Infectious Diseases

What is an infectious disease?

Infectious disease is caused by an agent such as a virus or bacteria; example: Influenza, COVID-19.

What is a non-infectious disease?

Disease not caused by an agent or pathogen; example: heart disease, asthma.

What is a communicable disease?

Infectious disease spread person-to-person; not all infectious diseases are communicable.

What is a contagious disease?

A disease that is highly communicable and spreads rapidly.

Why are infectious diseases still important globally?

They remain leading causes of death especially in low-income nations and children.

What is an eliminated disease?

Disease that no longer exists in a specific geographic region; example: measles in the U.S.

What is an eradicated disease?

Disease that no longer exists anywhere except labs; example: smallpox.

What are common diseases of concern?

Influenza, pneumonia, HIV, STIs/STDs, tuberculosis.

Why are emerging infectious diseases important?

They increase unpredictably and require prevention for unknown future diseases.

What is a zoonotic disease?

Disease transmitted between animals and humans.

What causes antibiotic resistance?

Improper antibiotic use that allows resistant bacteria to survive and replicate.

What does the EPI triad show?

It shows the interaction between host, agent, and environment that determines disease risk.

What is an example of the EPI triad?

RSV: host (age), agent (virus), environment (season/weather).

What are bacterial agents?

One-celled organisms that multiply quickly; example: cholera.

What are viral agents?

Genetic material that hijacks host cells; example: influenza.

What are fungi as agents?

Yeasts and molds that cause infections.

What are protozoa?

Single-celled organisms often transmitted through water.

What are helminths?

Parasitic worms.

What is infectivity?

The ability of a pathogen to invade and multiply.

What is pathogenicity?

The ability of a pathogen to cause disease.

What is a host?

Organism that becomes ill; includes humans, birds, bats, and other vertebrates.

What is a vector?

Organism that carries pathogens between hosts; examples: mosquitoes, ticks, flies.

What is direct transmission?

Transmission through skin, mucous membranes, placenta, breast milk, or respiratory droplets.

What is indirect transmission?

Transmission through food, water, vectors, or air.

What environmental factors increase disease spread?

clean water, food handling, natural disasters, exotic pets, global travel.

How does climate change affect infectious disease?

Leads to longer summers, milder winters, warmer water, and extreme weather that increase outbreaks.

What are WHO priority diseases?

Diseases with high epidemic risk and insufficient countermeasures requiring rapid research.

What are coronaviruses?

A family of viruses causing illness in humans and animals, including COVID-19.

How is COVID-19 transmitted?

Through respiratory droplets.

What increases COVID-19 severity?

Age, chronic conditions, obesity, and behaviors such as smoking.

When was the major Ebola outbreak?

2014, mainly in West Africa.

How did Ebola spread?

Through close contact with infected people and traditional burial practices.

Why were burial practices important in Ebola prevention?

Cultural practices increased spread; required culturally sensitive interventions.

When did the Zika outbreak occur?

2015-2016.

What was the major concern with Zika?

Microcephaly and neurological disorders in infants of infected pregnant women.

How is Zika transmitted?

By mosquito bites and from mother to baby.

What is Disease X?

An unknown pathogen that could cause a future severe epidemic.

Why are infectious diseases still a concern in the U.S.?

They require constant research, monitoring, and improved interventions.

What causes influenza?

Influenza viruses, mainly types A and B.

Why is influenza unpredictable?

Type A constantly mutates, making antibodies less effective.

What disease was eliminated in 2000 but is rising again?

Measles.

Why are measles cases rising?

Declining vaccination rates.

What are healthcare-associated infections?

Infections caused by increased exposure in healthcare settings, often through IVs or surgery.

What are the main tracked STIs?

Chlamydia, gonorrhea, and syphilis; HPV is most common; HIV tracked separately.

Why are STIs difficult to manage?

Behavioral determinants and stigma reduce testing and prevention.

What factors affect disease eradication strategies?

Reservoir type, survival outside host, symptoms, immunity, vaccines, and number of strains.

What is herd immunity?

Percent of population needed to be vaccinated to protect those who cannot be vaccinated.

What is water treatment?

Public health method that reduces pathogens in water.

What is vector control?

Reducing mosquitoes to lower disease risk.

What is rodent reduction?

Reducing rats in communities to lower disease exposure.

What is isolation?

Keeping sick (symptomatic) individuals away from others.

What is quarantine?

Keeping exposed individuals away from others.

What are screenings used for?

Early identification, preventing worsening symptoms, and aiding contact tracing.

What are immunizations?

Stimulate immune system to produce antibodies against pathogens.

What is a live attenuated vaccine?

A weakened version of a pathogen.

What is an inactivated vaccine?

A killed pathogen.

What is a subunit or recombinant vaccine?

A vaccine containing only parts of a pathogen.

What is a toxoid vaccine?

A vaccine made from inactivated toxins produced by pathogens.

What is an mRNA vaccine?

A vaccine using RNA instructions to trigger an immune response.

What are pros and cons of vaccines?

Herd immunity, boosters needed, variable effectiveness, ongoing R&D, distribution challenges.

What are public health immunization goals?

Maintain elimination of diseases, increase vaccination rates, improve lifetime vaccine tracking.

What are personal public health tools?

Handwashing, PPE, voluntary isolation, immune system care, healthy lifestyle.

What is misinformation?

Misleading information spread without harmful intent.

What is disinformation?

False information spread intentionally to cause harm or discourage healthy behavior.

What are "infodemics"?

Information overload or voids that spread confusion and misinformation.

How does mis/disinformation affect health?

Increases disease rates and reduces protective behaviors.

How can misinformation be reduced?

Use reputable sources, prepare early, share accurate info, use community resources, time messages well.