Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

Epidemiology of hepatitis D in patients infected with hepatitis B virus in bucharest: a cross-sectional study

Epidemiological analyses indicate a decreasing level of hepatitis D (HDV) infections in most developed countries during the last 15 years. Romania, however, is one of the European countries that still has high morbidity from HDV; this study was performed in order to estimate the HDV prevalence in the Bucharest area. Three thousand four hundred sixty-one hepatitis B (HBV) infected patients were invited to participate and 1,094 were recruited. Serum anti-HDV IgG was detected in 223 patients indicating a hepatitis D seroprevalence of 20.4% (95% CI = 18.1-22.9) in patients chronically infected with HBV, less than that seen in previous studies. Seroprevalence was not gender related, but patients over 40 years were more likely to have anti-HDV antibodies, RR = 1.9 (1.2; 3.0). Detectable hepatitis D viraemia was found in 67.7% of the patients who were positive for anti-HDV. The HDV genotype was characterized for 40 isolates; all were very similar and belonged to genotype 1. Serum HBV-DNA was detectable less frequently in patients positive for anti-HDV than in patients infected with HBV alone: 68.5% versus 89.3%, OR 3.9 (1.7; 10.0), but the extent of this HDV replicative dominance varies with the sensitivity of the HBV-DNA detection. 19.3% of the subjects who tested positive for anti-HDV IgG had a HBV-DNA level higher than four logs. This high prevalence prompts the need for better HBV vaccination coverage and measures to prevent super infection with HDV in patients infected with HBV.