Comprehensive Infectious Disease and Public Health Concepts for Students

Herd Immunity

The protection of unvaccinated individuals in a population when a sufficient number of people are immunized against a disease, slowing or stopping its spread.

Zoonotic Disease (Zoonosis)

An infectious disease that can be transmitted between humans and animals, such as rabies, salmonella, or COVID-19.

MMWR (Morbidity and Mortality Weekly Report)

The CDC's flagship publication that provides rapid, peer-reviewed dissemination of surveillance data, outbreak investigations, public health recommendations, and ACIP vaccine updates.

Infectious Period

The time during which an infected person can spread the disease to others.

Reservoir (or Reservoir Host)

A place or organism where a pathogen lives and multiplies before infecting a susceptible person. Contaminated water or food may serve as a reservoir.

Vaccine Hesitancy

Reluctance or refusal to be vaccinated, contributing to the re-emergence of diseases like measles.

Vector-borne Disease

A disease transmitted by the bite of an arthropod (e.g., flea or mosquito) or arachnid (e.g., tick), such as malaria, yellow fever, dengue, Zika, West Nile, or chikungunya.

Secondary Prevention

Testing and screening to detect an illness early, when the condition is already present in the population, to prevent progression.

Influenza (Flu)

An infectious disease caused by a virus that mutates frequently, causing new strains to spread worldwide regularly. Vaccines are effective but must be updated each year.

Climate Change

Associated with the re-emergence of vector-borne, food-borne, water-borne, and zoonotic diseases.

Incidence Rate

The number of new cases of a disease in a specified time period divided by the number of individuals at risk for the condition.

Mosquitoes

Vectors responsible for spreading diseases such as malaria, yellow fever, dengue, Zika, West Nile, and chikungunya.

Antibiotic Resistance

The ability of bacteria to evolve and survive despite the presence of antibiotics, making infections harder to treat.

Incubation Period

The time from when someone is infected to when symptoms first appear.

Chain of Infection

The sequence of events that allows a disease to spread; public health measures aim to interrupt this chain at its most vulnerable points.

Spillover Event

When a zoonotic disease jumps from animals to humans.

Reemerging Disease

A disease that, after a significant decline, reappears as a public health threat.

Outbreak

A sudden increase in the incidence of a disease. (Larger-scale increases may be called an epidemic.)

DOT (Directly Observed Therapy)

A program in which a trained healthcare worker or designated individual provides prescribed medications and watches the patient swallow every dose, often used for tuberculosis treatment.

Aerosol Transmission

The suspension of liquid or solid particles in the air, which can carry pathogens that cause respiratory infections when inhaled.

Primary Prevention

Actions taken to prevent a disease or injury before it occurs. Examples include vaccination programs, mosquito control techniques, handwashing, health education, and laws banning hazardous products.

Secondary Prevention (definition)

Actions taken to detect and treat disease early, preventing progression. Examples include screening tests, regular checkups, and early treatment interventions.

Tertiary Prevention

Actions taken to reduce complications or severity of an existing disease and improve quality of life. Examples include rehabilitation, disease management programs, and long-term treatment to prevent disability.

17. Fifty patrons ate green salad with diced tomatoes at a restaurant party on June 1st. One June 16th, 15 attendees developed vomiting and diarrhea; by June 30, 13 more developed fatigue, dark urine, and jaundice. When investigated, diagnostic tests revealed that the 28 individuals who became sick all were positive for the hepatitis A virus (HAV). From the scenario presented, which option best describes the incubation period of HAV (most consistent with infection acquired at the June 1 meal)?

11-15 DAYS AFTER THE MEAL

18. A 10-year-old with measles attended school on Monday. Their rash began Thursday. The health department advises exclusion of exposed students and wants to know when the child was most infectious around the rash.

Which window best represents the measles infectious period relevant to exposure at school?

4 days before rash onset through 4 days after rash onset

After some flooding, a coastal town reports a surge of acute watery diarrhea. Testing confirms the presence of the Vibrio cholerae bacteria in patient stools and in a municipal well. It's determined that the well became contaminated when latrines overflowed. Cases cluster (cluster = an aggregation of cases grouped in place and time that are suspected to be greater than the number expected) among households drawing from that well; households using sealed bottled water are spared.

Which option correctly maps the epidemiological triangle in the presented scenario?

agent: vibrio cholerae, host: residents consuming well water, environment: flooding, latrine overflow, contaminated municipal well

Some microbes become drug resistant, but this has no effect on public health.

False

Pneumonia, tuberculosis, gonorrhea, syphilis and gonorrhea have reemerged in drug-resistant form.

true

When a zoonotic disease jumps from animals to humans, it is a _______ event.

spillover

A _______ disease is one that is transmitted by the bite of an arthropod, such as a flea or mosquito, or an arachnid, such as a spider or tick.

vector- borne

Zoonoses involve host, host animal, pathogen, and mode of transmission.

true

Which of the following represent the causes of antibiotic resistance?

All of the above describe causes of antibiotic resistance.

As humans destroy natural habitats, spillover events become more likely.

true

Public health as a field emerged with sanitation reforms, vaccination campaigns, and surveillance systems to combat infectious diseases like cholera and smallpox.

true

Communicable diseases are similar to Noncommunicable diseases in that one person's infection does not become another's risk.

false

Antibiotics and vaccines give us tools, but pathogens can evolve, increasing human vulnerability.

true

Includes vaccination programs, mosquito control, laws banning hazardous products.

true

Vaccines not only protect individuals but also protect the community.

true

Bats and mosquitoes do not spread disease

false

Climate change associated with emergence/reemergence of vector-, food-, water-, and zoonotic diseases.

true

Outbreak of contagious disease anywhere is a threat everywhere.

true

A zoonotic disease cannot be eliminated due to animal reservoirs.

true

The time from when something gets infected to when symptoms start is called the: 

incubation period

The time during which the infected person can spread the disease and infect others is called:

infectious Period

A county health department is building a cervical-cancer control plan tied to HPV. Which action below is the best representation of secondary prevention strategies?

pap/HPV co-testing every 5 years for women aged 30-65

Which option correctly lists primary → secondary → tertiary prevention measures (in that order) to reduce hepatitis B burden?

universal HepB vaccination for healthcare workers and newborns → HBsAg screening of pregnant patients and blood donors → Antiviral therapy and long-term monitoring for chronic HBV

A city sees a measles spike centered on one middle school. Most cases are among unvaccinated students; classrooms are crowded with poor ventilation.

agent: measles virus, host: unvaccinated students, environment: crowded and poorly ventilated classroms

Within the Chain of Infection, the habitat or source in which the agent normally lives, grows, and multiplies (e.g., humans, animals, water, soil) is called the __________

reservoir

A state epidemiology team is tracking a multistate Salmonella outbreak and needs timely, authoritative guidance to inform alerts to clinicians and food-safety partners. Which statement best describes the role of the MMWR (Morbidity and Mortality Weekly Report) in this context?

it is CDC's primary vehicle for rapid, peer-reviewed dissemination of surveillance data, outbreak investigations, and public-health recommendations (including ACIP vaccine updates), enabling timely action across jurisdictions.