45 Questions
What is the difference between prevalence and incidence?
Prevalence measures the total number of cases at any time in a given population, while incidence measures the number of new cases occurring over a specific period in a given population.
What does case-fatality rate measure?
The percentage of the population that dies from a specific disease.
What distinguishes common/single-source epidemics from propagated epidemics?
Common/single-source epidemics result from exposure to a single source of the pathogen, while propagated epidemics suggest contagious disease spreading in the population.
What characterizes a pandemic?
A global outbreak
What is the role of gut microbiota in food digestion?
Breaking down complex carbohydrates resistant to human digestive enzymes
How does gut microbiota become colonized and change with age?
Influenced by factors such as mode of delivery and early diet
How does the gut microbiota impact the host immune system?
Stimulating immune maturation through exposure to environmental microbes
What are commensals in the context of gut microbiota?
Permanent residents that neither benefit nor harm the host
What is gene richness in the context of microbiota?
Number of different genes within a microbial community
What is colonization resistance related to gut microbiota?
Ability to exclude invading pathogens and inhibit overgrowth of opportunistic pathogens
How do factors like smoking, antibiotics, and diet alter the microbiota?
Smoking can change the abundance of specific bacterial groups, antibiotics reduce bacterial diversity, and diet influences the relative abundance of major bacterial phyla.
What is dysbiosis associated with?
Imbalance or disruption in the composition of the microbiota. It is associated with various diseases including metabolic disorders, inflammatory bowel diseases, and infections.
Which type of vaccine contains weakened live pathogens?
Attenuated
What is the term for the transfer of genetic material between bacterial cells?
Conjugation
Inactivated vaccines contain which type of pathogens?
Killed pathogens
What do purified antigens (toxoids/subunit vaccines) require to stimulate an immune response effectively?
Adjuvants
What is the term for integrated viral genomes within a bacterium's DNA that can carry virulence factors?
Prophages
What type of immunity prevents infection completely?
Sterilizing immunity
What type of infections persist for a long duration?
Chronic infections
What term is used for large DNA segments in a microbial genome?
Genomic islands
Which type of vaccine is made from specific parts of a pathogen?
Subunit vaccine
Which term describes the ability of a pathogen to cause disease?
Virulence
What is the term for the uptake of external DNA by a bacterial cell?
Transformation
Which type of toxin affects the nervous system?
Neurotoxins
What are the B subunits of AB toxins responsible for?
Binding to host cell receptors
Which bacteria produce toxic shock syndrome toxin-1 causing toxic shock syndrome?
Staphylococcus aureus
What is the cause of 'Scalded Child Syndrome'?
Exfoliative toxins produced by Staphylococcus aureus
What is the main objective of the Human Microbiome Project?
To identify major organisms in the human microbiota and determine associations with disease.
Which factor contributes to tissue damage due to chronic inflammation?
Release of reactive oxygen species and proteolytic enzymes
What is the primary difference between exotoxins and endotoxins?
Exotoxins are released by living bacteria, while endotoxins are lipopolysaccharides present in the outer membrane of Gram-negative bacteria.
What do superantigens do?
Activate a large number of T cells
What is a strategy used by bacteria to avoid host defenses?
Capsule formation
Which organisms are part of the gut microbiota?
Bacteria, viruses, fungi, and archaea
Which bacterial phyla are dominant in the gut microbiota?
Firmicutes and Bacteroidetes
Which type of transmission occurs from pregnant woman to fetus?
Vertical transmission
What distinguishes endemic diseases from outbreaks?
Endemic diseases are constantly present, while outbreaks are sudden increases in disease cases
What is the purpose of contact tracing in epidemiology?
To prevent further spread of contagious diseases by tracking down exposed individuals
What are reservoirs in the context of epidemiology?
Natural habitats where pathogens live
Which type of immunity protects against microbial invasion as a first-line defense?
Innate immune responses
$PRRs$ and $PAMPs$ are crucial components of which type of immunity?
$Innate immunity$
What type of epidemic results from exposure to a single source?
Common-source epidemic
What is the primary purpose of prospective studies in epidemiology?
Predict disease tendencies
What characteristics influence disease epidemiology in the context of pathogens and hosts?
Virulence, immunity, and age
What is the purpose of descriptive studies in epidemiology?
Collect data on outbreak occurrence
What is the primary origin of many emerging human infectious diseases?
Zoonotic origin transmitted from animals to humans
Study Notes
Epidemiology and Disease Emergence
- Endemic diseases are constantly present in a population, while an outbreak is a sudden increase in disease cases over a specific time.
- Reservoirs are natural habitats where pathogens live, and vectors are living organisms that can carry and transmit pathogens.
- Contact tracing aggressively tracks down individuals exposed to a contagious disease to prevent further spread.
- Vertical transmission occurs from pregnant woman to fetus, while horizontal transmission is person-to-person via various means.
- Mechanisms of spread include fomites, droplet transmission, and natural host, transmission host, and terminal host distinctions.
- Prospective, cross-sectional, and retrospective studies predict disease tendencies, identify risk factors, and compare causative events following an outbreak, respectively.
- Pathogen and host characteristics such as virulence, immunity, and age influence disease epidemiology.
- Descriptive studies collect data on outbreak occurrence, analytical studies determine relevant risk factors, and experimental studies study cause and effect.
- Common-source epidemics result from exposure to a single source, while propagated epidemics spread contagiously in the population.
- Many emerging human infectious diseases have a zoonotic origin, transmitted from animals to humans.
- Human, environmental, and microbial factors contribute to the emergence of diseases, which can be classified based on various scenarios.
- Immunity and Vaccines: First-line defenses, innate immune responses, and adaptive immune responses protect against microbial invasion. The immune system distinguishes between self and non-self and activates the complement cascade. Major immune cell subsets and functions, PRRs and PAMPs, and the inflammatory response are crucial in immunity. Adaptive and innate immunity, humoral and cell-mediated immunity, antigens and epitopes, primary and secondary antibody responses, antibody functions, antigen presentation, and principles of active and passive immunity are key concepts.
Test your knowledge about the characteristics and types of vaccines, including attenuated, inactivated, toxoid, recombinant, and subunit vaccines. Explore concepts such as sterilizing immunity and herd immunity.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
