Primary antiretroviral drug resistance among HIV type 1-infected individuals in Brazil.
Infection with drug-resistant human immunodeficiency virus type 1 (HIV-1) has been documented in all countries that have surveyed for it and may result in an unfavorable response to therapy. The prevalence and characteristics of individuals with transmitted resistance to antiretroviral drugs have been scarcely described in Brazil. We performed antiretroviral resistance testing prior to initiation of therapy in 400 subjects enrolled from 20 centers in 13 Brazilian cities between March and September 2007. Genotyping was conducted using PCR-amplified HIV pol products by automated sequencing, and genotype interpretation was done according to the IAS-USA consensus. Of 400 eligible participants, 387 (95.8%) were successfully tested. Seven percent of antiretroviral-naive patients carried viruses with one or more major mutation associated with drug resistance. The prevalence of these mutations was 1.0% for protease inhibitors, 4.4% for nonnucleoside reverse transcriptase inhibitors, and 1.3% for nucleoside reverse transcriptase inhibitors. The frequency of multidrug resistance among the resistant strains was 13.6%. Among subjects infected with drug-resistant virus, the majority were infected with subtype B viruses (91%). Subjects from the city of São Paulo had higher transmitted resistance mutations compared to the rest of the country. Reporting a partner taking antiretroviral medications was associated with a higher chance of harboring HIV variants with major drug resistance mutations [odds ratio = 2.57 (95% confidence interval, 1.07-6.16); p = 0.014]. Resistance testing in drug-naive individuals identified 7% of subjects with mutations associated with reduced susceptibility to antiretroviral drugs. Continued surveillance of drug-resistant HIV-1 in Brazil is warranted when guidelines for HIV prophylaxis and treatment are updated. Resistance testing among drug-naive patients prior to treatment initiation should be considered, mainly directed at subjects whose partners are already on antiretroviral therapy.
Sprinz
Eduardo
E
Hospital de Clínicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. esprinz@hcpa.ufrgs.br
Netto
Eduardo M
EM
Patelli
Maria
M
Lima
J S
JS
Lima
Maria Patelli J S
MP
Furtado
Juvênao J D
JJ
da Eira
Margareth
M
Zajdenverg
Roberto
R
Madruga
José V
JV
Lewi
David S
DS
Machado
Alcyone A
AA
Pedro
Rogério J
RJ
Soares
Marcelo A
MA
D000293:Adolescent; D000328:Adult; D000368:Aged; D044966:Anti-Retroviral Agents / Q000494:pharmacology*; D001938:Brazil; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D055815:Young Adult; D054302:pol Gene Products, Human Immunodeficiency Virus / Q000235:genetics
D044966:Anti-Retroviral Agents; D054302:pol Gene Products, Human Immunodeficiency Virus