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• Study guide for book exam 1, multiple choice, essay and short answer

Penicillin

• Antibiotics that have saved many lives
• Discovered by Alexander Fleming

Jesuits Bark

• Cinchona bark; a natural medicine for malaria
• Found in Peru’s forest

Historical Figures

• Key people to know are Jenner, Snow, Fracastoro, Fleming, etc.

• Edward Jenner is credited with inventing the smallpox vaccine using cowpox

• John Snow mapped and recorded cholera cases in London to track the source

  • He disabled the Lambeth street pump where the cholera cases were coming from

• Alexander Fleming discovered penicillin, which has helped millions of Americans

• Hippocrates trusted science over magic

  • He categorized disease and used words like epidemic

• Fracastoro believed "seminaria", invisible molecules, caused infectious disease

• Giovanni Morgagni wrote "On the Seats and Causes of Diseases Investigated through Anatomy"

  • He studied corpses to find out more about all kinds of diseases and their effect on the body

• Thomas Sydenham wrote "Observations Medicae"

  • He kept detailed and accurate records of patients
  • Sydenham was called "English Hippocrates"
  • He was the founder of epidemiology

• Peter Panum observed the importance of immunities

  • He observed that people over 65 who had survived to previous measles epidemic had long life immunity

• Ignaz Semmelweis investigated postpartum deaths and found that doctors and medical students did not wash their hands between patients which passed disease to mothers

  • He then introduced a handwashing protocol

• Britons Sir William Petty & John Graunt started keeping data numbers of disease, births, christening and deaths specifically

• Edwin Chadwick said hygiene, health and morality were closely associated

  • He observed the struggles of the working poor

Infectivity and Incubation

• Infectivity is a pathogen's ability to infect
• Incubation Period is the time between when a person was exposed to a disease and the time they start showing symptoms

Pathogenicity and Virulence

• Pathogenicity is the ability of a pathogen to cause disease
• Virulence is how harmful a disease is

Sensitivity & Specificity

• Specificity is the ability of a test to identify a disease
• Sensitivity is a measure of how well a test detects a disease

Latency Period and Immunogenicity

• Latency Period is the time between exposure and the appearance of symptoms
• Immunogenicity is the ability of a pathogen to trigger an immune response

Measles Vaccine

• First live attenuated (LAV) vaccine approved in early 1960s
• Late 1960s, Enderson-Edmonston strain LAV introduced and measles cases dropped about 99% since then

Vaccine Types

• Two main types of vaccines
  • Inactivated vaccines contain pathogens that have been killed/inactivated
    • Examples include vaccines for flu, polio, and hepatitis A
  • Live attenuated vaccines (LAVs) are created by reducing the virulence of a pathogen but still keeping it alive
    • Examples include vaccines for MMR, smallpox, and yellow fever

Recombinant Vaccines

• Genetically modified organisms produce certain antigens so the body's ready to defend itself
  • Examples include vaccines for HPV, hepatitis B, and some flu vaccines

Polysaccharide and DNA Vaccines

• Polysaccharide vaccines have sugar molecules on the organisms
  • An example is the typhoid vaccine and Hib vaccine
• DNA vaccines have DNA in them to introduce certain antigens in body
  • Examples include vaccines for rabies, rubella, and COVID 19

Populations and Nutrition

• Populations without proper sanitation or water are susceptible to diseases that don't have to happen if there was proper sanitation and clean water, like cholera, polio, typhoid, e. coli, and NTDs like guinea worm.
• Pepto Bismol is a nutritional supplement used to help with diarrhea.

Outbreaks

• Outbreak: an epidemic that is geographically and time constrained
• Epidemic: health related state or event in a defined population above the expected over a given period
• Endemic: persistent, usual, expected health-related state or event in a defined population over a given period
• Pandemic: epidemic affecting many people, multiple countries, continents or regions

Polio Vaccines

• Jonas Salk's: inactivated intramuscular vaccine
  • Very effective but outbreaks would still happen among fully vaccinated children
• Albert Sabin's: oral LAV (live activated vaccine)
  • More effective than Salks
• Still transmission in Pakistan and Afghanistan

Types of Immunity

• T cells kill pathogens and help coordinate immune responses
• B cells produce antibodies
• Immune response does not fully prevent disease, it mainly prevents you from getting worse
  • Things like fever are designed to help your body respond to pathogens
  • Too strong of an immune response can do more bad than good
  • The immune system is not able to protect you from everything
    • Autoimmune diseases occur when the immune system attacks itself
    • Examples include allergies, asthma, and diabetes

Meningitis

• Meningitis is an inflammation of the membranes that cushion the head and spinal cord
  • It can be bacterial, viral, protozoan or fungal, and it can be fatal

Polio

• Caused by a virus and is contagious
• Can cause paralysis on some patients and can stiffen up the diaphragm area
  • Before the vaccine, patients got "iron lung" treatment in order to breathe
• Transmitted through fecal-oral route, contaminated food/water and droplets (cough/sneeze)
• Incubation period can be as long as a month

Yellow Fever

• Vector-borne disease transmitted by mosquitoes
• It attacks the liver, causing jaundice (yellowing of the skin)
• Mainly found in Africa and South America
• Can cause organ failure, seizures, and delirium
• Incubation period can be up to a week

Study Design

• Case-control design is the most effective study design for infectious diseases
  • Because it examines all potential sources and connections to a disease, so it can help with discovering the roots of the problem

Internal and External Validity

• Internal validity: the accuracy that information holds in a specific area or population
• External validity: the accuracy that observations a

Vaccine Properties and Obstacles

• A perfect vaccine is cost-effective, easy to administer, simple to store, and provides long-life immunity after
• Reasons for lower vaccine rates in developing countries:
  • Lack of resources
  • Poverty
  • Government does not prioritize public health

Barriers to Access and Food Safety

• Lack of access to clinics and hospitals
• Lack of education
• WHO's 5 keys to safer foods:
  • Keeping space clean
  • Separating raw and cooked foods
  • Cook thoroughly
  • Keeping food at safe temperatures
  • Using safe water and raw materials

Vaccine Requirement

• Vaccine requirements for children:
  • MMR (measles, mumps, rubella)
  • Hepatitis B
  • Chickenpox/varicella
  • DTaP (diphtheria, tetanus, pertussis/whooping cough)
  • Polio (IPV)
  • Hib

Smallpox

• Smallpox is easy to identify from the spots a person developed from it, so cases were easy to track down
  • The vaccine was very easy, accessible and gave people life-long immunity

Jacobson V Massachusetts

• Jacobson was fined $5 by the Supreme Court for refusing to get vaccinated for smallpox
  • His argument was that he got a bad reaction from vaccines when he was a kid
  • Appealed multiple times and refused to pay fine

Koch's Postulates

• Koch's Postulates help to figure out if a certain microorganism is causing a disease
  • Isolate the microorganism.
  • Grow in culture.
  • Test on animal.
  • Re-isolate.

Chain of Infection

• A chain or cycle that shows how an infection spreads
  • Must break the chain in order to stop it
  • Infectious agent (pathogen; virus, bacteria, etc)
  • Reservoir (place where agent lives/multiplies)
  • Portal of exit (contaminated saliva, blood, cough, sneeze)
  • Mode of transmission/transport (how pathogen moves from reservoir to susceptible host, like skin contact, bite, droplets, etc.)
  • Portal of entry (opening where the pathogen can infect susceptible host, like wound opening or breathing in air where a person with disease has coughed, etc.)
  • Susceptible host (the person at risk, like healthcare worker, patient, etc)

Neglected Tropical Diseases (NTDs)

• Infectious diseases where the most who get it live in very poor tropical parts of the world
• Examples: Leprosy, Buruli ulcer, dengue, Dracunculiasis (guinea worm), rabies, chikungunya
• People can get discriminated from diseases, cannot work or go to school
• Major causes:
  • Governments where these diseases happen the most do not prioritize in managing these diseases, lack of political intervention
  • Lack of access to clinics due to physical isolation (people living in tropical villages)
  • Stigma surrounding these diseases including social isolation
  • Poverty and limited resources
  • They can cause disabilities, disfigurements, etc
• Millions and millions of people in developing countries are affected by NTDs

MMR & Autism

• "Dr." Wakefield directed a study on the supposed link between autism and MMR vaccine and claimed that it would be better to get vaccines “separately"
  • Study only included a handful of kids who already had development and behavioral concerns before
  • Did unnecessary procedures like colonoscopies and somehow made up this "discovery" that the MMR vaccine caused an intestinal inflammation making it release proteins that led to the brain and made it cause autism
  • Very unethical and information/data was faked
  • Conflict of interested was found, Wakefield was funded by lawyers suing MMR vaccine manufacturers
  • Wakefield's medical license revoked

Herd Immunity and Vaccine Exemptions

• Herd Immunity occurs when a population is immune to a certain infectious disease
• Vaccine Exemptions include pregnant people, people with certain allergies or reactions to vaccines, philosophical reasons, and religious reasons

Diphtheria

• Bacterial infection
• Vaccine: diphtheria
• Treatment: antitoxin
• The Diphtheria Outbreak of Nome, Alaska
  • "Race of Mercy”: sled dog rushing to transport medicine to children with Diphtheria

Pertussis and Rubella

• Pertussis (whooping cough)
  • A bacterial infection that is transmitted through droplets
  • Vaccine: Tdap but has no lifelong immunity; need boosters
  • Sounds like a whip when coughing from patients finding it hard to breathe
• Rubella
  • Viral infection also called "3-day measles" or "German measles"
  • It is mild in both kids and adults but can be a problem if a woman is infected in early pregnancy, can cause Congenital Rubella Syndrome (CRS)
  • Vaccine: MMR (mumps, measles, rubella)

Mumps and Meningitis

• Mumps
  • Viral and affects parotid gland (lateral to the head, from around ear to jaw), making it look like there's a ball in your jaw
  • Vaccine: MMR
• Meningitis
  • Inflammation of the meninges
  • Can lead to the inflammation of the brain if severe
  • Can be bacterial or viral
  • Diagnostic test includes collecting cerebrospinal fluid in lumbar puncture
  • Teens and kids under 5 most susceptible, overcrowded conditions like freshman dorms and military training camps
  • An incubation period can be divided into:
    • Enteroviruses: 3-6 days
    • Arboviruses: 2-15 days
  • "Meningitis belt" consists of bacteria that causes meningitis that is very easy to spread from the bacteria getting in the back of the throat. Impoverished and overcrowded places most spreadable

Meningitis Prevention

• Meningitis outbreaks happen in Africa where there are vaccine shortages and is mainly an issue in Niger and Nigeria
  • Prevention for bacterial meningitis -Meningococcal: MCV4 (meningococcal conjugate vaccine) can be administered at 11-12 with a booster at 16; for college freshmen living in a dorm; military recruits and to those traveling or living in countries where this disease is common -Pneumococcal: PCV13 is to be administered routinely to infants -Hemophilus meningitis:HiB (Haemophilus influenza B vaccine)
  • Treatments consist of antibiotics
  • Viral/Aseptic Meningitis that have multiple causes: -Varicella -Measles virus -Herpes simplex virus -Enteroviruses -arbovirus -Etc

Reservoir, Transmission, Treatments, Complications, and Tetanus

• Reservoirs include humans for infectious diseases as well as birds and rodents
• Modes of transmission involves person to person
• Most patients with meningitis recover without needing treatment
• Complications:
  • Sepsis: extreme response to infection, high mortality
  • Neurological complications
  • Deafness
  • Other cranial nerve lesions
  • May improve or recover
  • Arthritis between fingers and knees is common
  • Skin necrosis scarring and painful lesions
• Tetanus -Bacterial -Tetanus toxin
• Found in soils, especially soils with a lot of manure
• Pathogenicity is related to
  • Surgery/Burns/Deep puncture wounds/Ear infections/Dental infections/Animal bites/Abortion/Pregnancy/No person to person transmission
  • It is considered a neurotoxin

Types of Tetanus and Viral Hepatitis

• Tetanus
  • Unique characteristics are muscular contraction and spasms -Generalized tetanus: Lockjaw, neck stiffness, difficulty swallowing, rigidity of abdominal/back muscles, spasms continue for a few weeks, can take months to recover -Neonatal Tetanus happens when the baby is without passive immunity and usually happens through unhealed umbilical stump, especially when cut with unsterilized instrument
• Acute viral hepatitis lasts for less than 6 months while chronic lasts more than 6 months
• Types: -Hepatitis A (HAV) -Hepatitis B (HBV) -Hepatitis C (HCV/ non-A/ non-B) -Hepatitis D (HDV/ Delta type) -Hepatitis E

Etiology of Toxic Damage

• Infectious agents consist of viruses, bacteria, fungi and protozoa while toxic damage from alcohol
• HAVirus
  • Caused by drugs/poisons/chemicals
  • Risk is directly related to age -Majority of infections in children, normally asymptomatic -Normally lasts less than 2 months -Acute liver failure is very rare
  • No specific treatment but is preventable through the vaccine and immunoglobin (IG)