MXene‐Based Aptameric Fluorosensor for Sensitive and Rapid Detection of COVID‐19

MXene‐Based Aptameric FluorosensorsThe aptamer‐functionalized MXene nanosheet acts as an effective bionanosensor for fluorescence‐enhanced detection of COVID‐19 with high sensitivity and specificity. This fluosensor is capable of detecting SARS‐CoV‐2 spike protein (limit of detection: 38.9 fg mL−1) and SARS‐CoV‐2 pseudovirus (limit of detection: 7.2 copies) within 30 min, and can also detect clinical samples. More details can be found in article number 2301146 by Binwu Ying and co‐workers.

Insights and progress on epidemic characteristics, genotyping, and preventive measures of PEDV in China: A review.

Porcine Epidemic Diarrhoea (PED) is an acute, extremely infectious intestinal disease of pigs caused by the Porcine Epidemic Diarrhoea Virus (PEDV). The virus can affect pigs of all breeds and age groups and shows varying degrees of symptoms, with piglets, in particular, being infected with mortality rates of up to 100%. PEDV was first identified in China in the 1980s and in October 2010 a large-scale PED outbreak caused by a variant of PEDV occurred in China, resulting in huge economic losses. Initially, vaccination can effectively prevent the classical strain, but since December 2010, the PEDV variant has caused "persistent diarrhoea" with severe vomiting, watery diarrhoea, and high morbidity and mortality in newborn piglets as the dominant clinical features, with a significant increase in morbidity and mortality. This indicates that PEDV strains have mutated during evolution and that traditional vaccines no longer provide effective cross-immune protection, so it is necessary to optimize immunization programs and find effective treatments through epidemiological surveys of PEDV to reduce the economic losses caused by infections with mutated strains. This article reviews the progress of research on the aetiology, epidemiological characteristics, genotyping, pathogenesis, transmission routes, and comprehensive control of PEDV infection in China.

Immunogenicity and Safety of Homologous Booster Doses of CoronaVac COVID-19 Vaccine in Elderly Individuals Aged 60 Years and Older: A Dosing Interval Study - Yunnan Province, China, 2021-2022.

What is already known about this topic?: Neutralization levels induced by inactivated vaccines rapidly wane after primary immunization, and a homologous booster can recall specific immune memory, resulting in a remarkable increase in antibody concentration. The optimal interval between primary and booster doses has yet to be determined. What is added by this report?: Booster doses given at three months or more after the two-dose regimen of the CoronaVac COVID-19 vaccine in elderly individuals aged 60 years and older triggered good immune responses. The geometric mean titers of neutralizing antibody on Day 14 after the booster doses increased by 13.3-26.2 fold of baseline levels, reaching 105.45-193.59 in groups with different intervals (e.g., 3, 4, 5, and 6 months). What are the implications for public health practice?: A 4- to 5-month interval between receiving the primary and booster series of CoronaVac could be an alternative to the 6-month interval in order to promote vaccine-induced immunity in elderly individuals. The findings support the optimization of booster immunization strategies.

MXene-Based Aptameric Fluorosensor for Sensitive and Rapid Detection of COVID-19.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-caused COVID-19 pandemic has rapidly escalated into the largest global health emergency, which pushes to develop detection kits for the detection of COVID-19 with high sensitivity, specificity, and fast analysis. Here, aptamer-functionalized MXene nanosheet is demonstrated as a novel bionanosensor that detects COVID-19. Upon binding to the spike receptor binding domain of SARS-CoV-2, the aptamer probe is released from MXene surface restoring the quenched fluorescence. The performances of the fluorosensor are evaluated using antigen protein, cultured virus, and swab specimens from COVID-19 patients. It is evidenced that this sensor can detect SARS-CoV-2 spike protein at final concentration of 38.9 fg mL-1 and SARS-CoV-2 pseudovirus (limit of detection: 7.2 copies) within 30 min. Its application for clinical samples analysis is also demonstrated successfully. This work offers an effective sensing platform for sensitive and rapid detection of COVID-19 with high specificity.

The 5'UTR of HCoV-OC43 adopts a topologically constrained structure to intrinsically repress translation.

The emergence of SARS-CoV-2, which is responsible for the COVID-19 pandemic, has highlighted the need for rapid characterization of viral mechanisms associated with cellular pathogenesis. Viral UTRs represent conserved genomic elements that contribute to such mechanisms. Structural details of most CoV UTRs are not available, however. Experimental approaches are needed to allow for the facile generation of high-quality viral RNA tertiary structural models, which can facilitate comparative mechanistic efforts. By integrating experimental and computational techniques, we herein report the efficient characterization of conserved RNA structures within the 5'UTR of the HCoV-OC43 genome, a lab-tractable model coronavirus. We provide evidence that the 5'UTR folds into a structure with well-defined stem-loops (SLs) as determined by chemical probing and direct detection of hydrogen bonds by NMR. We combine experimental base-pair restraints with global structural information from SAXS to generate a 3D model that reveals that SL1-4 adopts a topologically constrained structure wherein SLs 3 and 4 coaxially stack. Coaxial stacking is mediated by short linker nucleotides and allows SLs 1 to 2 to sample different cojoint orientations by pivoting about the SL3,4 helical axis. To evaluate the functional relevance of the SL3,4 coaxial helix, we engineered luciferase reporter constructs harboring the HCoV-OC43 5'UTR with mutations designed to abrogate coaxial stacking. Our results reveal that the SL3,4 helix intrinsically represses translation efficiency since the destabilizing mutations correlate with increased luciferase expression relative to wildtype without affecting reporter mRNA levels, thus highlighting how the 5'UTR structure contributes to the viral mechanism.

Excess risk for acute myocardial infarction mortality during the COVID-19 pandemic.

The COVID-19 pandemic has had a detrimental impact on the healthcare system. Our study armed to assess the extent and the disparity in excess acute myocardial infarction (AMI)-associated mortality during the pandemic, through the recent Omicron outbreak. Using data from the CDC's National Vital Statistics System, we identified 1 522 669 AMI-associated deaths occurring between 4/1/2012 and 3/31/2022. Accounting for seasonality, we compared age-standardized mortality rate (ASMR) for AMI-associated deaths between prepandemic and pandemic periods, including observed versus predicted ASMR, and examined temporal trends by demographic groups and region. Before the pandemic, AMI-associated mortality rates decreased across all subgroups. These trends reversed during the pandemic, with significant rises seen for the youngest-aged females and males even through the most recent period of the Omicron surge (10/2021-3/2022). The SAPC in the youngest and middle-age group in AMI-associated mortality increased by 5.3% (95% confidence interval [CI]: 1.6%-9.1%) and 3.4% (95% CI: 0.1%-6.8%), respectively. The excess death, defined as the difference between the observed and the predicted mortality rates, was most pronounced for the youngest (25-44 years) aged decedents, ranging from 23% to 34% for the youngest compared to 13%-18% for the oldest age groups. The trend of mortality suggests that age and sex disparities have persisted even through the recent Omicron surge, with excess AMI-associated mortality being most pronounced in younger-aged adults.

Racial and Ethnic Disparities in Years of Potential Life Loss Among Patients With Cirrhosis During the COVID-19 Pandemic in the United States.

INTRODUCTION: Our aim was to evaluate the impact of race/ethnicity on cirrhosis-related premature death during the COVID-19 pandemic. METHODS: We obtained cirrhosis-related death data (n = 872,965, January 1, 2012-December 31, 2021) from the US National Vital Statistic System to calculate age-standardized mortality rates and years of potential life lost (YPLL) for premature death aged 25-64 years. RESULTS: Significant racial/ethnic disparity in cirrhosis-related age-standardized mortality rates was noted prepandemic but widened during the pandemic, with the highest excess YPLL for the non-Hispanic American Indian/American Native (2020: 41.0%; 2021: 68.8%) followed by other minority groups (28.7%-45.1%), and the non-Hispanic White the lowest (2020: 20.7%; 2021: 31.6%). COVID-19 constituted >30% of the excess YPLLs for Hispanic and non-Hispanic American Indian/American Native in 2020, compared with 11.1% for non-Hispanic White. DISCUSSION: Ethnic minorities with cirrhosis experienced a disproportionate excess death and YPLLs in 2020-2021.

Structural and Biochemical Analysis Reveals Catalytic Mechanism of Fucoidan Lyase from Flavobacterium sp. SA-0082.

Fucoidans represent a type of polyanionic fucose-containing sulfated polysaccharides (FCSPs) that are cleaved by fucoidan-degrading enzymes, producing low-molecular-weight fucoidans with multiple biological activities suitable for pharmacological use. Most of the reported fucoidan-degrading enzymes are glycoside hydrolases, which have been well studied for their structures and catalytic mechanisms. Little is known, however, about the rarer fucoidan lyases, primarily due to the lack of structural information. FdlA from Flavobacterium sp. SA-0082 is an endo-type fucoidan-degrading enzyme that cleaves the sulfated fuco-glucuronomannan (SFGM) through a lytic mechanism. Here, we report nine crystal structures of the catalytic N-terminal domain of FdlA (FdlA-NTD), in both its wild type (WT) and mutant forms, at resolutions ranging from 1.30 to 2.25 Å. We show that the FdlA-NTD adopts a right-handed parallel ß-helix fold, and possesses a substrate binding site composed of a long groove and a unique alkaline pocket. Our structural, biochemical, and enzymological analyses strongly suggest that FdlA-NTD utilizes catalytic residues different from other ß-helix polysaccharide lyases, potentially representing a novel polysaccharide lyase family.

The Discovery of Antivirals and Targets for SARS‐CoV‐2 and EV‐A71

Positive Strand RNA (PSR) viruses, such as coronaviruses and enteroviruses, cause serious health and economic threats worldwide, as currently seen with the COVID‐19 pandemic. This has drawn attention to the importance of identifying new antivirals and molecular targets in RNA viruses. The multifunctionality of PSR genomes make them desirable targets for therapeutic intervention. Here, we present a class of antivirals that can inhibit SARS‐CoV‐2 replication invitro by targeting conserved viral RNA structures at the 5’‐end. Specifically, stem loops 1, 4, 5a, and 6 of the viral 5’‐region have shown a degree of binding with these small molecules as determined by NMR structural analysis. These results open the door to potentially develop specific small molecules against SARS‐CoV‐2 and related coronaviruses. Additionally, Enterovirus A71 (EV‐A71), which is the etiological agent of the hand, foot, and mouth disease, has caused severe morbidity and high mortality rates in children for decades. Thus, understanding the mechanisms by which EV‐A71 replicates within the cellular environment can bring to light efficient drug targets for viral inhibition. The multifunctional viral protein, 3C protease (3Cpro), is essential for viral protein and RNA synthesis. Here, we investigate how RNA binding allosterically modulates the enzymatic activity of 3Cpro. We identify an overlooked dimerization surface on 3Cpro that is proximal to its active site and distal to its RNA binding domain. Our data show that RNA binding is allosterically coupled to 3Cpro dimerization, and we posit that this is a novel mechanism to regulate its enzymatic function. To that point, single, double, and triple point mutations in the 3Cpro dimerization domain attenuates viral growth and kinetics. Taken together, we present compelling data that demonstrates novel targeting surfaces on 3Cpro that can be pursued as antiviral targets.

Cross-sectional study of traumatic stress disorder in frontline nurses 6 mo after the outbreak of the COVID-19 in Wuhan.

BACKGROUND: Frontline nurses in Wuhan directly fighting severe acute respiratory syndrome coronavirus-2 diseases are at a high risk of infection and are extremely susceptible to psychological stress, especially due to the global coronavirus disease 2019 (COVID-19) pandemic. The psychological after-effects of this public health emergency on frontline nurses will last for years. AIM: To assess factors influencing post-traumatic stress disorder (PTSD) among frontline nurses in Wuhan 6 mo after the COVID-19 pandemic began. METHODS: A total of 757 frontline nurses from five hospitals in Wuhan, China, participated in an online survey from July 27 to August 13, 2020. This cross-sectional online study used a demographic information questionnaire, the PTSD Checklist for the Diagnostic and Statistical Manual of Mental Disorders, the Connor-Davidson Resilience Scale, and the Patient Health Questionnaire-4. The chi-square test and logistic regression were used to analyze the association of demographics, COVID-19-related variables, and PTSD. Logistic regression was also conducted to investigate which variables were associated with PTSD outcomes. RESULTS: A total of 13.5%, 24.3%, and 21.4% of the frontline nurses showed symptoms of PTSD, depression, and anxiety, respectively. The multivariate logistic regression analysis showed that the following factors were strongly associated with PTSD: Having a relative, friend, or colleague who died of COVID-19; experiencing stigma; or having psychological assistance needs, depressive symptoms or anxiety. Showing resilience and receiving praise after the COVID-19 outbreak were protective factors. CONCLUSION: Frontline nurses still experienced PTSD (13.5%) six months after the COVID-19 outbreak began. Peer support, social support, official recognition, reward mechanisms, exercise, better sleep, and timely provision of information (such as vaccine research progress) by the government via social media, and adequate protective supplies could mitigate the level of PTSD among nurses responding to COVID-19. Stigmatization, depression, and anxiety might be associated with a greater risk of PTSD among nurses.

Prompt and precise identification of various sources of infection in response to the prevention of malaria re-establishment in China.

Prompt and precise diagnosis of patients is an essential component of malaria control and elimination strategies, it is even more vital for the prevention of malaria re-establishment in the post elimination phase. After eliminating malaria in China, the strategy for prevention of malaria re-establishment was updated in a timely manner from the elimination strategy focusing on each case/focus to the prevention of re-establishment focusing on timely identification of the source of infection. However, there are numerous challenges, such as the persistent large number of imported malaria cases, the long-term threat of border malaria, unknown levels of asymptomatic infections and Plasmodium falciparum HRP2/3 gene deletions, and the continuous spreading of antimalarial drug resistance. Meanwhile, the detection capacity also need to be further improved to meet the timely detection of all sources of infection, otherwise it is bound to occur introduced malaria cases and malaria re-establishment in the presence of malaria vector mosquitoes. Therefore, it is necessary to continuously strengthen the malaria detection competency at all levels, promote the research and development on the malaria parasitological testing technologies, thus improving the timely detection of various sources of infection, and preventing the re-establishment of malaria.

Selecting Key Resilience Indicators for Indigenous Community Using Fuzzy Delphi Method

Resilience is the concept that emphasizes change and adaptation and focuses on the capacity to absorb shocks and still maintain function. How can an Indigenous community assess the resilience of the tribe when it is affected by an array of obstacles? What are the assessment factors of resilience? This study consolidated relevant literature on resilience through in-depth interviews and the Fuzzy Delphi Method (FDM) to identify the resilience indicators for Indigenous community development. It eventually identified 5 domains, 26 types, and 45 evaluation indicators. The final indicators are divided into five domains: economic, social, cultural, environmental, and policy. The social resilience indicators: “the ability to overcome obstacles”, “the ability to accept stimuli”, and “the degree of connection between tribal and external resources” were not mentioned in the past studies of resilience. For the first time, the following cultural resilience indicator was also included: “maintain the traditional ancestral teachings and respect for ancestral norms”. Finally, this study suggests that follow-up research may extend these resilience indicators and apply them to other Indigenous tribes. These 26 types of assessment will also be the factors that must be considered in the process of adaptation and reconstruction when the community is faced with emergencies or catastrophes.

Factors affecting telepractice use in COVID-19

BackgroundThe use of telepractice as an alternate method of delivering healthcare to people increased significantly after COVID-19 became a global pandemic.ObjectivesThis study aimed to identify factors contributing to the accelerated adoption of telepractice during COVID-19 in Singapore. It also sought to examine whether there are differences in the perspectives of staff in nursing facilities and caregivers in personal homes towards telepractice.MethodsA cross-sectional mixed method design was used. A survey with 20 items was adapted from the Telehealth Usability Questionnaire and translated into Mandarin. Anonymous responses were obtained from 70 patients and caregivers who had received speech therapy services via telepractice from a restructured hospital before and/or during Singapore?s Circuit Breaker period. Analyses were conducted using descriptive statistics and content analysis.ResultsSociodemographic variables of age, gender, education level and language preference did not impact user satisfaction and the likelihood of using telepractice again. Service-related factors were more influential. Participants chose to use telepractice as it saved travelling time (24.0%), was easy to use (19.3%), improved healthcare access (17.5%) and reduced waiting time (17.5%). Although all respondents expressed satisfaction in telepractice, 35.5% from personal homes and 37.5% from nursing facilities were not keen to use it again. Amongst caregivers, 26.7% from personal homes and 37.5% from nursing facilities preferred not to continue telepractice use. Technical and logistical disruptions and the lack of ?personal touch? were contributing factors.ConclusionImproving technological infrastructure, providing training for users and developing guidelines would help sustain telepractice as a form of service delivery beyond COVID-19.

Acyl-Coenzyme A Synthetase Long-Chain Family Member 4 Is Involved in Viral Replication Organelle Formation and Facilitates Virus Replication via Ferroptosis.

Enterovirus infections can cause severe complications, such as poliomyelitis, encephalitis, myocarditis, meningitis, neurological pulmonary edema, and even death. Here, we used genome-wide CRISPR screens to gain new insight into the mechanism by which enteroviruses co-opt host pathways to potentiate replication and propagation. We found that acyl-coenzyme A synthetase long-chain family member 4 (ACSL4) is involved in viral replication organelle formation. ACSL4 is a key component of ferroptosis, an iron-dependent, nonapoptotic programmed cell death. Our results indicated that enteroviruses and coronaviruses can induce ferroptosis via ACSL4. Most importantly, ferroptosis inhibitors, including two FDA-approved drugs, rosiglitazone (ROSI; ACSL4 inhibitor) and pioglitazone (PIO; ACSL4 inhibitor), decreased the viral load of human enteroviruses and coronaviruses, suggesting that ACSL4 is a target for counteracting viral infection. IMPORTANCE We provide the first evidence for the role of ACSL4 in enterovirus replication organelle formation. Moreover, both enteroviruses and coronaviruses induce ferroptosis via ACSL4. These findings establish a novel regulatory mechanism for viral replication. The inhibition of ACSL4 by ferroptosis inhibitors can reduce viral yields of enteroviruses and coronaviruses, including SARS-CoV-2, implying that ACSL4-mediated ferroptosis is a promising therapeutic target for viral diseases.

The clinical data from 19 critically ill patients with coronavirus disease 2019: a single-centered, retrospective, observational study.

Background: The objectives of this study were to analyze the clinical features of coronavirus disease 2019 (COVID-19) and evaluate the diagnosis and treatment. Methods: A retrospective analysis of the clinical manifestation and auxiliary examination of 19 patients with COVID-19 from the Liyuan Hospital intensive care unit (ICU) between January 16, 2020 and February 20, 2020 was undertaken. Results: There were 11 male and 8 female cases among the patients. The median (range) age was 73 (38-91) years. Of these patients, 8 (42.1%) had died and the median duration from ICU admission to death was 2 (interquartile range (IQR): 1-10.75) days. Seven of these 8 patients had underlying diseases. The auxiliary examination showed fever (68.4%), dry cough (15.8%), dyspnea (10.5%), and diarrhea (5.3%). All 19 cases showed ground-glass changes on chest computed tomography. Serum hypersensitive C-reactive protein (hs-CRP) and serum amylase A (SAA) were clearly increased in all of the cases. Among the 19 cases, there were 16 (84.2%) cases in which the total number of lymphocytes decreased, 12 cases (63%) had reduced liver function, and 11 cases (58%) had deviant results for fibrinogen (FIB) and D-dimer, in particular, the D-dimer level was significantly higher in the non-survivors compared with the survivors. Conclusion: There were more men than women among critically ill patients. All of the cases showed ground-glass changes on chest computed tomography and the vast majority of patients displayed fever and dry cough. The clinical laboratory indices change significantly, especially the D-dimer level among non-survivors.

Design of a Virtual Reality Interactive Training System for Public Health Emergency Preparedness for Major Emerging Infectious Diseases: Theory and Framework.

BACKGROUND: Sufficient public health emergency preparedness (PHEP) is the key factor in effectively responding to and recovering from major emerging infectious diseases (MEIDs). However, in the face of MEIDs, PHEP is insufficient, so it is necessary to improve PHEP. The rapid development of virtual reality and human-computer interaction provides unprecedented opportunities for innovative educational methods. OBJECTIVE: This study designed a virtual reality interactive training system (VRITS) to provide an effective path for improving PHEP in the context of MEIDs so that the public can effectively respond to and recover from MEIDs. METHODS: This study used interactive narrative, situated learning and human-computer interaction theories as a theoretical framework to guide the design of the system. We used the literature research method and the Delphi method; consulted multidisciplinary experts, such as infectious diseases, disease control, psychology, and public health personnel, to determine the educational content framework; and set up an interdisciplinary team to construct an operating system framework for the VRITS. RESULTS: We named the VRITS "People's War Against Pandemic." The educational content framework includes 20 knowledge, emotion, and behavior skills in 5 aspects (cooperating with prevention and control work, improving emergency response ability, guaranteeing supplies and equipment, preparing economic resources, and maintaining physical and mental health). The operating system framework includes virtual interactive training, knowledge corner, intelligent evaluation, and community forum modules, and the core module is the virtual interactive training module. In this module, users control virtual characters to move in various scenes, and then identify and analyze the controllability and harmfulness of the evolving pandemic and select the correct prevention and control strategy to avoid infecting themselves and others. CONCLUSIONS: The development and sharing of the multidisciplinary theoretical framework adopted by People's War Against Pandemic can help us clarify the design ideas and assumptions of the VRITS; predict training results; understand the ability of training to change emergency knowledge, emergency emotion, and behavioral responses to MEIDs; and promote the development of more effective training systems based on virtual reality.

Amilorides inhibit SARS-CoV-2 replication in vitro by targeting RNA structures.

The SARS-CoV-2 pandemic, and the likelihood of future coronavirus pandemics, emphasized the urgent need for development of novel antivirals. Small-molecule chemical probes offer both to reveal aspects of virus replication and to serve as leads for antiviral therapeutic development. Here, we report on the identification of amiloride-based small molecules that potently inhibit OC43 and SARS-CoV-2 replication through targeting of conserved structured elements within the viral 5'-end. Nuclear magnetic resonance­based structural studies revealed specific amiloride interactions with stem loops containing bulge like structures and were predicted to be strongly bound by the lead amilorides in retrospective docking studies. Amilorides represent the first antiviral small molecules that target RNA structures within the 5' untranslated regions and proximal region of the CoV genomes. These molecules will serve as chemical probes to further understand CoV RNA biology and can pave the way for the development of specific CoV RNA­targeted antivirals.

Prevalence and factors associated with post-traumatic stress disorder in healthcare workers exposed to COVID-19 in Wuhan, China: a cross-sectional survey.

BACKGROUND: The COVID-19 pandemic has posed significant threats to both the physical and psychological health of healthcare workers working in the front-line combating COVID-19. However, studies regarding the medium to long term impact of COVID-19 on mental health among healthcare workers are limited. Therefore, we conducted this cross-sectional survey to investigate the prevalence, factors and impact of post-traumatic stress disorder (PTSD) in healthcare workers exposed to COVID-19 8 months after the end of the outbreak in Wuhan, China. METHODS: A web-based questionnaire was delivered as a link via the communication application WeChat to those healthcare workers who worked at several COVID-19 units during the outbreak (from December 2019 to April 2020) in Wuhan, China. The questionnaire included questions on social-demographic data, the post-traumatic stress disorder checklist-5 (PCL-5), the family care index questionnaire (Adaptation, Partnership, Growth, Affection and Resolve, APGAR), and the quality-of-life scale (QOL). The prevalence, risk and protective factors, and impact of PTSD on healthcare workers were subsequently analyzed. RESULTS: Among the 659 participants, 90 healthcare workers were still suffering from PTSD 8 months after the end of the outbreak of COVID-19 in Wuhan, in which avoidance and negative impact were the most affected dimensions. Suffering from chronic disease, experiencing social isolation, and job dissatisfaction came up as independent risk factors for PTSD, while obtaining COVID-19 related information at an appropriate frequency, good family function, and working in well-prepared mobile cabin hospitals served as protective factors. The impact of PTSD on COVID-19 exposed healthcare workers was apparent by shortened sleeping time, feeling of loneliness, poorer quality of life and intention to resign. CONCLUSIONS: Eight months after the end of the COVID-19 outbreak in Wuhan, the level of PTSD in healthcare workers exposed to COVID-19 was still high. Apart from the commonly recognized risk factors, comorbid chronic disease was identified as a new independent risk factor for developing PTSD. For countries where the pandemic is still ongoing or in case of future outbreaks of new communicable diseases, this study may contribute to preventing cases of PTSD in healthcare workers exposed to infectious diseases under such circumstances.

A cross-sectional study of olfactory and taste disorders among COVID-19 patients in China.

To determine the prevalence and clinical features of olfactory and taste disorders among coronavirus disease 2019 (COVID-19) patients in China. A cross-sectional study was performed in Wuhan from April 3, 2020 to April 15, 2020. A total of 187 patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) completed face-to-face interviews or telephone follow-ups. We found that the prevalence of olfactory and taste disorders was significantly lower in the Chinese cohort than in foreign COVID-19 cohorts. Females were more prone to olfactory and taste disorders. In some patients, olfactory and taste disorders precede other symptoms and can be used as early screening and warning signs.

Thermal stability of diagnostic targets Plasmodium falciparum histidine rich protein II and Plasmodium lactate dehydrogenase in rapid detection

During the COVID-19 epidemic, blood samples are usually processed at 56 degrees C to attenuate the virus before pathogen detection. 71 blood samples of malaria patients reported by Shanghai Center for Disease Control and Prevention in 2017-2019 were collected, including 38 with Plasmodium falciparum infection, 8 P. malariae, 11 P. ovale and 14 P. vivax. The effect of inactivation on the thermal stability of P. falciparum histidine rich protein II (PfHRPII) and Plasmodium lactate dehydrogenase (pLDH) in blood samples was assessed before and after incubation at 56 degrees C for 30 min using the rapid diagnostic test (RDT) kit. The results showed that among the 38 P. falciparum T1-positive (PfHRPII) blood samples before heat treatment, 35 samples remained to be T1-positive (92.11%, 35/38, X 2 = 3.123, P > 0.05) after heat treatment;while 54 blood samples (26 P. falciparum, 6 P. vivax, 10 P. ovale and 12 P. vivax) that were T2-positive (pLDH) before heat treatment turned to be T2-negative (positive rate 0, 0/54, X 2 = 87.755, P < 0.01) after heat treatment. It was demonstrated that PfHRPII is stable during incubation at 56 degrees C for 30 min, while pLDH is unstable and degraded or inactivated during the heating. Therefore, the detection results of P. falciparum will not be affected by RDT, but diagnosis of the parasites other than P. falciparum in blood samples may be missed.