scholarly journals SARS-CoV-2 IgG Antibodies Seroprevalence and Sera Neutralizing Activity in MEXICO: A National Cross-Sectional Study during 2020

2021 ◽  
Vol 9 (4) ◽  
pp. 850
Author(s):  
José Esteban Muñoz-Medina ◽  
Concepción Grajales-Muñiz ◽  
Angel Gustavo Salas-Lais ◽  
Larissa Fernandes-Matano ◽  
Constantino López-Macías ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Neutralizing Antibodies ◽  
Herd Immunity ◽  
Cross Sectional Study ◽  
Molecular Techniques ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cross Sectional ◽  
Neutralizing Activity

Until recently, the incidence of COVID-19 was primarily estimated using molecular diagnostic methods. However, the number of cases is vastly underreported using these methods. Seroprevalence studies estimate cumulative infection incidences and allow monitoring of transmission dynamics, and the presence of neutralizing antibodies in the population. In February 2020, the Mexican Social Security Institute began conducting anonymous unrelated sampling of residual sera from specimens across the country, excluding patients with fever within the previous two weeks and/or patients with an acute respiratory infection. Sampling was carried out weekly and began 17 days before Mexico’s first officially confirmed case. The 24,273 sera obtained were analyzed by chemiluminescent-linked immunosorbent assay (CLIA) IgG S1/S2 and, later, positive cases using this technique were also analyzed to determine the rate of neutralization using the enzyme-linked immunosorbent assay (ELISA). We identified 40 CLIA IgG positive cases before the first official report of SARS-CoV-2 infection in Mexico. The national seroprevalence was 3.5% in February and 33.5% in December. Neutralizing activity among IgG positives patients during overall study period was 86.1%. The extent of the SARS-CoV-2 infection in Mexico is 21 times higher than that reported by molecular techniques. Although the general population is still far from achieving herd immunity, epidemiological indicators should be re-estimated based on serological studies of this type.

scholarly journals Evidence for Transmission of Taenia solium Taeniasis/Cysticercosis in a Rural Area of Northern Rwanda

2021 ◽  
Vol 8 ◽  
Author(s):  
Lucrecia Acosta Soto ◽  
Lucy Anne Parker ◽  
María José Irisarri-Gutiérrez ◽  
Javier Arturo Bustos ◽  
Yesenia Castillo ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Low Income ◽  
Taenia Solium ◽  
Parasitic Infection ◽  
Developed Countries ◽  
Cross Sectional Study ◽  
Low Income Countries ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cross Sectional ◽  
Hygiene Measures

Cysticercosis is a parasitic infection caused by the metacestode larval stage (cysticercus) of Taenia solium. In humans, cysticercosis may infect the central nervous system and cause neurocysticercosis, which is responsible for over 50,000 deaths per year worldwide and is the major cause of preventable epilepsy cases, especially in low-income countries. Cysticercosis infection is endemic in many less developed countries where poor hygiene conditions and free-range pig management favor their transmission. A cross-sectional study was conducted in 680 children from a rural primary school in Gakenke district (Northern province of Rwanda). Stool samples were collected from participants and analyzed using the Kato-Katz method (KK), formol-ether concentration (FEC), and/or copro-antigen enzyme-linked immunosorbent assay (CoAg-ELISA) to detect taeniasis. Blood samples were collected and analyzed using enzyme-linked immunoelectrotransfer blot (EITB) and antigen enzyme-linked immunosorbent assay (Ag-ELISA) to detect human cysticercosis. The overall proportion of taeniasis positivity was 0.3% (2/680), and both cases were also confirmed by CoAg-ELISA. A total of 13.3% (76/572) of the children studied were positive to cysticercosis (T. solium-specific serum antibodies detected by EITB), of whom 38.0% (27/71) had viable cysticercus (T. solium antigens by Ag-ELISA). This study provides evidence of the highest cysticercosis prevalence reported in Rwanda in children to date. Systematic investigations into porcine and human cysticercosis as well as health education and hygiene measures for T. solium control are needed in Gakenke district.

scholarly journals Seroprevalence of SARS-CoV-2 Antibodies in Symptomatic Individuals Is Higher than in Persons Who Are at Increased Risk Exposure: The Results of the Single-Center, Prospective, Cross-Sectional Study

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 627
Author(s):  
Alexandr Zurochka ◽  
Maria Dobrinina ◽  
Vladimir Zurochka ◽  
Desheng Hu ◽  
Alexandr Solovyev ◽  
...  
Keyword(s):  
High Risk ◽  
Risk Group ◽  
Herd Immunity ◽  
Cross Sectional Study ◽  
High Risk Group ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cross Sectional ◽  
Seropositivity Rate ◽  
Symptomatic Group ◽  
Increased Risk

The present study aimed to assess antibody seropositivity prevalence among symptomatic individuals and individuals with a high risk of occupational exposure to SARS-CoV-2. Participants from Chelyabinsk (Russian Federation) who were at an increased risk of exposure to SARS-CoV-2 (high-risk group, n = 1091) and participants who either had symptoms consistent with COVID-19 or were suspected to have experienced COVID-19 in the past (symptomatic group, n = 692) were enrolled between 28 September and 30 December 2020. Blood samples were tested by enzyme-linked immunosorbent assay D-5501 SARS-Cov-2-IgG-EIA-BEST and D-5502 SARS-Cov-2-IgM-EIA-BEST (AO Vector-Best, Novosibirsk, Russia). The overall seropositivity rate was 28.33–28.53%. SARS-CoV-2 antibodies were detected in 17.23% (adjusted prevalence of 17.17–17.29%) of participants in the high-risk and 45.95% (adjusted prevalence of 45.91–46.24%) in the symptomatic group. Higher IgG and IgM titers were observed in women compared to men, as well as in participants in the symptomatic group compared to those in the high-risk group. The results indicate that the seroprevalence among residents in several Russian regions is low (28.38%) and inadequate to provide herd immunity. The lower seroprevalence among participants in the high-risk group may be attributed to the enforcement of healthcare protocols and the use of adequate personal protective equipment.

scholarly journals Cross-sectional evaluation of humoral responses against SARS-CoV-2 Spike

2020 ◽  
Author(s):  
Jérémie Prévost ◽  
Romain Gasser ◽  
Guillaume Beaudoin-Bussières ◽  
Jonathan Richard ◽  
Ralf Duerr ◽  
...  
Keyword(s):  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Cross Sectional Study ◽  
Health Interventions ◽  
Cross Sectional ◽  
Neutralizing Activity ◽  
Main Target ◽  
Specific Igg ◽  
Human Coronaviruses ◽  
Humoral Responses

ABSTRACTThe SARS-CoV-2 virus is responsible for the current worldwide coronavirus disease 2019 (COVID-19) pandemic, infecting millions of people and causing hundreds of thousands of deaths. The Spike glycoprotein of SARS-CoV-2 mediates viral entry and is the main target for neutralizing antibodies. Understanding the antibody response directed against SARS-CoV-2 is crucial for the development of vaccine, therapeutic and public health interventions. Here we performed a cross-sectional study on 106 SARS-CoV-2-infected individuals to evaluate humoral responses against the SARS-CoV-2 Spike. The vast majority of infected individuals elicited anti-Spike antibodies within 2 weeks after the onset of symptoms. The levels of receptor-binding domain (RBD)-specific IgG persisted overtime, while the levels of anti-RBD IgM decreased after symptoms resolution. Some of the elicited antibodies cross-reacted with other human coronaviruses in a genus-restrictive manner. While most of individuals developed neutralizing antibodies within the first two weeks of infection, the level of neutralizing activity was significantly decreased over time. Our results highlight the importance of studying the persistence of neutralizing activity upon natural SARS-CoV-2 infection.

scholarly journals A Comprehensive Survey of Asymptomatic Malaria Cases in an Endemic Focus in Iran: A Successful Experience on the Road to Eliminate Malaria

2021 ◽  
Vol 16 (3) ◽  
Author(s):  
Habibollah Turki ◽  
Mohammad Shekari ◽  
Aboozar Soltani
Keyword(s):  
Malaria Elimination ◽  
Surveillance System ◽  
Protozoan Parasite ◽  
Cross Sectional Study ◽  
Molecular Techniques ◽  
Diagnostic Methods ◽  
Asymptomatic Malaria ◽  
Malaria Surveillance ◽  
Cross Sectional ◽  
On The Road

Background: Malaria is one of the important infectious blood diseases caused by the protozoan parasite of the genus Plasmodium and transmitted by female Anopheles mosquito bites. A malaria elimination plan is currently being followed in Hormozgan Province. The robust malaria surveillance system with appropriate active case findings, especially asymptomatic cases, plays an important role in the malaria elimination program. Objectives: The main objectives of this research were to determine the presence and prevalence of asymptomatic malaria cases and monitor asymptomatic parasitic reservoirs in Jask District, Hormozgan Province. Methods: This cross-sectional study aimed to evaluate and monitor asymptomatic cases in the Jask District. The purpose and stages of the study were explained to all participants/parents, and written informed consent was obtained. A total of 230 asymptomatic residents (124 females and 86 males) were randomly selected, and their blood samples (3 mL) were taken to assess Plasmodium infection using microscopic, RDT, and molecular (18ssrRNA) methods. Results: Of the 230 studied cases, 54.8% were females, and 454.2% were males. The age range was four to 65 years old, and the mean age was 24.5. None of the diagnostic methods, including the microscopic, serological, and molecular techniques, could find asymptomatic malaria cases in the study area. Conclusions: It can be concluded that Malaria Elimination Program is feasible in the Jask Region irrespective of asymptomatic parasitic reservoirs. The results also emphasize a robust and efficient malaria surveillance system to diagnose and treat positive cases and monitor treated cases successfully. Ongoing and continuous studies are recommended in the high-risk malarious area of Hormozgan Province to monitor asymptomatic cases of malaria.

scholarly journals Large-scale cross-sectional seroepidemiologic study of COVID-19 in Japan: Acquisition of herd immunity and the vaccines' efficacy

2022 ◽  
Author(s):  
Zhenxiao Ren ◽  
Mitsuhiro Nishimura ◽  
Lidya Handayani Tjan ◽  
Koichi Furukawa ◽  
Yukiya Kurahashi ◽  
...  
Keyword(s):  
Large Scale ◽  
Herd Immunity ◽  
Vaccination Rate ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cross Sectional ◽  
Neutralizing Activity ◽  
Polymerase Chain ◽  
Hyogo Prefecture ◽  
Seroepidemiologic Study ◽  
Roll Out

Background: The COVID-19 pandemic situation has been changing drastically worldwide due to the continuous appearance of SARS-CoV-2 variants and the roll-out of mass vaccination. Periodic cross-sectional studies during the surge of COVID-19 cases is essential to elucidate the pandemic situation. Methods: Sera of 1,000 individuals who underwent a health check-up in Hyogo Prefecture Health Promotion Association clinics in Japan were collected in August and December 2021. Antibodies against SARS-CoV-2 N and S antigens were detected in the sera by an electrochemiluminescence immunoassay (ECLIA) and an enzyme-linked immunosorbent assay (ELISA), respectively. The sera's neutralization activities for the conventional SARS-CoV-2 (D614G), Delta, and Omicron variants were measured. Results: The seropositive rates for the antibody against N antigen were 2.1% and 3.9% in August and December 2021 respectively, demonstrating a Delta variant endemic during that time; the actual infection rate was approximately twofold higher than the rate estimated based on the polymerase chain reaction (PCR)-based diagnosis. The anti-S seropositive rate was 38.7% in August and it reached 90.8% in December, in concordance with the vaccination rate in Japan. In the December cohort, 78.7% of the sera showed neutralizing activity against the Delta variant, whereas that against the Omicron was much lower at 36.6%. Conclusions: These analyses revealed that herd immunity against SARS-CoV-2 including the Delta variant was established in December 2021, leading to convergence of the variants. The low neutralizing activity against the Omicron variant suggests the need for the further promotion of the prompt three-dose vaccination to overcome this variant's imminent 6th wave in Japan.

scholarly journals The Incidence of Bordetella Pertussis Infections in Jahrom City, Southern Iran

2021 ◽  
Author(s):  
Rahim Raufi ◽  
Reza Shahriarirad ◽  
Nikta Taghipour
Keyword(s):  
Family Size ◽  
Bordetella Pertussis ◽  
Whooping Cough ◽  
Cross Sectional Study ◽  
Diagnostic Methods ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Cross Sectional ◽  
Persistent Cough ◽  
Two Stages

Abstract Background: Bordetella Pertussis, known as the causative agent of whooping cough, is one of the leading causes of recurrent persistent cough at all ages, even in vaccinated individuals. Methods: A total number of 110 patients coughing for at least two weeks who were admitted to clinical centers in Jahrom, Iran, were included in this cross-sectional study. For this purpose, blood samples were collected from these individuals at two stages, i.e., at the beginning of the study and on the 21st day. Afterward, anti-pertussis toxin (PT) immunoglobulin G (IgG) was measured in serum samples via the enzyme-linked immunosorbent assay (ELISA). The given cases were further evaluated in terms of age, gender, occupation, place of living, and family size.Results: Out of 110 patients recruited in this study, 77 cases were female (70%). Also, only seven patients were shown to be serologically positive (6.4%). Moreover, no significant association was observed between pertussis incidence rate and the study variables, namely, age, gender, occupation, residency area (urban or rural), and family size (p>0.05).Conclusions: This study aimed to emphasize pertussis occurrence in individuals who merely present persistent cough without typical symptoms. This requires the physicians to conduct more precise assessments along with more rapid diagnostic methods.

scholarly journals Angiogenin—A Proposed Biomarker for Cardiovascular Disease—Is Not Associated With Long-Term Survival in Patients With Peripheral Artery Disease

Angiology ◽  
2021 ◽  
pp. 000331972110043
Author(s):  
Clemens Höbaus ◽  
Gerfried Pesau ◽  
Bernhard Zierfuss ◽  
Renate Koppensteiner ◽  
Gerit-Holger Schernthaner
Keyword(s):  
Peripheral Artery Disease ◽  
Cox Regression ◽  
Ankle Brachial Index ◽  
Limb Ischemia ◽  
Cross Sectional Study ◽  
Enzyme Linked Immunosorbent Assay ◽  
Peripheral Artery ◽  
Cross Sectional ◽  
Term Survival ◽  
Artery Disease

We evaluated angiogenin as a prospective biomarker in peripheral artery disease (PAD) patients with and without claudication symptoms. A pilot study suggested an elevation of angiogenin in critical limb ischemia. However, in PAD patients, the predictive value of angiogenin has not yet been evaluated. For this purpose, 342 patients with PAD (age: 69 ± 10 years, 34.5% women) were followed-up for 7 years in a cross-sectional study. Angiogenin was measured by enzyme-linked immunosorbent assay. All-cause and cardiovascular mortality were analyzed by Cox regression. Angiogenin levels were higher in men ( P = .001) and were associated with patient waist-to-hip ratio ( P < .001), fasting triglycerides ( P = .011), and inversely with estimated glomerular filtration rate ( P = .009). However, angiogenin showed no association with age, characteristics of diabetes, markers of lipid metabolism, or C-reactive protein. Angiogenin did not correlate with markers of angiogenesis such as vascular endothelial growth factor, angiopoietin-2, or tie-2. Furthermore, angiogenin was not associated with PAD Fontaine stages or with patient ankle-brachial index in addition to all-cause mortality (hazard ratio [HR] = 1.09 [95% CI: 0.89-1.34]) or cardiovascular morality (HR = 1.05 [0.82-1.35]). These results suggest that angiogenin does not provide further information regarding outcome prediction in patients with PAD.

scholarly journals Prevalence of SARS-CoV-2 Infection at the University of Barcelona during the Third COVID-19 Pandemic Wave in Spain

2021 ◽  
Vol 18 (12) ◽  
pp. 6526
Author(s):  
Sebastián Videla ◽  
Aurema Otero ◽  
Sara Martí ◽  
M. Ángeles Domínguez ◽  
Nuria Fabrellas ◽  
...  
Keyword(s):  
Ad Hoc ◽  
Venous Blood ◽  
Herd Immunity ◽  
Cross Sectional Study ◽  
Rt Pcr ◽  
Igg Antibody ◽  
Cross Sectional ◽  
Total Prevalence ◽  
The University ◽  
The Impact

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic started in December 2019 and still is a major global health challenge. Lockdown measures and social distancing sparked a global shift towards online learning, which deeply impacted universities’ daily life, and the University of Barcelona (UB) was not an exception. Accordingly, we aimed to determine the impact of the SARS-CoV-2 pandemic at the UB. To that end, we performed a cross-sectional study on a sample of 2784 UB members (n = 52,529). Participants answered a brief, ad hoc, online epidemiological questionnaire and provided a nasal swab for reverse transcription polymerase chain reaction (RT-PCR) SARS-CoV-2 analysis and a venous blood sample for SARS-CoV-2 IgG antibody assay. Total prevalence of SARS-CoV-2 infection (positive RT-PCR or positive IgG) was 14.9% (95%CI 13.3 to 17.0%). Forty-four participants (1.6%, 95%CI: 1.2–2.1%) were positive for SARS-CoV-2 RT-PCR. IgG against SARS-CoV-2 was observed in 12.8% (95%CI: 11.6–14.1%) of participants. Overall, while waiting for population vaccination and/or increased herd immunity, we should concentrate on identifying and isolating new cases and their contacts.

scholarly journals Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 507
Author(s):  
Long Pham-Thanh ◽  
Thang Nguyen-Tien ◽  
Ulf Magnusson ◽  
Vuong Bui-Nghia ◽  
Anh Bui-Ngoc ◽  
...  
Keyword(s):  
Mosquito Control ◽  
Risk Mitigation ◽  
Significant Risk ◽  
Cross Sectional Study ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Cross Sectional ◽  
Major Health ◽  
Household Level

Diseases caused by flaviviruses, including dengue fever and Japanese encephalitis, are major health problems in Vietnam. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Hanoi city. A total of 475 dogs serum samples from 221 households in six districts of Hanoi were analyzed by a competitive enzyme-linked immunosorbent assay (cELISA) for antibodies to the pr-E protein of West Nile virus and other flaviviruses due to cross-reactivity. The overall flavivirus seroprevalence in the dog population was 70.7% (95% CI = 66.4–74.8%). At the animal level, significant associations between seropositive dogs and district location, age, breed and keeping practice were determined. At the household level, the major risk factors were rural and peri-urban locations, presence of pigs, coil burning and households without mosquito-borne disease experience (p < 0.05). Mosquito control by using larvicides or electric traps could lower seropositivity, but other measures did not contribute to significant risk mitigation of flavivirus exposure in dogs. These results will support better control of mosquito-borne diseases in Hanoi, and they indicate that dogs can be used as sentinels for flavivirus exposure.

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