Openstax Microbiology Chapter 16

World Health Organization

A specialized agency of the United Nations (UN) that is concerned with international public health

Center for Disease Control

The United States contribution to (WHO)

Protects US public health.

emerging infectious disease

New to human population or has shown an increase in prevalence in thee last 20 years.

reemerging infectious disease

A disease that's increasing in frequency after a previous period of decline.

Biological Vector

Carries pathogen from one host to another after becoming infected itself.

Usually Insects

Mechanical Vector

An animal that carries a pathogen on its body from one host to another, not as an infection.

Vehicle Transmission

Transmission of pathogens through vehicles such as water, food, air.

indirect contact transmission

Involves inanimate objects called foaminess that become contaminated by pathogens from an infected individual or reservoir.

direct contact transmission

person to person transmission

intermediate host

It is that host that harbors the non-sexual (reproductively/sexually immature) phases of the parasite.

Definitive Host

It is that host that harbors the sexually active phases of the parasite.

asymptomatic carrier

Active carriers who do not present signs or symptoms despite infection.

Active Carrier

An infected individual who can transmit the disease to others.

Passive Carrier

Contaminated with the pathogen and can mechanically transfer to another host.

Carrier not infected!

Carrier

An individual capable of transmitting a pathogen without displaying symptoms.

Reservoirs

Where pathogens normally reside to persist over long periods of time.

Can be living or nonliving.

Continuous common source spread

the infection occurs for an extended period of time

Intermittent source spread

infections occur for a period, stop, and then begin again.

Point source spread

common source operates for a time period shorter than the incubation period of the disease

Propagated spread

occurs through direct or indirect person-to-person contact

no single source for infection.

Common Source spread

Infectious disease in which there is a single source for all thee individuals infected.

Pandemic Disease

epidemic disease that occurs worldwide

Epidemic Disease

disease acquired by many people in a given area in a short time

Endemic Disease

disease constantly present at a low level in a population in a given area.

Sporadic Disease

disease that occurs occasionally in a population, usually without graphic concentration

Incidence

the number or proportion of new cases in a period of time.

Prevalence

The number or proportion of cases of a particular illness in a population at a given time.

Mortality

death

Morbidity

state of being diseased; You look like death.

Etiology

The study of causes of disease

Epidemiology

Branch of medical science concerned with the incidence, distribution, and control of diseases that affect large numbers of people.

Robert Koch

developed four criteria known as Koch's postulates, which had to be met in order to positively link a disease with a pathogenic microbe.

John Snow

known as the father of epidemiology

Florence Nightingale (1820-1910)

Considered the founder of organized, professional nursing.

--She is best known for her contributions to the reforms in the British Army Medical Corps, improved sanitation in India, improved public health in Great Britain, use of statistics to document health outcomes, and the development of organized training for nurses.

Joseph Lister

Began using disinfectants and antiseptics during surgery

descriptive epidemiology

The aspect of epidemiology concerned with organizing and summarizing health-related data according to time, place, and person

analytical epidemiology

analyzes a particular disease to determine its probable cause

observational study

observes individuals and measures variables of interest but does not attempt to influence the responses

retrospective studies

A study that monitors people who have been exposed to an environmental hazard at some time in the past.

cohort studies

the study of a group of people who share a common characteristic and move forward in time as a unit

experimental epidemiology

begins with a hypothesis about a particular disease; experiments to test the hypothesis are then conducted with a group of people

reservoirs

a large natural or artificial lake used as a source of water supply.

dormancy

A period when an organism's growth or activity stops

Carrier

A person capable of transmitting a pathogen without displaying symptoms.

Name 2 non-living reservoirs.

-soil

-water in environment

passive carrier

persons who mechanically transfer a pathogen without ever being infected by it

active carrier

an infected individual capable of transmitting disease during and after clinical disease

incubation period

active carriers may transmit the disease before they show sign and symptoms

asymptomatic carriers

infected but show no symptoms of disease

zoonotic disease

a disease communicable from animals to humans under natural conditions; also know as zoonosis

definitive host

the host in which the sexual reproduction of a parasite takes place

contact transmission

Transmission of an infectious agent by direct contact of the source or its reservoir with the host.

direct contact transmission

person to person transmission

vertical direct transmission

-Pathogens transmitted from woman to her fetus during pregnancy or

Woman to infant during birth or breastfeeding

horizontal direct contact transmission

- not mother to child

- mucous membrane to mucous membrane

Droplet transmission of disease

transmission via airborne droplets

indirect contact transmission

spreads to a host by a nonliving object called a fomite

vehicle transmission

transmission by an inanimate reservoir (food, water, air)

mechanical transmission

the passive transport of the pathogens on the insects feet or other body parts without the insect being infected

biological transmission

pathogen reproduces in the vector; transmitted via bites or feces

Name 6 biological vectors.

mosquitos

ticks

birds

lice

chickens

mites

quarantine

strict isolation imposed to prevent the spread of disease

What is the purpose of the WHO agency?

Monitoring and reporting on infectious diseases, and develops and implements strategies for their control and prevention.

emerging infectious diseases

Diseases that are new, increasing in incidence, or showing a potential to increase in the near future

reemerging infectious diseases

known diseases that have reappeared after a significant decline in incidence