Table 1.
Characteristics of the study population according to categories of cumulative parasite density.
| All participants | Categories of cumulative parasite density |
|||
|---|---|---|---|---|
| Low | Medium | High | ||
| N | 54 | 19 | 17 | 18 |
| Time pointa (N) | ||||
| -C-1 | 45 | 15 | 14 | 16 |
| -C+30 | 45 | 17 | 14 | 14 |
| -C+115 | 32 | 8 | 11 | 13 |
| Cumulative parasite densityb median (IQR) | 8.3 (7.0–9.8) | 6.2 (4.6–7.4) | 8.7 (8.2–9.2) | 10.0 (9.8–10.7) |
| Peak parasite densityc median (IQR) | 6.9 (2.0–31.6) | 1.0 (0.3–2.4) | 7.4 (5.1–19.1) | 42.6 (22.7–75.4) |
| Day of peak parasite density median (IQR) | 10.4 (7.0–12.3) | 7.0 (7.0–9.3) | 9.6 (7.0–11.5) | 12.2 (10.6–13.5) |
Categories of cumulative parasite density are based on tertiles of cumulative parasite density. IQR, interquartile range. aCitrate plasma samples for antibody detection were selected at three time points: 1 day pre-challenge (C-1), 21 or 35 days after challenge (median 30 days; C+30) and 64, 140, or 213 days after challenge (median 115 days; C+115). All available samples were analyzed. bCumulative parasite density is expressed as the log-transformed area under the curve for parasites/μl versus time in days until the day of treatment. One participant was not treated until day 36, however, this participant did not have a sample available at C+30 for antibody detection thus their total cumulative parasite density was used for categorization in this table. cPeak parasite density is the maximum number of parasites/μl during the infection until the day of treatment.