Week 10 Flashcards
which hepatitis can be vacinated agaisnt
A and B
Which Hepatitis are transmited enterically
- A and E (“Vowels in the Bowels”)
Which genus is hepatitis A from
Hepatovirus
Which family is Hepatitis A in
Picornavirus (like rhinoviruses)
What are main impacts of Hepatisis A
acute but self-limiting inflammation of the liver
What characteristic of hepatitis A virus is critical in fecal-enteral transmission?
lack of lipid envolope (HAV and HEV is stable in bile)
What allows hepatitis A and E to have large outbreaks
direct route to outside (anal transmission) allows for large outbreaks
Hepatitis A - incubation period
15-45 days for replication
Hepatitis A - why it causes symptoms abrubpty
virus is present in blood and shed in stools within a few days of exposure
Hepatitis A - onset of symptoms is…
abrupt
Hepatitis A - serum markers of infection (3)
- ALT and AST (liver serum transaminases) increases
- bilirubin increases
- IgM antibody for HAV
Prevention of Hepatitis A
Vaccine
Symptoms of Hepatitis A (9)
- fever, malaise, anorexia, N/V, RUQ pain
- dark urine, light clay coloured stools, frank icterus
- jaundice
Hepatitis A - risk factors (4)
- close contact with an active case
- sexual behaviour
- food and water borne transmission
- visiting developing countries
Hepatitis A - recovery (3)
- always acute, complete recovery is the rule
- does not cause chronic hepatitis/carrier state
- lifelong immunity
Hepatitis A - age as a factor
- under 2 = rarely diagnosed with hepatitis
- under 6 = asymptomatic
- over 40 = risk of hepatic failure –> transplant
Hepatitis A - who gets immunization (3)
- international travellers
- homosexually sexually active men
- illicit drug users
Hepatitis E - genus of virus
- calcivirus
Hepatitis E - incubation period
40 days
Hepatitis E - pregnant women
cause fatality in 15-20% of cases in women infected during third trimester of pregnancy (fulminant hepatitis = hepatic failure)
Hepatitis E - where do outbreaks occur
typically developing countries
Hepatitis E - diagnositis
- HEV-IgG antibody
- absence of markers for other hepatis viruses
Which Hepatitis vaccines are RNA based
- Hepatitis A, C, D, E, G
Hepatitis E - vaccination?
China has produced a vaccine but it is not availiable globally
Hepatitis B - family
Hepadnaviridae
Hepatitis B - acute infection severity
- asymptomatic to fulminant hepatitis
Hepatitis B - types of infection
Acute and Chronic
Hepatitis B - amount of chronic infections globally
350 million with chronic infection
Hepatitis B - complications are associated with which type of infection
Chronic infection
Hepatitis B - pathogenesis
cell-mediated immune response of the host
Which Hepatitis strains are DNA based
Hepatitis B
Chronic Hepatitis B - potential complications (2)
1) HBV –> cirrhosis –> cancer
2) hepatitis D development
Hepatitis B - incubation period
50-150 days (more serious health problem)
Hepatitis B - marker of infectivity
- HBSAg - first marker (before elevation in AST and ALT serum transaminases)
Hepatitis B - marker of recovery
HBSAb - immunity and recovery
Hepatitis B - what if both markers are absent (period between recovery and infectivity)
- IgM antibody
Hepatitis B - transmission
infected blood or serum, body secretions (oral/sexual contact)
Hepatitis B - at risk populations (5)
- people with multiple partners
- men who have sex with men
- healthcare worksers
- injection drug users
- mother to child
Chronic Hepatitis B - common symptoms (3)
- nonspecific/mild
- lack of energy
- malaise
Chronic Hepatitis B - symptoms w hen immune complexes are present
- myalgias
- arthralgias skin rash
- glomerulonephritis
Chronic Hepatitis B - unnoticed (2)
- can be slow to notice symptoms
- may be unnoticed until cirrhosis and end-stage liver disease is present
Chronic Hepatitis B - serum qualities
- persistent HBSAg
- failure to develop HBSAb for 6 months
Chronic Hepatitis B - recovery
- 1% per year become spontaneously immune
- no known cure
Hepatitis B - Prevention
- vaccine with HBSAg antigen
Hepatitis B Vaccine - populations (5)
- all people with lifestyle risk factors
- medical personel
- lots of sexual partners
- houshold contacts of HBV carriers
- infants of HBV carrier mothers
Hepatitis C - family
Flavivirus
Hepatitis C - pathology
- slowly progressive liver disease that is asymptomatic until the late development of liver disease/liver cancer
Hepatitis C - symptom prevelance
only 5% of cases
Hepatitis C - potential for chronic infection
70% develop chronic infection
Hepatitis C - potential for spontaneous recovery
40%
Hepatitis C - diagnosis
- increased serum transaminases
- confirmed with HCV Ab (marker of infection)
Hepatitis C 0 risk factors (4)
- intravenous drug abuse (in the remote past sometimes after a single episode)
- 60-90% of IV drug abusers have Hep C
- exposure to untested/non heat treated blood products
- some sexual transmission (0-5%)
Hepatitis C - incubation period
2-26 weeks
Hepatitis C - symptoms (6)
- asymptomatic
- nonspecific (fatigue, malaise, anorexia, weight loss)
- typically not jaundice or fulminant hepatitis
Hepatitis C - serious consequences
- progressive liver fibrosis –> cirrhosis
- end stage liver disease
- hepatocellular liver cancer
Hepatitis C - risk factors for progressive liver fibrosis (5)
- age of aquisition over 40
- male sex
- alcohol consumption over 50g/day
- immunocompromised state
- genotype of the virus
Hepatitis D
-
Hepatitis C - genotypes of the virus
- many (6+)
Hepatitis D - Genotype number
3
Hepatitis D transmission
- blood borne
- rarely sexual and perianal transmision
Hepatitis D and Hepatitis B
- can be acquired at the same time
- Hepatitis B must be present for Hepatitis D to infect
- Hepatitis D can make Hepatitis B worse
Hepatitis D - vaccination?
no vaccine is availiable for D but hep B vaccine will prevent it
What is diarrhea
- passage of more than 300 grams of stool per day
- due to excretion of excess fecal water (60-90%)
What is acute diarrhea
- diarrhea lasting 2 weeks or less
- often associated with infectious causes
What is acute gastroenteritis
- less than 2 weeks of vomitting and diarrhea
Infectious entercolittis - pathogenic mechanisms (3)
- ingestion of preformed toxins in contaminated foods
- infection by toxigenic organism proliferating in the gut lumen producing an enterotoxin
- infection by enteroinvasive organisms that proliferate in the lumen and invade/destroy mucosal epithelial cells
Rotavirus - type of genetic material
RNA viruses
Rotavirus - belongs to which family
Reoviridae
Rotavirus - serogroups
- A, B, C
Rotavirus - group A serotypes
1, 2, 3, 4
Rotavirus - common age group
- children under 5
- most severe in ages 3-24 months (hospital)
- under 3 months protected by transplancental antibodies
Rotavirus - transmission
- fecal oral route
Rotavirus - impact on intestine
- localizes in duodenum and proximal jujenum
-destruction of villous epithelium
Rotavirus - portal of exit
- virus shed before and for days after clinical illness (very few infectious ririons are needed to cause disease in susceptible host)
Rotavirus - common complication
- malabsorption complication is common, takes 3-8 weeks to resolve
Rotavirus - diagnosis (3)``
- electron microscopy of stool
- detection of antigen via latex agglutination
- enzyme immunoassay
Rotavirus - therapy
supportive, primarily oral rehydration
Rotavirus - prevention
oral vaccine is avaliable and may be given in infancy
Norovirus - family
caliciviridae
Norovirus - serotypes
at least 4
Norovirus - age group
- common in older children and adults
Norovirus - outbreaks
can cause large outbreaks
- 50% of adults are seropositive by 5th decadef
Norovirus - incubation period
10-51 hours
Norovirus - illness duration
1-2 days
Norovirus - symptoms
abrupt onset of vomiting and diarrhea
Norovirus - diagnosis
electron microscopy of stool
Norovirus - treatment
supportive treatment
Norovirus - portal of exit
viral shedding continues for 3-4 days after onset of illness
Norovirus - breaking chain of transmission
good hygeine (transmission is fecal-oral)
Listeria Monocytogenes - causes what disease
Listeriosis
Listeria Monocytogenes - gram status
gram positive
Listeria Monocytogenes - shape
rod shapped
Listeria Monocytogenes - oxygen?
anaerobic
Listeria Monocytogenes - mobility
flagella
Listeria Monocytogenes - resevoir location (6)
- soil –> vegetable contamination
- animal carriers
- stream water
- sewage
- plants
- food
Listeria Monocytogenes - how can it be given to humans (6)
- uncooked meats, uncooked veggies, fruits (cantalope/apples), milk, foods made from milk, processed foods
- NOTE: pasturization and cooking kill Listeria, but contamination can occur after
Listeria prevention
- effective sanitation of food contact surfaces
- keeping foods in home refrigerated below 4 degrees Celcius
- pasturizing dairy products
- cooking all meets to safe internal temp
Listeria - susceptible hosts (4)
- pregnant women
- newborns
- adults with weakened immune systems
- elderly
Listeria - pregnant woman complications (4)
- fetal death
- premature delivery
- birth of a fetus that dies shortly after birth
- spontaneous abortion
Listeria - pregnant woman - preventing complications (2)
- avoid unpasteurized dairy and cheeses as well as deli means
Clostridium Botulism - gram status
gram positive
Clostridium Botulism - oxygen
anaerobic
Clostridium Botulism - causes the following diseases (4)
- botulism
- tetanus
- gas gangrene
- pseudomembranous colitis
Adult botulism - route of transmission
1) spores float in air and land on food
2) f food is cooked thoroughly, spores will dies
3) if food is not cooked then placed in anaerobic environment (glass jar, freezer bag), bacteria grows and synthesizes neurotoxin
Adult botulism - at risk foods
- smoked fish or home-canned vegetables
Infant botulism - route of transmission/ pathogenesis (3)
- infants ingest food contaminated with spores
- spores germinate and bacteria colonizes infants intestinal tract
- from this location botulism toxin is released
Infant botulism - at risk food
- honey (don’t give to children under 1 years of age)
Campylobacter - shape
slender spiral
Campylobacter - gram status
gram negative
Campylobacter - movement (3)
- single polar flagellum
- corkscrew motion
-moves through fluids faster than other bacteria
Campylobacter - oxygen
- microareophillic and capnophillic (will not grow in air)
Campylobacter - common disease cause
- most common cause of acute enteritis in developed countries
Campylobacter - complications (3)
- bacteremia
- pseudoappendicitis
- rarely peripheral poloneuropathy (Guillain-Barré)
Campylobacter - at risk foods (5)
- raw or undercooked poultry, meat, fish, shellfish
- raw milk (fecal contaminating)
Campylobacter - transmission
- consumption of undercooked foods
- handling raw meat
- cross contamination of foods
Campylobacter - disease progression
- most strains produce a cholera-like enterotoxin and one or more cytotoxins –> explosive diarrhea
Campylobacter - incubation period
1-7 days
Gastrointestinal
- explosive diarrhea
- febrile prodrome (fever over 38 degrees)
Campylobacter - antibiotic treatment? (2)
- rarely required
- severely effected = fluroquinolones or erythromycin used
E. coli - location in the body
endemic to intestines of healthy people and animals
E. coli - gram status
gram negative
E. coli - oxygen
faculative anaerobic
E. coli - shape
rod shapped
E. coli - role in the body?
- normal
- helps digest food
E. coli - pathonogenic symptoms
- diarrhea
- stomach pain
- cramps
- low-grade fever
difference between normal E. coli and pathogenic E. coli
- different strains of E. coli can cause diseases
E. coli - number of diarrhea causeing strains
- 6 known strains
How does E. coli strain cause diarrhea - pathogenesis
- produce a toxin called Shiga
- this toxin damages lining of small intestine and causes diarrhea
- aka Shiga toxin-producing E. coli (STEC)
E. coli - at risk food (4)
- meats (contaminated during slaughterin process when E. coli in animal intestines get onto cuts of meat, meat from more than one animal is ground together), then eating this undercooked meat
- drinking raw milk
- unpasteurized apple cider or juices
- soft cheese made from raw milk
- fruit and veggies (growing near animal farms)
E. coli - people at greatest risk
- very young newborns/children
- elderly
- people with weakened immune systems
- people who travel to certain countries
E. coli (STEC strain) infection symptoms (6)
- stomach pain/cramps
- diarrhea (watery to bloody)
- fatigue
- loss of appetite/nausea
- vomiting
- low fever
Shigella - infects where
- intestinal infection
Shigella - main symptom
- diarrhea, which is often bloody
Shigella - gram status
- gram negative
Shigella - oxygen?
faculative anaerobic
Shigella - movement:
non motile
Shigella - shape
rod shapped
Shigella - how it survives in the body (2)
- genetically close to E. coli
- able to survive the proteases and acids of intestinal tract (easy to cause infection)
Shigella - why is it so contagious
- survives intestinal tract
- only 10 cells needed to cause infection
Shigella - pathogenesis (4)
- penetration of colonic mucosa
- degredation of epithelium
- acute inflammatory colitis
- leakage of blood, inflammation int the colon, mucus into intestinal lumen
Shigella - routes of transmission
- touching your mouth (washing hands)
- eating contaminated food (sewage)
- swallowing contaminated water
Shigella - risk factors (4)
- being a child (under 5)
- living in group housing/participating in group activities
- living or traveling in areas that lack sanitation
- men who have sex with men
Yernisa Enterocolitca - gram status
- gram negative
Yernisa Enterocolitca - shape
spherical (Coccus)
Yernisa Enterocolitca - oxygen
faculative anaerobes
Yersiniosis - at risk foods
- raw or undercooked pork
- contaminated milk-
- untreated water
- contact with infected animals or their feces
- (rarely) person to person
Yersiniosis - symptoms (4)
- depend on age
- CHILDREN = fever, abdominal pain, diarrhea (bloody)
- ADULT = right-side abd pain
Yersiniosis - onset of symptoms
4-7 days after exposure
Yersiniosis - duration of symptoms
1-3 weeks or longer
Yersiniosis - complications
- rash
- join pain
- sepsis
Salmonella Typhi - location of infection
intestinal tract and blood
Salmonella Typhi - causes which infection
typhoid fever
Salmonella Typhi - prevelent where
- developing countries
- areas where sewage and water treatment systems are poor
Salmonella Typhi - route of transmission
fecal-oral
Salmonella Typhi - shape
rod shapped
Salmonella Typhi - movement
flagellated
Salmonella Typhi - gram status
gram negative
Salmonella Typhi - pathogenic mechanism
- endotoxins cause damage
- inactivated by gastric acids (large inoculum required)
Salmonella Typhi - at risk foods
- consuming contaminated food or drink
- consuming food prepared by someone who is infected or a carrier of an illness
Helminths
- intestinal worms
Helminths - catagories (3)
- Nematodes (roundworms)
- Cestodes (tapeworms)
- Trematodes (flukes)
How are Helminths transmitted (2)
- soil transmitted (hookworms, whipworms, roundworms, tapeworms)
- oral ingestion of larval-infected tissue (undercooked meats)
Enterobius vermicularis - what
a roundworm (helminth)
Enterobius vermicularis - mode of transmission
- nocturnal pruitus ani when females migrate to perianal skin to lay eggs
(when infected person sleeps, female pinworms leave intestine through anus and deposit eggs on surrounding skin, causing itching around anus leading to difficulty sleeping and restlessness)
Enterobius vermicularis - common symptoms
- itching around anus
- difficulty sleeping and restlessness
- symtoms usually mild
Enterobius vermicularis - population
- school aged and pre-school aged children
- institutionalized persons
- household members/caretakers of persons with pinworm infection
Enterobius vermicularis - transmission
fecal-oral route (eggs from anus to someones mouth either directly or indirectly
Enterobius vermicularis - diagnosis
identifying the worm or its eggs (seen on skin near anus or on underclothing 2-3 hours after falling asleep)
Enterobius vermicularis - common name
pinworm
Roundworm example - ascaris lumbricoides - number
one billion infected worldwide
ascaris lumbricoide 0 mode of transmission
- females produce enourmous numbers of eggs that become inefective until 2-3 weeks in soil
ascaris lumbricoide - complication
- migration of adult worms
- hypersensitivity to larvae in lungs
Roundworm example: hookworms (2)
- ancylostoma duodenale
- necator americanus
Hookworms - mode of transmission
- soil transmission
- often in areas where human feces are used as fertilizer/defacation onto soil happens
- infected person defecates eggs onto soil, grows into larvae that can penetrate skin of human
- human barefoot walks on soil = transmission
- also ingestion of worm too
Hookworms - s/s of infection (8)
- itching and localized rash
- mild infection = no symptoms
- diarrhea
- loss of appetite
- weight loss
- fatigue
- anemia
- physical/cognitive decline in children
Hookworms - severe infection symptoms
- pulmonary symptoms (wheezing, blood tinged sputum, sputum with eosinophilla) occur when larvae migrate to lungs
Hookworms - diagnosis
- stool sample (microscope to look for presence of eggs)
Cestodes example
tapeworm
Tapeworm - what
flat segmented worms
Tapeworm - resevoir
live in intestines of some animals (infection due to grazing in pastures or drinking contaminated water)
Tapeworm - transmission to humans
- eating raw or undercooked meat
- 6 types of tapeworms that infect people: identified by animal they come from (pork, beef, etc)
Tapeworm - life cycle
1) egg
2) imature larva
3) adult that can make more eggs
parts of Tapeworm (3)
-head, neck, chain of segments called proglottids
Tapeworm - intestinal infection - pathogenesis
- tapeworm head adheres to intestinal wall
- proglottids grow and produce eggs
- adult tapeworms can live up to 30 years in a host
- usually only one or two adult tapeworms
- invasive larval infections are mroe severe
Tapeworm - s/s of infection (9)
- nausea
- weakness
- loss of appetite
- abdominal pain
- diarrhea
- dizziness
- salt craving
- weight loss
- inadequate absorption of nutrients from food
Trematodes example
flukes
Flukes - what
parasites that can infect humans
Flukes - at risk foods
- raw/undercooked fish, crabs, crayfish
Flukes infection - symptoms (4)
- indegestion
- abd pain
- diarrhea
- constipation
Flukes - where do they infect in the body (4)
- blood vessels
- gastroointestinal tract
- lungs
- liver
Giardia - causes what illness
- giardiasis
Giardia - parasite found where (4)
- surfaces
- soil
- food
- water
Giardia - protection
- outer shell that allows it to survive outside the body for a long time and makes it tolerant to chlorine disenfection
Giardia - transmission (6)
- swallowing Giardia picked up from surfaces that contain feces from infected person/animal
- drinking water/ice where Giardia lives
- swallowing water while swimming where Giardia lives (lakes, rivers)
- uncooked food containing Giardia
- contact with someone ill with Giardia
- travelling to countries where Giardia lives
Giardia - symptoms (7)
- diarrhea
- gas
- greasy stool that can float
- stomach or abdominal cramps
- upset stomach/nausea
- dehydration
- weight loss