Prevention of mother-to-child transmission of HIV in rural Uganda: Modelling effectiveness and impact of scaling-up PMTCT services

Figures & data

Fig. 1 Iganga-Mayuge Health and Demographic Surveillance Site – cohort of pregnant women.

Table 1 Input values to the decision tree analysis input

Data from the HDSS cohort (base case) on probability of coverage for individual PMTCT programme components (n=717)
Components	Probabilities
ANC attendance	0.96
Attending ANC at a facility with HIV testing services	0.78
HIV tested (attending ANC at a facility with HIV testing services)	0.85
HIV tested (attending ANC at a facility without HIV testing services)	0.06
HIV prevalence	0.035
HIV-positive women/baby pair receiving any ARV prophylaxis (n=13)	0.83
Mother ARV prophylaxis – sd-NVP^a	0.33
Mother ARV prophylaxis – dual prophylaxis AZT^b and 3TC^c	0.57
Mother ARV prophylaxis – ART (for her own health)	0.10
Women practicing safe feeding^d	0
HIV mother-to-child transmission rates^e
Peripartum transmission rates for different ARV regimens
No ARV prophylaxis	0.22
sd-NVP	0.12
Dual prophylaxis of AZT and 3TC	0.04
ART for her own health	0.02
Postpartum transmission rates per month of any breastfeeding (mixed or exclusive)
Mother’s CD4 cell count ≤350 mm^3	0.0157
Mother’s CD4 cell count >350 mm^3	0.0051
If mother receives ART for her own health	0.002

^asingle dose nevirapine; ^bzidovudine; ^clamivudine; ^dSafe feeding refers to exclusive breastfeeding or formula feeding; ^eAdopted from Ref. (16).

Table 2 Scenarios modelled for different coverage of PMTCT components, MTCT rates and number of children infected with HIV

		At birth^a		At 6 months – CD 4 cell count >350/mm^3 b		At 6 months – CD 4 cell count ≤350/mm^3 b
Scenario	Description	Number of children	MTCT rate (%)	Number of children	MTCT rate (%)	Number of children	MTCT rate (%)
1. Base case PMTCT coverage^c	Number of HIV-infected children in the Iganga-Mayuge district population based on the empirical HDSS cohort data	240	13.4	284	15.8	369	20.5
2. 100% ANC	Base case scenario but 100% ANC attendance	234	13.0	278	15.5	363	20.2
3. 100% HIV testing	Base case scenario but 100% HIV testing	172	9.6	217	12.1	303	16.9
4. 100% ART	Base case scenario but ART provided to all women who received ARV prophylaxis	197	11.0	227	12.6	265	14.8
5. Optimal scenario^a	A combination of Scenarios 2, 3, and 4	97	5.4	121	6.7	135	7.5
No PMTCT	No ARV prophylaxis given to HIV-infected women/babies	391	21.8	413	23.0	495	27.6

^aPeripartum transmission rates for different ARV regimens: No ARV prophylaxis: 0.22, sd-NVP: 0.12, dual prophylaxis AZT and 3TC: 0.04, ART: 0.02; ^bPostpartum transmission rates per month of any breastfeeding (mixed or exclusive). Mother’s CD4 cell count ≤350 mm³: 0.0157, mother’s CD4 cell count >350 mm³: 0.0051, if mother receives ART: 0.002; ^cBase case PMTCT coverage obtained from the HDSS cohort: ANC 0.96, HIV testing 0.64, and ARV prophylaxis 0.83.

Fig. 2 Estimated relative effects of an assumed increase in coverage of individual PMTCT programme components as compared to the base case PMTCT coverage.

Assuming 100% (a, b) and 50% (c, d) adherence.

UNAIDS Reference Group on Estimates Modelling and Projections. 2011; Geneva: UNAIDS. Working Paper on MTCT transmission rates for use in Spectrum.

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