epidemiology

Epidemiology

The study of diseases in populations and the factors that influence the frequency and distribution of diseases.

What is prevalence in epidemiology?

The total number of individuals in a population who have a disease or health condition at a specific time, usually expressed as a percentage of the population.

What is incidence in epidemiology?

The number of new cases of a specific disease or health-related event during a particular time period.

What is the mortality rate?

The number or percentage of deaths in a given population.

What does morbidity rate refer to?

The number or percentage of people who experience complications or illness from a disease.

What is an outbreak?

The occurrence of cases of a disease in excess of what is normally expected in a defined community, geographical area, or season.

What is an epidemic?

A sudden increase in the number of cases of a specific disease beyond what is normally expected.

What does endemic mean in epidemiology?

The usual occurrence of a disease in a specific geographical area.

What is a pandemic?

A disease that is widespread across multiple continents.

What is a common source epidemic?

An epidemic arising from a single contaminated site, e.g., cholera.

What is a host-to-host epidemic?

Spread from infected individuals to uninfected individuals, with multiple new sources created.

What is herd immunity?

The resistance to the spread of a contagious disease when a high proportion of the population is immune.

What is the epidemic threshold?

The minimum proportion of a population that must be immune to a specific pathogen to prevent an epidemic.

What are the three types of influenza viruses?

Types A, B, and C, with Influenza A causing the most severe illness.

What are hemagglutinin (H) and neuraminidase (N) in influenza?

H assists in attachment and adherence, while N allows the virus to leave the host cell.

What is antigenic drift in influenza?

Minor genetic changes due to random mutations, leading to small variations in the virus.

What is antigenic shift in influenza?

Major changes due to recombination of gene segments from different viral strains, creating new strains.

What is a case definition?

A list of common symptoms for a particular medical condition that helps identify if unusual cases are related.

What is a case-control study in epidemiology?

A study that determines what factors link affected individuals and distinguishes them from uninfected individuals.

What is the difference between emerging and re-emerging diseases?

Emerging diseases are new or changing, while re-emerging diseases are previously controlled but now causing serious problems.

How is Zika virus transmitted?

Primarily through infected mosquitoes, and also via vertical and sexual transmission.

What are key features of Ebola virus outbreaks?

Causes hemorrhagic fever with high mortality, transmitted through contact with infected individuals or materials.

How was polio historically transmitted and controlled?

Transmitted via the fecal-oral route and controlled through widespread vaccination.