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.

Infecton: a 99mTc-ciprofloxacin radiopharmaceutical for the detection of bone infection

OBJECTIVE

To evaluate Infecton scintigraphy, with technetium-99m-radiolabeled ciprofloxacin, as a means to detect bone infection, in comparison with other conventional scintigraphic and radiologic methods.

METHODS

Forty-five patients with known or suspected bone infection underwent 50 scans with Infecton. Almost all were also subjected to a three-phase 99mTc-methylene diphosphonate bone scan and most of them to a 99mTc-human polyclonal immunoglobulin scan as well as to a gallium-67-citrate scan, plus computerized tomography or magnetic resonance imaging or both. Clinical laboratory criteria for the presence of osteomyelitis were based on the definitions of the Centers for Disease Control and Prevention.

RESULTS

Staphylococcus aureus and Pseudomonas aeruginosa were the most frequently isolated pathogens. Based on the CDC clinical laboratory criteria as well as on conventional scan results, Infecton was characterized in 35 studies as 'true positive', in eight as 'true negative', in two as 'false positive', in one as 'false negative', and in four as 'indeterminate'. The sensitivity and specificity of Infecton scintigraphy were found to be 97.2% and 80%, respectively, with positive and negative predictive values of 94.6% and 88.9%.

CONCLUSIONS

It is concluded that Infecton is a very sensitive and quite specific marker of bone infection, but care must be taken in cases of excessive new bone formation and primary bone tumors, where false-positive results may be obtained.

Pharmacokinetics of intravenously administered pefloxacin in the prostate; perspectives for its application in surgical prophylaxis

In an attempt to define whether intravenously administered pefloxacin might be appropriate for surgical prophylaxis in prostatectomy, 50 patients undergoing transvesical prostatectomy for benign prostate hyperplasia were given a single intravenous dose of 800 mg; surgery was then performed after 2, 4, 6, 8 or 10 h. Concentrations of pefloxacin were determined in serum and in both the centre and periphery of the prostate adenoma using a microbiological plate assay. Elevated concentrations of pefloxacin were found in the adenoma from 2 h onwards. The central and peripheral concentrations were similar and had a mean value of 4.39 microg/g of tissue. These concentrations were similar to those achieved in serum. Although concentrations of pefloxacin were not determined separately in the intercellular, interstitial or excreted fluid, the tissue levels found were well above the MICs of pefloxacin for the bacteria commonly causing acute and chronic prostatitis. These data suggest the intravenous administration of pefloxacin to be a satisfactory alternative for the surgical prophylaxis before prostatectomy as well as in the therapy of acute prostatitis.

Pharmacokinetics of clarithromycin in the prostate: implications for the treatment of chronic abacterial prostatitis

PURPOSE

We studied the pharmacokinetics of orally administered clarithromycin in prostatic tissue to define its role in the treatment of chronic abacterial prostatitis caused by intracellular pathogens.

MATERIALS AND METHODS

A total of 45 men receiving 3 oral doses of 750 mg. clarithromycin at 12-hour intervals underwent suprapubic prostatectomy for benign prostate hyperplasia 4, 5, 6 and 7 hours after the last drug dose in 13, 12, 10 and 10 patients, respectively. Concentrations were determined in the prostate tissue and in plasma by an agar diffusion assay.

RESULTS

A mean peak level of clarithromycin of 3.22 and 3.08 microg./gm. of tissue was achieved 4 hours after the third drug dose at the center and periphery of the adenoma, respectively. Tissue levels remained statistically superior to plasma levels at all intervals.

CONCLUSIONS

The oral administration of clarithromycin achieved a prostate level much higher than the minimal inhibitory concentration of clarithromycin for the intracellular pathogens of chronic prostatitis. Thus, clarithromycin may be considered for treating chronic abacterial prostatitis.

Aztreonam versus cefamandole in the treatment of urinary tract infections

The in vivo efficacy and safety of aztreonam compared to that of cefamandole was randomly and prospectively studied in the treatment of 30 patients suffering from recurrent urinary tract infections with a patient ratio of 2 aztreonam to 1 cefamandole. The mean age was 51.6 +/- 15.4 and 59.8 +/- 13 years respectively. Both antibiotics were given at a dose of 1 g, 8 hourly i.m. for 7-13 days. Sixty-seven percent versus 70% of the patients given aztreonam and cefamandole respectively were suffering from upper urinary tract infections. X ray abnormalities predisposing to relapse or reinfections were present in 88% vs 80% of the patients, while all patients had typical symptoms of urinary tract infections, with high fever (greater than or equal to 38.5 degrees C) reported in 70% and 60% of the patients in the two treatment groups respectively. Escherichia coli and Proteus mirabilis were the predominant isolates in urine cultures. During treatment all patients responded favourably both clinically and bacteriologically, while after a 6-week follow-up 20% versus 30% relapsed clinically with 15% vs 30% bacteriologic relapses in the two groups, but only in patients suffering from upper urinary tract infections. No development of bacterial resistance was observed in the relapses, while mainly Enterococcus spp was implicated in reinfections. No appreciable side effects of toxicity were observed. It was concluded that aztreonam is a promising new antibiotic that deserves further clinical trials in systemic infections.