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The aim of this study was to investigate the serum neopterin level and ADA activity in acute measles infection and determine whether there is a correlation between the measles optical density values, and the neopterin and ADA levels. The neopterin level and ADA activities were investigated in the samples of 136 measles IgM-positive patients along with those of 40 measles IgM-negative patients as the control group. The most important findings of the study were the determination of significantly higher neopterin levels and ADA activity in the measles IgM-positive group when compared to the measles IgM-negative group. The high neopterin level and ADA activity in measles before IgM becomes positive in some of the patients in the first 3 days suggested that they can be used as a preliminary and supportive marker for the preliminary diagnosis of measles. These findings have shown that the neopterin level and ADA activity can assist in the diagnosis of measles in the acute period as biomarkers. [ABSTRACT FROM AUTHOR]

Background: Crimean-Congo Haemorrhagic Fever (CCHF) is a viral haemorrhagic fever with a case fatality rate of 5-25% that has been prioritised for research and development by the World Health Organisation. There are no CCHF rapid diagnostic tests (RDTs) commercially available. We describe the development and evaluation of an antigen-targeting lateral flow immunoassay RDT for CCHF., Methods: Prospective clinical samples were collected and tested between July and October 2023 in Türkiye. Retrospective stored samples were obtained from the Central Public Health Laboratory, Baghdad, Iraq. The sensitivity and specificity of the CCHF RDT was compared to reverse transcription quantitative polymerase chain reaction assays., Findings: On prospective clinical samples in Türkiye, the sensitivity and specificity of the CCHF RDT was 90.4% [95% CI 81.5-95.3%] (n = 73) and 96.2% [95% CI 87.0-99.3%] (n = 52), respectively with a sensitivity of 92.9% [95% CI 84.3-96.9%] (n = 70) in samples with a cycle threshold (Ct) ≤30. On retrospective stored samples in Iraq, sensitivity and specificity of the RDT was 71.7% [95% CI 59.2-81.5%] (n = 60) and 92.5% [95% CI 80.1-97.8%] (n = 40), respectively with a sensitivity of 82.2% [95% CI 68.7-90.7%] (n = 45) in samples of Ct ≤30., Interpretation: The CCHF RDT was an effective rapid diagnostic test in this preliminary clinical evaluation, showing this RDT has the potential diagnostic capability for use at the point-of-care. Definitive evaluation is now required to ensure the RDT meets the regulatory requirements for commercialisation., Funding: The Liverpool School of Tropical Medicine, National Institute for Health Research Health Protection Research Unit in Emerging Zoonotic Infections, The Medical Research Council and The Pandemic Institute., Competing Interests: Declaration of interests LSTM intends to out-license the antibodies to facilitate the future commercialisation of the rapid diagnostic test (RDT). Additionally, we are evaluating the potential for filing a patent application for the antibodies. EA collects salary from the Liverpool School of Tropical Medicine and Global Access Diagnostics., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

While most approved vaccines are based on the viral spike protein or its immunogenic regions, inactivated whole-virion vaccines (e.g., CoronaVac) contain additional antigens that may enhance protection. This study analyzes short-term humoral responses against the SARS-CoV-2 spike (S1) and nucleocapsid (NCP) protein in 50 Turkish adults without previous SARS-CoV-2 infection after CoronaVac immunization. Samples were collected before vaccination (t0), 28-29 days after the first vaccine dose and prior to the second dose (t1), as well as 14-15 days after the second dose (t2). Anti-S1 IgG and IgA as well as anti-NCP IgG were quantified using ELISA. At t1, seroconversion rates for anti-S1 IgG, anti-S1 IgA and anti-NCP IgG were 30.0%, 28.0% and 4.0%, respectively, increasing significantly to 98.0%, 78.0% and 40.0% at t2. The anti-NCP IgG median (t2) was below the positivity cut-off, while anti-S1 IgG and IgA medians were positive. Anti-S1 IgG levels strongly correlated with anti-S1 IgA (r s = 0.767, p < 0.001) and anti-NCP IgG (r s = 0.683, p < 0.001). In conclusion, two CoronaVac doses induced significant increases in antibodies against S1 and NCP. Despite strong correlations between the antibody concentrations, the median levels and seroconversion rates of S1-specific responses exceed those of NCP-specific responses as early as two weeks after the second vaccine dose.

Background: Crimean-Congo hemorrhagic fever virus (CCHFV) causes a highly contagious tick-borne disease with high case-fatality rates in humans. It is circulating not only in many Asian and African countries, but also spreading to and within Europe. To cope better with future outbreaks of Crimean-Congo hemorrhagic fever (CCHF), the WHO has prioritized the need for the development and validation of CCHF diagnostics, including serological assays. In this study, we evaluated the performance of the new EUROIMMUN anti-CCHFV IgM and IgG enzyme-linked immunosorbent assays (ELISAs). Materials and Methods: Both ELISAs were compared to the Vector-Best VectoCrimean-CHF-IgM and -IgG ELISAs using the EUROIMMUN CCHFV Mosaic 2 IgM and IgG indirect immunofluorescence assays (IFA) as reference. Forty-nine acute-phase serum samples from patients with CCHFV infection confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and/or anti-CCHFV IgM IFA positivity were used to determine assay sensitivity. The assessment of specificity was based on sera from 30 control patients, 30 healthy blood donors, and 29 patients with hantavirus or sandfly fever virus infections. All samples originated from Turkey. Results: Sensitivity of the EUROIMMUN ELISAs (IgM 98.0%, IgG 47.1%) exceeded that of the Vector-Best ELISAs (IgM 95.9%, IgG 35.3%). Specificity of the EUROIMMUN ELISA IgM (86.4%) was slightly higher compared with the Vector-Best ELISA IgM (84.7%), while specificity for IgG was 100% for both assays. Qualitative agreement between the EUROIMMUN and Vector-Best ELISAs was substantial for detecting anti-CCHFV IgM (84.1%, ĸ = 0.673) and IgG (94.9%, ĸ = 0.791), whereas the quantitative results indicated a very strong positive correlation (IgM: r = 0.868, IgG: r = 0.913). Conclusion: The new EUROIMMUN anti-CCHFV ELISAs are standardized and easy-to-use tools that reliably support the identification of acute CCHF cases, and thus suitable for laboratories involved in on-site outbreak support.

Introduction: The necessity of a booster dose is a matter that has not been as yet illuminated, although it is noted that neutralizing antibody titers decrease over time. We aimed therefore to evaluate antibody titers and seroconversion rates after a booster mRNA vaccine and a booster inactivated vaccine., Methods: A total of 322 participants were divided into three main groups, with two subgroups each, based on their vaccinations and previous infection history. The levels of anti-SARS-CoV-2 Ig-G were analyzed with the Elecsys® Anti-SARS-CoV-2 S assay., Results: The antibody titers showed a linear and significant increase from one vaccine group to the other, displaying progressive changes from group 2IV to group 3IV, and then to group 2IV/mRNA. All of the seronegative participants were in the 2IV(-) subgroup; 93.3% of the participants whose antibody titers were above the upper limit were in the 2IV/mRNA group. Doctors were much more inclined to have a booster dose and mRNA vaccines than nurses. The status of being a doctor increases the rate of having a booster dose 7.8 times; likewise, each annual increase in age increases the rate 1.05 times., Conclusion: Anti-SARS-CoV-2 IgG levels decrease over time. The antibody response rate to only two doses of the inactivated vaccine was meager, so a booster dose is necessary to maintain the effectiveness of inactivated vaccines. The third dose of the vaccine, especially that of the mRNA vaccine, which was found to be much more superior to the inactivated vaccine, should be strongly recommended., Competing Interests: The authors have indicated they have no conflicts of interest relevant to this article to disclose., (© 2022 The Author(s). Published by Elsevier Ltd.)

Healthcare workers (HCWs), as frontliners, are assumed to be among the highest risk groups for COVID-19 infection, especially HCWs directly involved in patient care. However, the data on the COVID-19 infection and seroprevalence rates are limited in HCWs. Therefore, we aimed to evaluate the seroprevalence rates in HCWs according to risk groups for COVID-19 contraction in a large cross-sectional study from a tertiary care hospital in Turkey. We enrolled 1974 HCWs before the vaccination programs. In two separate semi-quantitative ELISAs, either IgA or IgG antibodies against SARS-CoV-2 spike protein subunit 1 (S1) were measured. The proportion of positive test results for IgG, IgA, or both against SARS-CoV-2 of study subjects was 19% (375/1974). Frontline HCWs who had contact with patients (21.7%, RR 2.1 [1.51-2.92]) and HCWs in working in the COVID-19 units, intensive care units, or emergency department (19.7%, RR 1.61 [1.12-2.32]) had a notably higher Anti-SARS-CoV-2 IgG compared to the rest of HCWs who has no daily patient contacts ([11.1%]; p < 0.0001). HCWs who care for regular patients in the medium-risk group have also experienced a sustained higher risk of exposure to SARS-CoV-2. We should enhance the precaution against COVID-19 to protect HCW's safety through challenging times.

In the 10th month of the pandemic, coronavirus disease 2019 (COVID-19) vaccination was given first to healthcare workers in Turkey after receiving emergency use approval from the Ministry of Health. This study, which was performed at the COVID-19 reference center in Ankara (the capital of Turkey) aimed to evaluate the seroconversion rate of the CoronaVac vaccine. The anti-spike immunoglobulin G response to the two-dose vaccination was retrospectively examined in healthcare workers who had no previous history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The postvaccine seroconversion rate was investigated by measuring the antibody levels of healthcare workers who had received CoronaVac. Vaccination was administered as 600 SU in 28-day intervals. The healthcare workers' anti-SARS-CoV-2 immunoglobulin G levels were used to determine the seroconversion rate 2 months after the second dose of the vaccine. Of the healthcare workers, 22.9% (n = 155) were seronegative. The younger the age of the participant, the higher the level of anti-SARS-CoV-2 immunoglobulin G. Furthermore, anti-SARS-CoV-2 immunoglobulin G levels were much higher in women than men., (© 2021 Wiley Periodicals LLC.)