Evaluation of the accuracy of a multi-infection screening test based on a multiplex immunoassay targeting imported diseases common in migrant populations

Background In this study we have evaluated the performance of a novel multiplex serological assay with a panel of 8 antigens able to simultaneously detect IgG to HIV, chronic hepatitis B (HBV) and C (HCV), Chagas disease, strongyloidiasis and schistosomiasis as a screening tool for imported diseases in migrants. Methods Six panels of 40 well-characterized, anonymized serum samples from individuals with the respective confirmed infections (n=240) were used as positive controls to assess the sensitivity of the multiplex assay. One panel of 40 sera from non-infected subjects were used to estimate the seropositivity cutoffs for each infection, and 32 additional non-infected sera were used as negative controls to estimate the sensitivity and specificity for each serology. The multi-infection screening test was validated in a prospective cohort of 48 migrants from endemic areas to assess assay performance. The sensitivity of the Luminex assay was calculated as the proportion of positive test results over all positive samples by the primary reference test. The specificity was calculated using 32 negative samples. Uncertainty was quantified with 95% confidence intervals (CI) using receiver operating characteristic analyses. Results The sensitivity /specificity were 100%/100% for HIV (p41 antigen), 97.5%/100% (AUC:0.99,[95%CI: 0.96-1.00]) for HBV (core antigen), 100%/100% (AUC:1.00,[95%CI 1.00-1.00]) for HCV (core antigen), 92.5%/90.6%,(AUC:0.96,[95%CI 0.91-1.00]) for strongyloidiasis (31-kDa recombinant antigen (NIE)), 97.5%/100%,(AUC:0.97,[95%CI 0.93-1]) for schistosomiasis (combined serpin Schistosoma mansoni and S.haematobium antigens) and 92.5%/96.9%,(AUC: 0.96,[95%CI 0.92-1.00]) for Chagas disease ([ T.cruzi kinetoplastid membrane protein-11 (KMP11)]). In the migrant cohort, antibody response to KMP11 correctly identified 14/14(100%) individuals with Chagas disease, whereas HBV-core antigen and NIE-Strongyloides correctly identified 91.7% and 86.4% individuals with chronic hepatitis B and strongyloidiasis respectively. Conclusions We have developed a new 8-plex Luminex assay that is robust and accurate, and could facilitate the implementation of screening programmes for imported diseases in migrant populations. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was supported by two grants from Instituto de Salud Carlos III (ISCIII), co-financed by the European Regional Development Fund (FEDER) from the European Union, through the Fondo de Investigacion para la Salud (FIS), PI17/02020 and PI20/00866. ARM receives funding from the Strategic Research Program in Epidemiology at Karolinska Institutet. This research team was supported by CIBER-Consorcio Centro de Investigacion Biomedica en Red-(CB 2021), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovacion and Union Europea. MCL was supported by the Programa Estatal I+D+I, Spanish Ministry of Science and Innovation and FEDER (PID2019-109090RB-I00/AEI/10.13039/501100011033). Authors from IRCCS Sacro Cuore Don Calabria Hospital were supported by the Italian Ministry of Health Fondi Ricerca corrente-L2P4. ISGlobal receives support from the Spanish Ministry of Science and Innovation through the Centro de Excelencia Severo Ochoa 2019-2023 Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program. ### 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 study protocol and informed consent from migrants whose samples were prospectively collected were approved by the ethical committee at Hospital Clinic, (HCB/2017/0847). 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 in the present study are available upon reasonable request to the authors