Trends of prevalence of primary HIV drug resistance in Germany.

BACKGROUND: Primary HIV drug resistance (PDR) is associated with poor treatment outcome of first-line highly active antiretroviral therapy (HAART). The aim of the study was to observe the trend of prevalence of PDR between 2001 and 2005. METHODS: In a prospective multicentre study in the state of Nordrhein-Westfalen, Germany, 831 treatment-naive chronically HIV-infected patients underwent genotypic resistance testing. RESULTS: Six hundred and forty (77%) of them were male. Two-thirds of the patients (558, 67%) were infected with HIV subtype B. PDR was found in 75 of 831 [9%; 95% confidence interval (CI) 7.1-10.9] cases entering the study between January 2001 and December 2005. An increasing trend of PDR was found from 2001 (4.8%; CI 2.1-9.4) to 2005 (9.0%; CI 5.4-12.6; P = 0.08). A significant tendency to higher PDR was observed for ethnicity other than Caucasian (P = 0.04), HIV subtypes other than B (P = 0.02) and transmission routes other than homosexual (P = 0.03). CONCLUSIONS: A non-significant increase in prevalence of PDR was observed from 2001 to 2005. A significant trend to higher PDR rate was detected in non-Caucasian patients, patients infected with non-B subtypes, and in patients with risk factors for acquisition of HIV other than homosexual transmission. Based on the fact that there is a trend to higher PDR rate, resistance testing in untreated HIV-infected patients starting HAART becomes more important in clinical routine. The identification of patient subgroups with a remarkable risk of PDR makes continuous monitoring of PDR mandatory.