Associations between key PMTCT interventions and weighted perinatal infant HIV infection status in HIV-exposed infants, South Africa, 2010
| Indicators | Frequency of HIV-exposed infants with PCR results* n=3088 Nw=410 046 | Frequency of HIV-infected infant n=125 of 3088 Nw=14 192 | Unadjusted OR (95% CI) | Adjusted OR† Model 1 | Adjusted OR† Model 2 | Adjusted OR† Model 3 | Adjusted OR‡ Final model |
|---|---|---|---|---|---|---|---|
| Mothers self-reported last CD4 cell count | |||||||
| ≤350 | 839 | 19 | 1.67 (0.89 to 3.13) | – | – | – | – |
| >350 | 837 | 20 | Ref. | – | – | – | – |
| Missing | 1412 | 86 | NA | – | – | – | – |
| ARV coverage during pregnancy§ | |||||||
| Maternal ART (1a) | 873 | 15 | Ref. | Ref. | Ref. | ||
| ARVP >10 weeks (1b) | 822 | 23 | 1.03 (0.56 to 1.90) | 1.03 (0.54 to 1.99) | 0.98 (0.52 to 1.83) | ||
| ARVP ≤10 weeks (2a) | 710 | 28 | 1.42 (0.78 to 2.57) | 1.45 (0.76 to 2.75) | 1.31 (0.69 to 2.48) | ||
| Incomplete ARVP (2b) | 163 | 13 | 4.24 (2.06 to 8.73) | 3.95 (1.82 to 8.57) | 3.68 (1.69 to 7.97) | ||
| No ARV (3a) | 328 | 36 | 4.57 (2.63 to 7.95) | 4.04 (2.14 to 7.62) | 3.59 (1.94 to 6.66) | ||
| Missing ARV information (3b) | 192 | 10 | 2.68 (1.21 to 5.90) | 1.94 (0.66 to 5.75) | 2.26 (0.89 to 5.73) | ||
| Feeding (8 days recall) | |||||||
| No breast milk | 1870 | 50 | Ref. | Ref. | Ref. | ||
| Exclusive breast feeding | 618 | 32 | 1.82 (1.13 to 2.93) | 1.86 (1.11 to 3.10) | 1.79 (1.09 to 2.92) | ||
| Mixed breast milk | 600 | 43 | 2.32 (1.54 to 3.51) | 2.35 (1.49 to 3.71) | 1.70 (1.09 to 2.67) | ||
| Delivery type | |||||||
| Caesarean | 677 | 26 | Ref. | ||||
| Vaginal | 2411 | 99 | 0.88 (0.57 to 1.38) | 0.90 (0.56 to 1.47) | 0.87 (0.53 to 1.42) | ||
*19 (unweighted) exposed infants with missing HIV DNA test results were excluded from this analysis; thus, the total number of HIV-exposed infants differs between tables 1 and 2.
†Adjusted for maternal age, SES, marital status, education, gestational age at first ANC visit (4 week intervals), total number of lifetime pregnancies, whether or not the current pregnancy was planned and whether or not the infant weighed <2.5 kg at birth.
‡Adjusted for maternal age, SES, marital status, education, gestational age at first ANC visit (4 week intervals), total number of lifetime pregnancies, whether or not the pregnancy was planned and whether or not the infant weighed <2.5 kg at birth. In this model, missing gestational age was imputed using a Markov chain Monte Carlo multiple imputation algorithm (see methods).
§See figure 1 for definitions 1a, 1b, 2a, 2b, 3a, 3b.
ANC, antenatal care; ART, antiretroviral therapy; ARV, antiretroviral; ARVP, ARV prophylaxis; PMTCT, preventing mother-to-child transmission; SES, socioeconomic status.