Global Health Classes 1-3 (infectious disease) Flashcards
Active immunity
from past infection or vaccination -> “memory” immune cells form and provide long-term protection
Acute
Short-term
Agents That Cause Baterial Diarrhea
- E. coli
- Cholera (Vibrio cholerae)
- Typhoid (Salmonella typhi)
- Other Salmonella
- Shigella
- Campylobacteria
ARI
Acute Respiratory Infection
Often caused by a virus (adenoviruses, pneumococcus, rhinovirus)
Need drugs to treat ARI (pneumonia)
Arthropod vectors
Bugs like mesquitos that carry disease. Discovered in 19th century as a carriers for diseases such as malaria, yellow fever, sleeping sickness and typhus
Bacteria
- Shapes: rods (bacilli), spheres (cocci), spirals (spirochetes, vibrios, spirilla)
- Found everywhere from arctic to hot springs in ocean
- Helpful: decomposition, nitrogen fixation in plants, making cheese & yogurt & alcohol, aiding digestion
Bacterial STIs
- Chlamydia- most common STI
- Gonorrhea- Previously most common
- Syphilis- Also was previously most common
HPV is most common if you include diseases that don’t cause infection immediatelyThere are over 25 STIs
Bill Foege
American epidemiologist who is credited with devising the global strategy that led to the eradication of smallpox in the late 1970s.
Went on to be the head of the CDC and now works for the Bill and Melinda Gates Foundation
“Someday this may even be known to historians as the vaccine age. It started 215 years ago when Edward Jenner gave the first vaccination to James Phipps (1796), using material from the cowpox lesion on the hand of Sarah Nelms.”
“This was also the beginning of modern public health because now there was a tool that could be used to prevent disease. While the first vaccine goes back two centuries, the field has exploded in my lifetime.”
Brucellosis (aka Undulant fever, Malta fever)
Zoonoses: Transmission- sheep, goats, cattle
- handling and consumption
Symptoms: Chronic fevers
Cancer: President Grover Cleveland
Grover Cleveland had a cancerous growth in his mouth. The President used a friends yacht for 4 days saying he was going on a fishing trip. A team of 6 doctors performed one of the earliest cancer removal surgeries on the yacht in about 90 minutes. No press was informed or present
Carlos Finlay
1881- First to theorize that the mosquito vector was a carrier for yellow fever. His first time he tried the experiment on people, no one came down with yellow fever. Walter Reed tested and proved the theory was correct 20 years later. (turns out that the female mosquito had to be the one to bite someone in order to pass disease and multiple bites over time were usually necessary)
Cholera’s journey to Europe
Originally from India. Muslims brought it to the Arab world during their Mecca pilgrimage. It ultimately worked it’s way to Europe.
Chronic
Long-term
Dengue Fever
Viral Zoonoses: Transmission- mosquitoes (aedes aegypti)
4 serotypes (strains)
- Infection with 1st serotype
- severe headache & fever
- Infection with 2nd serotype
- may cause DHF (dengue hemorrhagic fever)
Vaccine in Phase 3 trials
Was previously a disease in poor countries.
It is endemic in Puerto Rico. Has made it to Florida and is working it’s way north.
Dracunculiasis (Guinea worm)
Caused by drinking water that contains larva-infected water fleas
Worm grows to about 3 feet then slowly & painfully emerges (1cm/day)
Prevent by filtering water and keeping infected people away from water sources
President Carter and the rest of the global health community is targeting guinea work for eradication without a vaccine
E.P.I.
Expanded Program in Immunization
- Vaccine for Preventable Diseases
Ectoparasites
On animals such as lice, mites (that cause scabies), and animals that live outside the body
Edward Jenner
1798: developed smallpox inoculation. Took cowpox and injected it into an 8 year old. After multiple injections over time, he was unable to catch smallpox
Endemic, Epidemic, Pandemic and Surveillance
Endemic: always present
Epidemic: more cases than normal
Pandemic: global epidemic: must be infectious
Surveillance: tracking infectious disease reports to catch outbreaks early
- Often look for clusters in time or space
Not precise terms. Depends on the disease to switch from endemic, epidemic and pandemic. At some point during increasing severity they switch terms
Endoparasites
Caused by intestinal worms, blood and liver flukes, and other animals that live inside the body.
- May live nearly anywhere in the body - Contracted through soil (STH: soil-transmitted helminth), food, water, contact with feces, etc.
Eradicated diseases
Rinderpest (2011). Infectious disease for cattle
Smallpox (1979)
Filippo Pacini
1854- First person to isolate and see cholera in a microscope (before Robert Koch’s more well known discovery). He and John Snow were not aware of each other or their work at the time.
Fungi
Fungal infections often develop when normal balance of helpful microflora disturbed by antibiotic use or immunosuppression
Ringworm (Athlete’s foot, jock itch, tinea)
Molds and yeasts
- May be helpful: bread, wine, cheese
Health
A state of complete physical, mental and social well-being and not merely an abscense of disease or infirmity
Herd immunity
Not everyone in a population has to be vaccinated to protect “the herd”
When there is herd immunity, it is impossible for a disease to be passed on as long as the person has been immunized.
Herd immunity takes about 80% immunity.
In the US there has been outbreaks of measles, whooping cough and polio
Cost of opting out of vaccination.
- There are people who have created a culture of not immunizing their kids. Many times the reasons are unknown. - NVIC is an organization against vaccination. It is in Vienna, VA
Infection
Agent reproduces inside a person. (not all exposures cause an infection)
Infectivity
# infected ------------------------------------ # exposed (and susceptible at time of exposure)
James Lind
1747: studied etiology and treatment of scurvy. Realized it wasn’t an infectious disease after assigning random treatment to sailors.
One group got starvation diet, one got double rations, one got sea water and one got oranges.
Realized oranges not only treated scurvy but also prevented it.
40 years later the Royal Navy issued a mandate to include citrus (limes) on ships
Jesse William Lazear
Worked with Walter Reed on yellow fever research and testing the mosquito vector theory.
He let himself be bitten by yellow fever carrying mosquitos and later died of the disease.
Joseph Goldberger
1914- Military doctor. Discovered that Pellagra was not an infectious disease. Performed multiple restricted diets on prisoners. Realized that it was caused by a Niacin deficit. Niacin is now mixed into modern bread so people now get enough
Joseph Schereschewsky
Joseph Schereschewsky was a professor at Harvard. Was brought to DC by President Grover Cleveland to set up the first national research team. That research department later evolved into the NIH.
Lawrence Kolb
Instrumental in early research into Shell Shock (PTSD, “battle fatigue). Found that it could cause physical signs and symptoms and often led to alcoholism, depression, etc.
