Almudarra, SamiKamel, ShadySaleh, EmanAlaswad, RehabAlruwaily, AmaalAlmowald, ShazaAlqunaibet, Ada MohammedAlmudiaheem, AbdullahAlmutlaq, HindAlserehi, HaleemaAlmalki, SafarBahlaq, Mohannad AbdulhafizAlsahafi, Abdullah JaberAlsaif, FaisalKhojah, Abdullah T.Al‑Tawfiq, Jaffar A.Asiri, Sari IbrahimAssiri, AbdullahJokhdar, Hani2023-04-142023-04-142022-06Almudarra S, Kamel S, Saleh E, et al. High seroprevalence of SARS-CoV-2 among high-density communities in Saudi Arabia. Infection. 2022;50(3):643-649. doi:10.1007/s15010-021-01726-2https://hdl.handle.net/1805/32393This article is made available for unrestricted research re-use and secondary analysis in any form or be any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Background: The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection had been investigated utilizing serology. Materials and methods: This community-based sero-survey was carried out in the neighborhoods of three cities in Saudi Arabia. Results: Of 5629 participants, 2766 (49.1%) were women; and 2148 (38.1%) were 18-34 years of age, and 3645 (64.7%) were from South East Asia. Positive serology was seen in 2825 (50.2% (95% CI: 48.8-51.5%) for SARS-CoV-2 anti-S1 IgG antibodies by ECLIA. Being in the age category of 18-34 years and being from Eastern Mediterranean Region (country A) were associated with higher COVID-19 seropositivity with estimated odds ratio of 1.3 [95% CI 1.1-1.8] and 2.5 [95% CI 1.1.5-4.2] respectively. Gender, social status, education, nationality, symptoms, presence of comorbidities and activity style were positively associated with increased seropositivity. Factors associated negatively with the rate of seropositivity were higher education and having outdoor activity with estimated OR of 0.92 [95% CI 0.46-0.95] and 0.59 [95% CI 0.47-0.74], respectively. Conclusion: The study showed high seroprevalence of SARS-CoV-2 among high density population. Health education campaigns should target middle-aged, those with low education, those living in lower standards and indoor workers.en-USPublic Health EmergencyCOVID-19High densitySARS-CoV-2SerologyArticle