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1.
S Afr Med J ; 111(11): 1078-1083, 2021 11 05.
Article in English | MEDLINE | ID: covidwho-1534499

ABSTRACT

BACKGROUND: Estimates of prevalence of anti-SARS-CoV-2 antibody positivity (seroprevalence) for tracking the COVID-19 epidemic are lacking for most African countries. OBJECTIVES: To determine the prevalence of antibodies against SARS-CoV-2 in a sentinel cohort of patient samples received for routine testing at tertiary laboratories in Johannesburg, South Africa. METHODS: This sentinel study was conducted using remnant serum samples received at three National Health Laboratory Service laboratories in the City of Johannesburg (CoJ) district. Collection was from 1 August to 31 October 2020. We extracted accompanying laboratory results for glycated haemoglobin (HbA1c), creatinine, HIV, viral load and CD4 T-cell count. An anti-SARS-CoV-2 targeting the nucleocapsid (N) protein of the coronavirus with higher affinity for IgM and IgG antibodies was used. We reported crude as well as population-weighted and test-adjusted seroprevalence. Multivariate logistic regression analysis was used to determine whether age, sex, HIV and diabetic status were associated with increased risk for seropositivity. RESULTS: A total of 6 477 samples were analysed, the majority (n=5 290) from the CoJ region. After excluding samples with no age or sex stated, the model population-weighted and test-adjusted seroprevalence for the CoJ (n=4 393) was 27.0% (95% confidence interval (CI) 25.4 - 28.6). Seroprevalence was highest in those aged 45 - 49 years (29.8%; 95% CI 25.5 - 35.0) and in those from the most densely populated areas of the CoJ. Risk for seropositivity was highest in those aged 18 - 49 years (adjusted odds ratio (aOR) 1.52; 95% CI 1.13 - 2.13; p=0.0005) and in samples from diabetics (aOR 1.36; 95% CI 1.13 - 1.63; p=0.001). CONCLUSIONS: Our study conducted between the first and second waves of the pandemic shows high levels of current infection among patients attending public health facilities in Gauteng Province.


Subject(s)
Antibodies, Viral/immunology , COVID-19/epidemiology , SARS-CoV-2/isolation & purification , Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , COVID-19/immunology , Child , Child, Preschool , Cross-Sectional Studies , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Prevalence , SARS-CoV-2/immunology , Sentinel Surveillance , Seroepidemiologic Studies , South Africa/epidemiology , Young Adult
2.
Southern African Journal of Infectious Diseases ; 36(1), 2021.
Article in English | EMBASE | ID: covidwho-1348731

ABSTRACT

Background: Serology testing is an important ancillary diagnostic to the reverse transcriptase polymerase chain reaction (RT-PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We aimed to evaluate the performance of the Roche Elecsys™ chemiluminescent immunoassay (Rotkreuz, Switzerland), that detects antibodies against the SARS-CoV-2 nucleocapsid antigen, at an academic laboratory in South Africa. Methods: Serum samples were collected from 312 donors with confirmed positive SARS-CoV-2 RT-PCR tests, with approval from a large university’s human research ethics committee. Negative controls included samples stored prior to December 2019 and from patients who tested negative for SARS-CoV-2 on RT-PCR and were confirmed negative using multiple serology methods (n = 124). Samples were stored at –80 °C and analysed on a Roche cobas™ 602 autoanalyser. Results: Compared with RT-PCR, our evaluation revealed a specificity of 100% and overall sensitivity of 65.1%. The sensitivity in individuals > 14 days’ post-diagnosis was 72.6%, with the highest sensitivity 31–50 days’ post-diagnosis at 88.6%. Results were also compared with in-house serology tests that showed high agreement in majority of categories. Conclusions: The sensitivity at all-time points post-diagnosis was lower than reported in other studies, but sensitivity in appropriate cohorts approached 90% with a high specificity. The lower sensitivity at earlier time points or in individuals without symptomatology may indicate failure to produce antibodies, which was further supported by the comparison against in-house serology tests.

3.
Adv Exp Med Biol ; 1321: 183-197, 2021.
Article in English | MEDLINE | ID: covidwho-1114247

ABSTRACT

We conducted a retrospective analysis on data of all adults tested for SARS-CoV-2 across our laboratory network in South Africa over a 4-month period. Out of 842,197 tests, 11.7% were positive and 88.3% negative. The prevalence of HIV was 6.25 and 6.31% in the SARS-CoV-2-positive and SARS-CoV-2-negative cohort, respectively (p = 0.444). However, the prevalence of HIV-positive individuals in the critical cohort (9.15%) was higher than in the noncritical group (6.24%) (p = 0.011). Active tuberculosis infection was approximately 50% less in SARS-CoV-2-positive than in SARS-CoV-2-negative individuals. The prevalence of uncontrolled diabetes was 3.4 times higher in SARS-CoV-2-positive cases but was not higher in the critical vs. noncritical cases (p = 0.612). The neutrophil-to-lymphocyte ratio, coagulation markers, urea, and cardiac- and liver-related analytes were significantly elevated in the critical compared to noncritical cases. Platelet count and creatinine concentration did not differ significantly between the two groups. These findings do not support increased prevalence of HIV or tuberculosis in individuals with SARS-CoV-2 infection but do suggest an association of increased disease severity with HIV-positive status. Uncontrolled diabetes was positively associated with a significantly higher prevalence of SARS-CoV-2, and our investigation into analyte changes associated with SARS-CoV-2 disease severity supported previous findings of raised inflammatory markers, coagulation markers, liver- and cardiac-related analytes, and urea but not for creatinine and platelet count.


Subject(s)
COVID-19 , HIV Infections , Adult , Glycated Hemoglobin A , HIV Infections/epidemiology , Humans , Laboratories , Retrospective Studies , SARS-CoV-2 , South Africa/epidemiology
4.
Adv Exp Med Biol ; 1321: 147-162, 2021.
Article in English | MEDLINE | ID: covidwho-1114244

ABSTRACT

The novel corona virus 2019 (COVID-19) outbreak which started in Hubei province in China has now spread to every corner of the earth. While the pandemic started later in Africa, it is now found in all African countries to varying degrees. It is thought that the prevalence and severity of disease is influenced by a number of non-communicable diseases (NCDs) which are all becoming increasingly prevalent in sub-Saharan Africa (SSA). In addition, SSA bears the major burden of human immunodeficiency virus (HIV) and tuberculosis (TB) infections. While data from Europe and the United States show that children are spared severe disease, it is uncertain if the same holds true in SSA where children suffer from sickle cell disease and malnutrition in addition to other infectious diseases. There is limited data from Africa on the effects of these conditions on COVID-19. In this review, we discuss the epidemiology of some of these conditions in Africa and the possible pathogenesis for the interactions of these with COVID-19.


Subject(s)
COVID-19 , Coronavirus , Africa South of the Sahara/epidemiology , Child , China , Europe , Humans , SARS-CoV-2 , United States , Vulnerable Populations
5.
Adv Exp Med Biol ; 1321: 127-138, 2021.
Article in English | MEDLINE | ID: covidwho-1114242

ABSTRACT

The SARS-CoV-2 virus which causes COVID-19 disease was initially described in the Hubei Province of China and has since spread to more than 200 countries and territories of the world. Severe cases of the disease are characterised by release of high levels of pro-inflammatory cytokines and other inflammatory mediators in a process characterised as a cytokine storm. These inflammatory mediators are associated with pathological leukocyte activation states with tissue damage. Here, we review these effects with a focus on their potential use in diagnosis, patient stratification and prognosis, as well as new drug targets.


Subject(s)
COVID-19 , SARS-CoV-2 , China , Cytokine Release Syndrome , Cytokines , Humans , Inflammation
6.
S Afr Med J ; 110(9): 842-845, 2020 07 17.
Article in English | MEDLINE | ID: covidwho-743542

ABSTRACT

Antibody tests for the novel coronavirus, SARS-CoV2, have been developed both as rapid diagnostic assays and for high-throughput formal serology platforms. Although these tests may be a useful adjunct to a diagnostic strategy, they have a number of limitations. Because of the antibody and viral dynamics of the coronavirus, their sensitivity can be variable, especially at early time points after symptom onset. Additional data are required on the performance of the tests in the South African population, especially with regard to development and persistence of antibody responses and whether antibodies are protective against reinfection. These tests may, however, be useful in guiding the public health response, providing data for research (including seroprevalence surveys and vaccine initiatives) and development of therapeutic strategies.


Subject(s)
Betacoronavirus , Clinical Laboratory Techniques , Coronavirus Infections , Immunologic Tests/methods , Pandemics , Pneumonia, Viral , Serologic Tests/methods , Betacoronavirus/genetics , Betacoronavirus/immunology , Betacoronavirus/isolation & purification , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques/methods , Clinical Laboratory Techniques/standards , Coronavirus Infections/diagnosis , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Humans , Pneumonia, Viral/diagnosis , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , Reproducibility of Results , SARS-CoV-2 , Sensitivity and Specificity , Seroepidemiologic Studies , South Africa/epidemiology
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