scholarly journals Pre-Pandemic SARS-CoV-2 Potential Natural Immunity Among Population of Central Africa

2021 ◽  
Author(s):  
Marc SOURIS ◽  
Léon TSHILOLO ◽  
Daniel PARZY ◽  
Line LOBALOBA INGOBA ◽  
Francine NTOUMI ◽  
...  
Keyword(s):  
Regional Differences ◽  
Blood Donors ◽  
Central Africa ◽  
Incidence Rates ◽  
Natural Immunity ◽  
Igg Antibodies ◽  
Major Significance ◽  
Significant Difference ◽  
Sera Samples ◽  
Control Samples

Abstract More than a year after the emergence of COVID-19, significant regional differences in terms of morbidity persist, showing lower incidence rates in central Africa. The work reported here aims to test for a pre-pandemic natural immunity among populations in this region. To identify such pre-existing immunity, sera samples collected before the emergence of COVID-19 were tested to detect IgG antibodies reacting against SARS-CoV-2 proteins of major significance. Sera samples from blood donors of France were used as control. The results showed a statistically significant difference for antibodies prevalence between the samples collected in central Africa and the control samples. Our results suggest that in the central African sub-region the populations have been potentially pre-exposed before the COVID-19 pandemic to the antigens of a SARS-CoV-2-like virus.

scholarly journals Pre-pandemic SARS-CoV-2 potential natural immunity among population of the Democratic Republic of Congo

2021 ◽  
Author(s):  
Marc SOURIS ◽  
Léon TSHILOLO ◽  
Daniel PARZY ◽  
Rachel KAMGAING ◽  
Destin MBONGI ◽  
...  
Keyword(s):  
Democratic Republic ◽  
Democratic Republic Of Congo ◽  
Serological Test ◽  
Close Contact ◽  
Incidence Rates ◽  
Sub Saharan Africa ◽  
Natural Immunity ◽  
Republic Of Congo ◽  
Significant Difference ◽  
Control Samples

More than a year after the emergence of COVID-19, significant regional differences in terms of morbidity persist, showing lower incidence rates in sub-Saharan Africa, Southeast Asia, and Oceania. Like SARS-CoV-1 and MERS viruses, SARS-CoV-2 is monophyletically positioned with parental species of chiropteran coronavirus. Furthermore, we observe that the spatial distribution of several targeted bat species (i.e., Coronavirus species hosts) overlaps the distribution of countries with low COVID-19 incidence. The work presented here aims to test the presence of natural immunity among population with a low COVD-19 prevalence, potentially due to a previous exposure to coronavirus antigens of a virus close related to SARS-CoV-2. To identify such pre-existing immunity, an ELISA serological test was used to detect IgG antibodies targeting main SARS-CoV-2 proteins including: the N-protein, the Spike 1 (S1) protein, the receptor binding domain (RBD) of the S1 protein, the N-terminal domain (NTD) of the S1 protein, and the S2 protein. A total of 574 sera samples collected before 2019 in the population of the Democratic Republic of Congo (DRC) were tested). 189 control sera from blood donors in France were used as control samples. The results showed a statistically significant difference between the DRC samples and control samples for all antigens (N, S1, S2, NTD) except for RBD. The percentage of positive samples presenting reactive antibodies for S1 antigen was respectively of 19.2% for RDC versus 2.11% for the control, and of 9.3% versus 1.6% for the S2 antigen. In conclusion, our data showed that the study population has been potentially exposed to a SARS-CoV-2-like virus antigen before the pandemic in the Central African sub-region. Therefore, it is quite legitimate to think that this prior immunity may be protective and responsible for the observed low prevalence of COVID-19. Moreover, we can assume that this not yet identified SARS-CoV-2-like could be associated to a chiropteran species in close contact with the studied population. In order to confirm the presence of SARS-CoV-2-like virus antibodies and ultimately identify the neutralizing potential for the detected antibodies, our study is underway in other African and Asian countries, where the COVID-19 prevalence is limited.

scholarly journals Seroprevalence of hepatitis E virus among blood donors on Corsica, France, 2017

2020 ◽  
Vol 25 (5) ◽  
Author(s):  
Lisandru Capai ◽  
Nathanaël Hozé ◽  
Jacques Chiaroni ◽  
Sylvie Gross ◽  
Rachid Djoudi ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Blood Donors ◽  
Acute Viral Hepatitis ◽  
Hepatitis E ◽  
Igg Antibodies ◽  
Zoonotic Pathogen ◽  
Force Of Infection ◽  
Hyperendemic Area ◽  
Annual Probability ◽  
Significant Difference

Background Hepatitis E virus (HEV) is an emerging zoonotic pathogen and an important cause of acute viral hepatitis in European countries. Corsica Island has been previously identified as a hyperendemic area for HEV. Aim Our aim was to characterise the prevalence and titres of IgG antibodies to HEV among blood donors on Corsica and establish a model of the annual force of infection. Methods Between September 2017 and January 2018, 2,705 blood donations were tested for anti-HEV IgG using the Wantai HEV IgG enzyme immunoassay. Results The overall seroprevalence was 56.1%. In multivariate analysis, seroprevalence was higher in men than in women (60.0% vs 52.2%; p < 0.01), increased with age and was significantly higher among donors born on Corsica (60.6% vs 53.2%; p < 0.01). No significant difference was observed between the five districts of the island. IgG anti-HEV titres were mostly low (70% of positive donors had titres < 3 IU/mL). In Corsican natives, increasing seroprevalence by age could be explained by models capturing a loss of immunity (annual probability of infection: 4.5%; duration of immunity: 55 years) or by age-specific probabilities of infection (3.8% for children, 1.3% for adults). Conclusion We confirmed the high HEV seroprevalence on Corsica and identified three aspects that should be further explored: (i) the epidemiology in those younger than 18 years, (ii) common sources of contamination, in particular drinking water, that may explain the wide exposure of the population, and (iii) the actual protection afforded by the low IgG titres observed and the potential susceptibility to secondary HEV infection.

scholarly journals Regional Differences in Overland Rainfall Estimation from PR-Calibrated TMI Algorithm

2005 ◽  
Vol 44 (2) ◽  
pp. 189-205 ◽  
Author(s):  
Tufa Dinku ◽  
Emmanouil N. Anagnostou
Keyword(s):  
Regional Differences ◽  
Rain Rate ◽  
Central Africa ◽  
Tropical Rainfall Measuring Mission ◽  
Error Statistics ◽  
Southern Plains ◽  
Significant Difference ◽  
Current Algorithm ◽  
Microwave Imager ◽  
Trmm Microwave Imager

Abstract The Tropical Rainfall Measuring Mission (TRMM) satellite carries a combination of active [precipitation radar (PR)] and multichannel passive microwave [the TRMM Microwave Imager (TMI)] sensors, which advance our ability to estimate rainfall over land. Rain retrieval from the TRMM PR is associated with an unprecedented accuracy and resolution but is limited in terms of sampling because of the narrow PR swath width (215 km). TMI provides wider coverage (760 km), but its observations are associated with a more complex relationship to precipitation in comparison with PR (especially over land). The PR rain estimates are used here for calibrating an overland TMI rain algorithm. The algorithm consists of 1) multichannel-based rain screening and convective/stratiform (C/S) classification schemes, and 2) nonlinear (linear) regressions for the rain-rate retrieval of stratiform (convective) rain regimes. This study examines regional differences in the algorithm performance. Four geographic regions consisting of central Africa (AFC), the Amazon (AMZ), the U.S. southern Plains (USA), and the Ganges–Brahmaputra–Meghna River basin (GBM) in south Asia are selected. Data from three summer months of 2000 and 2001 are used for calibration; validation is done using summer 2002 data. The current algorithm is also compared with the latest [version 6 (V6)] TRMM 2A12 product in terms of rain detection, and rain-rate retrieval error statistics on the basis of PR reference rainfall. The performance of the algorithm is different for the different regions. For instance, the reduction in random error (relative to 2A12 V6) is about 24%, 36%, 57%, and 165% for USA, AFC, AMZ, and GBM, respectively. However, significant difference between global (the four regions combined) and regional calibration is observed only for the GBM region.

scholarly journals Evaluation of factors influencing tick bites and tick-borne infections: a longitudinal study

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Bo Bødker Jensen ◽  
Mie Topholm Bruun ◽  
Per Moestrup Jensen ◽  
Andreas Kristian Pedersen ◽  
Pierre-Edouard Fournier ◽  
...  
Keyword(s):  
Blood Donors ◽  
Seroconversion Rate ◽  
Clinical Manifestations ◽  
Weather Conditions ◽  
Igg Antibodies ◽  
Tick Bites ◽  
Significant Difference ◽  
Study Population ◽  
June July

Abstract Background Various tick-borne infections like borreliosis and rickettsiosis pose a health risk to humans in many parts of the world. We investigated seroprevalence of and seroconversion to Borrelia burgdorferi and Rickettsia spp. and relation to tick-bites, weather and clinical manifestations in Denmark. Methods Blood donors were enrolled at the Hospital of Southern Jutland in June–July with follow-up November–February of 2018 and 2019. Blood samples were collected, and a questionnaire regarding tick bites, potential exposures and symptoms was completed at each visit. Samples were tested for presence of IgM and IgG antibodies directed against B. burgdorferi and Rickettsia spp. using R. helvetica and R. felis as antigens. Data were examined for correlation between tick bites, serological results, potential exposures and symptoms. Results Two-hundred and fourteen (93 follow-ups) and 130 (38 follow-ups) blood donors were included in 2018 and 2019, respectively. The total borrelia seroconversion rate was 6.3% (CI 2.1–10.5), while the prevalence of IgM and IgG antibodies was 7.8% (CI 4.9–10.6) and 6.7% (CI 4–9.3), respectively. Seroconversion to Rickettsia spp. was detected in one participant. Tick bites and seroconversion were not significantly associated with the reported unspecific symptoms, but unspecific symptoms were common in the study population. There was no significant difference in number of tick bites or seroconversion/prevalence between seasons with highly alternating weather. Conclusions Results suggest that weather conditions in an individual year have a limited impact. Anti-Borrelia-antibodies do not seem to persist in serum for several years. Rickettsiosis is of limited concern in Denmark. Graphic abstract

F.VIII R:Ag in Hepatitis

1979 ◽  
Author(s):  
R. Kotitschke ◽  
J. Scharrer
Keyword(s):  
Chronic Hepatitis ◽  
Blood Donors ◽  
Blood Donation ◽  
Normal Population ◽  
Rabbit Antiserum ◽  
Two Dimensional ◽  
Plastic Plate ◽  
Significant Difference ◽  
Acute Hepatitis B ◽  
The One

F.VIII R:Ag was determined by quantitative immunelectrophoresis (I.E.) with a prefabricated system. The prefabricated system consists of a monospecific f.VIII rabbit antiserum in agarose on a plastic plate for the one and two dimensional immunelectrophoresis. The lognormal distribution of the f.VIII R:Ag concentration in the normal population was confirmed (for n=70 the f.VIII R:Ag in % of normal is = 95.4 ± 31.9). Among the normal population there was no significant difference between blood donors (one blood donation in 8 weeks; for n=43 the f.VIII R:Ag in % of normal is = 95.9 ± 34.0) and non blood donors (n=27;f.VIII R:Ag = 94.6 ± 28.4 %). The f.VIII R:Ag concentration in acute hepatitis B ranged from normal to raised values (for n=10, a factor of 1.8 times of normal was found) and was normal again after health recovery (n=10, the factor was 1.0). in chronic hepatitis the f.VIII R:Ag concentration was raised in the majority of the cases (for n=10, the factor was 3.8). Out of 22 carrier sera 20 showed reduced, 2 elevated levels of the f.VIII R:Ag concentration. in 5 sera no f.VIII R:Ag could be demonstrated. The f.VIII R:Ag concentration was normal for n=10, reduced for n=20 and elevated for n=6 in non A-non B hepatitis (n=36). Contrary to results found in the literature no difference in the electrophoretic mobility of the f.VIII R:Ag was found between hepatitis patients sera and normal sera.

Seroprevalence of anti-SARS-CoV-2 IgG antibodies in hospitalized patients at a tertiary referral center in North India (Preprint)

2020 ◽  
Author(s):  
Dr. Animesh Ray ◽  
Dr. Komal Singh ◽  
Souvick Chattopadhyay ◽  
Farha Mehdi ◽  
Dr. Gaurav Batra ◽  
...  
Keyword(s):  
Tertiary Care ◽  
Age Groups ◽  
Hospitalized Patients ◽  
North India ◽  
P Value ◽  
Care Hospital ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Increased Risk ◽  
Significant Difference

BACKGROUND Seroprevalence of IgG antibodies against SARS-CoV-2 is an important tool to estimate the true extent of infection in a population. However, seroprevalence studies have been scarce in South East Asia including India, which, as of now, carries the third largest burden of confirmed cases in the world. The present study aimed to estimate the seroprevalence of anti-SARS-CoV-2 IgG antibody among hospitalized patients at one of the largest government hospital in India OBJECTIVE The primary objective of this study is to estimate the seroprevalence of SARS-CoV-2 antibody among patients admitted to the Medicine ward and ICU METHODS This cross-sectional study, conducted at a tertiary care hospital in North India, recruited consecutive patients who were negative for SARS-CoV-2 by RT-PCR or CB-NAAT. Anti-SARS-CoV-2 IgG antibody levels targeting recombinant spike receptor-binding domain (RBD) protein of SARS CoV-2 were estimated in serum sample by the ELISA method RESULTS A total of 212 hospitalized patients were recruited in the study with mean age (±SD) of 41.2 (±15.4) years and 55% male population. Positive serology against SARS CoV-2 was detected in 19.8%patients(95% CI 14.7-25.8). Residency in Delhi conferred a higher frequency of seropositivity 26.5% (95% CI 19.3-34.7) as compared to that of other states 8% (95% CI 3.0-16.4) with p-value 0.001. No particular age groups or socio-economic strata showed a higher proportion of seropositivity CONCLUSIONS Around, one-fifth of hospitalized patients, who were not diagnosed with COVID-19 before, demonstrated seropositivity against SARS-CoV-2. While there was no significant difference in the different age groups and socio-economic classes; residence in Delhi was associated with increased risk (relative risk of 3.62, 95% CI 1.59-8.21)

scholarly journals Association of Calcium Supplementation During Pregnancy with the Birth Weight of Single-Born Neonates in Rural Northwest China

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1106-1106
Author(s):  
Gao Xiangyu ◽  
Mi Baibing ◽  
Dang Shaonong ◽  
Yan Hong
Keyword(s):  
Birth Weight ◽  
Gestational Age ◽  
Regression Models ◽  
Calcium Supplementation ◽  
Northwest China ◽  
Incidence Rates ◽  
Shaanxi Province ◽  
Significant Difference ◽  
Birth Weight Percentile ◽  
Weight Percentile

Abstract Objectives To investigate the association of calcium supplementation during the pregnancy with the birth weight of single-born neonates. Methods The survey employed a multistage, stratified and random sampling to investigate 15–49 aged pregnant women in 2010 to 2013 in Shaanxi province. A self - designed questionnaire was utilized. Birth weight between the 10(th) and 90(th) percentile was classified as appropriate for gestational age(AGA) infants. Chi-square test and logistic regression models were conducted to evaluate the association of calcium supplementation with single-born neonatal birth weight. Results A total of 28,490 women was enrolled in this study, 17 349 (60.9%) of participants had calcium supplementation during pregnancy. The incidence rates of small and large gestational age infants were 13.5% and 8.3%, respectively. The study conducted that calcium supplementation had a statistically significant difference in SGA (birth weight percentile &lt;10) (P &lt; 0.01). After adjusting the regression models by confounding factors, we found that calcium supplementation was still protective towards SGA birth, the difference was statistically significant (OR = 0.89, 95% CI: 0.82–0.96, P &lt; 0.05), but there was no significant difference in the birth to LGA (birth weight percentile &lt;10). Conclusions Calcium supplementation during pregnancy reduced the risk of SGA, but was not associated with the birth of LGA. Funding Sources

scholarly journals The incidence of pneumonia in the paediatric population in Poland in light of the maps of health needs

2021 ◽  
Author(s):  
Joanna Lange ◽  
Jerzy Kozielski ◽  
Kinga Bartolik ◽  
Paweł Kabicz ◽  
Tomasz Targowski
Keyword(s):  
Average Length ◽  
Age Groups ◽  
Paediatric Population ◽  
Incidence Rates ◽  
Education Development ◽  
Average Length Of Stay ◽  
Significant Difference ◽  
Social Fund ◽  
Hospital Deaths ◽  
Reported Data

Abstract In Poland, no statistical data are available concerning the analysis of the incidence of pneumonia in inpatient children. The requirement for these data results mainly from the need to prepare systemic and economic solutions. Aim This study aimed to use reported data for evaluating pneumonia incidence rates among hospitalised children and other parameters in various age groups. Subject and methods A detailed analysis was performed as part of the Operational Programme Knowledge Education Development co-financed by the European Social Fund. Services reported to the National Health Fund in 2014 were considered, including pneumonia incidence among hospitalised children and mortality in specific age groups. Results In 2014, a total of 68,543 children were hospitalised for pneumonia (68% of all hospitalisations for acute respiratory diseases). Within each of the analysed age groups, boys were hospitalised more frequently. Irrespective of the place of residence, infants were most commonly hospitalised. It was observed that there was a significant difference between the incidence rate of pneumonia among hospitalised children in all analysed groups depending on the province. The average length of stay was 7.29 days, with infants requiring the longest stays (7.96 days), and 1.8% of children were rehospitalised within 30 days due to recurrence of pneumonia. The most commonly coded pathogens responsible for pneumonia included Mycoplasma pneumoniae, Streptococcus pneumoniae and Chlamydia spp. A total of 19 inpatient hospital deaths in the course of pneumonia were reported. Conclusions Based on our findings, it is warranted to utilize epidemiological knowledge for the planning of an appropriate level of service commissioned both in outpatient and inpatient facilities as well as for the estimation of institutional and staff needs necessary to secure these services.

Microfracture for the Treatment of Symptomatic Cartilage Lesions of the Knee: A Survey of International Cartilage Regeneration & Joint Preservation Society

Cartilage ◽  
2020 ◽  
pp. 194760352095450
Author(s):  
Jesus Medina ◽  
Ignacio Garcia-Mansilla ◽  
Peter D. Fabricant ◽  
Thomas J. Kremen ◽  
Seth L. Sherman ◽  
...  
Keyword(s):  
Surgical Technique ◽  
Regional Differences ◽  
Current Practice ◽  
Cartilage Regeneration ◽  
Postoperative Management ◽  
Cartilage Lesions ◽  
Significant Difference ◽  
Rehabilitation Protocols ◽  
Joint Repair ◽  
Vertical Walls

Objective The purpose of this study was to describe the current practice trends for managing symptomatic cartilage lesions of the knee with microfracture among ICRS (International Cartilage Regeneration & Joint Repair Society) members. Design A 42-item electronic questionnaire was sent to all ICRS members, which explored indications, surgical technique, postoperative management, and outcomes of the microfracture procedure for the treatment of symptomatic, full thickness chondral and osteochondral defects of the knee. Responses were compared between surgeons from different regions and years of practice. Results A total of 385 surgeons answered the questionnaire. There was a significant difference noted in the use of microfracture among surgeons by region ( P < 0.001). There was no association between the number of years in practice and the self-reported proportion of microfracture cases performed ( P = 0.37). Fifty-eight subjects (15%) indicated that they do not perform microfracture at all. Regarding indication for surgery, 56% of surgeons would limit their indication of microfracture to lesions measuring 2 cm2 or less. Half of the surgeons reported no upper age or body mass index limit. Regarding surgical technique, 90% of surgeons would recommend a formal debridement of the calcified layer and 91% believe it is important to create stable vertical walls. Overall, 47% of surgeons use biologic augmentation, with no significant difference between regions ( P = 0.35) or years of practice ( P = 0.67). Rehabilitation protocols varied widely among surgeons. Conclusions Indications, operative technique, and rehabilitation protocols utilized for patients undergoing microfracture procedures vary widely among ICRS members. Regional differences and resources likely contribute to these practice pattern variations.

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