Anosmia as a presenting symptom of SARS-CoV-2 infection in healthcare workers – A systematic review of the literature, case series, and recommendations for clinical assessment and management

Background: Healthcare workers are at the forefront of the ongoing COVID-19 pandemic and are at high risk for both the contraction and subsequent spread of virus. Understanding the role of anosmia as an early symptom of infection may improve monitoring and management of SARS-CoV2 infection. Methodology: We conducted a systematic review of the literature of SARS-CoV2 infection/COVID-19 and anosmia to help inform management of anosmia in healthcare works. We report a case series of healthcare workers, who presented with a loss of sense of smell secondary to COVID-19 infection to demonstrate management principles. RT-PCR was used to confirm COVID-19 positivity and psychophysical testing of olfaction was performed using the British version of the University of Pennsylvania Smell Identification Test, UPSIT. Results: The systematic literature search returned 31 articles eligible for inclusion in the study and informed our recommendations for clinical assessment and management. All three healthcare professionals who presented with loss of sense of smell subsequently tested positive for SARS-CoV-2. Psychophysical testing of olfaction using the UPSIT confirmed mild and moderate microsmia in two, respectively, and normosmia at day 17 in one. Conclusions: Olfactory (± gustatory) dysfunction is indicative of COVID-19 infection and thus has important implications in the context of healthcare workers, or key workers in general, who work in close contact with others if not recognised as suffering from COVID. This leads to a potentially higher likelihood of spreading the virus. In conjunction with our literature review these findings have helped with creating recommendations on the assessment and management of olfactory dysfunction during the ongoing COVID-19 pandemic, both for healthcare workers and patients

TmPrime: fast, flexible oligonucleotide design software for gene synthesis

Herein we present TmPrime, a computer program to design oligonucleotide sets for gene assembly by both ligase chain reaction (LCR) and polymerase chain reaction (PCR). TmPrime offers much flexibility with no constraints on the gene and oligonucleotide lengths. The program divides the long input DNA sequence based on the input desired melting temperature, and dynamically optimizes the length of oligonucleotides to achieve homologous melting temperatures. The output reports the melting temperatures, oligonucleotide sequences and potential formation of secondary structures. Our program also provides functions on sequence pooling to separate long genes into smaller pieces for multi-pool assembly and codon optimization for expression. The software has been successfully used in the design and synthesis of green fluorescent protein fragment (GFPuv) (760 bp), human protein kinase B-2 (PKB2) (1446 bp) and the promoter of human calcium-binding protein A4 (S100A4) (752 bp) using real-time PCR assembly with LCGreen I, which offers a novel approach to compare the efficiency of gene synthesis. The purity of assembled products is successfully estimated with the use of melting curve analysis, which would potentially eliminate the necessity for agarose gel electrophoresis. This program is freely available at http://prime.ibn.a-star.edu.sg

Course of symptoms for loss of sense of smell and taste over time in one thousand forty-one healthcare workers during the Covid-19 pandemic: Our experience

On April 21, 2020, the Centers for Disease Control and Prevention (CDC) and on May 5, 2020, the World Health Organisation added 'new loss of taste or smell' to their list of symptoms related to Covid-19, respectively. Public Health England (PHE) only included loss of smell and taste as official symptoms on May 20th . However, whether individual hospitals were including smell and taste disturbances in their initial work-up for Covid-19 diagnosis is unknown

The tomato xylem sap protein XSP10 is required for full susceptibility to Fusarium wilt disease

XSP10 is an abundant 10 kDa protein found in the xylem sap of tomato. The protein displays structural similarity to plant lipid transfer proteins (LTPs). LTPs are involved in various physiological processes, including disease resistance, and some are able to bind and transfer diverse lipid molecules. XSP10 abundance in xylem sap declines upon infection with Fusarium oxysporum f. sp. lycopersici (Fol), implying involvement of XSP10 in the plant–pathogen interaction. Here, the biochemical characterization of XSP10 with respect to fatty acid-binding properties is reported; a weak but significant binding to saturated fatty acids was found. Furthermore, XSP10-silenced tomato plants were engineered and it was found that these plants exhibited reduced disease symptom development upon infection with a virulent strain of Fol. Interestingly, the reduced symptoms observed did not correlate with an altered expression profile for known reporter genes of plant defence (PR-1 and WIPI). This work demonstrates that XSP10 has lipid-binding properties and is required for full susceptibility of tomato to Fusarium wilt

Community seroprevalence and risk factors for SARS-CoV-2 infection in different subpopulations in Vellore, India, and their implications for future prevention

Objectives The aim of this study was to inform public health policy decisions through the assessment of IgG antibody seroprevalence in the population and the risk factors for SARS-CoV-2 infection. Methods The seroprevalence of IgG antibodies among different subpopulations at the end of the first and second waves of the pandemic was estimated. Various risk factors associated with seropositivity, including sociodemography, IgG antibodies against endemic human coronavirus, and vaccination status, were also assessed. Results For all 2433 consenting participants, the overall estimated seroprevalences at the end of first and second waves were 28.5% (95% CI 22.3–33.7%) and 71.5% (95% CI 62.8–80.5%), respectively. The accrual of IgG positivity was heterogeneous, with the highest seroprevalences found in urban slum populations (75.1%). Vaccine uptake varied among the subpopulations, with low rates (< 10%) among rural and urban slum residents. The majority of seropositive individuals (75%) were asymptomatic. Residence in urban slums (OR 2.02, 95% CI 1.57–2.6; p < 0.001), middle socioeconomic status (OR 1.77, 95% CI 1.17–2.67; p = 0.007), presence of diabetes (OR 1.721, 95% CI 1.148–2.581; p = 0.009), and hypertension (OR 1.75, 95% CI 1.16–2.64; p = 0.008) were associated with seropositivity in multivariable analyses. Conclusion Although considerable population immunity has been reached, with more than two-thirds seropositive, improved vaccination strategies among unreached subpopulations and high-risk individuals are suggested for better preparedness in future