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.