5.1 Human Pathogens

Flashcards covering key terminology from Chapter 1 to 8 on microbial laboratory identification, pathogenicity, steps of infection, immune evasion mechanisms, transmission methods, and infection precautions.

Universal Precautions

A laboratory standard where samples are treated as pathogenic and hazardous, requiring personnel to wear personal protective equipment (PPE).

Pathogenicity

Refers to whether or not a microbe is a pathogen and has the ability to cause disease.

Pathogen

A microbe that can cause disease.

Virulence

The relative ease with which a pathogen can infect its host.

Portal of Entry

The site through which a pathogen enters the host body to gain access to tissues, typically determined by its mode of transmission.

Parenteral Entry

A route of pathogen entry that bypasses the GI tract, typically occurring when a pathogen is injected or directly placed into the bloodstream.

Adhesion Factor

A protein or molecule on a pathogen's surface (also called an adhesion) that binds to specific receptors on target host cells.

Intracellular Pathogen

A pathogen that enters and resides inside host cells as a method to secure nutrients and evade the host's immune system.

Antigen Masking

An immune evasion mechanism where a pathogen hides or cloaks its own antigens so the host immune system does not detect them.

Antigen Mimicry

An immune evasion mechanism where a pathogen produces antigens similar to the host's own molecules to prevent immune detection.

Antigen Variation

An immune evasion strategy where a pathogen alters its surface antigens over time to prevent the host immune system from mounting an effective response.

Transmission

The successful movement or transfer of an infectious pathogen from one host or reservoir to another.

Direct Contact Transmission

Pathogen transfer occurring via physical contact between the source and host, including person-to-person, animal bites/scratches, environmental exposure, or vertical transmission.

Vertical Transmission

Direct contact transmission of a pathogen from a mother to her fetus or infant across the placenta, during vaginal delivery, or through breastfeeding.

Indirect Contact Transmission

Pathogen transfer occurring without direct contact between source and host, including respiratory aerosols, vehicle transmission, and vectors.

Vehicle Transmission

Indirect transmission of a pathogen introduced through contact with a contaminated object, such as a needle.

Biological Vector

An insect or animal in which a pathogen completes part of its life cycle before being transmitted to a human host.

Mechanical Vector

An insect or animal that passively transports a pathogen between hosts without being infected itself.

Airborne Isolation Rooms (AIR)

Pressurized isolation rooms designed to keep air carrying airborne aerosolized pathogens from escaping to other areas.