Infectious Diseases and Public Health: Review Flashcards

A comprehensive set of practice questions covering pandemics/epidemics terminology, key pathogens discussed in the lecture ( measles, influenza, pertussis, MRSA, Lyme, cryptosporidiosis, Chlamydia, etc.), vaccine concepts, transmission, prevention, and public health principles.

Define the terms epidemic, pandemic, endemic, outbreak, and sporadic in epidemiology.

Epidemic: a disease outbreak confined to a specific region or population. Pandemic: a disease that has spread worldwide. Endemic: a disease that is continuously present in a region. Outbreak: a cluster of cases occurring in a limited time and place. Sporadic: random, isolated cases with no clear pattern.

What is the causative organism and primary mode of transmission for measles, and how is it prevented?

Causative organism: measles virus. Transmission: respiratory droplets (can survive on surfaces for up to about two hours). Prevention: MMR vaccine; first dose at 12–15 months and a second dose before school.

What are Koplik spots and with which disease are they associated?

Koplik spots are small white-blue spots on the oral mucosa, associated with measles.

Which influenza type causes epidemics and pandemics, and what are its typical hosts and subtypes?

Influenza A causes epidemics and pandemics; it has multiple animal hosts. Subtypes are defined by HA and NA proteins (e.g., H1N1, H5N1).

What are the two key surface proteins of influenza that define subtypes?

Hemagglutinin (HA) and neuraminidase (NA).

What is antigenic shift and why is it important for influenza?

Antigenic shift is a major genetic change in influenza that produces a new strain, often leading to epidemics or pandemics due to immune escape.

What is a trivalent influenza vaccine?

A vaccine formulation that includes two influenza A strains and one influenza B strain.

What is herd immunity and what vaccination rate is described in the notes?

Herd immunity occurs when a large portion of the population is immune (about 75–80%), providing protection to those who are not immune.

What organism causes pertussis and what vaccine is used to prevent it?

Causative organism: Bordetella pertussis. Vaccine: DTaP (Diphtheria, Tetanus, acellular Pertussis).

What does 'acellular pertussis' mean in the context of vaccines?

Acellular pertussis means the vaccine contains only parts of the organism (no whole cells).

How do whole-cell and subunit vaccines differ?

Whole-cell vaccines use the entire organism (killed or inactivated). Subunit vaccines use only specific parts of the organism (e.g., toxoids, proteins) to stimulate immunity.

What is a toxoid vaccine and give an example?

A vaccine made from inactivated bacterial toxins (toxoids) to stimulate immunity; example: diphtheria and tetanus vaccines.

Why are DNA and RNA vaccines discussed, and what is a key difference between them?

DNA vaccines use plasmids encoding an antigen; RNA (mRNA) vaccines deliver mRNA encoding the antigen. mRNA vaccines can be developed rapidly (e.g., for COVID-19) by tweaking the antigen sequence.

What does the term 'two weeks prior' signify for vaccination in caregivers or pregnant individuals?

It takes about two weeks for antibodies to reach protective levels after vaccination.

What is MRSA and why is it clinically important?

MRSA stands for methicillin-resistant Staphylococcus aureus; a common hospital-acquired infection that can cause skin infections, sepsis, and invasive disease.

How is MRSA transmitted and what are key prevention measures?

Transmitted by contact; prevention includes aseptic techniques, isolating infected patients, screening staff, and not sharing personal items.

What is impetigo and which organisms commonly cause it?

Impetigo is a superficial skin infection commonly caused by Staphylococcus aureus or Streptococcus pyogenes.

What is Lyme disease and what is the causative agent?

Lyme disease is caused by the bacterium Borrelia burgdorferi and is transmitted by ticks.

Describe the stages of Lyme disease and typical symptoms.

Stage 1: flu-like symptoms with possible erythema migrans (bull’s-eye rash). Stage 2: joint pain and possible cardiac or neurologic symptoms. Stage 3: chronic symptoms, including arthritis and, rarely, neurologic effects.

What are key Lyme disease prevention measures?

Wear long sleeves and pants, tuck in socks, use insect repellent (DEET), perform tick checks after outdoor exposure, and remove ticks promptly.

What organism and disease are associated with Cryptosporidium parvum, and how is it transmitted?

Protozoan parasite causing cryptosporidiosis; transmitted via ingestion of contaminated water (fecal-oral route) and can also spread via contaminated food or surfaces.

What part of the intestine is affected by Cryptosporidium and what symptom results?

Infects the small intestine crypts; causes watery diarrhea due to malabsorption.

What are oocysts in Cryptosporidium life cycle?

Oocysts are the spore-like infectious form shed in feces, enabling waterborne and environmental transmission.

What is West Nile virus and chikungunya in terms of transmission?

Both are mosquito-borne viruses; West Nile involves birds and mosquitoes as part of the cycle; chikungunya is transmitted by mosquitoes to humans.

What is Chikungunya and what are common prevention strategies?

A mosquito-borne viral disease; symptoms include fever and joint pain; prevention focuses on avoiding mosquito bites (repellents, clothing, eliminating standing water).

What are the four goals of the emerging and reemerging infectious diseases framework established in 1995?

Surveillance; trained personnel; research; prevention and control.

What is the significance of 'emerging' vs 'reemerging' infectious diseases?

Emerging diseases are newly appearing or spreading in new areas; reemerging diseases exist in the past, disappeared, then reappear in new locations or populations.