What is HEPA?

High Efficiency Particulate Arresting" filter.

This type of air filter can remove at least 99.97% of airborne particles 0.3 micrometres (µm) in diameter. Particles of this size are the most difficult to filter and thus the most penetrating particle size (MPPS). Particles that are larger or smaller are filtered with even higher efficiency.

A HEPA (IPA: [ˈhɛpə]) filter is a type of air filter. "HEPA" is an acronym for "high efficiency particulate air filter" (as defined by the United States Department of Energy). The DOE version of the acronym is actually incorrect. The original derivation of HEPA represented "High Efficiency Particulate Arresting" filter. The term "Particulate Air" conveys no meaning.

This type of air filter can remove at least 99.97% of airborne particles 0.3 micrometres (µm) in diameter. Particles of this size are the most difficult to filter and thus the most penetrating particle size (MPPS). Particles that are larger or smaller are filtered with even higher efficiency.

HEPA Filter = High Efficiency Particulate Air Filter

Since you posted this in the infectious disease category, I would assume you mean Hepatitis A. This is a very common and contagious infection which does affect the liver. Common symptoms include: itchy skin, yellowing of the skin and whites of the eyes, stools change to a light color, and urine darkens.

You can contract Hep A from food, water, and secretions from infected persons. If you think you have it - get treated and also let your friends, family and contacts know that you have it. They may want to get checked out and get a shot Gama globulin, which will help to boost their immune system.

Sounds like Hepatitis A? Disease of the liver, very contagious, there is a vaccination against it, recommended (in general but also) if you going overseas, working with a lot of people, caring for the sick

high-efficiency particulate air (filter)