TABLE 1.
Clinical outcome in 19 volunteers exposed to C. parvum oocysts 1 year aparta
| Clinical outcome | No. of volunteers with outcome after
|
|
|---|---|---|
| First challenge (n = 19) | Second challenge (n = 19) | |
| Presumed infection | 15 | 16 |
| Diarrhea | 11 | 11 |
| Oocysts detected by DFA | 9 | 2b |
| Oocysts not detected by DFA | 2 | 9 |
| Enteric symptoms, oocysts detected by DFA | 2 | 1 |
| Enteric symptoms, oocysts not detected by DFA | 0 | 4 |
| Asymptomatic, oocysts detected by DFA | 2 | 0 |
| No infection | 4 | 3 |
| Asymptomatic, oocysts not detected by DFA | 4 | 3 |
a
The initial challenge was conducted with 30 to 106 oocysts. Volunteers were rechallenged with 500 oocysts. Clinical outcomes are defined in Materials and Methods.
b
P < 0.01 compared to first challenge.