Intl Drug Resistance Workshop 12 Mexico 2003

XII International HIV Drug Resistance Workshop, Los Cabos, Mexico, 10-14 June 2003

Transmission of drug resistance – at 11% in Europe and 17% in the UK

HIV coinfection, reinfection and superinfection

Single-dose nevirapine resistance in over 75% of mothers

Transmission of drug resistant virus does not revert to wild-type and does not appear ‘less fit’

Standard genotype assays may miss 75% of mutations when present in less than 35% of plasma sample

Low-level resistance and minority populations: cross resistance between nevirapine and efavirenz occurs even in the absence of genotypic mutations found using population sequencing

Persistent effect of d4T and 3TC, but not NNRTIs in the presence of associated genotypic mutations

Replicative capacity results complicated by minority wild-type virus

Response to STI is determined by virus rather than immunological response

Why resistance rarely develops with viral suppression <50 copies/mL

Long-term persistence of distinct mutations in genital tract