Comparing HIV Post-Exposure Prophylaxis, Testing, and New Diagnoses in Two Australian Cities with Different Lockdown Measures during the COVID-19 Pandemic.

Australia introduced a national lockdown on 22 March 2020 in response to the COVID-19 pandemic. Melbourne, but not Sydney, had a second COVID-19 lockdown between July and October 2020. We compared the number of HIV post-exposure prophylaxis (PEP) prescriptions, HIV tests, and new HIV diagnoses during these lockdown periods. The three outcomes in 2020 were compared to 2019 using incidence rate ratio. There was a 37% and 46% reduction in PEP prescriptions in Melbourne and Sydney, respectively, with a larger reduction during lockdown (68% and 57% reductions in Melbourne's first and second lockdown, 60% reduction in Sydney's lockdown). There was a 41% and 32% reduction in HIV tests in Melbourne and Sydney, respectively, with a larger reduction during lockdown (57% and 61% reductions in Melbourne's first and second lockdowns, 58% reduction in Sydney's lockdown). There was a 44% and 47% reduction in new HIV diagnoses in Melbourne and Sydney, respectively, but no significant reductions during lockdown. The reduction in PEP prescriptions, HIV tests, and new HIV diagnoses during the lockdown periods could be due to the reduction in the number of sexual partners during that period. It could also result in more HIV transmission due to substantial reductions in HIV prevention measures during COVID-19 lockdowns.