Table 1.
Comparison of symptomatic and asymptomatic index infection episodes
| Total | Asymptomatic (n=275) | Symptomatic (n=69) | p-value* | |
|---|---|---|---|---|
| Age, no. (%) | 0.003 | |||
| < 5y | 52 (15) | 43 (16) | 9 (13) | |
| 5–15 | 129 (38) | 91 (33) | 38 (55) | |
| > 15y | 162 (47) | 140 (51) | 22 (32) | |
| Sex, no. (%) | 0.3 | |||
| Female | 194 (56) | 159 (58) | 35 (51) | |
| Male | 150 (44) | 116 (42) | 34 (49) | |
| Transmission season, no. (%) ** | < 0.001 | |||
| High | 148 (43) | 102 (37) | 46 (67) | |
| Low | 196 (57) | 173 (63) | 23 (33) | |
| Multiplicity of infection, no. (%) *** | < 0.001 | |||
| 1 | 100 (35) | 69 (31) | 31 (48) | |
| 2–5 | 100 (35) | 74 (34) | 26 (41) | |
| > 5 | 84 (30) | 77 (35) | 7 (11) | |
| Parasite density, parasites/μL, median (IQR) | 2.42 (0.47 – 62.79) | 1.11 (0.40 – 9.62) | 637 (50.0 – 4,770) | < 0.001 |
| Read coverage, median (IQR) | ||||
| pfcsp | 6,719 (1,957 – 13,206) | 4,679 (1,526 – 11,791) | 12,380 (7,312 – 16,136) | < 0.001 |
| pfama1 | 7,432 (3,200 – 12,939) | 6,318 (2,720 – 12,014) | 10,380 (7,015 – 14,880) | < 0.001 |
μL: microliter; pfcsp: Plasmodium falciparum circumsporozoite protein; pfama1: P. falciparum apical membrane antigen 1
*
Computed by either the chi-square test or Wilcoxon rank sum test.
**
Classified on the basis of the abundance of mosquitos collected in the prior two weeks into high (> 50) or low (≤ 50).
***
Defined as the larger of the number of unique pfcsp or pfama1 nucleotide sequences in the last positive sample of an episode.