Transmission of SARS-CoV-2 among underserved pastoralist communities in Kajiado County, Kenya: 2020-2022

PLoS One. 2024 Aug 8;19(8):e0308318. doi: 10.1371/journal.pone.0308318. eCollection 2024.

Abstract

Initial transmission of severe acute respiratory syndrome virus-2 (SARS-CoV-2) was highest in densely populated regions of Kenya. Transmission gradually trickled down to the less densely populated, remote and underserved regions such as the pastoral regions of Kajiado County which are characterized by poor healthcare systems. Molecular assays that were pivotal for COVID-19 diagnosis were not available in these regions. Serology is an alternative method for retrospectively tracking the transmission of SARS-CoV-2 in such populations. Dry blood spots (DBS) were prepared from consenting patients attending six health facilities in Kajiado County from March 2020 to March 2022. Upon elution, we conducted an enzyme-linked immunosorbent assay (ELISA) for the detection of SARS-Cov-2 IgG antibodies. Of the 908 DBSs we analyzed, 706 (78%) were from female participants. The overall seropositivity to SARS-Cov-2 antibodies was 7.3% (95% CI 5.7-9.1). The elderly (over 60 years) and male participants had a high likelihood of testing positive for SAR-CoV-2 infections. Mashuru (15.6%, 14/90) and Meto (15%, 19/127) health facilities registered the highest proportion of seropositive participants. Evidence of SARS-CoV-2 transmission among pastoralists in the remote and underserved regions of Kajiado County was established by DBS sampling and serologic testing.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibodies, Viral* / blood
  • COVID-19* / diagnosis
  • COVID-19* / epidemiology
  • COVID-19* / transmission
  • Child
  • Child, Preschool
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Immunoglobulin G / blood
  • Infant
  • Kenya / epidemiology
  • Male
  • Middle Aged
  • Retrospective Studies
  • SARS-CoV-2* / immunology
  • SARS-CoV-2* / isolation & purification
  • Young Adult

Substances

  • Antibodies, Viral
  • Immunoglobulin G

Grants and funding

Funding for the study was provided by the US Defense Threat Reduction Agency for a project entitled “Building Laboratory Diagnostic Capacity for Zoonotic Disease Risk Mitigation in Underserved Arid and Semi-Arid Areas of Kenya” (DTRA Project HDTRA11910029). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.”.