CPH- Epidemiology

Epidemiology

· Is the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems.

upon

Epi-

the people

Domos

the study of

Ology

the study of epidemics

Epidemiology=

The ultimate goal is to use this  knowledge to CONTROL and PREVENT  the spread of disease.

GOAL OF EPIDEMIOLOGY

Hippocrates

he is known as the father of medicine, and was the first epidemiologist

• Blood (Sanguine, Live)

• Phlegm (Phlegmatic, lungs)

• Yellow Bile (Choleric, gallbladder

• Black Bile (Melancholic, Spleen)

· 4 Humor

IDA- Iron Deficiency Anemia

· low in iron

· Iron Overload/ Hemochromatosis

Too much iron can cause

John Graunt

· Published a landmark analysis of mortality data in 1662.

· Father of Demography

On the Bills of Mortality

· is a list of deaths in London in 70^th year period (Black Death)

James Lind (1700)

· Designed first experiments to use concurrently treated control group

· He discovered the treatment for scurvy.

Scurvy

Severe Vitamin C deficiency

• Swollen bleeding gums

• Jaundice

• Hemorrhage

• Severe Stage (death)

· Signs and symptoms of Scurvy

Edward Jenner

· Pioneered clinical trials for Vaccination to control spread of smallpox

• Variola

• Varicella zoster virus

• IgG

• Smallpox-

• Chickenpox-

· Immunization and immunity

. Primary Immunity

• IgM (Malaki, Mauuna, Malamig)

• Lag- longer

• Pentametric Structure

· Secondary Immunity/ Anamnestic

• ____ (warm)- only anti- body that can cross placenta

• Lag- shorter

. Lag Log Plateau Decline

William Farr (1800)

• Given the task for medical statistics in London and Wales

• The father of modern vital statistics and surveillance, developed many of the basic practices used today in vital statistics and disease classification.

• one of the founder of Statistics

Ignaz Semmelweis(1840)

• Puerperal fever/ childbed fever (Beta hemolytic streptococcus)

• Pioneered hand washing to help prevent the spread of septic infections in mothers following birth

• Father of Handwashing

• Discovered the cause of ____________, a bacterial infection on the upper congenital track (causative agent: ___)

Dr. Jhon Snow

• Used non medical means to discover cholera outbreak in 1854

• Father of field Epidemiology

Miasma; miasmata

was considered to be a poisonous vapor or mist filled with particles from decomposed matter (________) that caused illnesses

Miasma

Poisonous Magical vapor from swamps 

Mary Mallon

• Salmonella typhi

• A cook responsible for most famous outbreak of carrier-borne disease in medical history

• Cause the outbreak of Typhoid fever (___________)

  From ingestion of contaminated food and drinks  

Epidemiologist

· Is a public health scientist, who is responsible for carrying out all useful and effective activities needed for successful epidemiology practice

· ______ are public health professionals who investigate patterns and causes of disease and injury in humans.

· Megaloblastic anemia

- deficiency in Vitamin B12 and folic acid

Diphyllobothrium latum

- fish tape worm, from ingestion of uncooked fish

• Taenia solium

• Taenia saginata

• ___________- pork tapeworm

• ___________- beef tapeworm

alcohol

Taenia are sensitive in _____

• Descriptive Epidemiology

• Analytic Epidemiology

two broad types of epidemiology

Descriptive Epidemiolgy

· examining the distribution of disease in a population, and observing the basic features of its distribution

Analytic Epidemiology

· investigating a hypothesis about the cause of disease by studying how exposures relate to disease

• Person

• Place

• Time

3 ESSENTIAL CHARACTERISTICS OF DISEASE THAT WE LOOK FOR IN DESCRIPTIVE STUDIES

• Syphilis

• Malaria

• Hepa C

• Hepa B

• HIV

· 5 TTI- Transfusion Transmitted Infections (Philippines)

Streptococcus agalactiae

Neonates=

Haemophilus influenzae

Children=

Neisseria meningitidis

Adolescence=

Streptococcus pneumoniae

Geriatric=

Listeria monocytogenes

Immunocompromised=

• Agent

• Host

• Environment

3 ESSENTIAL CHARACTERISTICS OF DISEASE THAT WE LOOK FOR IN ANALYTIC EPIDEMIOLOGY

Agent

· originally referred to an infectious microorganism or pathogen.

· Causes disease

Host

· refers to the human who can get the disease.

· The person itself

 

Environment

· refers to extrinsic factors that affect the agent and the opportunity for exposure.

Ex: poor sanitation in community

Portal of Entry

· refers to the manner in which a pathogen enters a susceptible host.

· Inhalation, absorption by mucus membrane, inoculation, ingestion, skin penetration

Host

· The final link in the chain of infection is a susceptible host.

o Susceptibility of a host depends on genetic or constitutional factors, specific immunity, and nonspecific factors that affect an individual's ability to resist infection or to limit pathogenicity.

 

Modes of Transmission

· An infectious agent may be transmitted from its natural reservoir to a susceptible host in different ways.

• Direct transmission

• Indirect Transmission

• Airborne

Different Classification of modes of transmission

Direct Transmission

· immediate transfer of infectious agent a receptive portal of entry

. Handshaking, physical contact, kissing, sexual contact

1. Vehicle borne

2. Vector borne

3. Mechanical Vector

4. Biological Vector

Indirect Transmission:

Vehicle borne

contaminated inanimate objects or materials

Vector borne

from other living organism (ex. Insects)

• Gametocyte

• Sporozoites

a) Biological vector

• _________ (mosquito bite) person to mosquito

• __________- mosquito to human

Airborne

· dissemination of microbial aerosols to a suitable portal of entry usually the respiratory tract

Droplet nuclei

-usually small residues which result from evaporation of fluid from droplets emitted by an infected host

Droplet nuclei, Dust

Airborne types:

RESERVOIR OF AN INFECTIOUS AGENT

· is the habitat in which the agent normally lives, grows, and multiplies.

• Human reservoirs

• Animal reservoirs

• Environmental reservoirs

Portal of Exit

· is the path by which a pathogen leaves its host.

· Secretion, skin lesion, transplacental

• Sporadic

• Endemic

• Hyperendemic

• Epidemic

• Outbreak

• Cluster

• Pandemic

Epidemic Disease Occurrence

Sporadic

· refers to a disease that occurs infrequently and irregularly.

· Ex: Uncommon; tetanus, rabies

Endemic

-refers to the constant presence and/or usual prevalence of a disease or infectious agent in a population within a geographic area

Hyperendemic

· refers to persistent, high levels of disease occurrence.

 

Epidemic

· refers to an increase, often sudden, in the number of cases of a disease above what is normally expected in that population in that area.

· Ex: smallpox, black death, HIV

 

Outbreak

· carries the same definition of epidemic, but is often used for a more limited geographic area.

· Ex: One area (kindergarten students were absent because of diarrhea)

Cluster

-refers to an aggregation of cases grouped in place and time that are suspected to be greater than the number expected, even though the expected number may not be known.

 

Pandemic

· refers to an epidemic that has spread over several countries or continents, usually affecting a large number of people.

· Ex: COVID-19