Evolution and possible explanations for the trends in new HIV diagnoses in Alberta, Saskatchewan, and Manitoba, compared to the rest of Canada, 1985–2022

BACKGROUND: Canada aims to end the HIV epidemic as a public health threat by 2030. However, the provinces Alberta, Saskatchewan, and Manitoba reported 564 new HIV diagnoses in 2021 and over 600 in 2022. This study describes changes in HIV epidemiology in these three provinces compared to the rest of Canada between 1985 and 2022. METHODS: This was an ecological study that used data from publicly available HIV reports published by the Governments of Manitoba, Saskatchewan, Alberta, and Canada from the first reported HIV diagnoses to the latest available information. Variables of interest included number of HIV diagnoses per year (new, introduced), advanced HIV disease, proportion of diagnoses by sex (female/male), ethnicity, age, self-reported HIV mode of transmission, and mortality. We report the HIV incidence, advanced HIV disease, and mortality over time by province, and by sex, ethnicity, age, and mode of HIV transmission when data are available. RESULTS: Canadian HIV incidence decreased over time, while new HIV diagnoses in Manitoba and Saskatchewan increased to the highest ever recorded. In Saskatchewan and Manitoba, the male-to-female ratio is 1:1, while in Alberta and Canada, it is 2:1. Indigenous people have been overrepresented in Saskatchewan and Manitoba diagnoses since 2006 and 2016, respectively. The most common modes of HIV transmission are injection drug use and heterosexual sex in Saskatchewan and Manitoba for several years, while “out-of-country” is the most common category in Alberta. The advanced HIV disease and mortality statistics have decreased over time in Canada and the three provinces.