Evolution of human papilloma virus prevalence in a highly vaccinated region in Belgium: a retrospective cohort study in Flemish women (2010-2019).

OBJECTIVE: In order to lower the incidence of cervical cancer, vaccines against high-risk types of the human papilloma virus (hrHPV) were approved and brought on the market in 2007, with a partial reimbursement for Belgian citizens younger than 18 years old. Since 2010, a school-based vaccination program ensures a high vaccination coverage in young women. In this study, the impact of the Belgian vaccination program on the prevalence of HPV 16/18 is studied, together with the evolution of the prevalence of other hrHPV types and precancerous lesions. METHODS: Results of HPV typing and cytology in papanicolaou-smears from women aged 20-23 years taken between 2010 and 2019 were used. An older, nonvaccinated group of women of 40-45 years old served as a control group. RESULTS: A significant decrease in prevalence of HPV types 16 and 18 was found in the 20-23-years-old women, whereas no decrease was found in the age group 40-45. Alongside this decrease, a significant decrease in prevalence of subtypes 6, 11 and 31 was observed, whereas type 31 is not included in the administered vaccines. Remarkably, there was no decrease in prevalence of cytological abnormalities in the study group during this study. There was even an increase in prevalence of high-risk types 53, 58 and 67. CONCLUSION: These findings emphasise the need to maintain the screening programs, even in areas with high vaccination coverage.

Performance of the FREND™ COVID-19 IgG/IgM Duo point-of-care test for SARS-CoV-2 antibody detection.

PURPOSE: In the context of the current COVID-19 pandemic, multiple serological assays for the detection of severe acute respiratory syndrome 2 (SARS-CoV-2) immune response are currently being developed. This study compares the FRENDTM COVID-19 IgG/IgM Duo (NanoEntec) a point of care (POCT) assay with the automated Elecsys anti-SARS-CoV-2 electrochemiluminescent assay (Roche Diagnostics). METHODS: Serum samples (n = 81) from PCR-confirmed SARS-CoV-2 positive patients at different time points after the onset of symptoms were analyzed with both assays. An additional 24 serum samples with cross reactivity potential were also included. RESULTS: The sensitivity of the COVID-19 IgG/IgM Duo assay was higher as compared to the Elecsys anti-SARS-CoV-2 assay, especially when using the combined IgM/IgG result in samples analyzed within 6 days after the onset of symptoms (46.2% vs. 15.4%). The sensitivity of both assays increased with increasing time interval after the onset of symptoms and reached 100% for the COVID-19 IgG/IgM Duo assay in samples taken 14 days or more after symptom onset. Specificity of the COVID-19 IgG/IgM Duo assay was 95.8% for IgM, 91.7% for IgG and 87.5% for the combination of both. CONCLUSION: This study shows that the sensitivity of both assays was highly dependent on the time interval between the onset of the COVID-19 symptoms and serum sampling. Furthermore, rapid serological testing for SARS-CoV-2 antibodies by means of the FRENDTM COVID-19 IgG/IgM Duo POCT assay showed a comparable diagnostic performance as the reference automated immunoassay.

Comparison of the QuantiFERON-TB® Gold Plus on LIAISON® XL and T-SPOT.TB for the diagnosis of latent Mycobacterium tuberculosis infection in a low tuberculosis incidence population.

The current study compared the QuantiFERON-TB® Gold Plus on LIAISON® XL to the T-SPOT.TB for the diagnosis of latent Mycobacterium tuberculosis infection on 125 patient samples. A high agreement of qualitative results (90%) was observed between both methods with 3% major discrepancies, half of which were false negative results with the T-SPOT.TB.

Performance of three automated SARS-CoV-2 antibody assays and relevance of orthogonal testing algorithms.

Objectives: Development and implementation of SARS-CoV-2 serologic assays gained momentum. Laboratories keep on investigating the performance of these assays. In this study, we compared three fully automated SARS-CoV-2 antibody assays. Methods: A total of 186 samples from 84 PCR-positive COVID-19 patients and 120 control samples taken before the SARS-CoV-2 pandemic were analyzed using commercial serologic assays from Roche, Siemens and DiaSorin. Time after the positive COVID-19 PCR result and onset of symptoms was retrieved from the medical record. An extended golden standard, using the result of all three assays was defined, judging if antibodies are present or absent in a sample. Diagnostic and screening sensitivity/specificity and positive/negative predictive value were calculated. Results: Diagnostic sensitivity (ability to detect a COVID-19 positive patient) ≥14 days after positive PCR testing was 96.7% (95% CI 88.5-99.6%) for DiaSorin, 93.3% (95% CI 83.8-98.2%) for Roche and 100% (95% CI 94.0-100%) for Siemens. Lower diagnostic sensitivities were observed <14 days after onset of symptoms for all three assay. Diagnostic specificity (ability to detect a COVID-19 negative patient) was 95.0% (95% CI 89.4-98.1%) for DiaSorin, 99.2% (95% CI 95.4-99.9%) for Roche and 100% (95% CI 97.0-100%) for Siemens. The sensitivity/specificity for detecting antibodies (ability of detecting absence (specificity) or presence (sensitivity) of COVID-19 antibodies) was 92.4% (95% CI 86.4-96.3%)/94.9% (95% CI 90.5-97.6%) for DiaSorin, 97.7% (95% CI 93.5-99.5%)/97.1% (95% CI 93.5-99.1%) for Roche and 98.5% (95% CI 94.6-99.8)/97.1 (95% CI 93.5-99.1%) for Siemens. Conclusions: This study revealed acceptable performance for all three assays. An orthogonal testing algorithm using the Siemens and Roche assay achieved the highest positive predictive values for antibody detection in low seroprevalence settings.