Towards the elimination of hepatitis C: implementation of reflex testing in Andalusia

BACKGROUND AND AIM

undiagnosed hepatitis C virus (HCV) infection and/or inadequate access to care are barriers to the elimination of HCV. Reflex testing has proven to facilitate referral to care, treatment and viral elimination. In this study, a reflex testing program was implemented in Andalusia and its impact on access to care was evaluated.

PATIENTS AND METHODS

an observational, retrospective and prospective study was performed across diagnostic laboratories responsible for HCV diagnosis in southern Spain. After surveying the barriers to performing reflex testing, the number of patients that were not referred for care in 2016 was retrospectively studied (pre-reflex cohort). Subsequently, several measures were proposed to overcome the identified barriers. Finally, reflex testing was implemented and its impact evaluated.

RESULTS

the pre-reflex cohort included information from 1,053 patients. Slightly more than half of the patients (n = 580; 55%) visited a specialist for treatment evaluation during a median period of 71 days (interquartile range = 35-134) since the date of diagnosis. The post-reflex cohort (September 2017 to March 2018) included 623 patients. Only 17% (n = 106) of the patients had not been referred for care or evaluated for treatment in a median period of 52 days (interquartile range = 28-86).

CONCLUSIONS

in 2016, nearly half of new HCV diagnoses in southern Spain were not referred for care. Barriers to the implementation of reflex testing were overcome in our study. Moreover, this strategy was effectively implemented in 2017. Reflex testing contributed to improving referral for care. This program will contribute to the micro-elimination of hepatitis C in Spain.

Breast Abscesses Caused by Anaerobic Microorganisms: Clinical and Microbiological Characteristics

The objectives of this study were to report the antimicrobial susceptibility of 35 clinically significant anaerobic bacteria isolated from breast abscesses between March 2017 and February 2020 in a tertiary hospital in Granada (Spain) and to describe key clinical features of the patients. Species identification was performed mainly by MALDI-TOF MS. Antimicrobial susceptibility tests were carried out against benzylpenicillin, amoxicillin-clavulanic acid, imipenem, moxifloxacin, clindamycin, metronidazole, and piperacillin-tazobactam using the gradient diffusion technique and European Committee on Antimicrobial Susceptibility Testing EUCAST breakpoints (except for moxifloxacin). The most frequent anaerobes were Finegoldia magna (31.4%; n = 11), Actinomyces spp. (17.1%; n = 6), Propionibacterium spp. (17.1%; n = 6), and Prevotella spp. (14.2%; n = 5). Imipenem, amoxicillin-clavulanic acid, and piperacillin-tazobactam were universally active against all genera tested. High overall resistance rates to clindamycin were observed, especially for Gram-positive anaerobic cocci (56.2%) and Gram-positive anaerobic bacilli (38.4%). High resistance rates to metronidazole were also observed for Gram-positive (76.9%) and Gram-negative anaerobic bacilli (50%). High resistance rates to moxifloxacin were found for Gram-negative anaerobic bacilli (50%) and Gram-positive anaerobic cocci (31.2%). No breast abscess cases of Bacteroides spp. were detected. Routine antimicrobial susceptibility testing for anaerobes in breast abscesses may contribute to allow empirical therapies to be selected in accordance with local data on resistant strains.

Use of cohort data to estimate national prevalence of transmitted drug resistance to antiretroviral drugs in Spain (2007-2012)

Prevalence of transmitted drug resistance (pTDR) to antiretroviral drugs in Spain (2007-2012) was estimated using the CoRIS cohort, adjusting its territorial distribution and transmission route to the reference population from the Spanish Information System on New human immunodeficiency virus diagnoses. A total of 2702 patients from ten autonomous communities and with naive FASTA sequence within 6 months of human immunodeficiency virus diagnosis were selected. Weighted pTDR, estimated using the inverse probability of selection in the sample by autonomous communities and transmission group, was 8.12% (95% CI 6.44-9.80), not significantly different from unweighted pTDR. We illustrate how proportional weighting can maximize representativeness of cohort-based data, and its value to monitor pTDR at country level.

Transmitted drug resistance to rilpivirine in newly diagnosed antiretroviral naive adults

We characterized transmitted drug resistance to rilpivirine and the predicted efficacy of first-line rilpivirine-containing regimens in antiretroviral-naive Spanish patients. International Antiviral Society-USA mutations were detected in 138 of 2781 patients (4.9%), E138A (3.4%) being the most prevalent. Using the Stanford Algorithm, 121 patients (4.4%) showed low-level or intermediate resistance. No differences in the predicted efficacy of first-line non-nucleoside reverse transcriptase inhibitor-based regimens were observed. As rilpivirine becomes more widely used in clinical practice, the evolution of its transmitted drug resistance will need to be monitored. In addition, the exact role of E138A singletons on rilpivirine activity as part of first-line regimens merits further evaluation.

Improving Clinical Laboratory Efficiency: Introduction of Systems for the Diagnosis and Monitoring of HIV Infection

Since the first tests for identifying individuals with suspected human immunodeficiency virus (HIV) infection were introduced in the mid-1980s, diagnostic virology testing has greatly evolved. The technological advances, automating in the laboratories and the advances in molecular biology techniques have helped introduce invaluable laboratory methods for managing HIV patients. Tests for diagnosis, specially for screening HIV antibodies, are now fully automated; in the same way, tests for monitoring HIV viral load (HIV RNA copies/ml of plasma), which is used for monitoring infection and response to antiretroviral treatment, are also fully automated; however, resistance testing, tropism determination and minor variant detection, which are used to make decisions for changing antiretroviral treatment regimens in patients failing therapy, still remain highly laborious and time consuming. This chapter will review the main aspects relating to the automating of the methods available for laboratory diagnosis as well as for monitoring of the HIV infection and determination of resistance to antiretrovirals and viral tropism.

[Laboratory diagnosis of HIV infection, viral tropism and resistance to antiretrovirals]

The accurate diagnosis of HIV infection demands that to consider a positive result, at least three assays with different antigenic base should be used, one of them, Western-Blot being mandatory for confirmation. Fourth generation ELISAs shorten the window phase to 13-15 days, as they now include p24 antigen detection. Proviral DNA or Viral RNA detection by molecular methods have proved useful for addressing complex situations in which serology was inconclusive. Viral load (HIV-RNA) is routinely used to follow-up HIV infected patients and is used for treatment initiation decisions. It is also used to monitor viral failure. When this happens, resistance tests are needed to guide treatment changes. Resistance is also used to assess the transmission of drug resistance to newly diagnosed patients. Finally, before using an anti-CCR5 drug, viral tropism needs to be determined. This can be done using genotypic tests, widely available in many HIV labs, or phenotypic tests, only available at certain sites.

Synthesis, ligand pK(a), and Fe(III) complexation constants for a series of bipodal dihydroxamic acids

The synthesis of four bipodal dihydroxamic acids containing an apical C atom and amide linkages is described, where Ia,b represent "normal" and "retro" hydroxamate isomers: (R)CH[C(=O)NH(CH(2))(2)NHC(=O)(CH(2))(n)()R'](2) (Ia, R = CH(3), R' = N(OH)(C=O)CH(3), n = 2; Ib, R = CH(3), R' = (C=O)N(OH)CH(3), n = 2; Ic, R = CH(3), R' = (C=O)N(OH)CH(3), n = 3; Id, R = C(4)H(9), R' = (C=O)N(OH)CH(3), n = 2.). The pK(a1) and pK(a2) values in aqueous solution are reported, and some degree of cooperativity is noted. Complexation equilibria with Fe(aq)(3+) are described, and values for stepwise and overall equilibrium constants are reported. log beta(230) values for Ia-d are 59.22, 59.45, 58.91, and 58.46, slightly lower than for rhodotorulic acid, although the pFe values for the synthetic siderophores are comparable to that for rhodotorulic acid.

Cytoprotection and iron mobilization in rat hepatocyte cultures by a new synthetic dihydroxamate chelator

The cytoprotection and iron mobilization effect of a new dihydroxamate chelator 1,1 bis [(11-N-hydroxy)-2,5,11-triaza-1,6,10-trioxo dodecanyl] ethane or KD was studied in primary rat hepatocyte cultures exposed to iron-citrate. Lactate dehydrogenase (LDH) release and malondialdehyde (MDA) production were measured as indexes of cytotoxicity. Cell viability was evaluated using the [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyl tetrazolium bromide] (MTT) reduction test. To demonstrate that this chelator was able to decrease iron uptake or increase iron release from the hepatocytes, labelled cells were obtained by maintaining the cultures in the presence of 0.02 microM 55Fe-citrate. The efficacy of KD was compared to desferrioxamine B (DFO) at stoechiometry concentrations. After 24 h of exposure to 50 microM of iron-citrate, a significant release of LDH and MDA was observed. Cell viability was also significantly decreased. When 100 microM of KD were added at the same time as iron, LDH and MDA release was decreased and cell viability was improved. In the presence of the same chelator concentration, a net decrease of iron uptake by the cells was observed as attested by the low intracellular 55Fe level. Moreover, in the 55Fe loaded hepatocytes, the chelator increased the iron extracellular level indicating its iron release effect from the cells. In all tested experimental conditions, the efficacy of 100 microM of the dihydroxamate chelator KD was close to that of 50 microM of the trihydroxamate chelator DFO. In conclusion, KD is effective at a level comparable to DFO in protecting rat hepatocytes against the toxic effect of iron-citrate by decreasing the uptake of the metal and increasing its release from the cells. This synthetic compound appears to have some potential therapeutical interest and the results obtained encourage the synthesis of new hydroxamate ligands.