Med Conditions- Infectious Diseases

Agent

Host

Environment

What is the epidemiologic triad of infectious diseases?

Infectious agent

Reservoir

Exit pathway

Means of transmission

Entry pathway

Susceptible host

What is the chain of infection?

Virus

Bacteria

Fungus

Parasite

Prion

What does the infectious agent consist of?

Direct transmission

Occurs when the pathogen is passed via direct contact from one person to another.

Airborne

Contact

Droplet

Vector

Vehicle

What are the means of transmission?

Indirect transmission

Occurs through airborne, vector-borne, or vehicle-borne means.

Airborne transmission

When infectious agents are carried out via droplet nuclei and can remain in the air for long periods

Tuberculosis (TB)

What is an example of an infectious agent that is airborne?

Tuberculosis (TB)

What is an example of an infectious agent that is a bacteria?

Vector transmission

Transmission of an infectious agent by an insect, arthropod, or animal

Vehicle borne

Transmission of an infectious agent via food, water, biologic products, or inanimate objects.

COVID, HIV, influenza

What is an example of an infectious agent that is a virus?

HIV

What is an example of an infectious agent that is transmitted via contact?

Lyme disease

What is an example of an infectious agent that is transmitted via vector-borne?

Ringworm

What is an example of an infectious agent that is fungal?

Malaria

What is an example of an infectious agent that is parasitic?

Creutzfeldt-Jakob disease (CJD)

What is an example of an infectious agent that is a prion?

Handwashing

Cover your cough

Clean surfaces & equipment

PPE as appropriate

What are standard precautions?

PPE

- gloves

- various types of masks

- face shields

- gowns

What are transmission-based precautions?

Economic

Stability

Education access & quality

Health care access & quality

Neighborhood & built environments

Social & community context

Social and Structural Determinants

Fear of contracting infectious diseases

Misinformation of transmissions

Incorrect assumptions about prognosis

Social judgements about behaviors that make people more vulnerable for exposure to pathogens

Factors that contribute to stigmas of infectious diseases

Human Immunodeficiency Virus (HIV)

Virus that attaches to CD4+T cells that cause damage to body's immune response

Blood

Serum

Semen

Breast-milk

Body tissues

Ways HIV is transmissible

Unprotected sexual intercourse

Exposure to infected blood

Prenatal

Needle sharing

Transfusions and transplants

What are some ways HIV is transmitted?

1. Highly infectious (2-4 weeks), flu-like symptoms

2. Virus active and transmissible; CD4 count lowers, up to a decade, antiretroviral tx can suppress viral load

3. Acquired immunodeficiency syndrome (AIDS) when CD4 cells are below 200 cells/ml

3 stages of HIV:

Tuberculosis (TB)

Infectious bacterial disease with a presence in sputum. Most commonly affects the lungs by causing bronchial inflammation and lung tissue infection that scars pulmonary tissue

20%

About what % of TB cases will spread to other body structures?

Meninges

Bones & joints

Gastrointestinal

What body structures will TB usually spread to?

Fever

Night sweats

Weight loss

Fatigue/weakness

Cough

Chest pain

SOB

Symptoms of active TB:

Overcrowding

Poor nutrition

What are 2 factors that are directly linked to rates of TB?

India

China

Indonesia

Philippines

Pakistan

Nigeria

Bangladesh

South Africa

8 countries that account for two-thirds of new TB cases:

Australia

Canada

New Zealand

USA

Eastern Europe

Lower burden TB countries:

15-64 years old

Span of ages of TB

True

Men are more likely to be affected with TB than women.

True or False?

15-22x

People living with HIV are __ - __ times more likely to develop TB than people without TB.