Table 4.
Sources of Brucella exposure among laboratory workers and subsequent laboratory-acquired brucellosis
| Source | No. exposed (n = 167) | No. with LAB (n = 71) | Attack rate (%) |
|---|---|---|---|
| Route of exposure | |||
| Aerosol | 155 | 59 | 38 |
| Contact/ingestion | 6 | 6 | 100 |
| Unknown | 6 | 6 | |
| Exposure method | |||
| Routine | 147 | 52 | 35 |
| Accidental | 18 | 18 | 100 |
| Unknown | 2 | 1 | |
| Exposure | |||
| Culture | 155 | 63 | 41 |
| Clinical specimens | 9 | 5 | 56 |
| Vaccine | 1 | 1 | 100 |
| Unknown | 2 | 2 | |
| Activity | |||
| Open bench | 82 | 46 | 56 |
| Subculture | 56 | 24 | 43 |
| Gram stain | 46 | 20 | 43 |
| Commercial tests | 30 | 5 | 17 |
| Biochemicals | 44 | 18 | 41 |
| Break | 15 | 15 | 100 |
| Catalase | 13 | 3 | 23 |
| Use of BSC | 11 | 9 | 82 |
| Sniff | 9 | 5 | 56 |
| Misread Gram stain | 3 | 3 | 100 |
| Proximity | |||
| Work with agent | 85 | 49 | 58 |
| No work with agent | 75 | 15 | 20 |
| Not in room | 4 | 4 | 100 |
| Unknown | 7 | 7 | |
| Species | |||
| B. melitensis | 135 | 49 | 36 |
| B. abortus | 13 | 13 | 100 |
| B. suis | 9 | 0 | 0 |
| B. canis | 1 | 1 | 100 |
| Marine species | 1 | 1 | 100 |
| Brucella species | 5 | 5 | 100 |
| Unknown | 3 | 2 | |
| Risk class | |||
| High risk | 82 | 36 | 44 |
| No PEP | 49 | 36 | 73 |
| PEP | 33 | 0 | 0 |
| Low risk | 52 | 4 | 8 |
| No riska | 4 | 4 | 100 |
| Unknown | 29 | 27 | |
| PEP | |||
| Yes | 34 | 0 | 0 |
| No | 128 | 66 | 52 |
| Unknown | 5 | 5 |
a
“No risk” refers to workers who do not meet the CDC's high- or low-risk exposure criteria (17).