Ch 35: Epidemiology and Public Health Microbiology

Who was the first to view microorganisms in a microscope?

Antonie van Leeuwenhoek

Who developed the first vaccine against smallpox?

Edward Jenner

Who created postulates that helped establish a relationship between microorganisms and disease?

Robert Koch

Who fully disproved spontaneous generation with Swan-Neck experiment; developed pasteurization?

Louis Pasteur

Who introduced antiseptic techniques in surgery to reduce infections?

Joseph Lister

Who is the Father of Epidemiology and solved cholera outbreak in London?

John Snow

What is the term for a disease that is consistently present at a baseline level in a specific geographic area?

Endemic

What do we call an epidemic that spreads across multiple countries or continents?

Pandemic

What is a widespread outbreak of a disease affecting many individuals in a community or region?

Epidemic

What term describes a sudden increase in the number of disease cases in a limited area?

Outbreak

What is the term for the rate of death caused by a disease within a population?

Mortality

What is the term for the condition of being diseased or the rate of illness in a population?

Morbidity

Why are more deaths in the U.S. increasingly attributed to cancers and metabolic syndromes?

Advances in medical diagnostics allow earlier and more accurate detection of these diseases, and longer life expectancy with more sedentary lifestyles leads to increased metabolic disease.

How do infectious and communicable diseases differ?

Infectious diseases are caused by microorganisms, while communicable diseases are a type of infectious disease that can be transmitted from person to person.

How are communicable diseases different from other infectious diseases?

Communicable diseases can be transmitted from person to person, while other infectious diseases, like tetanus, cannot spread between individuals.

How does a common-source epidemic spread?

It spreads when many individuals are exposed to the same contaminated source, such as tainted food or water, leading to a rapid rise in cases.

How does a propagated epidemic spread?

It spreads through person-to-person transmission, typically showing a slower, more gradual increase in cases over time.

How do changes in vaccination rates affect the herd immunity threshold?

Higher vaccination rates increase population immunity and raise the herd immunity threshold needed to prevent disease spread.

How does the emergence of more contagious variants impact herd immunity?

Increase the reproduction number (R0), raising the herd immunity threshold.

What role does natural immunity from previous infections play in herd immunity?

Contributes to overall immunity and can alter the herd immunity threshold.

How can population density and social behavior influence herd immunity?

Increase transmission risk, affecting the herd immunity threshold.

What are nosocomial infections?

Infections acquired in a hospital or clinical care facility, affecting 5 to 10% of patients.

What factors contribute to nosocomial infections?

Presence of normal microbiota and antibiotic-resistant pathogens.

What does the acronym ESKAPE stand for in the context of nosocomial pathogens?

Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.

Which nosocomial infection is the most common?

Urinary Tract Infection (UTI).

What is the second most common nosocomial infection?

Surgical Site Infection.

Which nosocomial infection ranks third in frequency?

Pneumonia.

Which nosocomial infection is the least common?

Bloodstream Infection.

What are the main types of vaccines?

Whole-pathogen vaccines, acellular or subunit vaccines, and recombinant/DNA/RNA vaccines.

What role do adjuvants play in vaccines?

Nontoxic materials added to vaccines to enhance the immune response.

What are examples of common adjuvants used in vaccines?

Oil-in-water emulsions, aluminum hydroxide salts, and beeswax.

At what age should vaccination of children typically begin?

Around 2 months of age.

What factors influence the need for further vaccinations after childhood?

Risk factors such as living in close communities, reduced immunity, international travel, and health-care work.

What is the advantage of live attenuated vaccines?

They provide strong, long-lasting immunity.

What is a key disadvantage of live attenuated vaccines?

They pose a risk for immunocompromised individuals.

What is an advantage of recombinant vaccines?

Rapid development and strong immunity.

What is a disadvantage of recombinant vaccines?

Risk of disrupting genomic DNA due to genetic manipulation.

What advantage do subunit vaccines have?

They cause fewer side effects.

What disadvantage do subunit vaccines commonly have?

They often require booster shots.

What advantage do inactivated vaccines provide?

They are safer for immunocompromised individuals.

What disadvantage is associated with inactivated vaccines?

They often require boosters to maintain immunity.

What does a live attenuated vaccine contain?

Weakened but live pathogens.

What does an inactivated vaccine contain?

Killed pathogens.

What does a subunit vaccine contain?

Purified antigenic parts of the pathogen.

How do mRNA vaccines work?

They use messenger RNA to instruct host cells to produce the antigen.

What is a DNA vaccine?

DNA directly introduced into host cells; pathogen DNA is expressed to trigger immune response.

Which COVID-19 vaccines use DNA delivered by adenovirus vectors?

Johnson & Johnson and AstraZeneca

What are some challenges for mRNA vaccines?

Producing mature mRNA, avoiding detrimental innate immune activation, and delivering mRNA effectively.

What diseases can mRNA vaccines be used for?

Bacterial, eukaryotic, viral diseases, and cancer.

What is bioterrorism?

The intentional or threatened use of viruses, bacteria, fungi, or toxins to cause death or disease in humans, animals, or plants.

Name some historical bioterrorism tactics used before modern times.

Infecting wells with ergots, dipping arrows in decomposing bodies, and throwing infected bodies over city walls.

What type of biological agents are often used in bioterrorism?

Bacterial spores.

What are some diseases commonly associated with bioterrorism?

Anthrax, Botulism, Smallpox, Plague, Cholera, Hemorrhagic fever.