Prevalence of anti-SARS-CoV-2 antibody in hemodialysis facilities: a cross-sectional multicenter study from Madinah.

BACKGROUND: Since the occurrence of coronavirus disease in 2019 (COVID-19), the global community has witnessed its exponential spread with devastating outcomes within the general population and specifically within hemodialysis patients. OBJECTIVES: Compare the state of immunity to SARS-CoV-2 among hemodialysis patients and staff. DESIGN: Cross-sectional study with a prospective follow-up period. SETTING: Hemodialysis centers in Madinah region. PATIENTS AND METHODS: We prospectively tested for SARS-CoV-2 antibodies in dialysis patients using dialysis centers staff as controls. The participants were tested on four occasions when feasible for the presence of anti-SARS-CoV-2 antibodies. We also analyzed factors that might be associated with seropositivity. MAIN OUTCOME MEASURES: SARS-CoV-2 positivity using immunoglobulin G (IgG) levels SAMPLE SIZE: 830 participants, 677 patients and 153 dialysis centers staff as controls. RESULTS: Of the total participants, 325 (257 patients and 68 staff) were positive for SARS-CoV-2 IgG antibodies, for a prevalence of 38.0% and 44.4% among patients and staff, respectively (P=.1379). Participants with a history of COVID-19 or related symptoms were more likely to have positive IgG (P<.0001). Surprisingly, positivity was also center-dependent. In a multivariable logistic regression, a history of infection and related symptoms contributed significantly to developing immunity. CONCLUSION: The high prevalence of SARS-CoV-2 antibody among hemodialysis patients and previously asymptomatic staff suggested past asymptomatic infection. Some centers showed more immunity effects than others. LIMITATIONS: Unable to collect four samples for each participant; limited to one urban center. CONFLICT OF INTEREST: None.

Enzyme-Linked Immunosorbent Assay for the Detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) IgM/IgA and IgG Antibodies Among Healthcare Workers.

Background The outbreak of the novel coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been spreading rapidly across the world. A nucleic acid real-time quantitative polymerase chain reaction (RQ-PCR) test of nasopharyngeal samples is the standard method for the diagnosis of an active SARS-CoV-2 infection. However, many limitations of the RQ-PCR tests make them unsuitable for the simple and rapid diagnosis of COVID-19 patients. Moreover, some individuals with COVID-19 present an asymptomatic infection. Thus, assessing the asymptomatic transmission of COVID-19, especially in healthcare workers (HCWs), is crucial for evaluating the efficiency of the current preventive measures. Serological tests such as enzyme-linked immunosorbent assay (ELISA) are needed to quickly identify a large number of asymptomatic carriers to prevent the further spread of the virus and assess level of possible serological immunity in a community. Method Between April 18 and June 17, 2020, 330 HCWs from five Madinah region-affiliated hospitals underwent a seroprevalence screening for anti-SARS-CoV-2 antibodies (immunoglobulin [Ig]M/IgA and IgG) using indirect ELISA testing. Result Among the 330 samples, 80 (24.24%) were positive for SARS-CoV-2 IgM/IgA and/or IgG antibodies. There were no significant differences observed in the seroprevalence among the different occupations of the HCWs (excluding the pharmacists) with respect to the percentage of their seropositive samples. Conclusion The current study presented the seroprevalence of anti-SARS-CoV-2 IgM/IgA and IgG antibodies in HCWs. The regular screening of HCWs for these antibodies is necessary; subsequently, a molecular test is recommended for those with seropositive (IgM, IgA, and IgG) samples to assess their viral load and potential shedding.