi Arabia, 2014
Table 2
Animal-related exposures, underlying health conditions, current tobacco use, and siwak use for Middle East respiratory syndrome coronavirus case-patients compared with matched controls. Saudi Arabia, March 16–November 13, 2014
| Variable | No. (%) with exposure* |
Odds ratio (95% CI) | p value | |
|---|---|---|---|---|
| Case-patients, n = 30 | Controls, n = 116 | |||
| Animal-related exposures | ||||
| Household members frequently visit farms with dromedaries†‡ | 12/30 (40) | 14/115 (12) | 7.06 (2.23–26.46) | <0.001 |
| Household members visited a farm with dromedaries during exposure period‡ | 9/30 (30) | 14/115 (12) | 3.95 (1.23–13.72) | 0.018 |
| Household members had direct contact with dromedaries during exposure period‡§ | 12/30 (40) | 17/114 (15) | 5.03 (1.66–16.88) | 0.004 |
| Spouse | 4/30 (13) | 4/116 (3) | 4.26 (0.86–23.41) | 0.065 |
| Other relatives‡ | 7/30 (23) | 7/116 (6) | 4.59 (1.36–16.27) | 0.012 |
| Domestic help‡ | 5/30 (17) | 3/116 (3) | 15.04 (1.96−369.59) | 0.006 |
| Dromedaries kept in/around home during exposure period‡§ | 9/30 (30) | 17/115 (15) | 3.34 (1.04–10.98) | 0.047 |
| Goats kept in/around home during exposure period‡§ | 1/30 (3) | 22/115 (19) | 0.08 (0.003–0.58) | 0.011 |
| Horses kept in/around home during exposure period§ | 1/29 (3) | 0/115 (0) | 4.00 (0.44–∞) | 0.200 |
| Bats in/around house during exposure period§ | 3/28 (11) | 11/112 (10) | 1.60 (0.24–9.23) | 0.646 |
| Sheep kept in/around home during exposure period§ | 10/30 (33) | 22/115 (19) | 3.34 (0.97–12.19) | 0.057 |
| Sheep present at a slaughterhouse visited during exposure period‡§ | 1/30 (3) | 18/116 (16) | 0.15 (<0.001–0.56) | 0.040 |
| Visited farm where livestock were kept during exposure period§ | 10/29 (34) | 32/116 (28) | 1.67 (0.52–5.42) | 0.393 |
| Dromedary present on farm‡ | 9/10 (90) | 17/32 (53) | 11.57 (2.67–∞) | 0.013 |
| Milked dromedaries while on farm‡ | 5/10 (50) | 7/31 (23) | 10.36 (2.47–∞) | 0.013 |
| Visited other livestock venue (i.e., not farm, market, slaughterhouse, racetrack, or stable) during exposure period‡§ | 7/29 (24) | 12/111 (11) | 3.33 (1.001–11.05) | 0.040 |
| Direct physical contact with dromedary during last 6 mo‡ | 11/30 (37) | 15/116 (13) | 7.67 (2.10–36.08) | 0.001 |
| Any direct contact with a dromedary during exposure period‡§¶ | 10/30 (33) | 17/116 (15) | 3.73 (1.24–11.80) | 0.020 |
| Any direct contact with a goat during exposure period§ | 4/30 (13) | 22/116 (19) | 0.64 (0.17–2.02) | 0.584 |
| Any direct contact with a§ sheep during exposure period§¶ | 10/30 (33) | 38/116 (33) | 1.03 (0.37–2.77) | 1.000 |
| Any direct contact with a horse during exposure period§¶ | 1/30 (3) | 0/116 (0) | 4.00 (0.44–∞) | 0.200 |
| Any direct contact with cattle during exposure period§¶ |
4/30 (13) |
4/116 (3) |
6.00 (1.02–48.44) |
0.043 |
| Underlying health conditions and behaviors | ||||
| Diabetes‡ | 16/29 (55) | 32/116 (28) | 3.72 (1.45–10.25) | 0.005 |
| Emphysema, chronic bronchitis, or other chronic lung disease‡ | 4/30 (13) | 1/113 (1) | 17.68 (4.22-∞) | 0.003 |
| Heart disease‡ | 11/30 (37) | 14/114 (12) | 5.11 (1.81–15.46) | 0.002 |
| Current smoker‡ | 11/30 (37) | 22/116 (19) | 3.14 (1.10–9.24) | 0.030 |
| Any underlying condition‡# | 21/30 (70) | 49/116 (42) | 5.11 (1.70–18.67) | 0.004 |
| Any underlying condition, including current smoking‡ | 27/30 (90) | 64/116 (55) | 7.55 (2.32–33.45) | <0.001 |
| Using siwak during exposure period‡§ | 7/28 (25) | 56/114 (49) | 0.24 (0.06–0.77) | 0.023 |
*Denominators vary on the basis of completeness of responses or reflect subsets.
†Dromedaries, dromedary camels.
‡Statistically significant (p<0.05).
§The exposure period of cases is defined as the 14 days before the date of the first symptom onset. For controls, the exposure period is the same as for the case to which they are matched.
¶Direct animal contact includes any of the following specific exposures: physical contact with animals or animal products (i.e., carcasses, body fluids, secretions, urine, excrement, or raw meat) in any setting (i.e., farm, livestock market, slaughterhouse, racetrack or stable, or other animal-related venues) or engaging in certain animal-related activities (i.e., feeding animals, cleaning their housing, slaughtering them, assisting with their birth, milking them, kissing or hugging them, or other related tasks).
#Diabetes, asthma, emphysema, chronic bronchitis, other chronic lung disease, kidney failure, chronic liver disease, heart disease, history of cancer treatment, blood disorder.