SARS-CoV-2 IgG antibodies in adolescent students and their teachers in Saxony, Germany (SchoolCoviDD19): persistent low seroprevalence and transmission rates between May and October 2020

AbstractIntroductionSchool closures have been part of the SARS-CoV-2 pandemic control measures in many countries, based on the assumption that children play a similar role in transmitting SARS-CoV-2 as they do in transmitting influenza virus. The contribution of schools in driving the pandemic, however, is still unclear. We therefore performed a SARS-CoV-2 seroprevalence study in students and teachers at two time points in June and October 2020, respectively.MethodsStudents grade 8–11 and their teachers in 13 secondary schools in eastern Saxony, Germany, were invited to participate in the SchoolCoviDD19 study. Blood samples were collected in May/June 2020 after the reopening of the schools following the March 2020 lockdown, and again in September/October 2020, 4 weeks after the end of the summer holidays. SARS-CoV-2 IgG were assed using chemiluminescence immunoassay technology and all samples with a positive or equivocal test result were retested with two additional serological tests.Results1538 students and 507 teachers were initially enrolled, and 1334 students and 445 teachers completed both study visits. The seroprevalence for SARS-CoV-2 antibodies was 0.6% in May/June and the same in September/October. Even in schools with reported Covid-19 cases before the lockdown of March 13th no clusters could be identified. Of 12 persons with positive serology 5 had a known history of confirmed COVID-19; 23 out of 24 participants with a household history of COVID-91 were seronegative. By using a combination of three different immunoassays we could exclude 16 participants with a positive or equivocal results after initial testing.ConclusionsSchools do not play a crucial role in driving the SARS-CoV-2 pandemic in a low prevalence setting. Transmission in families occurs very infrequently, and the number of unreported cases is low in this age group. These observations do not support school closures as a strategy fighting the pandemic in a low prevalence setting.

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SARS-CoV-2 seroprevalence in students and teachers: a longitudinal study from May to October 2020 in German secondary schools

BMJ Open ◽

10.1136/bmjopen-2021-049876 ◽

2021 ◽

Vol 11 (6) ◽

pp. e049876

Author(s):

Carolin Kirsten ◽

Manja Unrath ◽

Christian Lück ◽

Alexander H Dalpke ◽

Reinhard Berner ◽

...

Keyword(s):

Secondary Schools ◽

Secondary Outcome ◽

Secondary Outcome Measure ◽

Positive Serology ◽

Igg Antibody ◽

School Closures ◽

Population Number ◽

Registration Number ◽

History Of ◽

Low Prevalence

ObjectiveTo quantify the number of SARS-CoV-2 infections in secondary schools after their reopening in May 2020.DesignRepeated SARS-CoV-2 seroprevalence study after the reopening of schools and 4 months later.SettingSecondary school in Dresden, Germany.Participants1538 students grades 8–12 and 507 teachers from 13 schools.InterventionsSerial blood sampling and SARS-CoV-2 IgG antibody assessment.Primary and secondary outcome measureSeroprevalence of SARS-CoV-2 antibodies in study population. Number of undetected cases.Results1538 students and 507 teachers were initially enrolled, and 1334 students and 445 teachers completed both study visits. The seroprevalence for SARS-CoV-2 antibodies was 0.6% in May/June and the same in September/October. Even in schools with reported COVID-19 cases before the lockdown of 13 March, no clusters could be identified. Of 12 persons with positive serology five had a known history of confirmed COVID-19; 23 out of 24 participants with a household history of COVID-91 were seronegative.ConclusionsSchools do not play a crucial role in driving the SARS-CoV-2 pandemic in a low-prevalence setting. Transmission in families occurs very infrequently, and the number of unreported cases is low in this age group. These observations do not support school closures as a strategy fighting the pandemic in a low-prevalence setting.Trial registration numberDRKS00022455.

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Detection of SARS-COV-2 Antibodies in Pediatric Kidney Transplant Patients

10.21203/rs.3.rs-140932/v1 ◽

2021 ◽

Author(s):

Alanoud Alshami ◽

Rabab Alattas ◽

Ahmed Azzam ◽

Amani Mohammed

Keyword(s):

Kidney Transplant ◽

Igg Antibodies ◽

Positive Serology ◽

Serological Tests ◽

Humoral Immune ◽

Transplant Patients ◽

History Of ◽

Serology Test ◽

Kidney Transplant Patients

Abstract Background The seroprevalance of SARS-COV-2 infection have been studied in immunocompetent children. However, data in pediatric Kidney Transplant population (PKT) is lacking. Methods We screened 72 PKT patients who came for routine blood work in the outpatient clinic using two commercial immunoassays that measures IgG antibodies against SARS-COV-2 spike protein and IgG against the Nucleocapsid protein. Majority of patients with positive serology had their serology test repeated at least once during subsequent clinic follow up. Patients were confirmed to have SARS-COV-2 infection if they only have both tests positive. Results Eight patients out of the 72 screened (11.1%) had positive SARS-COV-2 IgG antibodies in both serological tests. Of those tested positive, 4 had positive SARS-COV-2 PCR before screening. All patients were asymptomatic or had history of mild symptoms. All tested patient had persistently positive antibodies at median follow-up time of 75 days (IQR, 44.5, 86.5). One patient remained to have positive PCR at 75 days and positive serology test at 120 days post infection. conclusion The Serooprevalence of SARS-COV-2 was relatively high (11.1%) in our population. SARS-COV-2 PCR seems to remain positive in PKT population for longer duration than general population. Although, all patients were asymptomatic or mildly symptomatic, they mounted a strong humoral immune response that persisted for few months despite being on triple immunosuppressants. These findings will have positive implications on vaccination efficacy in this group.

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Detection of SARS-CoV-2 antibodies in pediatric kidney transplant patients

BMC Nephrology ◽

10.1186/s12882-021-02325-x ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Alanoud Alshami ◽

Rabab Al Attas ◽

Ahmad Azzam ◽

Amani Mohammed ◽

Norah Al-Quhaidan

Keyword(s):

Kidney Transplant ◽

Igg Antibodies ◽

Positive Serology ◽

Serological Tests ◽

N Protein ◽

Humoral Immune ◽

Transplant Patients ◽

History Of ◽

Serology Test

Abstract Background The seroprevalence of SARS-CoV-2 infection has been studied in immunocompetent children. However, data in the pediatric kidney transplant population (PKT) are lacking. Methods Using two commercial immunoassays that measured IgG antibodies against SARS-CoV-2 spike protein and IgG against the nucleocapsid (N) protein, we screened 72 PKT recipients who attended the outpatient clinic for routine blood work. The majority of patients with positive serology underwent an additional serology test at least once during subsequent clinical follow-up. Patients were confirmed to have SARS-CoV-2 infection if they had two positive tests. Results Eight patients out of the 72 screened (11.1%) had positive results for SARS-CoV-2 IgG antibodies in both serological tests. Of those who tested positive, 4 had positive SARS-CoV-2 PCR results before screening. All patients were asymptomatic or had a history of mild symptoms. All tested patients had persistently positive antibodies at a median follow-up time of 75 days (IQR, 44.5, 86.5 days). One patient had a positive PCR test at 75 days and a positive serology test at 120 days post infection. Conclusion The seroprevalence of SARS-CoV-2 was relatively high (11.1%) in our population. Although all patients were asymptomatic or mildly symptomatic, they mounted a strong humoral immune response that persisted for a few months despite being on triple immunosuppressants. These findings have positive implications regarding vaccination efficacy in this group.

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Serological Investigations of Brucellosis in Cattle, Farmers and Veterinarians in the Kars District of Turkey

Acta Veterinaria Brno ◽

10.2754/avb200877010117 ◽

2008 ◽

Vol 77 (1) ◽

pp. 117-121 ◽

Cited By ~ 7

Author(s):

S. Otlu ◽

M. Sahin ◽

H. I. Atabay ◽

A. Unver

Keyword(s):

Control Measures ◽

Serum Samples ◽

Serological Tests ◽

Significant Difference ◽

High Prevalence ◽

History Of ◽

And Control

The prevalence of brucellosis was investigated in cattle, farmers and veterinarians in the Kars district of Turkey between 2004 - 2006. In order to achieve this, a total of 407 serum samples of cattle from 27 herds having history of abortions were examined for Brucella antibodies by RBPT and SAT. In addition, the sera collected from 246 farmers (130 males and 116 females) and 28 veterinarians in the same district were analysed serologically by RBPT, SAT and ELISA. Of the cattle sera analysed, 134 (32.92%) and 141 (34.64%) were determined as positive by RBPT and SAT, respectively. Thirty-two (13%), 35 (14.22%) and 44 (17.88%) of the farmers' sera were found positive for brucellosis by RBPT, SAT and ELISA, respectively. There was no significant difference between sexes for Brucella seropositivity. Of the 28 sera from veterinarians, 13 (46.42%) were positive by the three serological tests. The high prevalence of brucellosis both in cattle and humans suggests that brucellosis is common in this area. Preventive and control measures should be implemented and pursued more strictly to reduce and/or eradicate brucellosis from the area.

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Hepatitis por citomegalovirus: Presentación de dos casos

Revista Medica Herediana ◽

10.20453/rmh.v6i2.498 ◽

2013 ◽

Vol 6 (2) ◽

Author(s):

Carlos Tori ◽

Raúl Leon Barua ◽

Carlos Roe

Keyword(s):

Blood Test ◽

Liver Enzymes ◽

The Other ◽

General Malaise ◽

Igg Antibodies ◽

Premature Babies ◽

Normal Individuals ◽

Elevated Liver Enzymes ◽

History Of ◽

Low Prevalence

Two cases of hepatitis by cytomegalovirus are described, one in a child and the other in a young adult, presenting with a history of fever, general malaise, hepatomegaly and no jaundice. Their blood test showed atypical lymphocytes, normal bilirubin, elevated liver enzymes, and IgG antibodies against cytomegalovirus. Their course was un was unremarkable except for asthenia which persisted in spite of clinical and laboratory improvement. This course was unremarkable except for asthenia which persisted in spite of clinical and laboratory improvement. This presentation is done because of the low prevalence or infrequent diagnosis of anicteric hepatitis due to cytomegalovirus in normal individuals. Most of the literature refers to congenital cases, premature babies, or patients with debilitating or immunocompromising diseases.

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Sero-pravelence of SARS CoV-2 IgM and IgG Antibodies Amongst Blood Donors in Nigeria

10.21203/rs.3.rs-151037/v1 ◽

2021 ◽

Author(s):

Ijeoma Ifeorah ◽

Emmanuel Nna ◽

Uchenna Okeke ◽

Emo Ivo ◽

Ojor Ayemoba ◽

...

Keyword(s):

Blood Donors ◽

Control Measures ◽

Igg Antibodies ◽

Infection Control Measures ◽

Bank Staff ◽

Blood Banks ◽

High Index Of Suspicion ◽

Age Range ◽

Test Result ◽

Transmissible Infection

Abstract Background: Currently in Nigeria, SARS CoV-2 infection control measures rely solely on RT-PCR testing of cases with high index of suspicion for COVID-19. The sero-prevalence of SARS-CoV-2-specific antibodies in the populations remains unknown. We aimed to determine the sero-prevalence of SARS CoV-2 IgM and IgG in screened blood donors in two selected cities in Nigeria. Methods: A total of 113 blood samples from screened and accepted blood donors were tested for both SARS CoV-2 IgM and IgG antibodies using NOVATECH ELISA kits from Eurofins Germany. Results: The age range of donor was 21-48 years. Males were 96 %. Of the 113 blood donors 42% were positive for SARS CoV-2 IgG while 41% were positive for SARS CoV-2 IgM respectively. Only 11% and 19% of blood donors had equivocal test result for IgG and IgM respectively.Conclusions: Nearly a half of accepted blood donors in Nigeria had been exposed to SARS CoV-2 infection. Although it is not a blood transmissible infection, the blood banks must take adequate preventive measures to prevent spread amongst the bank staff and potential donors. It also implies a wider spread of the infection in Nigeria.Trial Registration: The study does not require registration.

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Parvovirus B19 in Croatia: A Large-Scale Seroprevalence Study

Medicina ◽

10.3390/medicina57111279 ◽

2021 ◽

Vol 57 (11) ◽

pp. 1279

Author(s):

Tatjana Vilibic-Cavlek ◽

Irena Tabain ◽

Branko Kolaric ◽

Klara Mihulja ◽

Lana Blazevic ◽

...

Keyword(s):

General Population ◽

Large Scale ◽

Parvovirus B19 ◽

Adult Population ◽

Hemodialysis Patients ◽

Enzyme Linked Immunosorbent Assay ◽

Age Group ◽

Igg Antibodies ◽

Serological Tests ◽

Recent Infection

Background and Objectives: Seroepidemiological studies indicate that parvovirus B19 circulates in all areas of the world, although with some differences. The aim of this study is to analyze the seroprevalence of parvovirus B19 in the Croatian population. Materials and Methods: From 2010 to 2021, 1538 serum samples from different populations were tested for the presence of parvovirus B19 IgM/IgG antibodies. Serological tests were performed using a commercial enzyme-linked immunosorbent assay. Results: IgG antibodies were detected in 986/64.1% of participants with differences (p < 0.001) among the following population groups: 42.4% of children and adolescents, 67.1% of the adult general population, 66.7% of hemodialysis patients, and 65.6% of liver transplant recipients. Seroprevalence increased with age, from 30.0% in the 6 months–9 years age group to 69.0% in the 40–49 years age group, and remained stable thereafter (68.8–73.3%). There was no difference in the seropositivity among males (66.1%) and females (63.1%), as well as the place of residence (suburban/rural 63.9%, urban 64.1%). IgM antibodies (current/recent infection) were found in 61/4.0% of participants with the highest seropositivity in the youngest age group (11.1%). In pregnant women, seroprevalence was higher in women with an unfavorable obstetric history compared with a normal pregnancy (IgG 71.0% vs. 62.6%; IgM 6.5% vs. 2.4%), but these differences were not significant. Logistic regression showed that the adult population had almost three times higher risk of IgG seropositivity compared to children/adolescents (general population OR = 2.777, 95% CI = 2.023–3.812; hemodialysis patients OR = 2.586, 95% CI = 1.531–4.367; and transplant patients OR = 2.717, 95% CI = 1.604–4.603). A one-year increase in age increased the risk of IgG seroprevalence (OR = 1.017; 95% CI = 1.011–1.022). Conclusions: Older age was the main risk factor for IgG seropositivity. Hemodialysis and organ transplantation seem unrelated to the increased parvovirus B19 seroprevalence. The role of parvovirus B19 in the etiology of TORCH infections needs to be studied further.

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SEROLOGICAL SCREENING FOR INFECTIOUS CATTLE DISEASES: II. ASSOCIATION BETWEEN PREVALENCE AND LEVEL OF ELISA RESPONSE

Ciência Rural ◽

10.1590/s0103-84781993000200014 ◽

1993 ◽

Vol 23 (2) ◽

pp. 193-196 ◽

Cited By ~ 3

Author(s):

José Alfonso Barajas- Rojas ◽

Hans Riemann ◽

Charles Franti

Keyword(s):

Infectious Disease ◽

Igg Antibodies ◽

Antibody Prevalence ◽

Serological Tests ◽

Serological Screening ◽

Disease Eradication ◽

Cattle Diseases ◽

The Difference ◽

Disease Antibody ◽

Low Prevalence

A herd of cattle (Holstein-Zebu crosses) was screened every two months by ELISA during a period of two years for IgG antibodies against 19 infectious disease agents. Two hundred and ninety five sera were collected from 157 young animals (0-4 months of age), 1037 sera from 292 developing animals (4-36 months of age) and 1468 sera from 259 producing animals (> 36 months of age). The results indicate that the difference in ELISA between positive and negative tests is associated with the overall prevalence of positive tests. When the prevalence of positive tests is low the difference between positive and negative tests is greater than when the prevalence is intermediate or high. This means that ELISA, presumably other serological tests for IgG antibodies, is more reliable at low disease (antibody) prevalence. This will tend to offset the declining predictive value of positive tests at low prevalence and may contribute to the successful use of serological tests in disease eradication.

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Status of Brucellosis in Dairy Cattle of Kapilvastu and Bhaktapur Districts of Nepal

Nepalese Veterinary Journal ◽

10.3126/nvj.v34i0.22907 ◽

2017 ◽

Vol 34 ◽

pp. 95-100

Author(s):

B. Ghimire ◽

S. Thapa Chhetri ◽

D.R. Khanal

Keyword(s):

Dairy Cattle ◽

Control Measures ◽

Serological Tests ◽

Plate Test ◽

History Of ◽

Awareness Programs ◽

June July ◽

And Control ◽

Legislative Measures ◽

Sera Samples

Brucellosis is a zoonotic disease that causes abortion in dairy cattle. To find out its status, serological tests were conducted, during June-July 2013, in 48 sera samples from dairy cattle (23 from Kapilvastu and 25 from Bhaktapur districts) having the recent history of abortion. Out of 48 samples 6 (12.5%) were positive on Rose Bengal Plate Test. Among 6 positive samples, 2 (8.69%) were from Kapilvastu and 4 (16%) from Bhakhtapur. Considering the positive cases of brucellosis in the dairy pocket areas and its threat of transmission to other animals and human, a suitable preventive and control measures including the regular test and segregation of sero-positive animals, effective quarantine, legislative measures and awareness programs for farmers, veterinarian, technicians and stakeholders are recommended.

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Clinical and epidemiological profile of blood donors with positive serology for viral hepatitis in southern Brazil

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/s0037-86822011005000028 ◽

2011 ◽

Vol 44 (3) ◽

pp. 269-273 ◽

Cited By ~ 4

Author(s):

Luciana da Silveira ◽

Leonardo de Lucca Schiavon ◽

Kerley Pereira da Silva ◽

Thiago Barbieri Lopes ◽

Marcos da Rocha Zaccaron ◽

...

Keyword(s):

Viral Hepatitis ◽

Blood Donors ◽

Blood Donation ◽

Previous History ◽

Southern Brazil ◽

Positive Serology ◽

Serological Tests ◽

History Of ◽

Epidemiological Profile ◽

Epidemiological Characteristics

INTRODUCTION: Positive serological tests for hepatitis viruses B and C at blood banks are an important reason for blood deferral. Additionally, high residual risk for transfusing hepatitis-contaminated blood has been estimated in southern Brazil. This study aimed to identify risk factors for positive serological tests for viral hepatitis (VH) in blood donors (BD). METHODS: A case-control study included consecutive BD with positive serology for VH, between 2008 and 2009. Cases and controls (BD with negative serology for VH) were paired 1:1 by sex and donation date. Assessment of clinical and epidemiological characteristics related to viral hepatitis was conducted. RESULTS: Among 1,282 blood donors (641 cases and 641 controls), those with positive serology for viral hepatitis had higher mean age (p<0.001); higher proportion of replacement donation (p<0.001); first donation (p<0.001); and interviewer deferment (p=0.037), compared to controls. Furthermore, donors with positive tests were less regular donors (p<0.001), had less previous history of rejection (p=0.003) and showed lower hematocrit median before donation (p=0.019). Multivariate analysis demonstrated that age (OR=1.056, 95%CI 1.042-1.069, p<0.001), replacement donation (OR=1.545, 95%CI 1.171-2.038, p=0.002) and first donation (OR=9.931, 95%CI 7.486-13.173, p<0.001) were independently associated with positivity of serological tests for viral hepatitis. CONCLUSIONS: Specific characteristics of blood donors were associated with positive serology for viral hepatitis. These peculiarities should be taken into account when assessing candidates for blood donation.

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