Global Health Classes 1-3 (infectious disease)

Question 1

Active immunity

Answer 1

from past infection or vaccination -> “memory” immune cells form and provide long-term protection

Question 2

Acute

Answer 2

Short-term

Question 3

Agents That Cause Baterial Diarrhea

Answer 3

1. E. coli
2. Cholera (Vibrio cholerae)
3. Typhoid (Salmonella typhi)
4. Other Salmonella
5. Shigella
6. Campylobacteria

Question 4

ARI

Answer 4

Acute Respiratory Infection

Often caused by a virus (adenoviruses, pneumococcus, rhinovirus)

Need drugs to treat ARI (pneumonia)

Question 5

Arthropod vectors

Answer 5

Bugs like mesquitos that carry disease. Discovered in 19th century as a carriers for diseases such as malaria, yellow fever, sleeping sickness and typhus

Question 6

Bacteria

Answer 6

• 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

Question 7

Bacterial STIs

Answer 7

1. Chlamydia- most common STI
2. Gonorrhea- Previously most common
3. Syphilis- Also was previously most common

HPV is most common if you include diseases that don’t cause infection immediatelyThere are over 25 STIs

Question 8

Bill Foege

Answer 8

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.”

Question 9

Brucellosis (aka Undulant fever, Malta fever)

Answer 9

Zoonoses: Transmission- sheep, goats, cattle
- handling and consumption

Symptoms: Chronic fevers

Question 10

Cancer: President Grover Cleveland

Answer 10

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

Question 11

Carlos Finlay

Answer 11

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)

Question 12

Cholera’s journey to Europe

Answer 12

Originally from India. Muslims brought it to the Arab world during their Mecca pilgrimage. It ultimately worked it’s way to Europe.

Question 13

Chronic

Answer 13

Long-term

Question 14

Dengue Fever

Answer 14

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.

Question 15

Dracunculiasis (Guinea worm)

Answer 15

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

Question 16

E.P.I.

Answer 16

Expanded Program in Immunization

- Vaccine for Preventable Diseases

Question 17

Ectoparasites

Answer 17

On animals such as lice, mites (that cause scabies), and animals that live outside the body

Question 18

Edward Jenner

Answer 18

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

Question 19

Endemic, Epidemic, Pandemic and Surveillance

Answer 19

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

Question 20

Endoparasites

Answer 20

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.

Question 21

Eradicated diseases

Answer 21

Rinderpest (2011). Infectious disease for cattle

Smallpox (1979)

Question 22

Filippo Pacini

Answer 22

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.

Question 23

Fungi

Answer 23

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

Question 24

Health

Answer 24

A state of complete physical, mental and social well-being and not merely an abscense of disease or infirmity

Question 25

Herd immunity

Answer 25

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

Question 26

Infection

Answer 26

Agent reproduces inside a person. (not all exposures cause an infection)

Question 27

Infectivity

Answer 27

``` # infected ------------------------------------ # exposed (and susceptible at time of exposure) ```

Question 28

James Lind

Answer 28

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

Question 29

Jesse William Lazear

Answer 29

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.

Question 30

Joseph Goldberger

Answer 30

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

Question 31

Joseph Schereschewsky

Answer 31

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.

Question 32

Lawrence Kolb

Answer 32

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.

Question 33

Louis Pasteur

Answer 33

Developed the process of boiling liquids to kill bacteria (pasteurization). His work in germ theory also led him and his team to create vaccinations for anthrax and rabies.

Question 34

Modes of Transmission

Answer 34

1. Direct (person-to-person) transmission - Contact with blood or body fluids - Sexual contact - IDU (injecting drug use) - Fecal-oral spread 2. Airborne 3. Vector-borne: spread by an insect or other animal 4. Vehicle-borne: spread by inanimate objects 5. Mother-to-child (MTC) / vertical

Question 35

ORT/S

Answer 35

``` Oral Rehydration Therapy (Solution) 1 Liter of WaterSodium Chloride: 3.5 gramsSugar (glucose): 20.0 gramsSodium Bicarbonate: 2.5 gramsPotassium Chloride: 1.5 grams ________________________________ Zinc ``` Zinc improves the effectiveness of ORT/SORT/S is a rehydration process. Dehydration is generally what kills with dehydration. ORT/S was initially only administered my doctors. As time went on and public health progressed, the health community realized anyone could do this and began training mothers how to make and feed this solution. ICDDRB (The International Centre for Diarrhoeal Disease Research, Bangladesh)/Matlab discovered that for every molecule of carbohydrate, six molecules of water attached themselves. By including some carbohydrates in the ORT/S, the rehydration process was enormously accelerated. - Rice works the best

Question 36

Passive immunity

Answer 36

from breast-milk or Ig (immunoglobulin or antibodies) shot -> temporary protection (a few months)

Question 37

Pathogenicity

Answer 37

``` # ill (symptomatic) ------------------------------ # infected ```

Question 38

Plague

Answer 38

Zoonoses: Transmission- rodent flea Symptoms: - Bubonic Plague- swollen lymph nodes ("boubos") - Pneumonic Plague- severe pneumonia Plague is endemic to Kyrgyzstan

Question 39

Protozoa

Answer 39

Single-celled organisms that live in water Examples: Paramecium and Amoeba Causes amoebic dysentery

Question 40

Reservoirs

Answer 40

The ‘environment’ is which the infection is found 1. Soil 2. Water 3. Humans 4. Animals (zoonosis) *Air is not one of them. Infection may appear to be in the air but it is actually on a mater molecule or dust particle rather than the air itself.

Question 41

Robert Koch

Answer 41

1843-1910: Worked on immunization for a range of diseases including anthrax. One of the father of vaccines. Known for his role in identifying the specific causative agents of tuberculosis (1882), cholera (1883), and anthrax and for giving experimental support for the concept of infectious disease. Sharp rivalry with Pasteur

Question 42

San Francisco Plague Epidemic

Answer 42

1900-1904 and 1907. Plague broke out in China town. Plague was blamed on Chinese. Governor of SF denied outbreak for years because he didn't want to discourage trade. Plague is actually transferred to humans by the fleas on infected rats.

Question 43

Types of Infectious Agents

Answer 43

1. Bacteria 2. Viruses 3. Fungi 4. Parasites - Protozoa - Helminths (worms) - Prions: sub-atomic proteins – mad cow, Creutzfeldt-Jakob (not a major source of human infection. don't need to learn) You get Helminths by walking barefoot outdoors

Question 44

Types of Parasites

Answer 44

1. Ectoparasites 2. Endoparasites 3. Protozoa

Question 45

Types of Viral STIs

Answer 45

HIV Herpes Hepatitis C Human papilloma virus (HPV)

Question 46

Common Viruses

Answer 46

Measles Mumps Rubella (German measles) Polio

Question 47

Vector-borne Protozoa

Answer 47

Malaria: 5 types of Plasmodium parasites - Falciparum - Vivax - Ovale - Malariae - Knowlesi (zoonose- carried by macaques monkeys) Transmission: - female Anopheles mosquitoes

Question 48

Virulence

Answer 48

``` # dead ---------------- # sick. ``` An infection that has a high case fatality rate is said to have high virulence.

Question 49

Viruses

Answer 49

Technically not alive – take over your cells and use them to replicate Common examples: colds, influenza

Question 50

Walter Reed

Answer 50

An U.S. Army physician who, in 1901, led the team that tested and confirmed the theory that yellow fever is transmitted by a particular mosquito species, rather than by direct contact. Walter Reed became famous for publishing results but always gave credit to Carlos Finlay's work.

Question 51

What makes an infectious agent unique?

Answer 51

1. Type (strain) 2. Mode of transmission, reservoir, etc. 3. Drug resistance

Question 52

Where is polio endemic?

Answer 52

Polio is endemic in three countries: - Afghanistan - Pakistan - Nigeria Polio is Dr. Swezy's favorite disease because it is being focused for eradication and his daughter works to stop it in India. Syria is not officially considered endemic yet.

Question 53

William Gorgas

Answer 53

Army chief sanitary officer on the Panama canal project. Implemented sanitary programs including draining ponds/swamps, fumigation, mosquito netting, and public water systems. These measures were instrumental in permitting the construction of the Panama Canal. Significantly prevented illness due to yellow fever and malaria.

Question 54

Yellow Fever

Answer 54

Viral Zoonoses: Transmission - Aedes aegypti mosquitoes Symptoms: jaundice (yellow skin because of liver problems) There is still Yellow Fever in Argentina and Africa. Belief is that Yellow Fever originated in Africa and came to the Americas during the slave trade.

Question 55

Yellow Fever in the US

Answer 55

US epidemics: New York, 1668 Philadelphia, 1793 New Orleans, 1833, 1853 Yellow Fever would periodically flare up in the US. Dolly Madison married to a business man who died of yellow fever. She remarried a lawyer who later became President James Madison.

Question 56

Zoonoses

Answer 56

When a disease is transferred from an animal to a human

Question 57

HIV Modes of Transmission

Answer 57

1. Sex 2. IDU 3. Blood transfusions 4. MTCT (vertical) - Breastfeeding - Birth Capsid is the protein that allows the virus to attach to the cell

Question 58

Components of AIDS: Acquired Immunodeficiency Syndrome

Answer 58

This refers to persons diagnosed with AIDS, based on the CDC definition in adults and adolescents and children. HIV infection + onset of opportunistic infections (OIs) = AIDS Syndrome= collection of symptoms Symptoms appear as CD4 cell counts decrease and HIV viral counts increase.

Question 59

Common Opportunistic Infections

Answer 59

1. TB (most common AIDS OI) 2. Chronic diarrhea 3. Chronic pneumonia (like PCP: Pneumocycstis carinii) 4. Fungal infections like Cryptococcus and thrush 5. Kaposi sarcoma (cancerous tumor)

Question 60

HIV Stages

Answer 60

Symptoms appear as CD4 cell counts decrease and HIV viral counts increase. Primary infection: “flu-like symptoms” for a few weeks after infection Stage 1 and 2: no or mild symptoms Stage 3: weight loss and onset of OIs Stage 4 (AIDS): serious OIs, continued weight loss, CD4 count <200 particles per mm3

Question 61

HIV/AIDS

Answer 61

This refers to cases of HIV infection, regardless of whether they have progressed to AIDS.

Question 62

KAP study.

Answer 62

(knowledge, attitude, preference) People need to have knowledge of issue, an attitude that they want to prevent disease and a preference to make choices that protect them

Question 63

Incidence

Answer 63

1. New cases 2. Specific Population 3. Specific Timeframe INCLUDE ALL THREE FACTORS FOR TEST

Question 64

Prevalence

Answer 64

1. Existing cases 2. Specific population 3. Specific timeframe INCLUDE ALL THREE FACTORS FOR TEST

Question 65

ART: antiretroviral drug therapy

Answer 65

Combinations of drugs like reverse transcriptase inhibitors and protease inhibitors Prolongs duration of time between infection and onset of clinical AIDS and duration of life after onset of AIDS Do not work for all people with HIV: side effects, drug-resistant strains, inability to adhere to schedule Do not cure infection, just reduce viral load in blood Millions who would benefit from ART do not have access to them - Once ARVs are stopped, viral load quickly rises again

Question 66

Dates for major AIDS events

Answer 66

1981: first identified in homosexual men in the U.S. 1990: 10 million people with HIV worldwide 1995: 20 million 2000: >30 million 2008: 31.1 – 35.8 million 2013: ~ 34 million infected 2013: 10 million on ARVs 2013: 2.5 new infections per year 2013: 1.7 million deaths per year(worldwide HIV/AIDS is the leading cause of death of women of reproductive age (15-45)) 2014: ~ 35 million people living with HIV 2014: 97% in low and middle income countries 2014: ~ 30 million deaths from epidemic

Question 67

AIDS and Sub-saharan Africa

Answer 67

- 10% of world’s population but >60% of all HIV cases - >6% of adults (ages 15-49) have HIV - In some communities >30% - Highest in young women and urban residents - Highest in men of highest quintile - Social structure disrupted as young adults die, putting burden on older adults to raise children - AIDS orphan: loss of at least 1 parent to AIDS

Question 68

OVC

Answer 68

orphans and vulnerable children

Question 69

U.S. AIDS annual incidence rate

Answer 69

10 per 100,000

Question 70

Mozambique AIDS annual incidence rate

Answer 70

550 per 100,000

Question 71

Asia and AIDS (2008)

Answer 71

3.8 – 5.5 million living with AIDS 270,000 – 410,000 new infections 260,000 – 400,000 deaths Adult prevalence: <1%, except Thailand HIV/AIDS education is limited

Question 72

AIDS Special Populations

Answer 72

``` IDU (injecting drug users) Paid sex workers MSM (gay men) MTCT (mother to child) People who's spouses cheat Prisoners Mobile workers Older heterosexual couples Discordant couples ```

Question 73

Why are women more vulnerable to AIDS?

Answer 73

1. Biologically vulnerable (thin vaginal walls) - More than 2x more likely than men to contract HIV during heterosexual intercourse 2. Social vulnerability - In sub-Saharan Africa women ages 15-24 are 3x more likely than men ages 15-24 to become HIV infected

Question 74

MTCT AIDS Transmission

Answer 74

- 3.3 million children under age 15 living with HIV; >90% infected through MTCT (mother-to-child) transmission ``` - Pregnancy, birth process, breastfeeding Without drugs (zidovudine / AZT) during delivery, 15-30% of newborns infected (much, much less if on ARVs) ``` - Risk over several months of breastfeeding is 30-45% (lower if on ARVs) - HIV+ mothers: risk diarrhea (unclean water) and malnutrition (no formula) or risk MTCT HIV infection

Question 75

Tuberculosis (TB)

Answer 75

Caused by bacteria: Mycobacterium tuberculosis You can get TB by breathing in air droplets from a cough or sneeze of an infected person Most common in Africa, Asia, and former USSR High rates of HIV/TB co-infection, especially in sub-Saharan Africa Most people are asymptomatic (dormant disease). >30% of the world is infected ~10% of people infected become symptomatic

Question 76

TB Incidence/Prevalence rates

Answer 76

>9 million new cases of TB disease each year 14 million existing cases About 1.4 million deaths each year 95% in low and middle income countries

Question 77

TB drug resistance

Answer 77

B bacteria is becoming more drug resistant -DR = drug resistant -MDR: multi-drug resistant. - At least 4% of TB cases (up to >30% in some countries) do not respond to at least one of the standard drugs -XDR = extremely drug resistant -TDR = totally drug resistant An issue for the US because as more cases come to the country, we are not vaccinated

Question 78

TB/AIDS

Answer 78

Closely associated with HIV/AIDS Most common OI for AIDS patients the AIDS weakened immune system often causes dormant carriers to become symptomatic carriers

Question 79

DOTS

Answer 79

Tuberculosis control strategy recommended by the World Health Organization Directly-Observed Therapy, Short-course - People observed taking pills each day - 5 types of pills daily for at least 6 months DOTS is particularly for drug resistant TB

Question 80

DOTS-Plus

Answer 80

at least 2 years of pills

Question 81

TB vaccine

Answer 81

BCG: (Bacillus Calmette-Guerin) Only works for about half of people who get it and protection wanes over time

Question 82

TB testing

Answer 82

PPD (Mantoux) small amount of bacterial protein placed under skin of arm to see if a reaction occurs Chest X-ray to look for pockets of infection Sputum test