SARS-CoV-2 Viral Load Analysis at Low and High Altitude: A Case Study from Ecuador

Int J Environ Res Public Health. 2022 Jun 28;19(13):7945. doi: 10.3390/ijerph19137945.

Abstract

SARS-CoV-2 has spread throughout the world, including remote areas such as those located at high altitudes. There is a debate about the role of hypobaric hypoxia on viral transmission and COVID-19 incidence. A descriptive cross-sectional analysis of SARS-CoV-2 infection and viral load among patients living at low (230 m) and high altitude (3800 m) in Ecuador was completed. Within these two communities, the total number of infected people at the time of the study was 108 cases (40.3%). The COVID-19 incidence proportion at low altitude was 64% while at high altitude was 30.3%. The mean viral load from those patients who tested positive was 3,499,184 copies/mL (SD = 23,931,479 copies/mL). At low altitude (Limoncocha), the average viral load was 140,223.8 copies/mL (SD = 990,840.9 copies/mL), while for the high altitude group (Oyacachi), the mean viral load was 6,394,789 copies/mL (SD = 32,493,469 copies/mL). We found no statistically significant differences when both results were compared (p = 0.056). We found no significant differences across people living at low or high altitude; however, men and younger populations had higher viral load than women older populations, respectively.

Keywords: COVID-19; RT-PCR; SARS-CoV-2; cycle threshold (Ct); high altitude; hypoxia; viral load.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Altitude
  • COVID-19* / epidemiology
  • Cross-Sectional Studies
  • Ecuador / epidemiology
  • Female
  • Humans
  • Male
  • SARS-CoV-2*
  • Viral Load

Grants and funding

This research was funded by Universidad de Las Américas and by Fundación CRISFE (Fondo “Sumar juntos”).