Infrared spectroscopy as a predictive tool for the severity of COVID-19 using patient's saliva: A strategy to avoid hyperinflammation.

Discriminate the severity level of COVID-19 disease is still a challenge. Here we investigate the capability of micro-infrared absorption spectroscopy (micro-FTIR) to probe COVID-19 severity level and predict hyperinflammation, correlating the assigned vibrational data to relevant biomolecules related to the immune system. Saliva of 184 patients was analysed by ELISA assay (Hepcidin) and micro-FTIR. Vibrational bands related to IgM and IgA can discriminate healthy from Severe individuals (sensitivity ≥ 0.749, specificity ≥ 0.945) and are less effective in discriminating Mild or Moderate individuals from the Severe group (sensitivity ≥ 0.628, specificity ≥ 0.867). Analysis of the second derivative of spectra probed increased levels of IL-6 in the saliva a key additional information for the degree of severity prediction. Because the model discriminates all the groups regarding the Severe group, it predicts an intense state of inflammation based on FTIR analysis. It is a powerful tool for predicting hyperinflammation conditions related to SARS-CoV-2 infection and may be an ally in implementing drugs or therapeutic approaches to manage COVID-19 in the Severe stage in healthcare facilities.

MALDI-TOF mass spectrometry of saliva samples as a prognostic tool for COVID-19.

BACKGROUND: The SARS-CoV-2 infections are still imposing a great public health challenge despite the recent developments in vaccines and therapy. Searching for diagnostic and prognostic methods that are fast, low-cost and accurate are essential for disease control and patient recovery. The MALDI-TOF mass spectrometry technique is rapid, low cost and accurate when compared to other MS methods, thus its use is already reported in the literature for various applications, including microorganism identification, diagnosis and prognosis of diseases. METHODS: Here we developed a prognostic method for COVID-19 using the proteomic profile of saliva samples submitted to MALDI-TOF and machine learning algorithms to train models for COVID-19 severity assessment. RESULTS: We achieved an accuracy of 88.5%, specificity of 85% and sensitivity of 91.5% for classification between mild/moderate and severe conditions. When we tested the model performance in an independent dataset, we achieved an accuracy, sensitivity and specificity of 67.18, 52.17 and 75.60% respectively. CONCLUSION: Saliva is already reported to have high inter-sample variation; however, our results demonstrates that this approach has the potential to be a prognostic method for COVID-19. Additionally, the technology used is already available in several clinics, facilitating the implementation of the method. Further investigation using a larger dataset is necessary to consolidate the technique.

Lack of direct association between oral mucosal lesions and SARS-CoV- 2 in a cohort of patients hospitalised with COVID-19.

Background: COVID-19 is a disease affecting various human organs and systems, in which the virus seeks to interact with angiotensin-converting enzyme 2 receptors. These receptors are present in the oral cavity, but the direct relationship between such an interaction and possible oral manifestations of COVID-19 is still unclear. Aim: The present study evaluated oral manifestations in a cohort of COVID-19 patients during the period of hospitalisation. Methods: In total, 154 patients presenting moderate-to-severe forms of COVID-19 had their oral mucosa examined twice a week until the final outcome, either discharge or death. The oral alterations observed in the patients were grouped into Group 1 (pre-existing conditions and opportunistic oral lesions) and Group 2 (oral mucosal changes related to hospitalization). Results: Oral lesions found in the patients of Group 1 are not suggestive of SARS-CoV-2 infection as they are mainly caused by opportunistic infections. On the other hand, oral alterations found in the patients of Group 2 were statistically (P < 0.001) related to intubation and longer period of hospitalisation. Conclusion: It is unlikely that ulcerative lesions in the oral cavity are a direct manifestation of SARS-CoV-2 or a marker of COVID-19 progression.

Molecular typing of PPRV strains detected during an outbreak in sheep and goats in south-eastern Gabon in 2011.

BACKGROUND: Peste des petits ruminanats (PPR) is an economically important viral disease affecting goats and sheep. Four genetically distinct lineages of peste des petits ruminants virus (PPRV) have been identified. In Gabon, the virus has not so far been detected. FINDINGS: Epidemiological investigations of Aboumi PPR outbreak revealed a high case fatality rate in sheep (98.9%). We detected and characterized peste des petits ruminants virus (PPRV), in October 2011, during the suspected outbreak in sheep and goats in Aboumi village located in the south-eastern. PPRV RNA was detected in 10 of 14 samples from three sick animals. Phylogenetic analysis revealed that the PPRV strain belonged to lineage IV and was closely related to strain circulating in neighboring Cameroon. CONCLUSIONS: This is the first molecular detection and typing of the PPRV strain associated with fatal PPR infection in these small ruminants and concrete evidence that PPRV is present and circulating in Gabon.

Rhinovirus C and respiratory exacerbations in children with cystic fibrosis.

To investigate a possible role for human rhinovirus C in respiratory exacerbations of children with cystic fibrosis, we conducted microbiologic testing on respiratory specimens from 103 such patients in São Paulo, Brazil, during 2006-2007. A significant association was found between the presence of human rhinovirus C and respiratory exacerbations.