Nucleic Acid Testing Research Articles

Combined modalities for the rapid diagnosis of patients with suspected tuberculous lymphadenitis: A cross-sectional study.

In settings with high burden of extrapulmonary tuberculosis, the use of various diagnostic modalities can result in superior and quick diagnosis leading to prompt initiation of treatment. This study assessed the diagnostic performance of the fine-needle aspiration cytology (FNAC), Ziehl-Neelsen (ZN) stain, fluorescence microscopy (FM) and cartridge-based nucleic acid amplification test (CBNAAT) in patients with suspected tuberculous lymphadenitis (TBLN). This cross-sectional studyodes, who underwent FNAC. The FNAC samples were subjected to cytomorphological examinati involved 255 patients clinically suspected of TBLN with palpable lymph non, ZN stain, FM and CBNAAT. The diagnostic performance of each modality was compared with CBNAAT, and combined performance was determined. The diagnostic performance of CBNAAT was determined by comparing it with composite reference standard. Of 255 patients, 148 (58.04%) showed features of TBLN on FNAC. The presence of epithelioid cell granulomas with caseous necrosis (67.57%) was the predominant cytomorphological pattern. On ZN stain, FM and CBNAAT, 31 (20.95%), 63 (42.57%) and 100 (67.57%) patients were found to be positive for TBLN, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of CBNAAT was 58.59%, 91.83%, 92% and 58.06%, respectively. Finally, the combination of ZN stain, FM and CBNAAT led to the detection of 88.51% patients with TBLN. Combined use of ZN stain, FM and CBNAAT leads to superior and swift diagnosis of patients with clinically suspected TBLN.

Infectivity of Hepatitis B Virus Surface Antigen-Positive Plasma With Undetectable HBV-DNA: Can HBsAg Screening Be Discontinued in Egyptian Blood Donors?

Hepatitis B Virus (HBV) infectivity data were reviewed and the 50% infectious dose (ID50) was reassessed in different HBsAg-positive infection stages enabling modelling of transfusion-transmitted (TT)-HBV infection risk if HBsAg donor screening was replaced by individual donation nucleic acid amplification technology (ID-NAT). Quantitative HBsAg and HBV-DNA assays were performed against international standards to compare the ratio between potential infectious HBV virions and subviral HBsAg particles in Egyptian HBsAg-positive blood donors as well as in Japanese chimpanzee samples of known infectivity. HBV-DNA load below the quantification limit of detection was estimated against a reference standard by replicate NAT testing (n = 25). Infectivity of chimpanzee samples collected during ramp-up and declining viremic phase were tested in a human liver chimeric mice (HLCM) model and compared with published infectivity data from different HBsAg-positive infection stages. Lowest estimates of ID50 in HBsAg-positive plasma were 3-6 HBV virions in chimpanzee studies. Infectivity decreased approximately 10-100-fold in the declining viremic phase using HLCM. In acute phase samples, HBV to HBsAg particle ratios varied between 1:102-104 but in HBsAg-positive blood donors this particle ratio reached 1:106-1012 when viral load was below 100 HBV-DNA copies/mL. Modelled TT-HBV risk of an HBsAg-positive/ID-NAT nonreactive blood transfusion was estimated at 5.5%-27% for components containing 20-200 mL of plasma when assuming an ID50 of 316 (point estimate between 100 and 1000) virions. It cannot be ensured that discontinuation of HBsAg donor screening and reliance on ID-NAT alone is safe.

Reactive arthritis in connective tissue diseases; one should be vigilant for joint tuberculosis.

The incidence of tuberculosis (TB) is increasing worldwide. Bone and joint TB are the most common types of extra-pulmonary TB, but can easily be misdiagnosed, since articular TB commonly mimics other joint diseases, including reactive and degenerative arthritis, and articular manifestations associated with systemic autoimmune diseases. Furthermore, patients with systemic auto-immune diseases are often more prone to mycobacterial infection. The diagnosis of joint TB can be made using a combination of the following methods: clinical evaluation, imaging, tuberculin skin test, interferon-gamma release assays, nucleic acid amplification tests, and Gene X-pert MTB/rifampicin assay.

Chinese Public Attitudes and Opinions on Health Policies During Public Health Emergencies: Sentiment and Topic Analysis.

By the end of 2021, the new wave of COVID-19 sparked by the Omicron variant spread rapidly due to its highly contagious nature, affecting more than 170 countries worldwide. Nucleic acid testing became the gold standard for diagnosing novel coronavirus infections. As of July 2022, numerous cities and regions in China have implemented regular nucleic acid testing policies, which have had a significant impact on socioeconomics and people's lives. This policy has garnered widespread attention on social media platforms. This study took the newly issued regular nucleic acid testing policy during the COVID-19 pandemic as an example to explore the sentiment responses and fluctuations of netizens toward new policies during public health emergencies. It aimed to propose strategies for managing public opinion on the internet and provide recommendations for policy making and public opinion control. We collected blog posts related to nucleic acid testing on Weibo from April 1, 2022, to July 31, 2022. We used the topic modeling technique latent Dirichlet allocation (LDA) to identify the most common topics posted by users. We used Bidirectional Encoder Representations from Transformers (BERT) to calculate the sentiment score of each post. We used an autoregressive integrated moving average (ARIMA) model to examine the relationship between sentiment scores and changes over time. We compared the differences in sentiment scores across various topics, as well as the changes in sentiment before and after the announcement of the nucleic acid price reduction policy (May 22) and the lifting of the lockdown policy in Shanghai (June 1). We collected a total of 463,566 Weibo posts, with an average of 3799.72 (SD 1296.06) posts published daily. The LDA topic extraction identified 8 topics, with the most numerous being the Shanghai outbreak, nucleic acid testing price, and transportation. The average sentiment score of the posts was 0.64 (SD 0.31), indicating a predominance of positive sentiment. For all topics, posts with positive sentiment consistently outnumbered those with negative sentiment (χ27=24,844.4, P<.001). The sentiment scores of posts related to "nucleic acid testing price" decreased after May 22 compared with before (t120=3.882, P<.001). Similarly, the sentiment scores of posts related to the "Shanghai outbreak" decreased after June 1 compared with before (t120=11.943, P<.001). During public health emergencies, the topics of public concern were diverse. Public sentiment toward the regular nucleic acid testing policy was generally positive, but fluctuations occurred following the announcement of key policies. To understand the primary concerns of the public, the government needs to monitor social media posts by citizens. By promptly sharing information on media platforms and engaging in effective communication, the government can bridge the information gap between the public and government agencies, fostering a positive public opinion environment.

Long-term outcomes of heart re-transplantation from HCV-viremic donors based on UNOS registry

Abstract Background The use of hepatitis C virus (HCV) viremic donors increased the heart donor pool, and reduced waitlist time and mortality among first-time single-organ heart transplant (HT) candidates without compromising their post-transplant survival. The outcomes of heart re-transplantation (re-HT) with the use of HCV-viremic donor grafts have not been investigated. Methods Using the United Network of Organ Sharing (UNOS) Registry we analyzed all adult patients who underwent single-organ heart re-HT in the United States between January 1, 2016, and December 31, 2022. HCV-viremic donors were defined by a positive nucleic acid amplification test (NAT+). Graft survival rates between HCV-viremic and HCV-non-viremic donor graft recipients were compared using a log rank test. Results During the study period, of 18,259 HTs performed, 427 (2.3%) constituted single-organ heart re-transplantations. Recipients of NAT+ grafts (n=19) compared to NAT- grafts (n=408) were more often male (84.2% vs 61.3%, p=0.04). Otherwise, there were no significant differences between the two groups in age, ethnicity, BMI, blood type, history of diabetes rates or stroke, creatinine or bilirubin levels, reason for re-HT, hemodynamics, use of mechanical circulatory support, and waitlist time. Ischemic time, frequency of female donors, HLA, ABO, CMV mismatch rates, and calculated panel reactive antibodies levels were comparable across the two groups. There were no significant differences in demographics or comorbidities rates between HCV-viremic and HCV-non-viremic donors apart from the cause of death. Among the donors of HCV-viremic grafts brain anoxia was reported more often (89.5%) than among HCV-non-viremic donors (40%), p &amp;lt;0.01. Rates of acute rejection treated in the first year after re-HT were comparable across the two groups. Over a mean follow-up of 3.0±2.1 and 3.3±1.8 years after re-HT from NAT- and NAT+ organ donors, respectively, graft survival rate at 1 year was 82% vs. 95% (p=0.3) and at 3 years 79% vs. 89%, respectively (p=0.6) (Figure). Conclusion Graft survival rates at 1 and 3 years post-heart re-HT in adult recipients of HCV-viremic donor grafts were comparable to those of recipients of HCV-non-viremic donor grafts. The current study provides compelling preliminary evidence that HCV-viremic donors constitute a viable donor pool for patients in need of heart re-transplantation.

High prevalence of cardiotropic viruses in endomyocardial biopsies from patients with inflammatory cardiomyopathy demonstrated by a novel targeted NGS approach

Abstract Background Viral infection of the heart muscle is a common cause of myocarditis and viral persistence can lead to chronic inflammatory cardiomyopathies (DCMi). A number of viruses including parvovirus B19 (B19V), adenovirus (AdV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes virus 6 (HHV-6) and enteroviruses (EV) are known to infect the myocardium, but their prevalence and role in persisting DCMi are not well understood. Virological etiologies can only be determined via endomyocardial biopsy (EMB), but the low tissue amount limits the number of conventional viral nucleic acid tests (virus-specific PCR) that can be performed in parallel. This study aimed to detect known and novel cardiotropic viruses in EMB of DCMi patients using a targeted next generation sequencing (NGS) approach. Methods A cohort of 33 patients with inflammatory cardiomyopathy (DCMi) (LVEF=29±12%) were retrospectively analyzed and compared to previous results of virus-specific PCR. DNA and RNA extracted from EMB were used for sequencing library preparation, and viral nucleic acids were enriched via a custom myBaits hybridization capture approach. Enriched libraries were sequenced on an Illumina MiSeq-platform in paired-end mode (500.000 reads/sample), and reads were taxonomically classified via Kraken2 and mapped against viral reference genomes using BWA-MEM2 or HiSat2, and subsequently deduplicated. Viral reads detected via both Kraken2 and mapping were classified as valid. Results Targeted NGS confirmed 19 out of 22 (86%) of the previous PCR-based viral detections. However, NGS was able to detect B19V DNA and RNA in an additional 11 and 15 patient samples respectively; CMV DNA/RNA in additional 5 and 4 samples respectively; EBV DNA/RNA in additional 5 and 1 samples respectively; and HHV-6 DNA/RNA in additional 3 and 1 samples respectively. Furthermore, viral reads of adenovirus type 2, adenovirus-associated virus type 2 (AAV-2), herpes viruses 7 and 8, and human parvovirus 4 were also found among the cohort. Thus, targeted NGS was able to identify 82 viral infections in a cohort of 33 DCMi patients, while only 22 were found using routine PCR tests. For routinely tested B19V, the use of the new NGS diagnostic approach improved sensitivity by 42% and specificity by 72%. Conclusions The presented NGS method represents a powerful new tool for the diagnosis of viral and inflammatory heart disease. The sensitivity is significantly higher than with conventional PCR approaches and the taxonomic classification is more specific. This enables the detection of previously false-negative routine viruses as well as potentially new cardiotropic pathogens from limited bioptic patient material – thus significantly increasing the diagnostic yield of EMB. In addition, our study demonstrates a high prevalence of non-enteroviral cardiotropic viruses in DCMi patients, shedding new light on the etiology of this heterogenous diseases and paving the way for more specific future treatments.

Metabolomic alterations in the plasma of patients with various clinical manifestations of COVID-19

BackgroundThe metabolomic profiles of individuals with different clinical manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have not been clearly characterized.MethodsWe performed metabolomics analysis of 166 individuals, including 62 healthy controls, 16 individuals with asymptomatic SARS-CoV-2 infection, and 88 patients with moderate (n = 42) and severe (n = 46) symptomatic 2019 coronavirus disease (COVID-19; 17 with short-term and 34 with long-term nucleic-acid test positivity). By examining differential expression, we identified candidate metabolites associated with different SARS-CoV-2 infection presentations. Functional and machine learning analyses were performed to explore the metabolites’ functions and verify their candidacy as biomarkers.ResultsA total of 417 metabolites were detected. We discovered 70 differentially expressed metabolites that may help differentiate asymptomatic infections from healthy controls and COVID-19 patients with different disease severity. Cyclamic acid and N-Acetylneuraminic Acid were identified to distinguish symptomatic infected patients and asymptomatic infected patients. Shikimic Acid, Glycyrrhetinic acid and 3-Hydroxybutyrate can supply significant insights for distinguishing short-term and long-term nucleic-acid test positivity.ConclusionMetabolomic profiling may highlight novel biomarkers for the identification of individuals with asymptomatic SARS-CoV-2 infection and further our understanding of the molecular pathogenesis of COVID-19.

Performance of the Flash10 COVID-19 point-of-care molecular test

After the COVID-19 pandemic, fever clinics urgently require rapid nucleic acid tests to enhance their capacity for timely pathogen detection. This study evaluated the analytical performance and clinical utility of the Flash10 SARS-CoV-2 point-of-care test (Flash10 POCT) for detecting SARS-CoV-2 in patients with fever in the adult fever clinic in Beijing Tsinghua Changgung Hospital from August 1 to August 30, 2023. The analytical performance and clinical utility of the Flash10 POCT for detecting SARS-CoV-2 were assessed in 125 patients with fever syndrome in the adult fever clinic. The Flash10 POCT demonstrated an analytical precision of 3.1% for the Ct values of the ORF1ab gene and 2.9% for the Ct values of the N gene in SARS-CoV-2 nucleic acid testing. Furthermore, the Flash10 POCT demonstrated a lower limit of detection (LoD) of 100 copies/mL, with no detected aerosol contamination leakage. Of the 125 patients (median age 61.9 years, 52% male and 48% female), both the Flash10 POCT and RT-PCR tests yielded positive results for 100 patients and negative results for 25 patients (Fisher’s exact test, p < 0.0001). The median turn-around-time for the Flash10 POCT was significantly shorter, at 1.05 h, compared to 16.15 h required for RT-PCR tests (Wilcoxon signed rank test, p < 0.0001). The Flash10 POCT showed high analytical performance, achieving a 100% detection rate for SARS-CoV-2 compared to RT-PCR tests, while also exhibiting a significantly shorter turn-around-time. Implementing the Flash10 POCT had the potential to expedite the care of adults presenting with fever.

Clinical utility of EBV DNA testing of blood in immunocompetent and immunocompromised patients: A single-center experience.

Epstein-Barr virus (EBV) causes different clinical presentations in immunocompetent and immunocompromised persons, and thus indications for testing vary between these populations. We reviewed our institution's EBV DNA testing across these populations to understand its clinical utility and appropriateness. We conducted a retrospective chart review of adult patients with positive EBV nucleic acid amplification (NAAT) testing from November 2022 to 2023. We recorded demographics, indications for testing, EBV-related diagnosis, laboratory results, and whether testing influenced patient treatment. Of 3560 EBV NAAT tests, 187 (5.3%) were positive, representing 124 unique adult patients (51 immunocompetent and 73 immunocompromised). Reactivation of EBV was the most common diagnosis in both populations, followed by acute EBV infection in the immunocompetent and non-posttransplant lymphoproliferative disorder malignancies in the immunocompromised. In immunocompromised patients, positive tests led to treatment changes more frequently than in immunocompetent patients (27.4% vs 11.7%, P=.06). Testing affected clinical management in 0% to 2% of cases when sent for sepsis/shock and nonspecific viral syndromes compared to 37% to 49% of cases when sent for posttransplant and malignancy screening/monitoring. EBV NAAT testinginfrequently influenced clinical management in immunocompetent individuals but had a notable impact in immunocompromised patients, particularly those undergoing posttransplant or malignancy screening. This underscores the need for targeted testing to optimize resource utilization and cost-effectiveness.

Review: Diagnostic Potential for Collaborative Pharyngitis Biomarkers.

Pharyngitis is an inflammatory condition of the pharynx and/or tonsils commonly seen in both children and adults. Viruses and bacteria represent the most common encountered etiologic agents-yeast/fungi and parasites are infrequently implicated. Some of these are predominantly observed in unique populations (eg, immunocompromised or unvaccinated individuals). This manuscript (part 3 of 3) summarizes the current state of biomarker diagnostic testing and highlights the expanding role they will likely play in the expedited diagnosis and management of patients with acute pharyngitis. Biomarkers, in conjunction with rapid antigen and/or nucleic acid amplification testing, will likely become the standard of care to accurately diagnose the etiologic agent(s) of pharyngitis. This novel testing paradigm has the potential to guide appropriate patient management and antibiotic stewardship by accurately determining if the cause of pharyngitis is due to a viral or bacterial etiology.

Review: Current Laboratory and Point-of-Care Pharyngitis Diagnostic Testing and Knowledge Gaps.

Pharyngitis is an inflammatory condition of the pharynx and/or tonsils commonly seen in both children and adults. Viruses and bacteria represent the most common encountered etiologic agents-yeast/fungi and parasites are infrequently implicated. Some of these are predominantly observed in unique populations (eg, immunocompromised or unvaccinated individuals). This manuscript (part 2 of 3) summarizes the current state of laboratory and point-of-care diagnostic testing and highlights the expanding role of nucleic acid amplification in the expedited diagnosis and management of patients with acute pharyngitis. It discusses preanalytical, analytical, and postanalytical variables that impact the performance of culture, rapid antigen, and nucleic acid amplification testing. Finally, it sets the stage for part 3, which discusses the emerging role of biomarkers in the management of individuals with acute pharyngitis.

Capillary flow velocity-based length identification of PCR and RPA products on paper microfluidic chips.

This work demonstrates a novel, non-fluorescence approach to the length identification of polymerase chain reaction (PCR) and recombinase polymerase amplification (RPA) products, utilizing capillary flow velocities on paper microfluidic chips. It required only a blank paper chip, aminated microspheres, and a smartphone, with a rapid assay time and under ambient lighting. A smartphone evaluated the initial capillary flow velocities on the paper chips for the PCR and RPA products from various bacterial samples, where the pre-loaded aminated microspheres differentiated their flow velocities. Flow velocities were analyzed at different time frames and compared with the instantaneous flow velocities and interfacial tension (γLV) data. Subsequent error analysis justified the use of the initial time frames. A robust linear relationship could be established between the initial flow velocities against the square root of the product lengths, with R2 values of 0.981 for PCR and 0.993 for RPA. The assay seemed not to have a significant dependency on the cycle numbers and initial target concentrations. This novel method can be potentially used with various paper microfluidic methods of nucleic acid amplification tests towards rapid and handheld assays.

A novel dual probe-based method for mutation detection using isothermal amplification.

Cost efficient and rapid detection tools to detect mutations especially those linked to drug-resistance are important to address concerns of the rising multi-drug resistance infections. Here we integrated dual probes, namely a calibrator probe and an indicator probe, into isothermal amplification detection system. These two probes are designed to bind distinct regions on the same amplicon to determine the presence or absence of mutation. The calibrator probe signal is used as an internal signal calibrator for indicator probe which detects the presence or absence of the mutation. As an illustrative example, we evaluated the applicability of this dual probe method for detecting mutations associated with rifampicin (RIF) drug resistance at codons 516, 526 and 531 of the rpoB gene in Mycobacterium tuberculosis. In this assessment, we examined 127 artificial samples comprising wild types and mutants with single or multiple mutations. Our results demonstrated 100% accuracy for both wild types and mutants for mutations at codons 526 and 531. As regards to mutations at codon 516, the wild type was identified with 100% accuracy, while the mutants were identified with 95% accuracy. Moreover, when we extended our evaluation to include clinical MTB strains and the Zeptometrix MTB Verification panel, our method achieved 100% accuracy (5 out of 5) in identifying wild-type strains. Additionally, we successfully detected a RIF-resistant strain with mutations at codon 531 of the rpoB gene in Zeptometrix verification panel. Our isothermal mutation detection system, relying on dual probes exhibits a versatile approach. With the capability to identify mutations without prior knowledge of their specific mutation direction, our dual-probe method shows significant promise for applications in drug resistance nucleic acid testing, particularly in resource-limited settings.

Infection risk factor measurement based on spatial and temporal distribution of COVID-19 nucleic acid test sites: an example from Shenzhen

COVID-19 has profoundly impacted global daily life, emphasizing the need for effective virus suppression strategies. In response, China has established numerous nucleic acid testing sites to facilitate rapid testing and curb outbreaks. However, these sites often experience congestion, increasing transmission risks and reducing testing efficiency. This study focuses on the spatial–temporal analysis of testing site distribution and associated infection risks in Shenzhen, China. Data from all Shenzhen testing sites were analyzed for the week of October 24–30, 2022, noting the percentage of busy hours per site and incorporating a population size factor by district to assess regional infection risks. Findings indicate three daily peak testing times—primarily in the evening—with the highest risk of transmission in Longgang District, followed by Yantian and Luohu, and the lowest in Futian. The risk coefficient varied from 0.040 to 0.349, with most areas showing stable risk levels between 0.06 and 0.20. This research underlines the necessity for policymakers to alleviate congestion at testing sites and suggests increasing site availability in Longgang District to mitigate COVID-19 spread, offering methodological guidance for managing infection risks in other major Chinese cities.

Preliminary survey of three mosquito-borne viruses using a self-established multiplex RT-qPCR assay in Chinese blood donors

BackgroundMosquito-borne pathogens pose a significant threat to both human health and blood safety. The primary mosquito-borne viruses that present this threat are Zika virus, Chikungunya virus, and Dengue virus. At present, there are limited efficacious vaccines or therapeutic drugs for the prevention and treatment of these viral infections. Blood donors can remain asymptomatically infected and unfortunately, screening for these three viruses in Chinese blood donors are not mandatory, leaving the residual risk to transfusion recipients uncertain. Objective: To address this, we developed a single-tube multiplex RT-qPCR assay for ZCD detection and was preliminarily employed to screen a total of 10,566 blood donations in Nanning Blood Center in order to assess the prevalence risk of these pathogens in blood donors. Results: None of the blood samples was reactive for ZCD by nucleic acid test (NAT). One out of 173 donations (1/173, 0.58 %) was IgG positive for ZIKV and 14 (14/173, 8.4 %) were IgG positive for DENV. None of these 173 donations was IgG positive for Chikungunya virus. These findings suggest that the prevalence of ZCD infection in blood donors in Nanning is very low although past DENV infection (IgG positive) was relatively common. Conclusion: A single-tube multiplex RT-qPCR assay for simultaneous detection of ZCD viruses was successfully established and applied for screening in blood donors. The residual risk of ZCD infection through transfusion is currently low in Nanning, China. The NAT assay for ZCD will serve as a technical reserve in response to future epidemic or pandemic of mosquito-borne pathogens.

Prevalence of HIV, Syphilis, and Hepatitis B and C Among Blood Donors in a Tertiary Care Hospital in Mexico

The prevalence of transfusion-transmissible infections (TTIs) among blood donors is critical for ensuring blood safety. Aim: To provide an updated assessment of TTIs at a tertiary care hospital in Mexico over a ten-year period. We conducted a retrospective cross-sectional study. Blood samples were analyzed from potential donors at tertiary care hospital between 2012 and 2022. Donors completed a questionnaire and were screened for HIV, syphilis, hepatitis B, and hepatitis C using nucleic acid testing and serological tests. Prevalence and trends were estimated. Among the 117,756 donors analyzed, 0.48% were positive for syphilis, with a significant annual decrease of −5.9% (p &lt; 0.001), although notable fluctuations occurred, including a peak in 2021. HIV showed a significant annual increase of 9.8% (p = 0.029), with a peak in approximately 2019–2020. Hepatitis C maintained a stable trend, with a slight annual decrease of −5.6% (p = 0.170). Hepatitis B consistently decreased, with an annual decrease of −11.3% (p = 0.06). This study highlights the importance of continuous monitoring and screening of blood donors to ensure blood safety. These findings underscore the need for localized public health interventions, particularly to address the increasing incidence of HIV. Further research should focus on enhancing donor screening practices and public health strategies to reduce the prevalence of TTIs.

Safety of Hepatitis B Virus Screening in Blood Donors from the Hospital Foundation of Hematology and Hemotherapy of the State of Amazonas (HEMOAM) in the Brazilian Amazon

Background: Hepatitis B is an infectious disease of worldwide importance and of great interest to transfusion medicine. The Amazon region has areas of high endemicity, outlining a worrying scenario for transfusion and epidemiological safety. Objective: To analyze the profiles of serological and molecular markers for HBV of blood donors from HEMOAM. Methods: Blood donors with different patterns of reactivity in serological and molecular screening for HBV were tested for viral load by the qPCR method at the reference center for liver diseases in the state of Amazonas. Results: A total of 230,591 donors were tested, with 3104 (1.34%) found reactive for HBV and 2790 (89.9%) found reactive for isolated anti-HBc. Viral load was not detected in 100% of donors reactive only to HBsAg, while 100% of donors with positive anti-HBc and positive HBsAg or HBV NAT demonstrated a detectable viral load. We also detected one case of occult hepatitis B (0.03%) only with reactive HBV NAT and five donors (0.2%) with positive anti-HBc and HBV NAT. Conclusions: With this result, the great importance of the anti-HBc test for the unsuitability of blood donors was verified, as well as the fundamental introduction of the HBV NAT test in screening for hepatitis B in Brazilian blood banks, as this was the only way to detect the viral infection burden in asymptomatic donors who previously would not be treated, which contributed to the maintenance of the endemicity of hepatitis B in the Brazilian Amazon.

HEV in Blood Donors in Switzerland: The Route to Safe Blood Products.

The hepatitis E virus (HEV) is an emerging infectious disease with zoonotic potential, causing acute hepatitis in humans. Infections in healthy individuals are often acute, self-limiting and asymptomatic, thus leading to the underdiagnosis of HEV infections. Asymptomatic HEV infections pose a problem for blood transfusion safety by increasing the risk for transfusion-transmitted HEV infections. Here, we describe the journey from determining the HEV seroprevalence among blood donors to the implementation of routine HEV RNA testing of all blood products in Switzerland in 2018 and summarise the HEV cases detected since. In total, 290 HEV-positive blood donations were detected by mini-pool nucleic acid testing (NAT) in Switzerland in the period of October 2018-December 2023, equal to an incidence of 20.7 per 100,000 donations. Thanks to the implemented scheme, no transfusion-transmitted infections occurred in this period. Furthermore, blood donation monitoring has proven to be an effective means of detecting HEV outbreaks in the general population. HEV cases in Swiss blood donors are caused by two major genotypes, the Swiss-endemic subtypes 3h3 and 3c. Interestingly, 11 HEV cases (5%) were of genotype 3ra, a variant found in wild and farmed rabbits. Our results indicate that mini-pool NAT is an efficient method to reduce the risk of transfusion-transmitted HEV infections.

Unnecessary antibiotic use in men who have sex with men (MSM) with anogenital symptoms attending a sexual health clinic: a retrospective analysis

ObjectivesTo quantify the amount of unnecessary antibiotics, in particular ceftriaxone, given to men who have sex with men (MSM) with anogenital symptoms as part of presumptive management in an urban...

Prevalence of sexually transmitted infections and associated risk factors among female sex workers in Guinea-Bissau

ObjectiveTo estimate the prevalence of the curable sexually transmitted infections (STIs) Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis and Treponema pallidum, to identify associated risk factors and to assess...