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.
Service of Infectious Diseases, Hospital Carlos III, Madrid, Spain.
Carmen
C
de Mendoza
Carmen
C
Rodriguez
José Maria
JM
Eiros
Javier
J
Colomina
Federico
F
Garcia
Pilar
P
Leiva
Julián
J
Torre-Cisneros
Jesús
J
Aguero
José
J
Pedreira
Isabel
I
Viciana
Angélica
A
Corral
Jorge
J
del Romero
Raúl
R
Ortiz de Lejarazu
Vincent
V
Soriano
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