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. 2022 Mar-Apr;42(2):69-74.
doi: 10.5144/0256-4947.2022.69. Epub 2022 Apr 7.

Seroprevalence of SARS-Cov-2 IgG antibodies in patients at a single center in Saudi Arabia

Waleed H Mahallawi  1 , Mohammad A Alsarani  2 , Rami H Aljohani  2 , Abdulrahman A Alluhaibi  2 , Turki H Alamri  2 , Nadir A Ibrahim  1 , Khalid H Mahallawi  3 , Omar F Khabourd  4
Affiliations

Seroprevalence of SARS-Cov-2 IgG antibodies in patients at a single center in Saudi Arabia

Waleed H Mahallawi et al. Ann Saudi Med. 2022 Mar-Apr.

Abstract

Background: The coronavirus disease 2019 (COVID-19) pandemic has had a massive impact on public health as well as the economy. Understanding the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among undiagnosed individuals is important for developing an informed pandemic response.

Objective: Investigate the prevalence of undiagnosed COVID-19 disease.

Design: Cross-sectional.

Setting: Tertiary care center in Madinah, Saudi Arabia.

Subjects and methods: All participants were on follow-up visits to various clinics and had not been previously diagnosed with COVID-19. Enzyme-linked immunosorbent assay was used to specifically assess the anti-spike IgG antibody seropositivity in serum samples. We associated the seropositivity rates of the participants with age, body mass index (BMI), nationality, blood groups, and sex with uni- and multivariate analyses.

Main outcome measures: Seropositivity for IgG anti-spike antibodies against SARS-CoV-2.

Sample size and characteristics: 527 subjects, with a median (interquartile percentiles) age of the 527 subjects was 34 (24-41).

Results: Of the 527 samples, about one-fourth (n=124, 23.5%) were positive for anti-spike IgG antibody against SARS CoV-2. Age was associated with anti-spike IgG antibody positivity (P<.002). Participants >30 years were more likely to be seropositive (28-29%) than younger participants (15.4%). Additionally, seropositivity was associated with female gender (P<.001) and a higher BMI (P<.006). In the multivariate logistic regression, age >30, female gender and BMI >40 were associated with seropositivity.

Conclusion: The percentage of seropositive individuals reflects the high level of undiagnosed COVID-19 patients among the population. Our results will help in a better evaluation of the public health measures applied during the COVID-19 pandemic and any future public health crises.

Limitations: Sample size was small, single-center study and no rural areas were included.

Conflict of interest: None.

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Figures

Figure 1.
Figure 1.. Number of seropositive subjects by age groups (P <.002).
Figure 2.
Figure 2.. Seropositivity by BMI category.
Figure 3.
Figure 3.. Age distribution by gender for seropositive subjects.
See this image and copyright information in PMC

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