Clinical follow-up and monitoring of patients on PrEP
Hepatitis B virus monitoring
For people who are hepatitis B virus (HBV) non-immune at baseline, clinicians should provide hepatitis B vaccination and confirm their immune response 1 month after the last vaccine dose.
For people who state that they have been vaccinated for hepatitis B at baseline, clinicians should test for hepatitis B surface antibody; if their hepatitis B surface antibody is below 10 IU/mL, they should be vaccinated with one dose of hepatitis B vaccine and their hepatitis B surface antibody titre should be checked 1 month later. If their titre does not rise above 10 IU/mL their hepatitis B vaccination should then be completed.
Both TD* and FTC are active against HBV (8). If people living with chronic HBV infection stop taking these medications, hepatic flares can occur, which can be severe (8). Patients with chronic HBV need to be counselled regarding the risks of poor adherence and the risks of self-ceasing PrEP medication. Patients who are known to have chronic HBV and are already taking treatment for this condition should consult their liver specialist before commencing PrEP. A person taking PrEP who has chronic HBV infection should be assessed by a clinician experienced in the management of hepatitis B before ceasing PrEP. If PrEP is discontinued, close monitoring is strongly advised.
Only daily PrEP should be offered to people with chronic HBV. For additional guidance about the management of PrEP in people with chronic hepatitis B, see Special clinical considerations.
Hepatitis C virus monitoring
All people who inject drugs including MSM, trans and gender diverse and heterosexual people should be monitored for Hepatitis C virus (HCV), as should MSM and trans and gender diverse people who engage in sexual contact that may pre-dispose to anal trauma. The incidence of HCV has currently been low at approximately 1% per annum in PrEP studies of MSM (9, 10), and higher in HIV-positive MSM (11, 12). However, there is concern that HCV incidence may increase following changes in sexual and serosorting behaviour in the era of PrEP. In this context, HCV can be sexually acquired and is considered as an STI. It should be tested at least annually, and more frequently if necessary, following sexual history taking and review of injecting practices (13).