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.