The Economic and Epidemiological Impact of Focusing Voluntary Medical Male Circumcision for HIV Prevention on Specific Age Groups and Regions in Tanzania

Abstract

Background: Since its launch in 2010, the Tanzania National Voluntary Medical Male Circumcision (VMMC) Program has focused efforts on males ages 10-34 in 11 priority regions. Implementers have noted that over 70% of VMMC clients are between the ages of 10 and 19, raising questions about whether additional efforts would be required to recruit men age 20 and above. This analysis uses mathematical modeling to examine the economic and epidemiological consequences of scaling up VMMC among specific age groups and priority regions in Tanzania.

Methods and findings: Analyses were conducted using the Decision Makers' Program Planning Tool Version 2.0 (DMPPT 2.0), a compartmental model implemented in Microsoft Excel 2010. The model was populated with population, mortality, and HIV incidence and prevalence projections from external sources, including outputs from Spectrum/AIDS Impact Module (AIM). A separate DMPPT 2.0 model was created for each of the 11 priority regions. Tanzania can achieve the most immediate impact on HIV incidence by circumcising males ages 20-34. This strategy would also require the fewest VMMCs for each HIV infection averted. Circumcising men ages 10-24 will have the greatest impact on HIV incidence over a 15-year period. The most cost-effective approach (lowest cost per HIV infection averted) targets men ages 15-34. The model shows the VMMC program is cost saving in all 11 priority regions. VMMC program cost-effectiveness varies across regions due to differences in projected HIV incidence, with the most cost-effective programs in Njombe and Iringa.

Conclusions: The DMPPT 2.0 results reinforce Tanzania's current VMMC strategy, providing newfound confidence in investing in circumcising adolescents. Tanzanian policy makers and program implementers will continue to focus scale-up of VMMC on men ages 10-34 years, seeking to maximize program impact and cost-effectiveness while acknowledging trends in demand among the younger and older age groups.

Fig 1. Modeled relative reduction in HIV incidence by scaling up VMMC for individual age groups, compared with no scale-up of VMMC over baseline levels, 2014–2050.

(a) immediacy of impact (5 years). (b) magnitude of impact (15 years). The HIV incidence ratio represents the incidence in the scale-up scenario divided by the HIV incidence in a population where circumcision is not scaled-up over baseline levels. Each line represents the HIV incidence ratio under a scenario in which only the indicated five-year age group is circumcised. Marker a represents a five-year period from the base year (2014). Marker b represents a 15-year period from the base year.

Fig 2. HIV infections averted in scenarios scaling up VMMC among different client age groups.

The time period for measuring HIV infections averted was 15 years, 2014–2028, inclusive. Error bars represent uncertainty bounds.

Fig 3

a and b. Cost per HIV infection averted in scenarios scaling up VMMC among different client age groups. The time period for measuring HIV infections averted was 15 years, 2014–2028, inclusive. Error bars represent uncertainty bounds.

Fig 4. Discounted cost per HIV infection averted by region, 2014–2028, given a scenario of scale-up to 80% of 10- to 34-year-olds.

Fig 5

a–c. Annual VMMCs required to scale up to 80% MC coverage among males ages 10–34.