Table 2. Trends in HIV Seroconversionsa.
| Age Group, y | 2016 Cohort | 2017 Cohort | Relative Change in HIV Incidence | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| HIV Seroconversions, No./Total No. | No. of Person-Years | IR per 100 Person-Years (95% CI)b | HIV Seroconversions, No./Total No. | No. of Person-Years | IR per 100 Person-Years (95% CI)b | IRR (95% CI) | P Value | Adjusted IRR (95% CI)c | P Value | |
| All | 163/3536 | 5746 | 2.31 (1.82-2.92) | 115/3907 | 5447 | 1.96 (1.62-2.37) | 0.85 (0.63-1.15) | .28 | 0.86 (0.63-1.18) | .35 |
| Men | ||||||||||
| All | 39/1573 | 2602 | 1.44 (0.96-2.24) | 31/1829 | 2560 | 1.32 (0.90-1.92) | 0.92 (0.51-1.65) | .78 | 0.95 (0.53-1.70) | .85 |
| 15-19 | 4/518 | 836 | 0.41 (0.14-1.21) | 3/668 | 940 | 0.24 (0.08-0.75) | 0.59 (0.12-2.79) | .50 | 0.58 (0.12-2.82) | .50 |
| 20-24 | 16/537 | 888 | 1.42 (0.76-2.65) | 11/572 | 800 | 1.18 (0.61-2.27) | 0.83 (0.34-2.06) | .69 | 0.88 (0.35-2.22) | .79 |
| 25-29 | 13/306 | 523 | 2.46 (1.18-5.15) | 13/339 | 467 | 2.84 (1.57-5.14) | 1.15 (0.45-2.97) | .77 | 1.23 (0.46-3.31) | .68 |
| 30-35 | 6/212 | 355 | 2.02 (0.69-5.96) | 4/250 | 354 | 1.45 (0.52-4.03) | 0.72 (0.16-3.18) | .66 | 0.72 (0.16-3.16) | .66 |
| Women | ||||||||||
| All | 124/1963 | 3144 | 3.44 (2.71-4.38) | 84/2078 | 2887 | 2.80 (2.22-3.53) | 0.81 (0.58-1.13) | .22 | 0.82 (0.58-1.16) | .26 |
| 15-19 | 51/660 | 1039 | 4.63 (3.29-6.52) | 30/743 | 1032 | 2.74 (1.84-4.09) | 0.59 (0.35-1.00) | .05 | 0.57 (0.34-0.96) | .04 |
| 20-24 | 41/639 | 1022 | 4.00 (2.74-5.85) | 41/668 | 923 | 4.26 (3.04-5.97) | 1.07 (0.64-1.77) | .81 | 1.07 (0.64-1.80) | .79 |
| 25-29 | 26/419 | 680 | 2.29 (1.43-3.67) | 10/416 | 580 | 1.87 (0.93-3.77) | 0.82 (0.35-1.90) | .64 | 0.85 (0.36-1.97) | .70 |
| 30-35 | 6/245 | 403 | 0.59 (0.26-1.37) | 3/251 | 352 | 0.47 (0.15-1.50) | 0.80 (0.19-3.32) | .75 | 0.85 (0.20-3.60) | .83 |
Abbreviations: IR, incidence rate; IRR, IR ratio.
a
A total of 278 Western blot analyses confirmed HIV seroconversions: 163 in the 2016 cohort and 115 in the 2017 cohort. This total excluded the 1 Western blot–unconfirmed positive result of enzyme-linked immunosorbent assay (ELISA) and 9 ELISA seroconversions among participants who were found to be HIV RNA positive at enrollment.
b
Weighted to account for the multilevel sampling design, estimated using survey Poisson regression models, and reported as per 100 person-years.
c
Adjusted for sex, age, educational level, and lifetime number of sex partners plus HIV testing history.