SARS-CoV-2 Specific IgG Antibodies Persist Over a 12-Month Period in Oral Mucosal Fluid Collected From Previously Infected Individuals

BackgroundDeveloping an understanding of the antibody response, seroprevalence, and seroconversion from natural infection and vaccination against SARS-CoV-2 will give way to a critical epidemiological tool to predict reinfection rates, identify vulnerable communities, and manage future viral outbreaks. To monitor the antibody response on a larger scale, we need an inexpensive, less invasive, and high throughput method.MethodsHere we investigate the use of oral mucosal fluids from individuals recovered from SARS-CoV-2 infection to monitor antibody response and persistence over a 12-month period. For this cohort study, enzyme-linked immunosorbent assays (ELISAs) were used to quantify anti-Spike(S) protein IgG antibodies in participants who had prior SARS-CoV-2 infection and regularly (every 2-4 weeks) provided both serum and oral fluid mucosal fluid samples for longitudinal antibody titer analysis.ResultsIn our study cohort (n=42) with 17 males and 25 females with an average age of 45.6 +/- 19.3 years, we observed no significant change in oral mucosal fluid IgG levels across the time course of antibody monitoring. In oral mucosal fluids, all the participants who initially had detectable antibodies continued to have detectable antibodies throughout the study.ConclusionsBased on the results presented here, we have shown that oral mucosal fluid-based assays are an effective, less invasive tool for monitoring seroprevalence and seroconversion, which offers an alternative to serum-based assays for understanding the protective ability conferred by the adaptive immune response from viral infection and vaccination against future reinfections.

Sanitary Passports and the Birth of the Immunized Self

This article sketches a short history of the Covid-19 passport by examining its earlier iterations, including the “sanitary passport” (passeport sanitaire), an epidemiological tool officially introduced on the global stage by the French delegation during the 1893 International Sanitary Conference in Dresden. The sanitary passport shares with the Covid-19 passport two features. First, a similar aim, that of controlling the movement of potentially infected individuals across borders. Second, a similar condition of possibility, that of being the product of a pandemic crisis. The article identifies key characteristics as well as departures with the reinvention of the Covid-19 vaccine or immunity passport. The paper also situates the birth of the sanitary passport within a security context of increasing use of national passports as a means for the continuous surveillance of criminals and vagabonds as well as a scientific context marked by a key mutation: the birth of the immunized self.

Genotypic Characterization of Mycobacterium bovis Isolates From Dairy Cattle Diagnosed With Clinical Tuberculosis

Molecular diagnosis of bovine tuberculosis plays an essential role in the epidemiological knowledge of the disease. Bovine tuberculosis caused by Mycobacterium bovis represents a risk to human health. This study aimed to perform the genotypic characterization of M. bovis isolated from bovines diagnosed as tuberculosis from dairy herds in the state of Pernambuco, Brazil. Granulomas from 30 bovines were sent for microbiological culture, and colonies compatible with Mycobacterium spp. were obtained in at least one culture from 17/30 granulomas. All isolates were confirmed to be M. bovis by spoligotyping and 24loci MIRU-VNTR typing. While spoligotyping characterized the isolates as SB0121, SB0295, SB0852, SB0120, and an unclassified genotype, 24loci MIRU-VNTR rendered two clusters of two isolates each and 13 unique profiles. Loci ETR-A showed higher discriminatory power, and loci (ETR-B, ETR-C, MIRU16, MIRU27, and QUB26) showed moderate allelic diversity. This is the first study on the genetic variability of the infectious agent cause of bovine TB in Pernambuco and demonstrates variability of strains in the state. Thus, it corroborates the importance of this microorganism as agent of bovine tuberculosis and its zoonotic potential, this epidemiological tool being a determinant in the rigor of the sanitary practices of disease control in dairy herds.

Monitoring SARS-CoV-2 variants alterations in Nice neighborhoods by wastewater nanopore sequencing

Background: Wastewater surveillance has been proposed as an epidemiological tool to define the prevalence and evolution of the SARS-CoV-2 epidemics. However, most implemented SARS-CoV-2 wastewater surveillance projects were relying on qPCR measurement of virus titers and did not address the mutational spectrum of SARS-CoV-2 circulating in the population. Methods: We have implemented a nanopore RNA sequencing monitoring system in the city of Nice (France, 550,000 inhabitants). Between October 2020 and March 2021, we monthly analyzed the SARS-CoV-2 variants in 113 wastewater samples collected in the main wastewater treatment plant and 20 neighborhoods. Findings: We initially detected the lineages predominant in Europe at the end of 2020 (B.1.160, B.1.177, B.1.367, B.1.474, and B.1.221). In January, a localized emergence of a variant (Spike:A522S) of the B.1.1.7 lineage occurred in one neighborhood. It rapidly spread and became dominant all over the city. Other variants of concern (B.1.351, P.1) were also detected in some neighborhoods, but at low frequency. Comparison with individual clinical samples collected during the same week showed that wastewater sequencing correctly identified the same lineages as those found in COVID-19 patients. Interpretation: Wastewater sequencing allowed to document the diversity of SARS-CoV-2 sequences within the different neighborhoods of the city of Nice. Our results illustrate how sequencing of sewage samples can be used to track pathogen sequence diversity in the current pandemics and in future infectious disease outbreaks.

SARS-CoV-2 antibodies rapid tests: a valuable epidemiological tool in challenging settings

Background: During the last year, mass screening campaigns have been carried out to identify immunological response to SARS-CoV-2 and establish a possible seroprevalence. The obtained results gained new importance with the beginning of SARS-CoV-2 vaccination campaign, as the lack of doses has persuaded several countries to introduce different policies for individuals who had a history of COVID 19. LFAs may represent an affordable tool to support population screening in LMICs, where diagnostic tests are lacking, and epidemiology is still widely unknown. However, LFAs have demonstrated a wide range of performance and the question of which one could be more valuable in these settings still remains. Methods: We evaluated the performance of 11 LFAs in detecting SARS-CoV-2 infection, analysing samples collected from 350 subjects. In addition, samples from 57 health care workers collected at 21-24 days after the first dose of Pfizer-BioNTech vaccine were also evaluated. Findings: LFAs demonstrated a wide range of specificity (92.31% to 100%) and sensitivity (50 to 100%). The analysis of serum samples post vaccination was used to describe the most suitable tests to detect IgG response against S protein RBD. History of TB therapy was identified as a potential factor affecting the specificity of LFAs. Conclusions: This analysis identified which LFAs represent a valuable tool not only for the detection of prior SARS-CoV-2 infection, but also to detect IgG elicited in response to vaccination. These results demonstrated that different LFAs may have different applications and the possible risks of their use in high TB burden settings.

Improved diagnosis of SARS-CoV-2 by using Nucleoprotein and Spike protein fragment 2 in quantitative dual ELISA tests

The novel Coronavirus, SARS-CoV-2, is the causative agent of the 2020 worldwide coronavirus pandemic. Antibody testing is useful for diagnosing historic infections of a disease in a population. These tests are also a helpful epidemiological tool for predicting how the virus spreads in a community, relating antibody levels to immunity and for assessing herd immunity. In the present study, SARS-CoV-2 viral proteins were recombinantly produced and used to analyse serum from individuals previously exposed, or not, to SARS-CoV-2. The nucleocapsid (Npro) and Spike subunit 2 (S2Frag) proteins were identified as highly immunogenic, although responses to the former were generally greater. These two proteins were used to develop two quantitative ELISA assays that when used in combination resulted in a highly reliable diagnostic test. Npro and S2Frag-ELISAs could detect at least 10% more true positive COVID-19 cases than the commercially available ARCHITECT test (Abbott). Moreover, our quantitative ELISAs also show that specific antibodies to SARS-CoV-2 proteins tend to wane rapidly even in patients that had developed severe disease. As antibody tests complement COVID-19 diagnosis and determine population-level surveillance during this pandemic, the alternative diagnostic we present in this study could play a role in controlling the spread of the virus.

Estimation of secondary household attack rates for emergent spike L452R SARS-CoV-2 variants detected by genomic surveillance at a community-based testing site in San Francisco

Background Sequencing of the SARS-CoV-2 viral genome from patient samples is an important epidemiological tool for monitoring and responding to the pandemic, including the emergence of new mutations in specific communities. Methods SARS-CoV-2genomicsequencesweregeneratedfrompositivesamplescollected,alongwithepidemiologicalmetadata,atawalk-up, rapid testing site in the Mission District of San Francisco, California during November 22-December 1, 2020 and January 10-29, 2021. Secondary household attack rates and mean sample viral load were estimated and compared across observed variants. Results A total of 12,124 tests were performed yielding 1,099 positives. From these, 928 high quality genomes were generated. Certain viral lineages bearing spike mutations, defined in part by L452R, S13I, and W152C, comprised 54.4% of the total sequences from January, compared to 15.7% in November. Household contacts exposed to the “California” or “West Coast” variants (B.1.427 and B.1.429) were at higher risk of infection compared to household contacts exposed to lineages lacking these variants (0.36 vs 0.29, RR=1.28; 95% CI:1.00-1.64). The reproductive number was estimated to be modestly higher than other lineages spreading in California during the second half of 2020. Viral loads were similar among persons infected with West Coast versus non-West Coast strains, as was the proportion of individuals with symptoms (60.9% vs 64.3%). Conclusions The increase in prevalence, relative household attack rates, and reproductive number are consistent with a modest transmissibility increase of the West Coast variants.

The ED/TEG Indicator for the Identification of Endocrine Disrupting or Toxic Effects on Endocrine Glands of Crop Protection Products Used in Organic and Conventional Agriculture in France

Studying the human health impacts of pesticides and their endocrine disruptor (ED) effects is a public health concern. The aim of this study is to identify phytopharmaceutical active substances (PAS) that are an ED or are toxic on endocrine glands (TEG), and to propose an ED/TEG effect indicator. Five international official databases were analyzed to identify the occurrence of health outcomes for 458 PAS. Health outcomes targeting seven endocrine systems were selected. For each substance, the level of evidence of the collected information and the number of outcomes were used to affect a level of concern about ED/TEG effects. Among the substances studied, 10% had a global ED/TEG effect classified as ‘high concern’, 55% as ‘medium concern’, 9% as ‘low concern’, and 26% as ‘unknown’. Ten of the high ED/TEG concern substances and 170 medium or low concern substances were licensed in 2018 in France. The outcomes were mainly on the reproductive organs, thyroid, and adrenal glands. Eight of the 41 biocontrol products studied were classified: 5 were ‘high’ or ‘medium concern’ and 3 had ‘unknown effect’. Although the proposed ED/TEG indicator is not an official classification, it can be used as an epidemiological tool for classifying the occupational and environmental risks of substances in retrospective population studies and be useful for occupational health physicians.

The Beighton Score as a measure of generalised joint hypermobility

The Beighton Score (BS) is a set of manoeuvres in a nine-point scoring system, used as the standard method of assessment for Generalised Joint Hypermobility (GJH). It was originally developed as an epidemiological tool used in screening large populations for GJH, but later adopted as a clinical tool for diagnostic purposes. Its ability to truly reflect GJH remains controversial, as joints within the scoring system are predominantly of the upper limb and disregard many of the major joints, preventing a direct identification of GJH. Furthermore, a consistent finding in the literature whereby the BS failed to identify hypermobility in joints outside the scoring system suggests its use as an indirect indicator of GJH is also not viable. As such, the collective findings of this review demonstrate a need for a change in clinical thinking. The BS should not be used as the principle tool to differentiate between localised and generalised hypermobility, nor used alone to exclude the presence of GJH. Greater emphasis should be placed on a clinician’s judgement to identify or exclude GJH, according to its full definition.