Related Experiment Video
Updated: Oct 14, 2025
Swabbing the Urban Environment - A Pipeline for Sampling and Detection of SARS-CoV-2 From Environmental Reservoirs
Published on: April 9, 2021
Seroprevalence of SARS-CoV-2 Among Firefighters/Paramedics in San Francisco, CA
Megan Grant1, Robert Harrison, Arlene Nuñez
1University of California (Ms Grant, Dr Harrison, Dr Kurtz, Dr Shusterman); San Francisco Fire Department (Ms Nunez, Dr Phelps, Dr Brokaw), San Francisco, California.
Objectives:
Despite having close contact with the general public, members of the San Francisco Fire Department (SFFD) reported relatively few cases of COVID-19 during the first half of 2020. Our objective was to explore evidence for prior undetected infections by conducting a seroprevalence survey, and to document both risk and protective factors for prior COVID-19 infection.
Methods:
This cross-sectional study assessed workplace practices and exposures of SFFD personnel during the first 6 months of 2020 via questionnaire and documented prior COVID-19 infections by serologic antibody testing using an orthogonal testing protocol.
Results:
Of 1231 participating emergency responders, three (0.25%) had confirmed positive COVID-19 antibody results.
Conclusions:
Safe workplace practices, community public health intervention, and low community infection rates appear to have been protective factors for emergency responders in San Francisco during our study period.
Related Concept Videos
01:25Transmission-based Precautions II: Airborne and Protective Environment
Airborne precautions:
Use airborne precautions when treating patients known or suspected to have diseases that spread through the air—for example, tuberculosis or measles. These organisms are present in smaller droplets expelled by an infected person and...
01:08Prevalence and Incidence
Prevalence indicates the proportion of individuals in a population who have a specific disease or health...