The model is an individual-based stochastic simulation model including sexual behaviour, HIV transmission, HIV progression and effects of ART within a sub-Saharan African context.

Being “individual-based” means that each time the model is run it generates a data set of the simulated lifetime adult experience of a population of people thought to reflect a setting (e.g. a country, district, town, or other small area). For each simulated person in the data set, there are variables such as age and condomless sex, male circumcision, oral PrEP use, HIV testing, and, if infected with HIV, on HIV diagnosis, CD4 count, viral load, use of specific ART drugs, adherence, resistance.

We apply the model by considering a series of “setting scenarios”, each generated by one run of the model by sampling several parameter values to reflect the range of settings in SSA and also to incorporate uncertainty in assumptions. The sampled parameters include

  • male circumcision rates
  • initiation of sex work
  • HIV testing
  • linkage and retention
  • ART adherence
  • resistance emergence, transmission and persistence
  • ART interruption
  • extent of implementation of viral load monitoring
  • rate of switching to 2nd line after detected virologic failure.

You can find more information in this presentation.

You can also donwload the latest version of the model code.