ABSTRACT
Serological tests developed for COVID-19 diagnostic are based on antibodies specific for SARS-CoV-2 antigens. Most of the antigens consist of a fragment or a whole amino acid sequence of the nucleocapsid or spike proteins. We evaluated a chimeric recombinant protein as an antigen in an ELISA test, using the most conserved and hydrophilic portions of the S1-subunit of the S and Nucleocapsid (N) proteins. These proteins, individually, indicated a suitable sensitivity of 93.6 and 100% and a specificity of 94.5 and 91.3%, respectively. However, our study with the chimera containing S1 and N proteins of SARS-CoV-2 suggested that the recombinant protein could better balance both the sensitivity (95.7%) and the specificity (95.5%) of the serological assay when comparing with the ELISA test using the antigens N and S1, individually. Accordingly, the chimera showed a high area under the ROC curve of 0.98 (CI 95% 0.958-1). Thus, our chimeric approach could be used to assess the natural exposure against SARS-CoV-2 virus over time, however, other tests will be necessary to better understand the behaviour of the chimera in samples from people with different vaccination doses and/or infected with different variants of the virus.
ABSTRACT
BACKGROUND: Acute Generalised Exanthematous Pustulosis (AGEP) is a rash with multiple sterile intraepidermal or subcorneal non-follicular pustules on edematous papules, with a sudden development and rapid evolution, triggered by drugs, vaccination, insect bites, exposure to mercury, and allergens. OBJECTIVES AND METHODS: We describe a female patient who developed extensive and abnormally prolonged AGEP following exposure to terbinafine and SARS-CoV vaccine. A detailed review of terbinafine-induced-AGEP cases was performed, with the aim of evaluating if the AGEP criteria would follow a different pattern when the disease is triggered by this drug. A PubMed search helped retrieve all terbinafine-induced AGEP case reports. AGEP-specific Sideroff criteria were analysed in terbinafine-induced cases and compared to other trigger causes. CONCLUSIONS: When the AGEP causative drug was terbinafine, a delay in recovery was observed, compared to the existing AGEP criteria when other causes are considered. Terbinafine frequently leads to delayed resolution AGEP probably due to the presence of the drug in the skin for several weeks after exposure, even after discontinuation, and the disease severity may be potentialised by additional factors such as concomitant viral infections or vaccination.
Subject(s)
Acute Generalized Exanthematous Pustulosis , Mercury , Acute Generalized Exanthematous Pustulosis/etiology , Female , Humans , Skin , Terbinafine/adverse effectsABSTRACT
BACKGROUND: Few tuberculosis (TB) control programmes in low-income countries have access to culture facilities in their primary care diagnostic centres and this scenario may have worsened with the coronavirus disease 2019 pandemic. Thus the aim was to develop and evaluate a simpler TB test that allows seeding on Löwenstein-Jensen (LJ) medium of several swab-embedded samples decontaminated with sodium hydroxide (NaOH). METHODS: A cotton swab containing each sample was decontaminated in NaOH before being dipped into a slightly acidic solution to neutralize the pH in order to allow the culture to develop on LJ medium. Samples (n=543) from suspected or confirmed pulmonary TB were analysed in two phases: standardization (n=167) and evaluation of the study method (n=376). RESULTS: The study method showed sensitivity >95% and specificity >93% using Ogawa-Kudoh (OK) and modified Petroff (MP) as standards and was comparable to MP-LJ (p>0.05) and slightly superior to OK (p=0.03) for sputum culture and more comprehensive than the latter for other pulmonary specimens. CONCLUSIONS: This article reports a more comprehensive, simpler and less costly method for diagnosing TB in the laboratory with fewer economic resources and biosafety equipment. Thus a patent application was filed (BR1020190103841).