Antiretroviral recommendations may influence the rate of transmission of drug-resistant HIV type 1.
BACKGROUND
Human immunodeficiency virus (HIV) treatment guidelines have evolved, shifting from more-aggressive to more-conservative approaches. The potential impact of these shifts on the transmission of drug-resistant virus is unknown.


METHODS
Drug-resistance genotypes were examined in all consecutive patients with recent HIV type 1 (HIV-1) seroconversion (hereafter, "HIV-1 seroconverters") seen at 10 Spanish hospitals since 1997. During the same period, the proportion of patients with chronic HIV-1 infection having undetectable viremia was examined, to estimate the extent and effectiveness of antiretroviral therapy.


RESULTS
A total of 141 recent HIV-1 seroconverters were identified, 67.4% of whom were men who have sex with men. The rate of primary drug-resistance mutations, by year of infection, was 33.3% for 1997, 29.4% for 1998, 20% for 1999, 14.3% for 2000, 3.4% for 2001, 15.4% for 2002, and 10.9% for 2003. On the other hand, the proportion of 8388 persons with chronic HIV-1 carriage who had an undetectable virus load was 33.4% for 1997, 34.6% for 1998, 39.7% for 1999, 47.5% for 2000, 52.9% for 2001, 39.7% for 2002, and 58.1% for 2003. A significant inverse correlation between transmission of drug-resistant HIV-1 and undetectable virus load was found (r=-0.955, by Spearman's test; P=.001). The lowest rate of transmission of drug-resistant HIV-1 was seen in 2001, when relatively "aggressive" treatment guidelines were used. Transmission of drug-resistant HIV-1 increased in 2002, in parallel with a reduction in the number of patients with chronic HIV-1 carriage and undetectable virus load, reflecting the popularity of drug holidays or treatment interruptions.


CONCLUSIONS
The rate of drug resistance in recent HIV-1 seroconverters inversely correlates with the proportion of chronically HIV-1-infected individuals who have undetectable virus loads in the same region, which indirectly reflects antiretroviral treatment rules at any given time.
de Mendoza
Carmen
C
Service of Infectious Diseases, Hospital Carlos III, Madrid, Spain.
Rodriguez
Carmen
C
Eiros
José Maria
JM
Colomina
Javier
J
Garcia
Federico
F
Leiva
Pilar
P
Torre-Cisneros
Julián
J
Aguero
Jesús
J
Pedreira
José
J
Viciana
Isabel
I
Corral
Angélica
A
del Romero
Jorge
J
Ortiz de Lejarazu
Raúl
R
Soriano
Vincent
V
D019380:Anti-HIV Agents / Q000494:pharmacology*; D024921:Drug Resistance, Multiple, Viral; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000635:transmission* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008297:Male; D009154:Mutation; D012367:RNA, Viral / Q000097:blood; D013997:Time Factors; D019562:Viral Load
D019380:Anti-HIV Agents; D012367:RNA, Viral