HIV Transmitted Drug Resistance in the Philippines: The Case for Baseline Genotyping and Drug Resistance Testing

Abstract

Abstract Background The Philippines has one of the fastest growing HIV epidemics in the world. Parallel to the increase is a shift in HIV subtype from B to CRF01_AE. No transmitted drug resistance (TDR) surveillance has ever been conducted. With the widespread rollout of antiretrovirals and the limited repertoire of 6 drugs (tenofovir, lamivudine, zidovudine, nevirapine, efavirenz, lopinavir/ritonavir) makes TDR monitoring imperative. In addition, a high rate of hepatitis B (HBV) co-infection (17%) in the general population raises the risk of TDR with prior NRTI monotherapy. Methods Following IRB approval, we performed TDR surveillance at the Philippine General Hospital, one of the largest tertiary referral centers in the country. Treatment-naïve patients had their HIV RT and PR genes sequenced using WHO approved-protocols for HIV genotyping. Generated sequences were analyzed using the Stanford Drug Resistance Database. Pertinent demographic and clinical data were collected. The current results represent year 1 of the study. Results 95 treatment naïve patients were analyzed. Median age was 30 years (range 20–68). There were 88 males and 7 females. Median CD4 count was 90 cells/mL (range 0–936) and median viral load was 1792000 copies/mL. 18 patients were co-infected with HBV, but all denied previous HBV treatment. Conclusion The TDR rate for HIV in the Philippines is 6.3%. This is above the threshold for recommending baseline TDR genotyping for all local HIV patients. All HIV with TDR were subtype CRF01_AE, and this may signal a higher risk of TDR as the epidemic shifts further to a non-B subtype. Disclosures E. M. Salvana, Merck: Scientific Advisor and Speaker’s Bureau, Consulting fee and Speaker honorarium