high seroprevalence
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2022 ◽  
Author(s):  
Mary-Ann Davies ◽  
Reshma Kassanjee ◽  
Petro Rousseau ◽  
Erna Morden ◽  
Leigh Johnson ◽  
...  

Objectives: We aimed to compare COVID-19 outcomes in the Omicron-driven fourth wave with prior waves in the Western Cape, the contribution of undiagnosed prior infection to differences in outcomes in a context of high seroprevalence due to prior infection, and whether protection against severe disease conferred by prior infection and/or vaccination was maintained. Methods: In this cohort study, we included public sector patients aged ≥20 years with a laboratory confirmed COVID-19 diagnosis between 14 November-11 December 2021 (wave four) and equivalent prior wave periods. We compared the risk between waves of the following outcomes using Cox regression: death, severe hospitalization or death and any hospitalization or death (all ≤14 days after diagnosis) adjusted for age, sex, comorbidities, geography, vaccination and prior infection. Results: We included 5,144 patients from wave four and 11,609 from prior waves. Risk of all outcomes was lower in wave four compared to the Delta-driven wave three (adjusted Hazard Ratio (aHR) [95% confidence interval (CI)] for death 0.27 [0.19; 0.38]. Risk reduction was lower when adjusting for vaccination and prior diagnosed infection (aHR:0.41, 95% CI: 0.29; 0.59) and reduced further when accounting for unascertained prior infections (aHR: 0.72). Vaccine protection was maintained in wave four (aHR for outcome of death: 0.24; 95% CI: 0.10; 0.58). Conclusions: In the Omicron-driven wave, severe COVID-19 outcomes were reduced mostly due to protection conferred by prior infection and/or vaccination, but intrinsically reduced virulence may account for an approximately 25% reduced risk of severe hospitalization or death compared to Delta.


Medicina ◽  
2021 ◽  
Vol 58 (1) ◽  
pp. 35
Author(s):  
Tudor Rares Olariu ◽  
Alina Cristiana Craciun ◽  
Daliborca Cristina Vlad ◽  
Victor Dumitrascu ◽  
Iosif Marincu ◽  
...  

Background and Objectives: The extent of SARS-CoV-2 infection among a population may be assessed by the presence of serum SARS-CoV-2 antibodies, which indicates previous exposure. The aim of this study was to determine the seroprevalence of SARS-CoV-2 infection in the adult population from Western Romania. Materials and Methods: Samples of 2443 consecutive individuals, referred for routine laboratory investigations, were tested for SARS-CoV-2 antibodies using the Elecsys immunoassay that targets the nucleocapsid protein, for identifying the presence of the total antibodies against SARS-CoV-2. Results: The overall SARS-CoV-2 seroprevalence was 45.60%. SARS-CoV-2 seroprevalence was significantly higher in age group 30–49 years (53.94%) compared to age groups 50–69 years (43.53%) and 70–91 years (30.79%) (p < 0.001, p < 0.001, respectively). No significant difference in seroprevalence was observed between females (44.83%) and males (47.05%). Conclusions: Our data revealed a high seroprevalence of SARS-CoV-2 infection in the adult population from Western Romania and indicate the rapid and significant spread of the virus. The estimated prevalence of 45.60% was 6 times higher than the rate of confirmed COVID-19 cases reported in the study area. This indicates the magnitude of virus transmission in the community.


Pathogens ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Amer Alić ◽  
Jovana Šupić ◽  
Teufik Goletić ◽  
Emina Rešidbegović ◽  
Ismar Lutvikadić ◽  
...  

Red foxes are the most abundant wild carnivore species in Europe commonly exposed to pathogenic Leptospira and Hepatozoon canis. Despite high seroprevalence, the clinical disease caused by these pathogens in red foxes has never been reported. Herein, we report the first-ever case of a fatal Leptospira spp. and H. canis coinfection in a two-month-old red fox cub with acute haemolytic anaemia, mild bronchopneumonia, intraalveolar haemorrhage, and tubulonephrosis. The presence of pathogenic Leptospira spp. DNA was detected in the kidney and lung tissues of the infected animal. In contrast to our previous knowledge, we believe that such fatal cases due to concomitant infection by Leptospira spp. and H. canis, especially in young animals, may commonly occur in nature. However, further studies are required to identify other factors that possibly contribute to the severity and the pathogenic effect of Leptospira spp. and H. canis infections in red foxes.


Infection ◽  
2021 ◽  
Author(s):  
Sami Almudarra ◽  
Shady Kamel ◽  
Eman Saleh ◽  
Rehab Alaswad ◽  
Amaal Alruwaily ◽  
...  

2021 ◽  
Vol 71 (4) ◽  
pp. 451-461
Author(s):  
Nuhu Abdulazeez Sani ◽  
Iniobong Chukwuebuka Ugochukwu ◽  
Ahmadu Saleh ◽  
Samson Eneojo Abalaka ◽  
Muhammed Shuaib Muhammed ◽  
...  

Abstract Previous reports indicate high seroprevalence of avian leukosis virus (ALV) p72 antigen in layer flocks suspected to have Marek’s disease (MD) in Kaduna and Plateau States. However, the specific subgroups responsible for ALV infection in layers in the States are still unknown, hence the need for this study. Therefore, the objective of this study was to determine the antibody profiles of ALV subgroups A/B and J in layer flocks suspected to have MD in Kaduna and Plateau States. Sera from 7 and 16 layer flocks suspected to have MD in Kaduna and Plateau States respectively, were screened for the presence of antibodies to ALV subgroups A/B and J using IDEXX enzyme linked immunosorbent assay (ELISA) kits. Out of the seven layer flocks screened in Kaduna State, antibodies to ALV subgroup A/B was detected in six of the flocks (85.7%), while antibodies to ALV subgroup J was detected in only one flock (14.3%). Antibodies to both ALV subgroups A/B and J were detected in one flock (14.3%), which suggests co-infection of the two ALV subgroups. Out of the 16 flocks screened in Plateau State, antibodies to ALV subgroup A/B were detected in 15 flocks (93.8%), while antibodies to ALV subgroup J were detected in six flocks (37.5%). Antibodies to both ALV subgroups A/B and J were detected in five flocks (31.3%). The high detection of antibodies to ALV A/B suggests that ALV infection in layers is mostly due to ALV subgroup A or B in the study areas.


2021 ◽  
Author(s):  
Ruchika Shakya ◽  
Morten Tryland ◽  
Rose Vikse ◽  
Javier Sánchez Romano ◽  
Kjetil Åsbakk ◽  
...  

Abstract Background: Mosquito-borne viruses pose a serious threat to humans worldwide. There has been an upsurge in the number of mosquito-borne viruses in Europe, mostly belonging to the families Togaviridae (Sindbis, Chikungunya), Flaviviridae (West Nile, Usutu, Dengue), and Peribunyaviridae (Inkoo, Batai, Tahyna). The principal focus of this study was Inkoo (INKV) and Sindbis (SINV) virus circulating in Norway because there is a knowledge gap regarding reservoirs and transmission. Therefore, we aimed to determine the prevalence of SINV and INKV in mosquitoes and seroprevalence of INKV in semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus).Methods: In total, 213 pools containing about 25 mosquitoes each and 480 reindeer sera were collected in eight Norwegian reindeer summer pasture districts during 2013-2015. The mosquito pools were analysed for INKV and SINV RNA, with reverse transcriptase (RT)-real time quantitative PCR (RT-qPCR), and pyrosequencing. Reindeer sera were analysed for INKV-specific IgG by Indirect Immunofluorescence Assay (IIFA) and Plaque Reduction Neutralization Test (PRNT).Results: Aedes spp. were the most dominant species among the collected mosquitoes. Two of the mosquito pools were positive for INKV-RNA by RT-PCR and were confirmed by pyrosequencing. The overall estimated pool prevalence (EPP) of INKV in Norway was 0.04%. IgG seroprevalence in reindeer revealed 60% positive for INKV by IIFA. Of the 55 borderline reindeer sera, 24% were positive on cytopathic effect (CPE)-neutralization test. Among 80% of 60 reindeer sera analysed with PRNT for INKV had a titre ≥ 20, and there was no cross-reactivity with the closely related Tahyna virus (TAHV) and Snow Shoe Hare virus (SSHV). None of the analysed mosquito pools were positive for SINV.Conclusions: The occurrence and prevalence of INKV in Aedes mosquitoes and its high seroprevalence among semi-domesticated reindeer in Norway indicate that further studies are required for monitoring this virus. SINV was not detected in the mosquitoes in this study, however, human cases of SINV infection have yearly been reported from Rjukan. Therefore, it is essential to investigate SINV among human population. Our findings are important to raise awareness regarding the geographical distribution of these mosquito-borne viruses in Northern Europe.


2021 ◽  
Vol 9 ◽  
Author(s):  
Chandima Jeewandara ◽  
Dinuka Guruge ◽  
Inoka Sepali Abyrathna ◽  
Saubhagya Danasekara ◽  
Banuri Gunasekera ◽  
...  

Background: As the Municipality Council area in Colombo (CMC) experienced the highest number of cases until the end of January 2021, in Sri Lanka, we carried out a serosurvey prior to initiation of the vaccination program to understand the extent of the SARS-CoV-2 outbreak.Methods: SARS-CoV-2 seropositivity was determined in 2,547 individuals between the ages of 10–86 years, by the Wantai total antibody ELISA. We also compared seroprevalence using the haemagglutination test (HAT) to evaluate its usefulness in carrying out serosurveys.Results: The overall seropositivity rate was 24.46%, while seropositivity by HAT was 18.90%. Although The SARS-CoV-2 infection detection rates by PCR were highest in the population between the ages of 20–60 years of age, there was no statistically significant difference in the seropositivity rates in different age groups. For instance, although the seropositivity rate was highest in the 10–20 age group (34.03%), the PCR positivity rate was 9.80%. Differences in the PCR positivity rates and seropositivity rates were also seen in 60–70-year-olds (8.90 vs. 30.4%) and in individuals &gt;70 years (4.10 vs. 1.20%). The seropositivity rate of the females was 29.70% (290/976), which was significantly higher (p &lt; 0.002) than in males 21.2% (333/1,571).Conclusions: A high seroprevalence rate (24.5%) was seen in all age groups in the CMC suggesting that a high level of transmission was seen during this time. The higher PCR positivity rates between the ages of 20–60 are likely to be due to increased testing carried out in the working population. Therefore, the PCR positivity rates, appear to underestimate the true extent of the outbreak and the age groups which were infected.


Author(s):  
Natalia Vargas-Herrera ◽  
Roger V Araujo-Castillo ◽  
Orson Mestanza ◽  
Marco Galarza ◽  
Nancy Rojas-Serrano ◽  
...  
Keyword(s):  

2021 ◽  
Vol 112 ◽  
pp. 25-34
Author(s):  
Isaac Ngere ◽  
Jeanette Dawa ◽  
Elizabeth Hunsperger ◽  
Nancy Otieno ◽  
Moses Masika ◽  
...  
Keyword(s):  

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Magdalena Materniak-Kornas ◽  
Tadeusz Frymus ◽  
Martin Löchelt ◽  
Jacek Kuźmak

Abstract Introduction Feline foamy virus (FFVfca) is widespread and its prevalence in naturally infected domestic cats ranges between 30% and 80% worldwide. The infection is persistent, with a sustained antibody response in FFVfca-positive cats; however to date, no defined disease or clinical symptoms have been proved to be associated with it. The goal of the presented study was to determine the prevalence of FFVfca infection in domestic cats in Poland. Material and Methods A total of 223 serum samples collected from domestic cats were tested with a glutathione S-transferase capture ELISA test to detect antibodies specific to capsid (Gag), accessory (Bet) and envelope (Env) FFVfca antigens. A Western blot test was used to confirm the ELISA results. Results The cut-off value for the Gag antigen was established by calculation and evaluation with the immunoblotting assay. The cut-off values for Bet and Env were calculated from the reactivity of Gag-negative samples. The sera of 99 cats (44%) showed reactivity to Gag, those of 80 did so (35.9 %) to Bet, while only 56 samples (25%) were reactive to Env. Only 51 (22.9%) sera were positive for all antigens. The main diagnostic antigen was selected to be Gag. A statistically significant association was found between FFVfca status and the age of the cat. Conclusions This study proved the high seroprevalence of FFVfca in domestic cats in Poland for the first time and confirmed that adult cats are at higher FFVfca infection risk than preadult cats. Its results correspond to those reported from other countries.


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