Viral haemorrhagic fevers (VHF) are high consequence infectious diseases (HCID) with the potential for outbreaks and considerable mortality. Accessible, up-to-date national guidelines are essential to ensure adequate preparedness. This includes prompt confirmation/exclusion of a VHF diagnosis through sample procurement and processing. Here, we assess and recommend improvements for the VHF testing algorithm in Ireland, for the purpose of ensuring alignment with international best practice. Irish VHF laboratory guidelines were reviewed. Each step of the process was compared to relevant international guidance. Gaps in current practice were identified, root causes identified, and recommendations for improvements proposed. Eight process categories were identified during process mapping. Compared with international best practice, gaps were identified in Irish guidelines for each category. Notable examples include the lack of scheduled access to out of hours testing and uncertainty around testing procedures for non-virological tests (haematology, biochemistry, and microbiology). Although Irish guidelines largely align with international recommendations, important gaps were identified. These gaps risk a delayed diagnosis (of either VHF or alternative causes), sub-standard clinical care due to delayed baseline laboratory investigations, delayed patient transfer to the National Isolation Unit (NIU), and excessive resources maintaining patient isolation subsequently proven to be unnecessary. Refining the VHF diagnostic process would improve patient management and ensure a more efficient use of resources. Internationally, test repertoires for VHF and alternative diagnoses are mostly devised by dedicated specialist services with appropriate laboratory biosafety measures, and we recommend that Ireland moves towards this model.

Background: EBV DNA monitoring is currently the main strategy to identify renal transplant recipients potentially at risk of EBV complications. EBV miRNA expression is markedly altered in different disease presentations associated with EBV. We performed a longitudinal assessment of the impact of rituximab on circulating EBV miRNA in 3 paediatric kidney transplant recipients. Methods: Forty-two miRNAs encoded within 2 EBV open reading frames (BART and BHRF) were examined over a 28-month period using miRNA qPCR custom panels. EBV DNA was measured using qPCR and lymphocyte subsets were measured by flow cytometry. Results: Patients were 3 years post kidney transplant and received cycles of rituximab infusions. Treatment with rituximab caused an immediate depletion of the circulating B cells and reduced the expression of the miRNAs and EBV DNA levels. About 4 months post treatment, as the circulating B cells repopulated, EBV miRNAs levels increased. A total of 29 plasma samples were studied and between 4 and 34 EBV miRNAs were detected. A significant correlation was observed between the numbers of EBV miRNAs expressed and the EBV DNA level (r = 0.63, p = 0.001). Conclusion: We provide an in-depth longitudinal assessment of the impact of rituximab on specific circulating EBV miRNA expression in three paediatric kidney transplant recipients. Rituximab treatment resulted in the reduction of EBV miRNA expression and EBV DNA viral loads. Larger studies are required to determine whether EBV miRNA levels could be useful biomarkers to predict transplant recipients at risk of developing post-transplant lymphoproliferative disease.

INTRODUCTION:Live attenuated influenza vaccine (LAIV) is recommended in Ireland for all children aged 2-17 years. Quadrivalent influenza vaccine (QIV) is recommended for all others eligible for vaccination, including those ≥ 18 years with underlying medical conditions and all aged ≥ 65 years. We aimed to estimate influenza vaccine effectiveness (IVE) against acute respiratory infection (ARI) presentations to primary care due to influenza over two influenza seasons in Ireland, to inform vaccination recommendations and communication campaigns. METHODS:We undertook a test-negative case control study within the Irish sentinel general practice surveillance network as part of the Vaccine Effectiveness Burden and Impact Studies (VEBIS) network. We compared influenza vaccination status among influenza PCR positive cases with influenza PCR negative controls, both with ARI presentations, of all ages. We estimated IVE using logistic regression adjusting for age, onset time, medical conditions and sex. RESULTS:In 2022/2023, there were 288 cases and 765 controls. In 2023/2024, there were 567 cases and 1832 controls. In 2022/2023, overall IVE was 42% (95% CI 9 to 64) and 50% (95% CI -30 to 83) in 2- to 17-year-olds. Overall IVE in 2023/2024 was 35% (95% CI 15 to 51) and 68% (95% CI 30 to 87) in 2- to 17-year-olds. CONCLUSION:Influenza vaccination reduced the risk of influenza among ARI patients presenting to general practice, demonstrating the benefits of vaccination, particularly among children. Promotion of the seasonal influenza vaccine to recommended groups, should remain a public health priority. Targeted vaccination campaigns for children promoting LAIV should emphasise the effectiveness of LAIV in children.

BackgroundMpox, caused by monkeypox virus (MPXV), was considered a rare zoonotic disease before May 2022, when a global epidemic of cases in non-endemic countries led to the declaration of a Public Health Emergency of International Concern. Cases of mpox in Ireland, a country without previous mpox reports, could reflect extended local transmission or multiple epidemiological introductions.AimTo elucidate the origins and molecular characteristics of MPXV circulating in Ireland between May 2022 and October 2023.MethodsWhole genome sequencing of MPXV from 75% of all Irish mpox cases (182/242) was performed and compared to sequences retrieved from public databases (n = 3,362). Bayesian approaches were used to infer divergence time between sequences from different subclades and evaluate putative importation events from other countries.ResultsOf 242 detected mpox cases, 99% were males (median age: 35 years; range: 15-60). All 182 analysed genomes were assigned to Clade IIb and, presence of 12 distinguishable subclades suggests multiple introductions into Ireland. Estimation of time to divergence of subclades further supports the hypothesis for multiple importation events from numerous countries, indicative of extended and sustained international spread of mpox. Further analysis of sequences revealed that 92% of nucleotide mutations were from cytosine to thymine (or from guanine to adenine), leading to a high number of non-synonymous mutations across subclades; mutations associated with tecovirimat resistance were not observed.ConclusionWe provide insights into the international transmission dynamics supporting multiple introductions of MPXV into Ireland. Such information supported the implementation of evidence-informed public health control measures.

Background mpox (formerly Monkeypox) virus (MPXV) was considered a rare zoonotic disease prior to May 2022, when a global epidemic of cases in non-endemic countries led to the declaration of a Public Health Emergency of International Concern. Previously, mpox infection was associated with symptoms similar to smallpox, although substantially less severe, including fever, an extensive characteristic rash and swollen lymph nodes. Aim Elucidating the origin and molecular characteristics of the virus circulating in the Republic of Ireland in the period between May and November 2022. Methods Whole-genome sequencing of all MPXV cases (80%; n=178/219) analysed against sequences from public databases (n=2695). Bayesian approaches were used to infer the divergence time between sequences from different subclades and transmission events involving different countries. Results The circulating virus belonged to the clade IIb B.1 lineage and, notably, the presence of twelve separable and highly-supported subclades consistent with multiple introductions into the country. Such a hypothesis of multiple importation events was supported further by the estimation of the time to the divergence of subclades. Additionally, inferred MPXV transmissions involving different countries and continents were indicative of an extended international spread. The analysis of the mutations in the Irish sequences revealed 93% of the mutations were from cytosine to thymine (or from guanine to adenine), leading to a high number of non-synonymous mutations across the subclades. Conclusion In the context of extremely high national sequencing coverage, we provide new insights into the international origin and transmission dynamics supporting multiple introductions into the Republic of Ireland. Conflict of Interests None to declare. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by the Irish Health Service Executive. Also, this study was partially supported by AMED under the grant number JP223fa627005. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The analysis of the data was approved by the University College Dublin Human Research Committee - Sciences analysed data with the Research Ethics Reference Number: LS-LRSD-23-197-Gonzalez-Hare. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced are available online at GenBank ([www.ncbi.nlm.nih.gov/genbank/][1]) and GISAID ([gisaid.org][2]). Accession numbers are provided in the manuscript. [1]: http://www.ncbi.nlm.nih.gov/genbank/ [2]: http://gisaid.org

Background In 2020, due to the COVID-19 pandemic, the European Centre for Disease Prevention and Control (ECDC) accelerated development of European-level severe acute respiratory infection (SARI) surveillance. Aim We aimed to establish SARI surveillance in one Irish hospital as part of a European network E-SARI-NET. Methods We used routine emergency department records to identify cases in one adult acute hospital. The SARI case definition was adapted from the ECDC clinical criteria for a possible COVID-19 case. Clinical data were collected using an online questionnaire. Cases were tested for SARS-CoV-2, influenza and respiratory syncytial virus (RSV), including whole genome sequencing (WGS) on SARS-CoV-2 RNA-positive samples and viral characterisation/sequencing on influenza RNA-positive samples. Descriptive analysis was conducted for SARI cases hospitalised between July 2021 and April 2022. Results Overall, we identified 437 SARI cases, the incidence ranged from two to 28 cases per week (0.7–9.2/100,000 hospital catchment population). Of 431 cases tested for SARS-CoV-2 RNA, 226 (52%) were positive. Of 349 (80%) cases tested for influenza and RSV RNA, 15 (4.3%) were positive for influenza and eight (2.3%) for RSV. Using WGS, we identified Delta- and Omicron-dominant periods. The resource-intensive nature of manual clinical data collection, specimen management and laboratory supply shortages for influenza and RSV testing were challenging. Conclusion We successfully established SARI surveillance as part of E-SARI-NET. Expansion to additional sentinel sites is planned following formal evaluation of the existing system. SARI surveillance requires multidisciplinary collaboration, automated data collection where possible, and dedicated personnel resources, including for specimen management.

Background: In 2021–22, influenza A viruses dominated in Europe. The I-MOVE primary care network conducted a multicentre test-negative study to measure influenza vaccine effectiveness (VE). Methods: Primary care practitioners collected information on patients presenting with acute respiratory infection. Cases were influenza A(H3N2) or A(H1N1)pdm09 RT-PCR positive and controls were influenza virus negative. We calculated VE using logistic regression, adjusting for study site, age, sex, onset date, and presence of chronic conditions. Results: Between week 40 2021 and week 20 2022, we included over 11,000 patients of whom 253 and 1595 were positive for influenza A(H1N1)pdm09 and A(H3N2), respectively. Overall VE against influenza A(H1N1)pdm09 was 75% (95%CI: 43–89) and 81% (95%CI: 44–93) among those aged 15–64 years. Overall VE against influenza A(H3N2) was 29% (95%CI: 12–42) and 25% (95%CI: -41–61), 33% (95%CI: 14–49) and 26% (95% CI: -22 to 55) among those aged 0–14, 15–64 and over 65 years, respectively. The A(H3N2) VE among the influenza vaccination target group was 20% (95%CI: -6–39). All 53 sequenced A(H1N1)pdm09 viruses belonged to clade 6B.1A.5a.1. Among 410 sequenced influenza A(H3N2) viruses, all but 8 belonged to clade 3C.2a1b.2a.2. Discussion: Despite antigenic mismatch between vaccine and circulating strains for influenza A(H3N2) and A(H1N1)pdm09, 2021–22 VE estimates against circulating influenza A(H1N1)pdm09 were the highest within the I-MOVE network since the 2009 influenza pandemic. VE against A(H3N2) was lower than A(H1N1)pdm09, but at least one in five individuals vaccinated against influenza were protected against presentation to primary care with laboratory-confirmed influenza.

IntroductionIn July and August 2021, the SARS-CoV-2 Delta variant dominated in Europe. We measured COVID-19 vaccine effectiveness (VE) against symptomatic infection, using a multicentre test-negative study at primary care/community level in Europe.MethodsPatients presenting with COVID-19/ARI symptoms at primary care/community level in 10 countries were tested for SARS-CoV-2. We measured complete primary course overall VE among those aged 30–44, 45–59, 60–74 and ≥75 years, and among those 30–59 and ≥60 years by vaccine brand and by time since vaccination.ResultsOverall VE was 74% (95%CI: 69–79), 76% (95%CI: 71–80), 63% (95%CI: 48–75), 63% (95%CI: 16–83) among those aged 30–44, 45–59, 60–74 and ≥75 years, respectively. VE among those aged 30–59 years was 78% (95%CI: 75–81), 66% (95%CI: 58–73), 91% (95%CI: 87–94) and 52% (95%CI: 40–61), for Comirnaty, Vaxzevria, Spikevax and COVID-19 Vaccine Janssen, respectively. VE among those aged ≥60 years was 67% (95%CI: 52–77), 65% (95%CI: 48–76), 83% (95%CI: 64–92) for Comirnaty, Vaxzevria and Spikevax, respectively. Comirnaty VE among those aged 30–59 years was 87% (95%CI: 83–89) and 65% (95%CI: 56–71%) at 14–29 days and ≥90 days between vaccination and onset of symptoms, respectively.ConclusionsVE against the symptomatic SARS-CoV-2 Delta variant infection varied among brands, ranging from 52–91%. While some waning of the vaccine effect may be present (sample size limited this analysis to only Comirnaty), protection was 65% ≥90 days between vaccination and onset.

Background: Despite widespread use of the mumps vaccine resulting in significant reduction in the incidence of symptomatic mumps infection, large outbreaks continue to occur in highly vaccinated populations.Objectives: We examined the mumps-specific IgG, IgG subclasses and neutralization titres to the outbreak Ge-notype G5 and Jeryl Lynn vaccine (Genotype A) mumps strains. Study design: Sera from 207 individuals were classified into five distinct cohorts: healthy controls and mumps cases of 5-17 years and 18-25 years, and naturally infected individuals of 50+ years. Mumps specific IgG and IgG subclass levels were measured using modified ELISA assays with lysates and nucleoprotein antigens from both the mumps vaccine and circulating Genotype G5 strains. All sera were investigated for in vitro neutralizing antibody titres (GMT) using focus reduction neutralization assays. Data was analysed using the Kruskal-Wallis test and pairwise Wilcoxon tests.Results: Mumps cases had higher mumps IgG levels compared to controls, to both the vaccine and outbreak strains, however levels decreased with age. Mumps IgG3 levels were significantly raised in mumps cases (p < 0.001). Neutralization titres were lower to the outbreak strain in all cohorts with titres markedly lower in the mumps cohorts compared to healthy controls. Mean GMT to the vaccine strain increased with age. The naturally infected group displayed the highest GMT to the JL vaccine and the lowest GMT to the outbreak strain.Conclusions: Antigenic differences between mumps vaccine strain and circulating mumps viruses decrease the cross-neutralization capacity of vaccine-induced antibodies which may play a role in breakthrough infection.

Background: Robust data on SARS-CoV-2 population seroprevalence supplement surveillance data in providing evidence for public health action. Aim: To conduct a SARS-CoV-2 population-based seroprevalence survey in Ireland. Methods: Using a cross-sectional study design, we selected population samples from individuals aged 12-69 years in counties Dublin and Sligo using the Health Service Executive Primary Care Reimbursement Service database as a sampling frame. Samples were selected with probability proportional to the general population age-sex distribution, and by simple random sampling within age-sex strata. Antibodies to SARS-CoV-2 were detected using the Abbott Architect SARS-CoV-2 IgG Assay and confirmed using the Wantai Assay. We estimated the population SARS-CoV-2 seroprevalence weighted for age, sex and geographic area. Results: Participation rates were 30% (913/3,043) and 44% (820/1,863) in Dublin and Sligo. Thirty-three specimens had detectable SARS-CoV-2 antibodies (1.9%). We estimated weighted seroprevalences of 3.12% (95% confidence interval (CI): 2.05-4.53) and 0.58% (95% CI: 0.18- 1.38) for Dublin and Sligo, and 1.69% (95% CI: 1.13- 2.41) nationally. This equates to an estimated 59,482 (95% CI: 39,772-85,176) people aged 12-69 years nationally having had infection with SARS-CoV-2, 3.0 (95% CI: 2.0-4.3) times higher than confirmed notifications. Ten participants reported a previous laboratory-confirmed SARS-CoV-2-infection; eight of these were antibody-positive. Twenty-five antibody-positive participants had not reported previous laboratory confirmed infection. Conclusion: The majority of people in Ireland are unlikely to have been infected with SARS-CoV-2 by June-July 2020. Non-pharmaceutical public health measures remained key pending widespread availability of vaccination, and effective treatments.

We measured COVID-19 vaccine effectiveness (VE) against symptomatic SARS-CoV-2 infection at primary care/outpatient level among adults ≥ 65 years old using a multicentre test-negative design in eight European countries. We included 592 SARS-CoV-2 cases and 4,372 test-negative controls in the main analysis. The VE was 62% (95% CI: 45–74) for one dose only and 89% (95% CI: 79–94) for complete vaccination. COVID-19 vaccines provide good protection against COVID-19 presentation at primary care/outpatient level, particularly among fully vaccinated individuals.

Human herpesvirus 8 (HHV‐8) seroprevalence varies geographically and between subpopulations. High seroprevalence rates have been ascribed to men who have sex with men (MSM), African migrants, and HIV‐infected individuals. The objective of this study was to determine the seroprevalence of HHV‐8 in an Irish population, including specific risk groups. A cross‐sectional study of 200 blood donors and 200 genitourinary medicine (GUM) and infectious diseases (ID) clinic patients was performed, with testing for Immunoglobulin G (IgG) antibodies to HHV‐8 lytic antigens using a commercial indirect fluorescence assay (Scimedx Corp.). Verification was performed at the Centers for Disease Control and Prevention (CDC). All 200 blood donor samples were negative for HHV‐8 IgG antibodies. 21% of GUM and ID patients were positive for HHV‐8 IgG antibodies. One hundred of these patients were MSM, 35% of whom were HHV‐8 seropositive (46% of HIV‐positive MSM and 24% of HIV‐negative MSM). Of 100 heterosexual patients, only 7% were HHV‐8 seropositive. The absence of seropositivity in 200 Irish blood donors may suggest that Ireland has a low overall population HHV‐8 seroprevalence. The proportion of HHV‐8 seropositivity in the MSM population was significantly higher than in the heterosexual population and most marked in HIV‐positive MSM.

Background Mycoplasma pneumoniae is a leading cause of community-acquired pneumonia, with large epidemics previously described to occur every 4 to 7 years. Aim To better understand the diagnostic methods used to detect M. pneumoniae; to better understand M. pneumoniae testing and surveillance in use; to identify epidemics; to determine detection number per age group, age demographics for positive detections, concurrence of epidemics and annual peaks across geographical areas; and to determine the effect of geographical location on the timing of epidemics. Methods A questionnaire was sent in May 2016 to Mycoplasma experts with national or regional responsibility within the ESCMID Study Group for Mycoplasma and Chlamydia Infections in 17 countries across Europe and Israel, retrospectively requesting details on M. pneumoniae-positive samples from January 2011 to April 2016. The Moving Epidemic Method was used to determine epidemic periods and effect of country latitude across the countries for the five periods under investigation. Results Representatives from 12 countries provided data on M. pneumoniae infections, accounting for 95,666 positive samples. Two laboratories initiated routine macrolide resistance testing since 2013. Between 2011 and 2016, three epidemics were identified: 2011/12, 2014/15 and 2015/16. The distribution of patient ages for M. pneumoniae-positive samples showed three patterns. During epidemic years, an association between country latitude and calendar week when epidemic periods began was noted. Conclusions An association between epidemics and latitude was observed. Differences were noted in the age distribution of positive cases and detection methods used and practice. A lack of macrolide resistance monitoring was noted.

Objectives: To summarise the evidence on the duration of infectiousness of individuals in whom SARS-CoV-2 ribonucleic acid is detected. Methods: A rapid review was undertaken in PubMed, Europe PubMed Central and EMBASE from 1 January 2020 to 26 August 2020. Results: We identified 15 relevant studies, including 13 virus culture and 2 contact tracing studies. For 5 virus culture studies, the last day on which SARS-CoV-2 was isolated occurred within 10 days of symptom onset. For another 5 studies, SARS-CoV-2 was isolated beyond day 10 for approximately 3% of included patients. The remaining 3 virus culture studies included patients with severe or critical disease; SARS-CoV-2 was isolated up to day 32 in one study. Two studies identified immunocompromised patients from whom SARS-CoV-2 was isolated for up to 20 days. Both contact tracing studies, when close contacts were first exposed greater than 5 days after symptom onset in the index case, found no evidence of laboratory-confirmed onward transmission of SARS-CoV-2. Conclusion: COVID-19 patients with mild-to-moderate illness are highly unlikely to be infectious beyond 10 days of symptoms. However, evidence from a limited number of studies indicates that patients with severe-to-critical illness or who are immunocompromised, may shed infectious virus for longer. (c) 2020 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

History illustrates the remarkable public health impact of mass vaccination, by dramatically improving life expectancy and reducing the burden of infectious diseases and co-morbidities worldwide. It has been perceived that if an individual adhered to the MMR vaccine schedule that immunity to mumps virus (MuV) would be lifelong. Recent mumps outbreaks in individuals who had received two doses of the Measles Mumps Rubella (MMR) vaccine has challenged the efficacy of the MMR vaccine. However clinical symptoms, complications, viral shedding and transmission associated with mumps infection has been shown to be reduced in vaccinated individuals, demonstrating a benefit of this vaccine. Therefore, the question of what constitutes a good mumps vaccine and how its impact is assessed in this modern era remains to be addressed. Epidemiology of the individuals most affected by the outbreaks (predominantly young adults) and variance in the circulating MuV genotype have been well described alluding to a collection of influences such as vaccine hesitancy, heterogeneous vaccine uptake, primary and/or secondary vaccine failures. This review aims to discuss in detail the interplay of factors thought to be contributing to the current mumps outbreaks seen in highly vaccinated populations. In addition, how mumps diagnoses has progressed and impacted the understanding of mumps infection since a mumps vaccine was first developed, the limitations of current laboratory tests in confirming protection in vaccinated individuals and how vaccine effectiveness is quantified are also considered. By highlighting knowledge gaps within this area, this state-of-the-art review proposes a change of perspective regarding the impact of a vaccine in a highly vaccinated population from a clinical, diagnostic and public perspective, highlighting a need for a paradigm shift on what is considered vaccine immunity.

We illustrate the potential for specialist laboratory networks to be used as preparedness and response tool through rapid collection and sharing of data. Here, the Emerging Viral Diseases-Expert Laboratory Network (EVD-LabNet) and a laboratory assessment of chikungunya virus (CHIKV) in returning European travellers related to an ongoing outbreak in Thailand was used for this purpose. EVD-LabNet rapidly collected data on laboratory requests, diagnosed CHIKV imported cases and sequences generated, and shared among its members and with the European Centre for Disease Prevention and Control. Data across the network showed an increase in CHIKV imported cases during 1 October 2018–30 April 2019 vs the same period in 2018 (172 vs 50), particularly an increase in cases known to be related to travel to Thailand (72 vs 1). Moreover, EVD-LabNet showed that strains were imported from Thailand that cluster with strains of the ECSA-IOL E1 A226 variant emerging in Pakistan in 2016 and involved in the 2017 outbreaks in Italy. CHIKV diagnostic requests increased by 23.6% between the two periods. The impact of using EVD-LabNet or similar networks as preparedness and response tool could be improved by standardisation of the collection, quality and mining of data in routine laboratory management systems.

The suitability of routine diagnostic HIV assays to accurately discriminate between recent and non-recent HIV infections has not been fully investigated. The aim of this study was to compare an established HIV recency assay, the Sedia limiting antigen HIV avidity assay (LAg), with the diagnostic assays; Abbott ARCHITECT HIV Ag/Ab Combo and INNO-LIA HIV line assays. Samples from all new HIV diagnoses in Ireland from January to December 2016 (n = 455) were tested. An extended logistic regression model, the Spiegelhalter–Knill–Jones method, was utilised to establish a scoring system to predict recency of HIV infection. As proof of concept, 50 well-characterised samples were obtained from the CEPHIA repository whose stage of infection was blinded to the authors, which were tested and analysed. The proportion of samples that were determined as recent was 18.1% for LAg, 6.4% with the ARCHITECT, and 14.5% in the INNO-LIA assay. There was a significant correlation between the ARCHITECT S/CO values and the LAg results, r = 0.717, p < 0.001. ROC analysis revealed that an ARCHITECT S/CO < 250 had a sensitivity and specificity of 90.32% and 89.83%, respectively. Combining the Abbott ARCHITECT HIV Ag/Ab Combo assay and INNO-LIA HIV assays resulted in an observed risk of being recent of 100%. Analysis of the CEPHIA samples revealed a strong agreement between the LAg assay and the combination of routine assays (κ = 0.908, p < 0.001). Our findings provide evidence that assays routinely employed to diagnose and confirm HIV infection may be utilised to determine the recency of HIV infection.