Communicable Diseases

History- Know the following and their contributions

Leeuwenhoek

He was the first to observe and describe single celled organisms which we now refer to as microorganisms

He was also the first to record microscopic observations of muscle fibers, bacteria, spermatozoa and blood flow in capillaries (small blood vessels)

Father of Microbiology

Jenner

Developed Smallpox Vaccine which has irradicated smallpox

Highly contagious often fatal- caused by Pox Virus – Blisters, Pustules

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'Father of Immunology’

Pasteur

He created the first vaccine for rabies and anthrax.

He was best known to the general public for inventing a method to stop milk and wine from causing sickness, a process that came to be called pasteurization.

Koch

A Prussian Physician • He is considered one of the founders of microbiology

• He was awarded the Nobel Prize in Physiology or Medicine for his tuberculosis findings in 1905.

•He became famous for isolating Bacillus anthracis

Lister

Lister was a British surgeon and a pioneer of antiseptic surgery, who promoted the idea of sterile surgery. Lister successfully introduced carbolic acid to sterilize surgical instruments and to clean wounds

Father of Modern Antiseptic Surgery

Salk

Best known for his discovery and development of the first safe and effective polio vaccine. (1955)

Vaccine killed Polio Virus of 3 types

Sabin

Developed Oral Polio Vaccine In 1957-1959 first tested outside of US

Chain of Infection

Methods of Spreading Infection

1. Contact 1. Direct Contact – Person to person2. Indirect Contact – Person to object to

person.

2. Droplet – Carry in air, three feet3. Airborne – Remain suspended in air

Spreading of Infection

Vehicle Mode of transmission of a microorganism

from one reservoir to susceptible host

VECTOR Insect, rodent, mosquito that transmit disease

FOMITE An object that transmits pathogens

List methods of controlling Infections:Breaking the chain of infection

Hand wash Use of PPE Use of correct isolation precautions Wearing no jewelry Wearing hospital scrubs

Immunization Antiseptics – Disinfectant - Sterilization

List 5 typical Microorganisms

Describe each and name at least two diseases caused by each

Bacteria Classified according to shape

Cocci Bacilla Spirilla

Diphtheria Pertussis Lyme Disease

Virus Virus

Can only be seen with electron microscope

Must live in another living cell to survive Measles Mumps Cold Hepatitis HIV

Rickettsia

Typhus Rocky Mount Spot Fever

Protozoa

Malaria Mosquito born disease caused by a

parasite Symptoms include:

Fever Chills Flu-like illness

Helminth

Worm Types include:

Flukes Tapeworms Roundworms

Fungi

Ringworm Thrush Yeast

Antiseptic Any agent that retards growth of

microorganisms

Disinfectant

Destroys microorganisms Process of destroying microorganism

by chemical means

Types of Disinfection

Concurrent disinfection Daily handling and disposing of

contaminated material or equipment

Terminal disinfection Cleansing of equipment and rooms when

patient is discharged

Communicable Disease Progression Communicable period

Time span when disease is contagious Incubation period

Time between exposure to a disease and the appearance of symptoms

Prodrome / Prodromal In medicine, a prodrome is an early symptom (or set

of symptoms) that might indicate the start of a disease before specific symptoms occur

Terms

ResistanceAbility to fight off a disease

CarrierPerson who harbors germs, transmits germs to others while not showing signs/symptoms

HostAn organism (may be himan) from which another obtains nourishment

Terms Parasite

Organism that lives in or on another at their expense

Pathogen An organism capable of causing disease

Virulent Strength of an organism to cause disease

Epidemiology

Epidemiology is the study of patterns of health and illness and associated factors at the population level. It is the cornerstone method of public health research, and helps inform evidence-based medicine for identifying risk factors for disease and determining optimal treatment

Types of “demics” Endemic

Usual number of cases of a disease in an area (expected)

Epidemic Occurrence of a large number of cases of a

disease in an area at a time (sudden unexpected)

Pandemic World wide high incidence of a communicable

disease

Mortality Rate Mortality rate is a measure of the

number of deaths in some population Mortality rate is typically expressed in

units of deaths per 1000 individuals per year; thus, a mortality rate of 9.5 in a population of 100,000 would mean 950 deaths per year in that entire population

Morbidity Rate

Morbidity rate, which refers to the number of individuals in poor health during a given time period or the number of newly appearing cases of the disease

Disease rate or number of cases of a specific disease

Terms Antigen

Foreign substance that invades body and stimulates immune response

Antibody Immune substance produced in the body in

response to specific antigen

Immunity When antigen enters body, specific antibody

neutralizes invading antigen

Types of Immunity Active

Natural-catching a cold Artificial-vaccine

Passive Natural-antibodies cross the placenta to

the fetus Passive-antibodies are injected into a

person (gamma globulins)

Gamma Globulin

Gammaglobulin is a type of protein found in the blood.

When gammaglobulins are extracted from the blood of many people and combined, they can be used to prevent or treat infections.

Toxin

A poisonous substance, especially a protein, that is produced by living cells or organisms and is capable of causing disease when introduced into the body tissues but is often also capable of inducing neutralizing antibodies or antitoxins.

Anti-toxin

An antitoxin is an antibody with the ability to neutralize a specific toxin. Antitoxins are produced by certain animals, plants, and bacteria. Although they are most effective in neutralizing toxins, they can kill bacteria and other microorganisms.

Types of Vaccines

Live-attenuated Inactivated Subunit Toxoid Conjugate DNA Recombinant vector

Live-attenuated Vaccine Weakened (attenuated) or killed antigen

developed to create immunity to a certain disease

A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe or its toxins.

Weakened, diluted, thinned, reduced, diminished.

An attenuated virus is a weakened, less vigorous virus.

Toxoid Vaccine

Toxoid a bacterial toxin whose toxicity has been

weakened or suppressed either by chemical or heat treatment

Toxoids are used in vaccines to produce immunity-secretes a toxin that is the main cause of the illness

Tetnus toxoid

Inactivated Vaccine

The disease is killed in this vaccine These vaccines are more stable and

safer than live vaccines The dead microbes cannot mutate

back to their disease producing state Easily stored and transportable Stimulate a weaker immune response

than live vaccines

Subunit Vaccines

Include only the antigens that best stimulate the immune system

Chemists grow the microbe in a lab, break it apart and only gather the antigens that are important

Example:Hepatitis B vaccine

Conjugate Vaccines If a bacterium possesses an outer coating of

sugar molecules called polysaccharides, as many harmful bacteria do, researchers may try making a conjugate vaccine for it.

Polysaccharide coatings disguise a bacterium’s antigens so that the immature immune systems of infants and younger children can’t recognize or respond to them.

Conjugate vaccines, a special type of subunit vaccine, get around this problem

DNA Vaccines Still in experimental stages Once the genes from a microbe have been analyzed,

scientists could attempt to create a DNA vaccine against it.

Researchers have found that when the genes for a microbe’s antigens are introduced into the body, some cells will take up that DNA. The DNA then instructs those cells to make the antigen

molecules. The cells secrete the antigens and display them on their surfaces. In other words, the body’s own cells become vaccine-making factories, creating the antigens necessary to stimulate the immune system.

Recombinant Vector Vaccines

Recombinant vector vaccines are experimental vaccines similar to DNA vaccines, but they use an attenuated virus or bacterium to introduce microbial DNA to cells of the body. “Vector” refers to the virus or bacterium used as the carrier.

Macule

Flat red Freckles

Papule

Papule a circumscribed, solid elevation of skin

with no visible fluid, varying in size from a pinhead to 1 cm.

They can be either brown, purple, pink or red in color.

The papules may open when scratched and become infected and crusty.

Vesicle

A vesicle and be visualized as a bubble of liquid

Fluid filled papule

Pustule

Elevated Pus filled

Types of Tests Dick Test

A skin test formerly used for determining susceptibility or immunity to scarlet fever

Inject toxin of Beta Hemolytic Streptococcus The Dick test is named after George Dick and Gladys Dick, American

bacteriologists who worked on the diagnosis and treatment of scarlet fever in the 1920s.

The Dick test involves administering two different injections, one into each arm of a patient.

In one arm, toxin (poison) taken from a culture of scarlet fever bacteria is injected.

In the other arm, neutralized toxin is injected to act as a control (a standard of comparison).

If the toxin causes redness, tenderness and swelling after 24 hours, the person is not immune to scarlet fever. The control normally shows no swelling for comparison.

Types of Tests

Schick test invented between 1910 and 1911 is a

test used to determine whether or not a person is susceptible to diphtheria.

Inject dilute diphtheria toxin A small amount of diphtheria toxin is injected into the skin; the

injection will produce an area of redness and swelling in individuals with low levels of antibody (i.e., little immunity) against the toxin.

If the individual is immune to diphtheria, the antibody in the system will neutralize the toxin and no skin reaction will occur.

Types of Tests

Mantoux test (also known as the Mantoux screening

test, Tuberculin Sensitivity Test, Pirquet test, or PPD test for Purified Protein Derivative) is a diagnostic tool for tuberculosis.