Evaluation of nine serological rapid tests for the detection of SARS-CoV-2

Objective. To evaluate the operative capacity of nine serological rapid tests to detect the IgM/IgG antibodies response in serum from patients with SARS-CoV-2 in different clinical stages. Methods. A cross-sectional study of serological rapid tests was designed to compare the performance of the evaluated immunochromatographic tests for the diagnosis of SARS-CoV-2. A total of 293 samples was used, including negatives, asymptomatic, and symptomatic serum samples. Results. The sensitivity of the evaluated tests was low and moderate in the groups of asymptomatic serum samples and the group of serums coming from patients with less than 11 days since the onset of the symptoms. The specificity for the anti-SARS-CoV-2 antibodies tests ranged between 86.5%-99% for IgM and 86.5%-99.5% for IgG. The sensitivity and the likelihood ratio were different according to the study groups. The usefulness of these tests is restricted to symptomatic patients and their sensitivity is greater than 85% after 11 days from the appearance of symptoms. Conclusions. Serological tests are not an adequate strategy for the identification of asymptomatic and pre-symptomatic patients. Serological rapid tests for the detection of specific anti-SARS-CoV-2 antibodies can be used as a diagnostic aid, but diagnosis must be confirmed by RT-PCR. Rapid tests should be reserved for patients with symptoms lasting more than 11 days.

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Cross-sectional Study on Sero-Prevalence of SARS-CoV-2 Infection in Jabalpur, Madhya Pradesh, India

JOURNAL OF COMMUNICABLE DISEASES ◽

10.24321/0019.5138.202114 ◽

2021 ◽

Vol 53 (01) ◽

pp. 82-88

Author(s):

Shashi Prabha Tomar ◽

Keyword(s):

Public Health ◽

Golden Rule ◽

Cross Sectional Study ◽

Sectional Study ◽

Rt Pcr ◽

Antibody Testing ◽

Serum Samples ◽

Cross Sectional ◽

Diagnostic Strategies ◽

Study Population

Introduction: In India, laboratory diagnosis of SARS - CoV-2 infection has been mostly based on real-time reverse transcriptase polymerase chain reaction (RT-PCR). Studies have shown that Viral titres peak within the first week of symptoms, but may decline post this time frame, thereby hampering RT-PCR based diagnostic strategies. These reasons have prompted the call for adoption of antibody testing as a potential source of data to address the gap in data and inform public health and governance policies oriented towards COVID-19. Materials and Methods: A Cross-sectional study with a sample size of 9000 was conducted for 11 days (Dec 11-21, 2020) including all the 79 wards under Jabalpur Municipal Corporation. Serum samples were tested for the presence of specific antibodies to COVID19 using ICMR-Kavach IgG ELISA kits. The data collected was compiled on Microsoft Excel and data analysis was carried out using STATA 15E statistical software. Result: Overall seroprevalence of the study population was found to be 28.70% (weighted). Wards of the city of Jabalpur were classified into three categories based on the case prevalence - High (27 wards), Medium (26 wards) and Low (26 wards). Based on the overall seroprevalence, the estimated number of total infections were calculated to be 3, 54,870 for the study population. Overall Case Infection Ratio was 31.41. Conclusion: The current seroprevalence study rightly provides information on proportion of the population exposed, however, the correlation between presence and absence of antibodies is not a marker of total or partial immunity. Hence, the golden rule of Social distancing, sanitization, personal protective equipment and public health measures have to be continued.

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PREVALENCE OF MOLECULAR AND SEROLOGICAL TESTS OF THE NEW CORONAVIRUS (SARS-CoV-2) IN CARLOS CHAGAS-SABIN LABORATORIES IN CUIABÁ

10.1101/2020.10.26.20219683 ◽

2020 ◽

Author(s):

Cristiane Coimbra de Paula ◽

João Pedro Castoldo Passos ◽

Walkiria Shimoya-Bittencour ◽

Caroline Aquino Vieira de Lamare ◽

Ruberlei Godinho de Oliveira

Keyword(s):

Mortality Rate ◽

Nasal Swab ◽

Cross Sectional Study ◽

High Rate ◽

Sectional Study ◽

Rt Pcr ◽

Serological Tests ◽

Cross Sectional ◽

Midwest Region ◽

Epidemiological Profile

AbstractBACKGROUNDCOVID-19, the disease caused by the new coronavirus (SARS-CoV-2), became a pandemic in 2020 with mortality rate of 2% and high transmissibility, which makes studies with an epidemiological profile essential.OBJECTIVESTo characterize the population that performed the SARS-CoV-2 molecular and serological tests in Carlos Chagas-Sabin laboratories in Cuiabá.METHODSA retrospective cross-sectional study was carried out with all the samples collected from nasal swab tested by RT-PCR and serological for SARM-CoV-2 IgM / IgG from the population served between April and July 2020.FINDINGSIn the analyzed period, 11,113 PCR-Covid-19 exams were registered. Of this total of cases, 3,912 (35.20%) tested positive, while 6,889 (61.90%) did not detect viral RNA and 312 (2.80%) of the visits resulted as undetermined. The peak of positive RT-PCR performed in July (n = 5878), with 35.65% (n = 2096). A total of 6,392 tests performed on SOROVID-19, with a peak of 1161 (18.16%) of the positive tests for SARS-CoV-2 in July.MAIN CONCLUSIONSMolecular positivity and serological tests, both peaked in July 2020, were mostly present in women aged 20-39, characterizing Cuiabá as the epicenter of the Midwest region in this period due to the high rate of transmissibility of SARS-CoV-2.

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Canine visceral leishmaniasis in the Krenak indigenous community, Resplendor, Minas Gerais State, Brazil, 2007

Cadernos de Saúde Pública ◽

10.1590/s0102-311x2011000300020 ◽

2011 ◽

Vol 27 (3) ◽

pp. 603-607 ◽

Cited By ~ 1

Author(s):

Eloiza Gonçalves Antônio ◽

Marcos Aurélio Fulgêncio Malacco ◽

Célia Maria Ferreira Gontijo ◽

Eliana Furtado Moreira ◽

Ivo Santana Caldas ◽

...

Keyword(s):

Diagnostic Techniques ◽

Cross Sectional Study ◽

Indigenous Community ◽

Molecular Diagnostic ◽

Molecular Diagnostic Techniques ◽

Sectional Study ◽

Serum Samples ◽

Serological Tests ◽

Cross Sectional ◽

Canine Infection

The authors conducted a cross-sectional study of the local canine population in the Krenak indigenous community to detect parasites of the genus Leishmania and identify the circulating species and the proportion of asymptomatic dogs, while investigating associations between canine infection and the dogs' sex, age, and hair length. A seroepidemiological survey was performed, including 63 dogs. All the animals underwent clinical examination to verify the presence of characteristic signs, and serum samples were taken for serological tests (ELISA, IIF). Infected dogs culled by the health service were necropsied and the material was analyzed using molecular diagnostic techniques. The cross-sectional study detected a 46% prevalence rate, and the circulating species was Leishmania (L.) chagasi. The statistical analysis showed no association between infection and the independent variables. The study generated data on the epidemiological situation with canine infection in the area, which was previously unknown.

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Nationwide seroprevalence of antibodies to SARS-CoV-2 in asymptomatic population in South Korea: a cross-sectional study

BMJ Open ◽

10.1136/bmjopen-2021-049837 ◽

2021 ◽

Vol 11 (4) ◽

pp. e049837

Author(s):

Eun-Hee Nah ◽

Seon Cho ◽

Hyeran Park ◽

Inhwan Hwang ◽

Han-Ik Cho

Keyword(s):

South Korea ◽

Clinical Status ◽

Herd Immunity ◽

Cross Sectional Study ◽

Secondary Outcome ◽

Age Group ◽

Sectional Study ◽

Serum Samples ◽

Serological Tests ◽

Cross Sectional

ObjectiveAsymptomatic active infection might be an important contributor to the COVID-19 outbreak. Serological tests can assess the extent of exposure and herd immunity to COVID-19 in general populations. This study aimed to estimate the nationwide seroprevalence of SARS-CoV-2 antibodies according to age, sex and clinical status in South Korea.Design, setting and participantsThis cross-sectional study randomly selected health examinees who underwent health check-up at 16 health promotion centres in 13 Korean cities across the country between late September and early December 2020. Residual serum samples were obtained from 4085 subjects (2014 men and 2071 women). Antibodies to SARS-CoV-2 were measured by electrochemiluminescence immunoassay using Elecsys Anti-SARS-CoV-2 (Roche Elecsys, Mannheim, Germany).Primary and secondary outcome measuresFisher’s exact test was used to compare the seroprevalence according to sex, age group and region. The relative risks of being seropositive according to the characteristics of the study subjects were analysed using logistic regression analysis.ResultsThe overall seroprevalence of anti-SARS-CoV-2 was 0.39% (95% CI=0.20% to 0.58%): 0.30% (95% CI=0.06% to 0.54%) for men and 0.48% (95% CI=0.18% to 0.78%) for women. The rate of anti-SARS-CoV-2 positivity varied significantly between different regions of Korea (p=0.003), but not with age group, sex, or the statuses of obesity, diabetes, hypertension or smoking.ConclusionsMost of the Korean population is still immunologically vulnerable to SARS-CoV-2, but the seroprevalence has increased relative to that found in studies performed prior to September 2020 in Korea.

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Serum Concentrations of Selected Organochlorines in Pregnant Women and Associations with Pregnancy Outcomes. A Cross-Sectional Study from Two Rural Settings in Cambodia

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17207652 ◽

2020 ◽

Vol 17 (20) ◽

pp. 7652

Author(s):

Margit Steinholt ◽

Shanshan Xu ◽

Sam Ol Ha ◽

Duong Trong Phi ◽

Maria Lisa Odland ◽

...

Keyword(s):

Polychlorinated Biphenyls ◽

Pregnant Women ◽

Gestational Age ◽

Low Income ◽

Cross Sectional Study ◽

Maternal Serum ◽

Sectional Study ◽

Serum Samples ◽

Cross Sectional ◽

Rural Settings

We conducted a cross-sectional study among 194 pregnant women from two low-income settings in Cambodia. The inclusion period lasted from October 2015 through December 2017. Maternal serum samples were analyzed for persistent organic pollutants (POPs). The aim was to study potential effects on birth outcomes. We found low levels of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCP), except for heptachlors, β-hexachlorocyclohexane (HCH), heptachlor epoxide, and p,p’-DDE. There were few differences between the two study locations. However, the women from the poorest areas had significantly higher concentrations of p,p’-DDE (p < 0.001) and hexachlorobenzene (HCB) (p = 0.002). The maternal factors associated with exposure were parity, age, residential area, and educational level. Despite low maternal levels of polychlorinated biphenyls, we found significant negative associations between the PCB congeners 99 (95% CI: −2.51 to −0.07), 138 (95% CI: −1.28 to −0.32), and 153 (95% CI: −1.06 to −0.05) and gestational age. Further, there were significant negative associations between gestational age, birth length, and maternal levels of o,p’-DDE. Moreover, o,p’-DDD had positive associations with birth weight, and both p,p’-DDD and o,p’-DDE were positively associated with the baby’s ponderal index. The poorest population had higher exposure and less favorable outcomes.

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Sources of psychological distress among primary care physicians during the COVID-19 pandemic’s first wave in Spain: a cross-sectional study

Primary Health Care Research & Development ◽

10.1017/s1463423621000566 ◽

2021 ◽

Vol 22 ◽

Author(s):

Ana Cebrián-Cuenca ◽

José Joaquín Mira ◽

Elena Caride-Miana ◽

Antonio Fernández-Jiménez ◽

Domingo Orozco-Beltrán

Keyword(s):

Primary Care ◽

Psychological Distress ◽

Primary Care Physicians ◽

Linear Regression Analysis ◽

Cross Sectional Study ◽

Multivariate Linear Regression Analysis ◽

Sectional Study ◽

Rt Pcr ◽

Cross Sectional ◽

Protective Measures

Abstract Background: The COVID-19 pandemic is affecting people worldwide. In Spain, the first wave was especially severe. Objectives: This study aimed to identify sources and levels of distress among Spanish primary care physicians (PCPs) during the first wave of the pandemic (April 2020). Methods: A cross-sectional study was conducted using a survey that included sociodemographic data, a description of working conditions related to distress [such as gaps in training in protective measures, cleaning, and hygiene procedures in work setting, unavailability of personal protective equipments (PPEs) and COVID-19 RT-PCR test, and lack of staff due to be infected] and a validated scale, the ‘Self-applied Acute Stress Scale’ (EASE). The survey was answered by a non-probability sampling of PCPs working in family healthcare centres from different regions of Spain. Analysis of variance and multivariate linear regression analysis were performed. Results: In all, out of 518 PCP participants, 123 (23.7%) obtained high psychological distress scores. Only half of them had received information about the appropriate use of PPE. PCP characteristics associated with higher levels of distress include female gender [1.69; 95% confidence interval (CI) 0.54, 2.84]; lack of training in protective measures (1.96; 95% CI 0.94, 2.99); unavailable COVID-19 RT-PCR for health care workers after quarantine or COVID-19 treatment (−0.77 (−1.52, −0.02). Reinforcing disinfection of the work environment (P < 0.05), availability of PPEs (P < 0.05), and no healthcare professional was infected (P < 0.05) were related to the lowest distress score. Conclusions: A better understanding of the sources of distress among PCPs could prevent its effect on future outbreaks.

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A cross sectional study of leptospirosis and fetal death in Yucatan, Mexico

Colombia Medica ◽

10.25100/cm.v47i1.1975 ◽

2016 ◽

pp. 11-14 ◽

Cited By ~ 2

Author(s):

María Fidelia Cárdenas Marrufo ◽

Ignacio Vado Solis ◽

Gaspar Fernando Peniche Lara ◽

Carlos Perez Osorio ◽

José Correa Segura

Keyword(s):

Spontaneous Abortion ◽

Low Income ◽

Fetal Death ◽

Indirect Elisa ◽

First Trimester ◽

Cross Sectional Study ◽

Sectional Study ◽

Serum Samples ◽

Recent Infection ◽

Cross Sectional

Introduction: Leptospirosis is a zoonotic disease affecting mainly to low income human population. Acute leptospiral infection during pregnancy has been associated with spontaneous abortion and fetal death during the first trimester and the abortion may occur as consequence of systemic failure. Objective: To estimate the frequency of Leptospira interrogans infection in women with spontaneous abortion in the state of Yucatan, Mexico. Methods: A cross sectional study on women with spontaneous abortion was conducted. Serum samples were tested for Leptospirosis by the microaglutination test, to estimate the frequency of the infecting serovar. The indirect ELISA IgM was used to detect recent infection by L. interrogans. DNA was extracted from paraffin-embedded tissue of placenta for PCR detection of L. interrogans. Results: Overall frequency of infection with L. interrogans in the 81 women with abortion was 13.6%. Five of the 12 serovars evaluated were found and included. Two of the 11 women with abortion and positive to microaglutination test were also positive to the ELISA IgM test. None samples were positive for PCR Leptospira diagnosis. Conclusion: two women could be associated with spontaneous abortion due to leptospirosis, because they showed antibodies against L. interrogans in the microaglutination test and ELISA IgM assays. Differences between regions were found with respect to the prevalences of lesptospirosis.

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Molecular study of sapovirus in acute gastroenteritis in children: a cross-sectional study

F1000Research ◽

10.12688/f1000research.29991.2 ◽

2021 ◽

Vol 10 ◽

pp. 123

Author(s):

Maysaa El Sayed Zaki ◽

Raghdaa Shrief ◽

Rasha H. Hassan

Keyword(s):

Stool Sample ◽

Acute Gastroenteritis ◽

Rna Extraction ◽

Winter Season ◽

Molecular Study ◽

Cross Sectional Study ◽

Sectional Study ◽

Rt Pcr ◽

Cross Sectional ◽

Presenting Symptoms

Background: Sapovirus has emerged as a viral cause of acute gastroenteritis. However, there are insufficient data about the presence of this virus among children with acute gastroenteritis. The present study aimed to evaluate the presence of sapovirus in children with acute gastroenteritis by reverse transcriptase-polymerase chain reaction (RT-PCR). Methods: A cross-sectional study enrolled 100 children patients with acute gastroenteritis from outpatient clinics with excluded bacterial pathogens and parasitic infestation. A stool sample was collected from each child for laboratory examination. Each stool sample was subjected to study by direct microscopic examination, study for rotavirus by enzyme-linked immunoassay (ELISA) and the remaining sample was subjected to RNA extraction and RT- PCR for sapovirus. Results: The most frequently detected virus was rotavirus by ELISA (25%). RT-PCR detected sapovirus in 7% of the stool samples. The children with sapovirus were all from rural regions and presented mainly during the winter season in Egypt (42.9%). The main presenting symptoms were fever (71.4%) and vomiting (57.1%). None of the children with sapovirus had dehydration. Rotavirus was significantly associated with sapovirus infections in 5 patients (71.4%, P=0.01). There was an insignificant difference between symptoms of gastroenteritis in children with sapovirus and children with gastroenteritis without sapovirus as regards vomiting (P=0.7), fever (P=0.46), and abdominal pain (P=0.69). Conclusion: The present study highlights the emergence of sapovirus as a frequent pathogen associated with acute gastroenteritis in children. There is a need for a national survey program for the study of sapovirus among other pathogens associated with acute gastroenteritis for better management of such infection.

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Immunological and molecular detection of rotavirus genotype in calves with gastroenteritis in Diyala-Iraq

10.53346/wjbpr.2021.1.1.0013 ◽

2021 ◽

Vol 1 (1) ◽

pp. 001-013

Author(s):

Ammar Talib Nasser ◽

Abdulrazak Shafiq Hasan ◽

Amer Khazaal Saleh ◽

Mohammad Kassem Saleh

Keyword(s):

Molecular Detection ◽

Cross Sectional Study ◽

Sectional Study ◽

Rt Pcr ◽

Cross Sectional ◽

Reverse Transcription Pcr ◽

Group A ◽

Stool Antigen ◽

Stool Samples ◽

Age Range

Aim: To explore the prevalence of rotavirus infection along with the molecular detection and genotyping of group A rotavirus (RVA) among bovine calves up to 5 months old in Diyala province-Iraq. Methods: This is a cross sectional study conducted in Diyala province-Iraq during the period of 2019-2020. One hundred bovine calves with age range of 1-5 months were included in the study. All were suffering acute gastroenteritis. Serum anti-rotavirus IgM and IgG plus fecal rotavirus Ag were tested for using ELISA techniques. Stool samples positive for rotavirus Ag were submitted for reverse transcription PCR (RT-PCR) for G and P genes, followed by sequencing and genotyping thereafter. Statistical analysis was done using SPSS version 25 and P values ≤ 0.05 were considered significant. Results: The positivity rate of anti-rotavirus IgM was 80% (P = 0.0001), and that of anti-rotavirus IgG was 79% (P = 0.0001). The rotavirus stool antigen was detected in 68% of calves (P = 0.01). A total of 45 stool samples which were positive for rotavirus Ag were submitted for RT-PCR; 13 (28.9%) were positive and 32 (71.1%) were negative (P = 0.084). 10 PCR positive samples were used for sequencing and genotyping and indicated that all investigated strains belonged to G1P[8] genotype. Conclusion: The current strains analyzed belonged to the G1P[8] RVA genotypes, affirming that employment of VP7 gene polymorphism accurately yielded uniform phylogenetic distances amongst investigated rotavirus strains and that there were no noticeable assortment events between human and animal rotavirus strains in Diyala province.

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Presence of Antibodies against Sindbis Virus in the Israeli Population: A Nationwide Cross-Sectional Study

Viruses ◽

10.3390/v11060542 ◽

2019 ◽

Vol 11 (6) ◽

pp. 542

Author(s):

Ravit Koren ◽

Ravit Bassal ◽

Tamy Shohat ◽

Daniel Cohen ◽

Orna Mor ◽

...

Keyword(s):

Sindbis Virus ◽

Metropolitan Areas ◽

Multivariable Analysis ◽

Neutralization Assay ◽

Cross Sectional Study ◽

Older Age ◽

Igg Antibodies ◽

Serum Samples ◽

Cross Sectional ◽

Israeli Population

Sindbis virus (SINV) is a mosquito-borne alphavirus circulating globally. SINV outbreaks have been mainly reported in North-European countries. In Israel, SINV was detected in 6.3% of mosquito pools; however, SINV infection in humans has rarely been diagnosed. A serologic survey to detect SINV IgG antibodies was conducted to evaluate the seroprevalence of SINV in the Israeli population. In total, 3145 serum samples collected in 2011–2014, representing all age and population groups in Israel, were assessed using an indirect ELISA assay, and a neutralization assay was performed on all ELISA-positive samples. The prevalence rates of SINV IgG antibodies were calculated. Logistic regressions models were applied to assess the association between demographic characteristics and SINV seropositivity. Overall, 113 (3.6%) and 59 (1.9%) samples were positive for ELISA and neutralization SINV IgG, respectively. Multivariable analysis demonstrated that SINV seropositivity was significantly associated with older age and residence outside metropolitan areas. These results demonstrate that, despite no outbreaks or clinical presentation, SINV infects the human population in Israel. Seropositivity is countrywide, more frequent in people of older age, and less diffuse in Israel’s metropolitan areas. Seroprevalence studies from other countries will add to our understanding of the global burden of SINV and the risk for potential SINV outbreaks.

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