An epidemiological modelling study to estimate the composition of HIV-positive populations including migrants from endemic settings. Â AIDS
Nakagawa et al. aimed to demonstrate a novel approach using a mathematical model with the United Kingdom (UK) as an example, to present key public health outputs on the national level, including the size of the undiagnosed population and HIV incidence. They used an individual-based stochastic simulation model to calibrate to routinely collected surveillance data in the UK.
An estimated 106’400 people were living with HIV in the UK in 2013. Twenty-three percent of these people, 24’600 (90% plausibility range: 15’000–36’200) were estimated to be undiagnosed; this number has remained stable over the last decade. An estimated 32% of the total undiagnosed population had CD4+ cell count less than 350 cells/ml in 2013. Twenty-five and 23% of black African men and women heterosexuals living with HIV were undiagnosed respectively.
In conclusion, the authors presented a method to generate national-level estimates about the size and characteristics of HIV-positive populations incorporating migrants from sub-Saharan Africa. These estimates should help inform and evaluate current and future public health responses to the epidemic by providing more information about the affected population than can be understood and achieved solely from surveillance.