scholarly journals COVID-19: Is it safe now? Study of asymptomatic infection spread and quantity risk based on SAIR model

2021 ◽  
pp. 100060
Author(s):  
Liu Ying ◽  
Tang Xiaoqing
Keyword(s):  
Asymptomatic Infection ◽  
Infection Spread

Effect of coronavirus disease in patients with kidney disease in India

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 1255-1259
Author(s):  
Shashi Prabha Singh ◽  
Preeti Sharma ◽  
Durgesh singh ◽  
Pradeep kumar ◽  
Rakesh Sharma ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Clinical Trials ◽  
Kidney Disease ◽  
Meta Analysis ◽  
Tertiary Care ◽  
Type Ii Diabetes Mellitus ◽  
Asymptomatic Infection ◽  
Type Ii ◽  
Cardiorespiratory Failure ◽  
Inflammatory State

Coronavirus disease 19 is a global pandemic which infects over millions of people worldwide in a limited time and changes the lifestyle, clinical spectrum lies from asymptomatic infection to pneumonitis with cardiorespiratory failure and finally death. Higher mortality occurs in senior and who are suffering from co-morbidities like chronic kidney disease, (HTN) hypertension, (DM TYPE II) diabetes mellitus or (CVD) cardiovascular diseases. However, rather than normal individuals, patients with chronic kidney disease (CKD) are under higher risk for infections. The chronic systemic inflammatory state is a significant cause for morbidity and mortality in CKD patients. The objective of this review is to discuss the pathogenesis of COVID-19 in CKD, changes observed in the immune system of CKD patients, COVID-19 infections risk in CKD and therapeutic approach of COVID-19 in CKD patients. From the standpoint of frequent renal co-morbidities in covid19 patients, renal complications were explored in covid19 patients received at level 2 tertiary care Santosh Hospital, Ghaziabad, U.P. Delhi-NCR India during March to August 2020 as per the protocol of Nephrology Society of India. Relevant clinical trials were reviewed in support. Meta-analysis and clinical trials are covered in this review study. Duplicate studies are not taken into account. The outcome of the studies shows that CKD patients are more prone to COVID-19. CKD patients are more likely infected with COVID-19 virus. Whereas in intensive care, CKD occurs more frequent than DM type II and CVD. So,COVID-19 pathogenesis in CKD patients, risk of COVID-19, immunologic changes and therapy COVID-19 in CKD can add support in the effective management of COVID-19.

The Experience of Plague in East Kent, 1636-38

2016 ◽  
pp. 9-27
Author(s):  
Margaret Bolton
Keyword(s):  
Surrounding Area ◽  
Infection Spread ◽  
The Hamlet

On 2 July 1637 43-year-old Elizabeth Burgess, from Canterbury, was buried at Birchington, Kent, having died of the plague in the hamlet of Wood in that parish. She was the first victim of an outbreak of plague in 1637. This article firstly examines that outbreak in Birchington in detail; then it considers how far the parish's experience matched that in nearby Faversham and Sandwich. It finally discusses the extent to which the infection spread to the surrounding area.

DETECTION OF LEISHMANIA INFECTION IN STRAY DOGS IN HUMAN LEISHMANIASIS ENDEMIC AREA IN MYMENSINGH DISTRICT WITH ITS POSSIBLE PUBLIC HEALTH SIGNIFICANCE IN BANGLADESH

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
M. A. Hossen
Keyword(s):  
Visceral Leishmaniasis ◽  
Asymptomatic Carrier ◽  
Asymptomatic Infection ◽  
Reservoir Host ◽  
Sand Fly ◽  
Leishmania Infection ◽  
Endemic Region ◽  
Stray Dogs ◽  
Human Leishmaniasis ◽  
Strip Test

Background: Leishmaniasis is primarily caused by two species of Leishmania (L. donovani and L. infantum) of which clinical infection with L. infantum has been recognized in both humans and dogs as zoonotic disease with dogs as the main reservoir hosts in the Mediterranean, the Middle East, Asia and South America. Although L. donovani has been associated with both clinical and asymptomatic infection in humans but it is still associated with asymptomatic infection in dogs in Indian sub-continent without any evidence of zoonotic infection. Objectives: The objective of this research was to investigate the potentiality of dog as reservoir host for visceral leishmaniasis in the human leishmaniasis endemic regions in Bangladesh. Materials and Methods: A total of 20 stray dogs in the human VL endemic areas of Mymensingh district were captured for the detection VL during the period of November 2010 to May 2011. The dipstick test rK39 (Bios International; n = 20), Giemsa’s stained impression smears of liver and spleen (n = 6) and PCR with the tissue of liver and spleen (n = 6) were tested as per manufacturer instructions and conventional standard methods. Results: Out of 20 stray dogs examined, 4 (20.0%) were positive for L. donovani infection with rK39 strip test. Of the six randomly selected dogs tested with Modified Giemsa’s stained of impression smears of spleen and liver showed 2 (33.33%) positive whereas PCR technique detected 5 (83.33%) positive for L. donovani. Results of PCR showed 145bp amplicon, specific for L. donovani infection in 83.33% stray dogs. Conclusions: This study reveals that a high percentage of L. donovani asymptomatic carrier infections occur in dogs and evidence indicates that dogs and humans may potentially serve as a source of infection to sand fly vectors and accordingly dogs can be recognized as a probable animal reservoir for the Leishmania infection in the endemic region in Bangladesh. However, further studies are required to determine the ability of dogs to transmit the L. donovani to the vector sand fly in nature and its evidence on ‘One Health’ perspectives. Keywords: Visceral leishmaniasis, Endemic region, Stray dogs, rK39 strip test, Giemsa’s stained liver and spleen impression smears, PCR, Reservoir host, Mymensingh

How much does human mobility behavior affect the COVID-19 infection spread?

2020 ◽  
Author(s):  
Shogo Isoda ◽  
Shogo Kawanaka ◽  
Yuki Matsuda ◽  
Hirohiko Suwa ◽  
Keiichi Yasumoto
Keyword(s):  
Human Mobility ◽  
Mobility Behavior ◽  
Infection Spread

scholarly journals Comprehensive and safe school strategy during COVID-19 pandemic

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Susanna Esposito ◽  
Nicola Cotugno ◽  
Nicola Principi
Keyword(s):  
School Attendance ◽  
Asymptomatic Infection ◽  
School Closure ◽  
Prevention Measures ◽  
Effective Measure ◽  
The Real ◽  
Definitive Answer ◽  
Mild Disease ◽  
Infectious Risk ◽  
Over Time

Abstract Background Although several studies have tried to evaluate the real efficacy of school closure for pandemic control over time, no definitive answer to this question has been given. Moreover, it has not been clarified whether children or teenagers could be considered a problem for SARS-CoV-2 diffusion or, on the contrary, whether parents and school workers play a greater role. The aims of this review are to discuss about children’s safety at school and the better strategies currently able to reduce the risk of SARS-CoV-2 infection at school. Main aim Compared to adults, very few cases of COVID-19 were diagnosed in children, who generally suffered from an asymptomatic infection or a mild disease. Moreover, school closure is systematically associated with the development of problems involving students, teachers and parents, particularly among populations with poor resources. Although several researches have tried to evaluate the real efficacy of school closure for pandemic control over time, no definitive answer to this question has been given. Available findings seem to confirm that to ensure adequate learning and to avoid social and economic problems, schools must remain open, provided that the adults who follow children at home and at school absolutely comply with recommendations for prevention measures and that school facilities can be optimized in order to significantly reduce the spread of infection. In this regard, the universal use of face masks in addition to hand hygiene and safe distancing in schools, at least starting from the age of 6 years, seems extremely useful. Moreover, since the beginning of the COVID-19 outbreak the use of telemedicine to manage suspected SARS-CoV-2-infected individuals in the community has appeared to be an easy and effective measure to solve many paediatric problems and could represent a further support to schools . Conclusions We think that schools must remain open, despite COVID-19 pandemic. However, several problems strictly related to school frequency and reduction of infectious risk must be solved before school attendance can be considered completely safe. A single more in-depth guideline agreed between countries with the same school problems could be very useful in eliminating doubts and fostering the compliance of students, teachers and non-teaching school staff reducing errors and misinterpretations.

scholarly journals Characterization of Salmonella serotypes prevalent in asymptomatic people and patients

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Haiyan Xu ◽  
Weibing Zhang ◽  
Kai Zhang ◽  
Yue Zhang ◽  
Zhenyu Wang ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Asymptomatic Infection ◽  
Resistance Rate ◽  
Human Infection ◽  
The Other ◽  
Resistance Testing ◽  
Multi Drug Resistance ◽  
Discriminative Ability ◽  
Source Of Infection ◽  
The Difference

Abstract Background Infection with Salmonella enterica usually results in diarrhea, fever, and abdominal cramps, but some people become asymptomatic or chronic carrier as a source of infection for others. This study aimed to analyze the difference in serotype, antimicrobial resistance, and genetic profiles between Salmonella strains isolated from patients and those from asymptomatic people in Nantong city, China. Methods A total of 88 Salmonella strains were collected from patients and asymptomatic people from 2017 to 2018. Serotyping, antimicrobial susceptibility testing, and PFGE analysis were performed to analyze the characteristics of these strains. Results Twenty serotypes belonging to 8 serogroups were identified in the 88 Salmonella strains. S. Typhimurium remained to be the predominant serotype in strains from both patients and asymptomatic people. Among the 27 strains from patients, S. Enteritidis and S. Rissen were shown as the other two major serotypes, while S. London, S. Derby, and S. Meleagridis were demonstrated as the other significant serotypes among the 61 strains from asymptomatic people. Antimicrobial resistance testing revealed that 84.1% of strains from both resources were multi-drug resistant. PFGE displayed a highly discriminative ability to differentiate strains belonging to S. Derby, S. Typhimurium, etc., but could not efficiently differentiate serotypes like S. Enteritidis. Conclusions This study’s results demonstrated that S. Typhimurium could cause human infection in both symptomatic and asymptomatic state; S. London, S. Derby, and S. Meleagridis usually cause asymptomatic infection, while S. Enteritidis infection mainly results in human diseases. The high multi-drug resistance rate detected in the antimicrobial resistance and diverse PFGE profiles of these strains implied that the strains were isolated from different sources, and the increased surveillance of Salmonella from both patients and asymptomatic people should be taken to control the disease.

scholarly journals Evaluating the effectiveness of measures to control the novel coronavirus disease 2019 in Jilin Province, China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qinglong Zhao ◽  
Yao Wang ◽  
Meng Yang ◽  
Meina Li ◽  
Zeyu Zhao ◽  
...  
Keyword(s):  
Prevention And Control ◽  
Good Control ◽  
Asymptomatic Infection ◽  
Jilin Province ◽  
Control Measures ◽  
First Case ◽  
Before And After ◽  
Novel Coronavirus ◽  
Reported Data ◽  
And Control

Abstract Background Based on differences in populations and prevention and control measures, the spread of new coronary pneumonia in different countries and regions also differs. This study aimed to calculate the transmissibility of coronavirus disease 2019 (COVID-19), and to evaluate the effectiveness of measures to control the disease in Jilin Province, China. Methods The data of reported COVID-19 cases were collected, including imported and local cases from Jilin Province as of March 14, 2019. A Susceptible–Exposed–Infectious–Asymptomatic–Recovered/Removed (SEIAR) model was developed to fit the data, and the effective reproduction number (Reff) was calculated at different stages in the province. Finally, the effectiveness of the measures was assessed. Results A total of 97 COVID-19 infections were reported in Jilin Province, among which 45 were imported infections (including one asymptomatic infection) and 52 were local infections (including three asymptomatic infections). The model fit the reported data well (R2 = 0.593, P < 0.001). The Reff of COVID-19 before and after February 1, 2020 was 1.64 and 0.05, respectively. Without the intervention taken on February 1, 2020, the predicted cases would have reached a peak of 177,011 on October 22, 2020 (284 days from the first case). The projected number of cases until the end of the outbreak (on October 9, 2021) would have been 17,129,367, with a total attack rate of 63.66%. Based on the comparison between the predicted incidence of the model and the actual incidence, the comprehensive intervention measures implemented in Jilin Province on February 1 reduced the incidence of cases by 99.99%. Therefore, according to the current measures and implementation efforts, Jilin Province can achieve good control of the virus’s spread. Conclusions COVID-19 has a moderate transmissibility in Jilin Province, China. The interventions implemented in the province had proven effective; increasing social distancing and a rapid response by the prevention and control system will help control the spread of the disease.

scholarly journals Impact of the COVID-19 Vaccine on Asymptomatic Infection Among Patients Undergoing Pre-Procedural COVID-19 Molecular Screening

2021 ◽  
Author(s):  
Aaron J Tande ◽  
Benjamin D Pollock ◽  
Nilay D Shah ◽  
Gianrico Farrugia ◽  
Abinash Virk ◽  
...  
Keyword(s):  
United States ◽  
Relative Risk ◽  
Healthcare System ◽  
The United States ◽  
Asymptomatic Infection ◽  
Screening Tests ◽  
Molecular Screening ◽  
Molecular Tests ◽  
Asymptomatic Individuals ◽  
The Impact

Abstract Background Several vaccines are now clinically available under emergency use authorization in the United States and have demonstrated efficacy against symptomatic COVID-19. The impact of vaccines on asymptomatic SARS-CoV-2 infection is largely unknown. Methods We conducted a retrospective cohort study of consecutive, asymptomatic adult patients (n = 39,156) within a large United States healthcare system who underwent 48,333 pre-procedural SARS-CoV-2 molecular screening tests between December 17, 2020 and February 8, 2021. The primary exposure of interest was vaccination with at least one dose of an mRNA COVID-19 vaccine. The primary outcome was relative risk of a positive SARS-CoV-2 molecular test among those asymptomatic persons who had received at least one dose of vaccine, as compared to persons who had not received vaccine during the same time period. Relative risk was adjusted for age, sex, race/ethnicity, patient residence relative to the hospital (local vs. non-local), healthcare system regions, and repeated screenings among patients using mixed effects log-binomial regression. Results Positive molecular tests in asymptomatic individuals were reported in 42 (1.4%) of 3,006 tests performed on vaccinated patients and 1,436 (3.2%) of 45,327 tests performed on unvaccinated patients (RR=0.44 95% CI: 0.33-0.60; p&lt;.0001). Compared to unvaccinated patients, the risk of asymptomatic SARS-CoV-2 infection was lower among those &gt;10 days after 1 st dose (RR=0.21; 95% CI: 0.12-0.37; p&lt;.0001) and &gt;0 days after 2 nd dose (RR=0.20; 95% CI: 0.09-0.44; p&lt;.0001) in the adjusted analysis. Conclusions COVID-19 vaccination with an mRNA-based vaccine showed a significant association with a reduced risk of asymptomatic SARS-CoV-2 infection as measured during pre-procedural molecular screening. The results of this study demonstrate the impact of the vaccines on reduction in asymptomatic infections supplementing the randomized trial results on symptomatic patients.

scholarly journals Intranasal Infection of Ferrets with SARS-CoV-2 as a Model for Asymptomatic Human Infection

Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 113
Author(s):  
Helen E. Everett ◽  
Fabian Z. X. Lean ◽  
Alexander M. P. Byrne ◽  
Pauline M. van Diemen ◽  
Shelley Rhodes ◽  
...  
Keyword(s):  
Genomic Sequence ◽  
Humoral Response ◽  
Asymptomatic Infection ◽  
Human Infection ◽  
Viral Rna ◽  
Post Inoculation ◽  
Upper Respiratory Tract ◽  
Infection Dynamics ◽  
Genomic Sequence Analysis ◽  
Upper Respiratory

Ferrets were experimentally inoculated with SARS-CoV-2 (severe acute respiratory syndrome (SARS)-related coronavirus 2) to assess infection dynamics and host response. During the resulting subclinical infection, viral RNA was monitored between 2 and 21 days post-inoculation (dpi), and reached a peak in the upper respiratory cavity between 4 and 6 dpi. Viral genomic sequence analysis in samples from three animals identified the Y453F nucleotide substitution relative to the inoculum. Viral RNA was also detected in environmental samples, specifically in swabs of ferret fur. Microscopy analysis revealed viral protein and RNA in upper respiratory tract tissues, notably in cells of the respiratory and olfactory mucosae of the nasal turbinates, including olfactory neuronal cells. Antibody responses to the spike and nucleoprotein were detected from 21 dpi, but virus-neutralizing activity was low. A second intranasal inoculation (re-exposure) of two ferrets after a 17-day interval did not produce re-initiation of viral RNA shedding, but did amplify the humoral response in one animal. Therefore, ferrets can be experimentally infected with SARS-CoV-2 to model human asymptomatic infection.

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