Mini review: current molecular methods for the detection and quantification of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus type 1

Screening and diagnostic testing protocols for HIV and Syphilis infections in health care setting in Qatar: Evaluation and recommendations

BACKGROUND

HIV and Syphilis are common STIs, which have become a concern and burden on healthcare systems, as many infections go untreated and lead to potentially serious complications. HIV is usually diagnosed with Western blot, PCR, and p24 antigen testing. Whereas, Syphilis is mainly diagnosed through clinical findings and serologic testing. The Medical Commission Department (MC) under MOPH is responsible for screening all newcomers to Qatar, aiming to keep the country free from serious infectious diseases.

OBJECTIVE

We aimed to evaluate the diagnostic efficiency of the protocols used in the MC for screening HIV and Syphilis infections.

METHODS

We conducted a retrospective study of samples analyzed by 4th Generation ARCHITECT® HIV Ag/Ab Combo and Rapid Plasma Reagin (RPR) between January to December 2019. ARCHITECT® HIV Ag/Ab Combo positive samples were confirmed by INNO-LIA™ HIVI/II and RT-PCR. RPR-reactive samples were confirmed by ARCHITECT® Syphilis Treponema pallidium Antibody (Syphilis TPA) assay.

RESULTS

For HIV, data were collected from 585,587 individuals, of which 595 (0.1%) were positive by the ARCHITECT® HIV Ag/Ab Combo (Analyzer A). When all initially positive sera were re-tested on newly collected blood samples using different ARCHITECT® HIV Ag/Ab Combo analyzer (analyzer B), 99.8% (594/595) of samples were also positive, suggesting high reproducibility. The positive predictive value (PPV) between ARCHITECT® HIV Ag/Ab Combo and the INNO-LIA™ HIVI/II confirmatory assay was 31.8%. The PPV between ARCHITECT® HIV Ag/Ab Combo and HIV-PCR assay was 26.8%. Retrospective data for Syphilis were collected from a total of 97,298 individuals who visited the MC, of which 198 (0.20%) were initially positive by RPR. The PPV between RPR and Syphilis TPA confirmatory assay was 36.6%.

CONCLUSION

Despite the high rate of false positivity using ARCHITECT® HIV Ag/Ab Combo and RPR screening assays, both assays have proven to be highly effective as screening testing methods.

An ultrasensitive electrochemical immunosensor for hepatitis C antibodies based on one-step-eletrosynthetized polypyrrole-graphene nanocomposite

An ultrasensitive label-free electrochemical immunosensor was developed for hepatitis C antibodies (anti-HCV). Worldwide, it is estimated 71 million people have HCV infection in a chronic stage that may lead to cirrose and cancer. To achieve HCV elimination, health programs should include screening testing based on anti-HCV detection allowing the early-stage treatment. The immunosensor was based on a graphene oxide-polypyrrole (PPy-GO) film one-step electropolymerized on the electrode surface. Ultrasensitive anti-HCV detection was ensured by HCV antigen conjugated to biotin that was immobilized in a great amount on streptavidin-coated nanostructured surface. Analytical responses were obtained by anodic peaks from the square wave voltammetry in the presence of ferrocyanide/ferricyanide as a redox probe. This immunosensor exhibited a linear range from 2 to 14 ng mL^-1 of anti-HCV and a limit of detection in the clinical range (1.63 ng mL^-1). Furthermore, the immunosensor presented an efficient performance for the determination of anti-HCV in spiked serum samples, becoming this developed nanosensor as potential tools for early HCV diagnosis and screening.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10853-022-06992-5.

Multicolorimetric ELISA biosensors on a paper/polymer hybrid analytical device for visual point-of-care detection of infection diseases

Enzyme-linked immunosorbent assay (ELISA) is widely used for the detection of disease biomarkers. However, it utilizes time-consuming procedures and expensive instruments, making it infeasible for point-of-care (POC) analysis especially in resource-limited settings. In this work, a multicolorimetric ELISA biosensor integrated on a paper/polymer hybrid microfluidic device was developed for rapid visual detection of disease biomarkers at point of care, without using costly equipment. This multicolormetric ELISA platform was built on multiple distinct color variants resulted from the catalytic oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and the etching of gold nanorods (AuNRs). The vivid color changes could be easily distinguished by the naked eye, and their red mean values allowed quantitative biomarker detection, without using any sophisticated instruments. When this multicolorimetric ELISA was integrated on a paper/polymer hybrid analytical device, it not only provided integrated processing and high portability but also enabled fast assays in about 50 min due to the unique advantages of paper/polymer hybrid devices. The limit of detection of 9.1 ng/μL of the hepatitis C virus core antigen, a biomarker for hepatitis C, was achieved using this multicolorimetric ELISA platform. This multicolor ELISA analytical device provides a new versatile, user-friendly, affordable, and portable immunosensing platform with high potential for on-site detections of various viruses, proteins, and biomarkers for low-resource settings such as at home, public venues, rural areas, and developing nations.

Hepatitis C virus (HCV) diagnosis via microfluidics

Humans are subjected to various diseases; hence, proper diagnosis helps avoid further disease consequences. One such severe issue that could cause significant damage to the human liver is the hepatitis C virus (HCV). Several techniques are available to detect HCV under various categories, such as detection through antibodies, antigens, and RNA. Although immunoassays play a significant role in discovering hepatitis viruses, there is a need for point-of-care tests (POCT). Some developing strategies are required to ensure the appropriate selection of POCT for HCV detection, initiate appropriate antiviral therapy, and define associated risks, which will be critical in achieving optimal outcomes. Though molecular assays are precise, reproducible, sensitive, and specific, alternative strategies are required to enhance HCV diagnosis among the infected population. Herein, we described and assessed the potential of various microfluidic detection techniques and confirmatory approaches used in present communities. In addition, current key market players in HCV chip-based diagnosis and the future perspectives on the basis of which the diagnosis can be made easier are presented in the present review.

Blood safety in Mexico and a perspective on Latin America

Blood safety has been of paramount concern worldwide over the last decades, and Latin America and Mexico are no exception. Factors of utmost importance include the use of highly efficient screening tests and the encouragement of voluntary donation. This review summarizes the current situation in Latin America and particularly in Mexico with respect to these key issues. Except for some specific regions, there is a lack of progress of voluntary donation in Mexico compared with other Latin American countries. A more efficient voluntary donation system could provide donors with lower prevalence of infectious agents such as human immunodeficiency, hepatitis B, and hepatitis C viruses. In Latin America, and specifically in countries such as Argentina, Brazil and Nicaragua, voluntary donation and blood safety are strongly encouraged. However, to date, in Mexico there has not been a specific blood safety project because of fragmentation of the health system model with structural differences among organisations. Although national policies are established to grant health coverages in Mexico, blood safety is still limited and outdated because of oversights in technical fields and regulations. Individual molecular biological tests for donor screening have recently been incorporated into the Mexican national regulations. Although the routine use of these tests as part of effective donor screening is still not compulsory, it is enabling a progressive improvement of blood safety.

The American Society of Transplantation Consensus Conference on the Use of Hepatitis C Viremic Donors in Solid Organ Transplantation

The availability of direct-acting antiviral agents for the treatment of hepatitis C virus (HCV) infection has resulted in a profound shift in the approach to the management of this infection. These changes have affected the practice of solid organ transplantation by altering the framework by which patients with end-stage organ disease are managed and receive organ transplants. The high level of safety and efficacy of these medications in patients with chronic HCV infection provides the opportunity to explore their use in the setting of transplanting organs from HCV-viremic patients into non-HCV-viremic recipients. Because these organs are frequently discarded and typically come from younger donors, this approach has the potential to save lives on the solid organ transplant waitlist. Therefore, an urgent need exists for prospective research protocols that study the risk versus benefit of using organs for hepatitis C-infected donors. In response to this rapidly changing practice and the need for scientific study and consensus, the American Society of Transplantation convened a meeting of experts to review current data and develop the framework for the study of using HCV viremic organs in solid organ transplantation.

Prevalence and characterization of occult hepatitis B infection among blood donors in central Saudi Arabia

OBJECTIVES

To evaluate the prevalence of occult hepatitis B viral infections (OBIs)  among blood donors considering the clinical and epidemiological importance of identifying OBIs.

METHODS

A cross-sectional study conducted at King Khalid University Hospital, Riyadh, Saudi Arabia between January 2011 and January 2012. Blood donors (n=8501) were screened for Hepatitis B virus surface antigen (HBsAg) and hepatitis B core antibodies (HBcAb). All HBsAg-negative and HBcAb-positive samples were tested further for hepatitis B surface antibodies (HBsAb), hepatitis B virus (HBV)-DNA, and HBV genotyping.  

RESULTS

Of the 8501 serum samples tested, 56 (0.7%) were positive and 8445 (99.3%) were negative for HBsAg. Among the HBsAg-negative samples, 198 (2.3%) were positive for HBcAb and these patients were suspected to have OBIs. Among the HBcAb-positive samples, 119 (60.1%) were positive while 79 (39.9%) were negative for HBsAb. Analysis of HBV-DNA for the suspected OBIs showed that 17 out of 198 samples (8.6%) yielded positive results, and all of them were HBsAb-negative. The viral load was low (less than 20-186 IU/mL) in all OBIs. Hepatitis B virus genotyping showed that 15 out of 17 samples (88.2%) were genotype D, and the other 2 samples (11.8%) were genotype E. 

CONCLUSION

The prevalence of OBIs among blood donors in Riyadh was 0.2%. Therefore, it is recommended that HBV molecular testing should be incorporated with serological assays for screening of blood donors.

Cost-effective HIV-1 virological monitoring in resource-limited settings using a modified commercially available qPCR RNA assay

Virological monitoring through plasma viral load (PVL) quantification is essential for clinical management of HIV patients undergoing antiretroviral treatment (ART), and for detecting treatment failure. Quantitative PCR (qPCR)-based tests are the gold standard for measuring PVL. Largely because of their high cost, however, implementation of these tests in low- and middle-income countries fails to cover the testing demand. In this study, we aimed at reducing the running cost of the commercially available Abbott RealTime™ HIV-1 assay by minimizing the reagent consumption. To this end, a modified version of the assay was obtained by reducing the assay's reagents volume to about a half, and validated using a panel of 104 plasma samples. Compared to the standard version, the modified Abbott assay allowed for a 50% reduction in running costs. At the same time, it showed a 100% concordance in identifying samples with detectable viral load, strong correlation (Pearson's r=0.983, P<0.0001), and a high agreement between PVL values (mean percent difference between PVL values±standard deviation=0.76±3.18%). In detecting viral failure (PVL>1000copiesmL^-1), the modified assay showed a sensitivity of 94.6%, a specificity of 93.8%, and a negative and positive predictive values of 93.8% and 94.6%, respectively. The modified assay therefore reliably quantifies PVL, predicts viral failure, and allows for a ca. 50% reduction in the assay's running costs. It may thus be implemented as an ART monitoring tool in resource-limited settings and for research purposes.

The new frontier of diagnostics: Molecular assays and their role in infection prevention and control

Recent advances in technology over the last decade have propelled the microbiology laboratory into a pivotal role in infection prevention and control. The rapid adaptation of molecular technologies to the field of clinical microbiology now greatly influences infectious disease management and significantly impacts infection control practices. This review discusses recent developments in molecular techniques in the diagnosis of infectious diseases. It describes the basic concepts of molecular assays, discusses their advantages and limitations, and characterizes currently available commercial assays with respect to cost, interpretive requirements, and clinical utility.

Simultaneous detection of multiple viruses based on chemiluminescence and magnetic separation

In this report, a DNA hybridization based chemiluminescent detection method has been proposed for reliable detection of multiple pathogens. The use of surface modified magnetic nanoparticles can help to integrate this system into an automated platform for high throughput applications.

Assessment of semi-automated nucleic acid testing programme in a Regional Blood Transfusion Centre

BACKGROUND

Detection of human immunodeficiency virus type-1 (HIV-1), hepatitis-C (HCV) and hepatitis-B virus (HBV) in the blood donors is crucial. An efficient form of detection is nucleic acid testing (NAT) in blood screening. We assessed the suitability of commercial NAT testing in a developing country, focusing on the Altona RealStar assay and the method of Sacace Biotechnologies.

METHODS

We have standardised and validated commercially available NAT kits with a semi-automated system for detection of HBV, HCV and HIV-1 in blood donations. The MP-NAT (mini-pool) assay consists of pooling of sample, virus extraction, amplification and detection with commercially available NAT kits. An internal control (IC) is incorporated in the assay to monitor the extraction, target amplification and detection process.

RESULTS

The sensitivity of the Altona RealStar assay at 10-MP for each viral target was evaluated, HBV showed amplification in all diluted positive samples of 100, 50, 25, 10 and 5 IU/ml. HIV and HCV infected samples showed amplification in all diluted positive samples of 500, 100, 50 and 30 IU/ml. For HIV, out of six diluted samples of 30 IU/ml, five were amplified. A total of 14,170 seronegative blood samples were tested by RealStar PCR kit in 10-MP and 6 (0.042%) samples/pools were positive. A total of 65,362 seronegative blood donations were also tested by kits of Sacace Biotechnologies, in 10-MP and 45 (0.075%) pools were positive. The prevalence of combined NAT yield cases among routine donors was 1 in 1559 donations tested for all the 3 viruses.

CONCLUSION

The semi-automated combined system for NAT screening assays is robust, sensitive, reproducible, and this gives an additional layer of safety with affordable cost.

Real-time polymerase chain reaction optimised for hepatitis C virus detection in dried blood spots from HIV-exposed infants, KwaZulu-Natal, South Africa

Background

There is a paucity of data on the prevalence of hepatitis C virus (HCV) in children, particularly in sub-Saharan Africa. A major obstacle in resource-limited settings for polymerase chain reaction (PCR) testing is the necessity for specimen transportation and storage at low temperatures. There are numerous recent studies of using real-time HCV PCR for diagnosis and screening of plasma and serum, but few have looked at using dried blood spot (DBS) specimens.

Objectives

The aim of this study was to optimise a real-time HCV PCR method to detect HCV RNA from infant DBS specimens for use as a tool for HCV surveillance in KwaZulu-Natal, South Africa.

Method

The LightCycler^® 2.0 instrument was used for the HCV PCR using the LightCycler^® RNA Master SYBR Green I kit. Template volume, primer concentration and primer annealing temperatures were optimised and the method was used on 179 DBS specimens from HIV-exposed infants in KwaZulu-Natal.

Results

Primer concentrations adjusted to 0.25 µM and a template volume of 10 µL improved the PCR amplification. Primer annealing temperatures lowered from 65 °C to 58 °C resulted in higher quantities of amplified PCR product. The limit of detection of the optimised HCV PCR assay was between 1200 IU/mL and 3580 IU/mL of HCV RNA. HCV was not detected in any of the 179 DBS specimens.

Conclusion

The optimised real-time HCV PCR on infant DBS specimens performed well, but HCV was not found in this surveillance study. HIV infection may have little impact on the vertical transmission of HCV in this region.

Automated Triplex (HBV, HCV and HIV) NAT Assay Systems for Blood Screening in India

This review is confined to triplex nucleic acid testing (NAT) assays to be used on fully automated platform. Around the world, these assays are being used at various transfusion medicine centres or blood banks to screen blood units for HBV, HCV and HIV. These assay systems can screen up to 1000 blood units for HBV, HCV and HIV simultaneously in a day. This area has been dominated by mainly two manufacturers: M/s Gen-Probe-Novartis and M/s Roche Molecular Systems. The triplex NAT assay systems of both manufacturers are licensed by United States Food and Drug Administration. There is not much awareness about the technology and procedures used in these assays. The main objective of this review is to create awareness about the technology and procedure of these assays.

Update on hepatitis B and C virus diagnosis

Viral hepatitis B and C virus (HBV and HCV) are responsible for the most of chronic liver disease worldwide and are transmitted by parenteral route, sexual and vertical transmission. One important measure to reduce the burden of these infections is the diagnosis of acute and chronic cases of HBV and HCV. In order to provide an effective diagnosis and monitoring of antiviral treatment, it is important to choose sensitive, rapid, inexpensive, and robust analytical methods. Primary diagnosis of HBV and HCV infection is made by using serological tests for detecting antigens and antibodies against these viruses. In order to confirm primary diagnosis, to quantify viral load, to determine genotypes and resistance mutants for antiviral treatment, qualitative and quantitative molecular tests are used. In this manuscript, we review the current serological and molecular methods for the diagnosis of hepatitis B and C.

Hepatitis C virus: Virology, diagnosis and treatment

More than twenty years of study has provided a better understanding of hepatitis C virus (HCV) life cycle, including the general properties of viral RNA and proteins. This effort facilitates the development of sensitive diagnostic tools and effective antiviral treatments. At present, serologic screening test is recommended to perform on individuals in the high risk groups and nucleic acid tests are recommended to confirm the active HCV infections. Quantization and genotyping of HCV RNAs are important to determine the optimal duration of anti-viral therapy and predict the likelihood of response. In the early 2000s, pegylated interferon plus ribavirin became the standard anti-HCV treatment. However, this therapy is not ideal. To 2014, boceprevir, telaprevir, simeprevir, sofosbuvir and Harvoni are approved by Food and Drug Administration for the treat of HCV infections. It is likely that the new all-oral, interferon-free, pan-genotyping anti-HCV therapy will be available within the next few years. Majority of HCV infections will be cured by these anti-viral treatments. However, not all patients are expected to be cured due to viral resistance and the high cost of antiviral treatments. Thus, an efficient prophylactic vaccine will be the next challenge in the fight against HCV infection.