Table 3.
Prevalence of IgM/IgG antibodies to Lassa virus by select self-reported animal, and environmental exposure histories of participants recruited from Abuja and Lagos, Nigeria, 2022a
| Variable | Abuja | Lagos | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Overall | Positive | Prevalence | Unadjusted Prevalence Ratio | (95% CI) | p-value | Overall | Positive | Prevalence | Unadjusted Prevalence Ratio | (95% CI) | p-value | |||||
| N | % | N | % | % | N | % | N | % | % | |||||||
| Wet or dry season | ||||||||||||||||
| Wet | 252 | (67) | 69 | (55) | 27.4 | Referent | — | — | 69 | (27) | 14 | (31) | 20.3 | Referent | — | — |
| Dry | 124 | (33) | 57 | (45) | 46.0 | 1.68 | (1.27, 2.22) | 0.0002 | 183 | (73) | 31 | (69) | 16.9 | 0.83 | (0.47, 1.47) | 0.5329 |
| Works as unskilled laborer | ||||||||||||||||
| Yes | 27 | (7) | 13 | (10) | 48.1 | Referent | — | — | 25 | (10) | 5 | (11) | 20.0 | Referent | — | — |
| No | 349 | (93) | 113 | (90) | 32.4 | 0.67 | (0.44, 1.02) | 0.0639 | 227 | (90) | 40 | (89) | 17.6 | 0.88 | (0.38, 2.03) | 0.7657 |
| Contact with sick animal | ||||||||||||||||
| No | 298 | (79) | 99 | (79) | 33.2 | Referent | — | — | 221 | (88) | 35 | (78) | 15.8 | Referent | — | — |
| Yes | 78 | (21) | 27 | (21) | 34.6 | 1.04 | (0.74, 1.47) | 0.8153 | 31 | (12) | 10 | (22) | 32.3 | 2.04 | (1.12, 3.69) | 0.0189 |
| Place of food preparation | ||||||||||||||||
| Indoor | 198 | (53) | 62 | (49) | 31.3 | Referent | — | — | 173 | (69) | 34 | (76) | 19.7 | Referent | — | — |
| Outdoor | 97 | (26) | 38 | (30) | 39.2 | 1.25 | (0.91, 1.73) | 0.1735 | 39 | (15) | 3 | (7) | 7.70 | 0.39 | (0.13, 1.21) | 0.1032 |
| Indoor and Outdoor | 81 | (22) | 26 | (21) | 32.1 | 1.03 | (0.70, 1.50) | 0.8978 | 40 | (16) | 8 | (18) | 20.0 | 1.02 | (0.51, 2.03) | 0.9603 |
| Cleaning of cooking environment | ||||||||||||||||
| Always | 321 | (85) | 101 | (80) | 31.5 | Referent | — | — | 162 | (64) | 30 | (67) | 18.5 | Referent | — | — |
| Other | 55 | (15) | 25 | (20) | 45.5 | 1.44 | (1.04, 2.01) | 0.0296 | 90 | (36) | 15 | (33) | 16.7 | 0.90 | (0.51, 1.58) | 0.7141 |
| Cleaning of cooking utensils after use | ||||||||||||||||
| Always | 310 | (82) | 97 | (77) | 31.3 | Referent | — | — | 191 | (76) | 35 | (78) | 18.3 | Referent | — | — |
| Other | 66 | (18) | 29 | (23) | 43.9 | 1.40 | (1.02, 1.93) | 0.0367 | 61 | (24) | 10 | (22) | 16.4 | 0.89 | (0.47, 1.70) | 0.7335 |
| Handwashing with soap and water before cooking | ||||||||||||||||
| Always | 156 | (41) | 53 | (42) | 34.0 | Referent | — | — | 82 | (33) | 9 | (20) | 11.0 | Referent | — | — |
| Other | 220 | (59) | 73 | (58) | 33.2 | 0.98 | (0.73, 1.30) | 0.8724 | 170 | (67) | 36 | (80) | 21.2 | 1.93 | (0.98, 3.81) | 0.0586 |
| Washing of fruits and vegetables thoroughly before consumption | ||||||||||||||||
| Always | 284 | (76) | 85 | (67) | 29.9 | Referent | — | — | 204 | (81) | 36 | (80) | 17.6 | Referent | — | — |
| Other | 92 | (24) | 41 | (33) | 44.6 | 1.49 | (1.12, 1.99) | 0.0070 | 48 | (19) | 9 | (20) | 18.8 | 1.06 | (0.55, 2.05) | 0.8570 |
| Food preservation by sun drying by the roadside or other surfaces | ||||||||||||||||
| Yes | 121 | (32) | 33 | (26) | 27.3 | Referent | — | — | 45 | (18) | 5 | (11) | 11.1 | Referent | — | — |
| No | 255 | (68) | 93 | (74) | 36.5 | 1.34 | (0.96, 1.87) | 0.0872 | 207 | (82) | 40 | (89) | 19.3 | 1.74 | (0.73, 4.16) | 0.2136 |
| Food storage in container with cover | ||||||||||||||||
| Yes | 237 | (63) | 73 | (58) | 30.8 | Referent | — | — | 238 | (94) | 40 | (89) | 16.8 | Referent | — | — |
| No | 139 | (37) | 53 | (42) | 38.1 | 1.24 | (0.93, 1.65) | 0.1423 | 14 | (6) | 5 | (11) | 35.7 | 2.12 | (1.00, 4.53) | 0.0511 |
| Food storage in container without cover | ||||||||||||||||
| Yes | 36 | (10) | 18 | (14) | 50.0 | Referent | — | — | 8 | (3) | 1 | (2) | 12.5 | Referent | — | — |
| No | 340 | (90) | 108 | (86) | 31.8 | 0.64 | (0.44, 0.91) | 0.014 | 244 | (97) | 44 | (98) | 18.0 | 1.44 | (0.23, 9.2) | 0.6983 |
| Food storage inside locker | ||||||||||||||||
| Yes | 28 | (7) | 9 | (7) | 32.1 | Referent | — | — | 11 | (4) | 4 | (9) | 36.4 | Referent | — | — |
| No | 348 | (93) | 117 | (93) | 33.6 | 1.05 | (0.6, 1.83) | 0.8746 | 241 | (96) | 41 | (91) | 17.0 | 0.47 | (0.20, 1.07) | 0.0728 |
| Food storage in cellophane bags | ||||||||||||||||
| Yes | 63 | (17) | 19 | (15) | 30.2 | Referent | — | — | 24 | (10) | 6 | (13) | 25.0 | Referent | — | — |
| No | 313 | (83) | 107 | (85) | 34.2 | 1.13 | (0.76, 1.7) | 0.5452 | 228 | (90) | 39 | (87) | 17.1 | 0.68 | (0.32, 1.45) | 0.3211 |
| Food storage in sacs | ||||||||||||||||
| Yes | 206 | (55) | 66 | (52) | 32.0 | Referent | — | — | 34 | (13) | 6 | (13) | 17.6 | Referent | — | — |
| No | 170 | (45) | 60 | (48) | 35.3 | 1.10 | (0.83, 1.46) | 0.5051 | 218 | (87) | 39 | (87) | 17.9 | 1.01 | (0.46, 2.21) | 0.9726 |
| Food storage inside cupboard | ||||||||||||||||
| Yes | 47 | (13) | 19 | (15) | 40.4 | Referent | — | — | 60 | (24) | 10 | (22) | 16.7 | Referent | — | — |
| No | 329 | (88) | 107 | (85) | 32.5 | 0.80 | (0.55, 1.18) | 0.2623 | 192 | (76) | 35 | (78) | 18.2 | 1.09 | (0.58, 2.07) | 0.7838 |
| Food storage by unlisted method | ||||||||||||||||
| Yes | 23 | (6) | 7 | (6) | 30.4 | Referent | — | — | 6 | (2) | 3 | (7) | 50.0 | Referent | — | — |
| No | 353 | (94) | 119 | (94) | 33.7 | 1.11 | (0.59, 2.09) | 0.7523 | 246 | (98) | 42 | (93) | 17.1 | 0.34 | (0.15, 0.80) | 0.0128 |
| Contact with a sick person? | ||||||||||||||||
| No | 181 | (48) | 54 | (43) | 29.8 | Referent | — | — | 150 | (60) | 24 | (53) | 16.0 | Referent | — | — |
| Yes | 195 | (52) | 72 | (57) | 36.9 | 0.81 | (0.61, 1.08) | 0.1484 | 102 | (40) | 21 | (47) | 20.6 | 0.78 | (0.46, 1.32) | 0.3501 |
| Contact with sick person, dead or alive? | ||||||||||||||||
| No | 181 | (48) | 54 | (43) | 29.8 | Referent | — | — | 150 | 59.52 | 24 | 53.33 | 16.0 | Referent | — | — |
| Yes | 195 | (52) | 72 | (57) | 36.9 | 1.24 | (0.93, 1.65) | 0.1484 | 102 | 40.48 | 21 | 46.67 | 20.6 | 1.29 | (0.76, 2.18) | 0.3501 |
aPrevalence of antibodies to Lassa virus by other self-reported animal, and environmental exposure histories of participants can be found in supplemental table 2