Table 2.
Characteristics of Longitudinal Exposure Risk Groups
| Characteristic | HIV-1 Exposure Score Group |
||||
|---|---|---|---|---|---|
| Highest (n = 475) | Decreasing (n = 214) | Pa | Lower (n = 2595) | Pa | |
| Mean HIV-1 exposure score during follow-upb | 1.7 (1.5–2.0) | 0.4 (−0.5 to 0.9) | <.001 | −0.2 (−1.0 to 0.5) | <.001 |
| Linked HIV-1 transmissionb | 49 (10) | 7 (3) | <.05 | 28 (1) | <.05 |
| Couples | |||||
| Married to study partner | 386 (81) | 154 (72) | <.05 | 1951 (75) | <.05 |
| Unprotected sex during studyb | 357 (75) | 139 (65) | <.05 | 1203 (46) | <.001 |
| Relationship duration, y | 4.1 (1.8–7.5) | 5.0 (2.4–9.7) | <.05 | 4.8 (2.0–10.1) | <.05 |
| HIV-1–seronegative partner | |||||
| Age, y | 30 (25–35) | 32 (27–40) | <.001 | 35 (29–42) | <.001 |
| Female sex | 238 (50) | 71 (33) | <.001 | 761 (29) | <.001 |
| Male circumcision | 74 (31) | 68 (48) | <.05 | 1077 (59) | <.001 |
| HSV-2 seropositive | 417 (88) | 146 (68) | <.05 | 1680 (65) | <.001 |
| Pregnant during studyb | 111 (47) | 17 (24) | <.05 | 163 (21) | <.001 |
| HIV-1–seropositive partner | |||||
| Mean plasma HIV-1 RNA level,b,c log10 copies/mL | 5.0 (4.6–5.3) | 4.0 (3.6–4.5) | <.001 | 3.9 (3.2–4.4) | <.001 |
| Mean CD4 cell count, copies/mm3b,c | 371 (291–488) | 373 (298–531) | 466 (351–626) | <.001 | |
| Initiated ART during studyb,d | 64 (13) | 83 (39) | <.001 | 181 (7) | <.001 |
| Time of ART initiation after enrollment, mob,d,e | 15 (15–21) | 9 (9–12) | <.001 | 15 (9–18) | <.05 |
| Genital ulcer disease during studyb | 224 (47) | 95 (44) | 905 (35) | <.001 | |
Data are no. (%), for categorical variables, and medians (interquartile ranges), for continuous variables. Numbers may not sum to the total number of participants included in the study, because of missing data.
Abbreviations: ART, antiretroviral therapy; HIV-1, human immunodeficiency virus type1.
a Values denote results of comparisons of groups with decreasing or lower HIV-1 exposure scores to those with the highest exposure scores. χ2 tests were used for categorical variables, and t tests were used for continuous variables.
b HIV-1 exposure scores, plasma HIV-1 RNA levels, and CD4 cell counts are provided as the mean value across all study visits. HIV-1 transmission, unprotected sex, pregnancy, and genital ulcer disease variables indicate if the condition was observed at any visit during follow-up. Baseline measurements from enrollment were used for all other covariates.
c Mean values of plasma HIV-1 RNA levels and CD4 cell counts for each individual across all study visits.
d Referrals for ART initiation were based on national guidelines at the time of the study.
e HIV-1–infected partners were eligible for the study if they had CD4 cell counts >250 copies/mm3 and were not receiving ART at enrollment following national guidelines.