Communicable Diseases

What is Epidemiology

The study of patterns of disease and health conditions within populations.

• It also studies the patterns causes and how they can be controlled.

• Epidemiologists ask who gets the diseases and why

• Start with a hypothesis and figure out how people get sick

What is Incidence

New cases over time (this is used to identify risks and outbreaks)

What is Prevalence

Existing Cases (used to understand disease burden)

What are Communicable diseases and types

Illnesses caused by viruses or bacteria that people spread to one another through contact with contaminated surfaces, bodily fluids, blood products, insect bites, or the air

• Respiratory viruses

• Sexually Transmitted Infections

• Salmonella

• Vector-borne diseases

What is an endemic

disease or condition regularly found among particular people or in a certain area; enough immunity to prevent epidemic

• Constantly present/baseline level in a population

• Examples:

  • Malaria - sub-Saharan Africa

  • Flu Season

  • TB - high burden countries

What is an epidemic

An increase — often sudden — in the number of cases of a disease above what is normally expected in that population in a specific area

• Sudden increase above what is expected

• Examples: Measles, opiod epidemic, cholera outbreaks

What is a pandemic

epidemic is worldwide in distribution crosses continents

• Examples: Covid

What are the 3 parts of the Epidemiologic triad

• Environment( Where): Housing, Sanitation, climate, access to care

• Agent( What): bacteria, virus, parasite

• Host(Who): age, sex, religion, genetics, occupation

What is a reportable communicable disease

A disease that, when diagnosed, requires health providers (usually by law) to report to state or local public health officials. Notifiable diseases are of public interest by reason of their contagiousness, severity, or frequency.

What are some reportable communicable diseases

• Anthrax

• HIV/AIDS

• Measles

• TB

• Viral Hepatitis (A,B,C)

• STI’s (Chlamydia, syphilis, gonorrhea)

• COVID-19

• West Nile and Zika

• Rabies

• Malaria

• Mpox

What is the chain of infection

a model used to understand how a microorganism or "germ" spreads from one person to another; need to break a chain to stop transmission

• Infectious Agent

• Reservoir

• Portal of Exit

• Mode of Transmission

• Portal of Entry

• Susceptible Host

What are the modes of transportation

Contact: Direct or Indirect

Droplet: Cough, Sneeze, Talking

Airborne: Small particles suspended in air

What is airborn transmission

Transmission occurs via infectious agentsb that can remain suspended in air for long periods of time

• considered a form of indircet transmission

What is direct transmission

Transmission that occurs when an infectious agent is transmitted by dircet contact or droplete spread

• can occurs via skin contact, kissing or sexual inercourse or from soil that habors bacteria

• droplete is considered dircet contact

What is indirect transmission

Transmission occurs when a infectious agent is transmistted via an inamate object

• Vehicle-borne vectors may indircetly tranmit infectious agents, like food, bedding and countertops

• can also be from touching a surface an dthen the face or froma mosquito or tick

What are some ways to break the chain of infection

• Airborne precautions

• Isolation

• PPE

• Vaccines

• Antibiotic stewardship

What is active immunity

Body produces antibodies

• vaccines

• natural infections

What is Passive immunity

Antibodies are given

• maternal antibodies

• immunoglobulin

What is Cross immunity

Immunity to similar organisms

• related viral strains

What is herd immunity

Population level protection

• high vaccination rates

What can nurses do to control communicable diseases

• Surveillance and reporting

• Health education and risk communication

• Infection prevention (hand hygiene, PPE, isolation)

• Immunization delivery and advocacy

• Case finding, contact tracing

• Addressing non-medical drivers of health (housing, access, trust)