Incorporating medical students into an interdisciplinary, population-based study of SARS-CoV-2 infection in asymptomatic individuals in South Texas.

BACKGROUND

Asymptomatic and pre-symptomatic infections may play a significant role in the spread of COVID-19 but determining prevalence of these infections in the general population is labor intensive.

PURPOSE

This approach describes an innovative surveillance strategy using teams of medical students and emergency medical technicians (EMTs). Medical students represent a highly trained but underutilized workforce in the pandemic response.

METHODS

A household-level sampling frame generated a population-weighted representative sample of households in San Antonio, Texas. Households were included if an English or Spanish-speaking adult (≥18yo) answered the door and was willing to participate; excluded if household members had past or present COVID-19 symptoms or close contact with confirmed COVID-19 infection. Interdisciplinary teams of medical or medical/public health dual degree students paired with EMTs conducted a survey and instructed participants on how to self-administer nasal swabs among 502 community members without symptoms of COVID-19 from June 1-6, 2020, weeks prior to a community case surge.

RESULTS

Of 502 participants, median age was 52 years and average household size was 3.1. Only 40% reported no medical risk factors for COVID-19 complications. Hypertension (23.6%) and diabetes (13.4%) were the most common pre-existing medical conditions; 29% of respondents reporting feeling at risk for SARS-CoV-2 during daily outside-of-the-home activities. All 502 SARS-CoV-2 PCR tests were negative, suggesting a prevalence range of 0%-1.2%.

PUBLIC HEALTH SIGNIFICANCE

It is unlikely that pre-symptomatic and asymptomatic COVID-19 infections in households without existing COVID-19 infections played a major role in the propagation of the epidemic at this point in time. While community-wide testing of individuals without symptoms of COVID-19 may be low yield in the context of low prevalence of symptomatic cases of COVID-19, medical students provided valuable support for community-based surveillance at a time when public health infrastructure was severely taxed.