viral load

American  

[vahy-ruhl lohd] / ˈvaɪ rəl ˈloʊd /

noun

Pathology.

1. the amount or concentration of a virus in a given quantity of blood, saliva, mucus, or other bodily fluid, often expressed as the number of viral particles per milliliter of the fluid: The droplets from a flu-infected person’s sneeze leave their viral load on whatever surface they land on.

   When HIV treatment is effective, the viral load in the blood becomes undetectable.

   The droplets from a flu-infected person’s sneeze leave their viral load on whatever surface they land on.

---

viral load Scientific  

/ vī′rəl /

1. The concentration of a virus, such as HIV, in the blood.

---

Etymology

Origin of viral load

First recorded in 1965–70

Example Sentences

Now Sam takes daily medication to keep his viral load at an undetectable level, meaning it cannot be passed to anyone else.

From BBC • Apr. 23, 2026

The trial evaluated the regimen’s success in preventing HIV-1 replication using viral load, a measure of the amount of HIV genetic material in the blood.

From Barron's • Feb. 25, 2026

Further testing suggested she had a high viral load of a novel influenza A infection, which researchers eventually discovered to be avian flu caused by the H5N1 virus.

From Salon • Jan. 13, 2025

The viral load in placentas and fetuses was significantly lower in the vaccinated group versus the unvaccinated group.

From Science Daily • Mar. 4, 2024

The treatment is effective enough that you reduce your viral load to the point where an infection doesn’t show up on a test; then after treatment ends, your viral load increases again.

From Los Angeles Times • Jul. 28, 2023