(A report back on Kavita Misra's session - New options and opportunities in PrEP: Impact of PrEP on drug resistance and acute HIV infection, New York City 2015-2017)

Data on PrEP and associated resistance comes from safety and efficacy studies.  Mathematical modelling has suggested that any contribution from PrEP to resistance mutations would be very small and lower than if HIV infections were not averted. Concerns relate to starting PrEP during seroconversion and acquiring HIV and continuing the two drug regimen. 


Routine collected information and surveillance data was utilised in this analysis from NYC. Between 2015-2017, 3685 HIV diagnoses were made. 

Only 91 (5% ) reported PrEP use in previous 12 months. PrEP uptake was highest in caucasian young MSM. Median duration of PrEP use before HIV diagnosis was 106 days and median days between start of PrEP and HIV diagnosis was 256 days.

NAAT testing is recommened in NY  prior to PrEP commencement if there are symptoms suggestive of acute HIV infection or a history of unprotected sex in the previous month.  Negatve NAAT testing was reported in 18%, 2% and 5% respectively >30days, 15-24 days and 0-2 days before PrEP commencement. 

Acute HIV infection was made in 33% of PrEP users and 9% of never users.

Genotying was available for 63%. Data was insufficient to differentiate between transmitted and acquired drug resistance.   Prevalence of resistance mutations to FTC was greater in PrEP users (29% v 2%).  Signature TDF mutation K65R was not detected in PrEP users. This data adds real life data to the available information. 

Australia is leading in making PrEP available subsidised under the PBS. For me as a PrEP prescriber, this study further re-inforces the importance of good history taking, excluding acute HIV in symptomatic individuals,considering PEP when assessing for PrEP, following up in one month (or earlier if indicated) at initiation and having regular three monthly follow-up.

Author bio: Mekala Srirajalingam has dual qualifications in Sexual Health Medicine (AChSHM) and Public Health Medicine (FAFPHM) and works at The Ipswich Sexual Health Service, Queensland, Australia .  Mekala also holds the academic title of Senior Lecturer with The University of QLD.