For example, the “interpersonal” level present in the original model has been changed to “social and sexual networks,” and an additional level specifying HIV/epidemic stage has been added. The MSEM is based on the premise that while individual-level risks are necessary for the spread of disease, they are not sufficient; higher order social and structural levels of risk (network, community, policy, level/stage of epidemic) represent risk factors outside of the control of any individual person (Wellings et al., 2006).