Good morning, and welcome to the Final microbiology review

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Good morning, and welcome to theFinal
microbiology review
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What well cover today

• EVERYTHING
• (but first, worms)

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Recap -general stuff

• Parasites can be
• Ectoparasites - live on outside of body
  infestation (e.g. scabies)
• Endoparasites - live inside body infection
• Must evade immune system somehow
• Humans, as hosts, can be
• Definitive harbor adult/sexual form
• Reservoir - animal with same form as we do
• Incidental - host not necessary to life cycle of
  bugwe fall into this category, often
• Intermediate harbor developing larval, asexual
  form
• Carrier harbor non-developing larval, asexual
  form

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Nematode infections

• Roundworms
• Separate sexes
• Intestinal nematodes
• Acquire by ingesting egg
• No intermediate host
• Adult worm lives in gut - disease Sx
• Some have minor tissue phase
• Tissue nematodes
• Acquire by filariform-directed penetration
• Ones get by ingestion burrow through GI tract
  wall
• Others have more direct access to lymphatics or
  blood
• Have an intermediate host
• Larvae or adults in tissues - disease Sx

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Enterobius (pinworm)

• Worldwide especially temperate
• Ingest eggs - hatch in small bowel - matures to
  adult, attaches to cecal mucosa
• Females migrate to perianum at night, lay eggs
• Eggs embryonate on skin 1-2 hours
• Eggs transported back to mouth and reswallowed
• Autoinfection, person- person fecal/oral via
  fingers, also inhaled
• Enterobiasis
• Pruritis ani (itchy butt) irritability,
  insomnia, eneuresis
• Dx scotch tape, no eosinophilia
• Rx albendazole, OTC

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Trichuris trichuria (whipworm)

• Warm, poorly sanitated areas rural, SE US
• Ingest eggs - hatch, larvae migrate to colon -
  head attaches to cecal mucosa - female passes
  eggs into feces
• Eggs must embryonate in soil 3 weeks
• Soil - fingers/food - mouth
• Transmission maintained by indiscriminate
  defecation by children
• Asymptomatic - nausea, diarrhea, abdominal pain
  - anemia, dysentery, rectal prolapse with heavy
  worm burden
• Dx stool OP eosinophilia in heavy infection
• Rx albendazole

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Ascaris lumbricoides

• Warm, poorly sanitated areas SE US
• Ingest eggs - hatch in small bowel - penetrate
  to lymphatics/veins - through liver to lungs -
  penetrate alveoli, travel up bronchi - cough
  swallow - hang out in jejunum 6-18 mo
• Pass eggs into feces
• Eggs must embryonate in soil 3 weeks
• Soil - fingers/food - mouth also inhalation
• Early bronchopneumonia, fever, cough, wheezing,
  eosinophilia - Loefflers syndrome
• Worse w/heavy infection, prior sensitization
• Late abdominal pain, diarrhea, vomiting,
  obstruction of appy, biliary/pancreatic duct
• Dx stool OP - eggs larvae in sputum
• Rx mass Rx, personal hygiene, sanitation

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Hookworm

• Ancylostoma duodenale (old world) Necator
  americanus (new world, including S US)
• Filariform larvae in soil - penetrate skin -
  circulate to pulmonary capillaries - penetrate
  alveoli - up air passages - get swallowed -
  attach to jejunal mucosa with mouth
  (teeth/cutting plates), migrate freely through
  intestine leaving bleeding sites - pass eggs
  into stool - embryonate in soil 1-2 weeks -
  hatch rhabditiform larvae, live free - back to
  filariform
• The nitty gritty parasite-directed penetration,
  crawl around thorough tissues, end up in gut

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Hookworm (2)

• Skin ground itch - red, pruritic rash
  w/previous sensitization
• Lungs Occasional pneumonitis wheezing
• Gut Abdominal pain, anemia, edema
• Dx
• Stool OP
• Larvae in sputum
• Eosinophilia
• Rx albendazole, iron supplementation

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Strongyloides

• Warm, poorly sanitated areas
• Reservoir domestic pets humans are definitive
  host
• Transmitted person- person, from soil
• Filariform larvae penetrate skin - reach veins,
  travel to lungs - coughed up, swallowed - adult
  females burrow into jejunal mucosa - lay eggs -
  hatch in submucosa, release rhabditiform larvae
  - enter feces, then
• To soil back to filariform - infect new host
• To soil mate, live as free adults
• To filariform in colon - penetrate intestinal
  wall or perianal skin (autoinfection)

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Strongyloides (2)

• Skin asymptomatic or red serpiginous lesions
• Lungs Loefflers syndrome w/eosinophilia
• Gut abdominal pain, vomiting, diarrhea, weight
  loss
• Hyperinfection syndrome in immunocompromised,
  due to hyperinfection
• Severe enterocolitis, intestinal ileus, G-
  bacteremia
• Dx eosinophilia, rhabditiforms in stool OP,
  serology
• Rx ivermectin prior to immunosuppression

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Toxocara canis cati

• Europe, USA
• Definitive hosts dogs cats (pets)
• Intermediate hosts humans
• Eggs ingested - hatch, larbae penetrate gut -
  migrate to liver, lungs - pass through pulmonary
  circulation - filtered out in systemic
  capillaries
• larva migrans
• Visceral ages 1-4 fever, HSM, rash, pneumo,
  myocarditis
• Ocular ages 7-8 exudative endophthalmitis
• Dx ELISA, eosinophilia, liver bx - NOT stool
• Rx steroids, deworm pets

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Trichinella spiralis

• Worldwide
• Definitive host humans
• Reservoir rat, pig, bear, cougar
• Ingest encysted larvae in undercooked meat -
  released in small bowel, mate, females burrow
  into mucosa - produces larvae that enter blood
  - through pulmonary circulation - spread to
  skeletal muscle - grow encyst eventually
  calcify die
• Trichinosis
• Diarrhea, abdominal pain, fever 1-2 days post
  ingestion
• 1 week later muscle aches, conjunctivitis,
  muscle pain, occasional CNS, heart involvement
• Dx eosinophilia, serology, muscle Bx
• Rx prevent by cooking pork steroids,
  albendazole

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Anisakis, Pseudoterranova

• Japan, US
• Definitive hosts marine mammals
• Intermediate hosts crustaceans, fish
• Humans are carriers - get when eat raw saltwater
  fish/squid (sushi transmission)
• Eggs released into salt water - larvae hatched,
  infect crustaceans - fish eat crustaceans -
  whales, humans eat fish - larvae penetrate small
  intestine
• Anisakiasis - abdominal pain
• Dx upper GI study
• Rx remove worm

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Dracunculus (guinea worm)

• Africa
• Definitive host humans
• Intermediate hosts crustaceans
• Drink water containing larval form in cycolps
  (crustaceans) - larvae penetrate intestinal
  wall, mate - female crawls through subQ tissue
  to skin - exposes uterus - blister forms,
  ruptures on contact w/H2O - eggs released -
  infect cyclops
• Dracunculiasis
• Allergic sx - n/v, urticaria, dyspnea leg ulcer
• Rx remove worm slowly (worm on a stick)

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Wucheria pacifica, bancroftiBrugia malayi

• Mosquito delivers filariform larvae while feeding
• Humans definitive hosts
• No animal reservoirs
• Filariforms penetrate skin near bite site-
  migrate to lymphatics - mature, mate, spawn
  microfilariae - migrate to blood at night -
  infect new mosquitoes

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Lymphatic filariasis

• Molting of adolescents, dead worms cause
  inflammation lymphatic obstruction
• Periodic lymphadenitis lymphangitis, edema,
  ascites, elephantiasis
• Dx ID microfilariae in blood at night, LN Bx
  reveals aduts
• Rx DEC, steroids, surgery for elephantiasis

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Ancylostoma braziliense

• Warm, moist climates - S. Atlantic/Gulf states
• Definitive hosts dogs cats (their hookworm)
• Carrier humans
• Eggs passed in dog/cat feces - embryonate in
  soil - rhabditiform - filariform - penetrate
  human skin stay there do not mature in humans.
  End of the road for the hapless worm.
• Cutaneous larva migrans
• Severe itching, red linear lesions, Loefflers in
  half
• Complication secondary bacterial infection
• Dx clinical
• Rx topical drug, pet control

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Loa loa(crawls across the eye)

• W and Central Africa
• Vector deerfly
• Reservoir monkey
• Humans are definitive host
• Filariform injected by bite - migrate constantly
  in subQ - produce microfilariae - blood, infect
  new deerfly
• Loiasis
• Calabar swellings - migratory, in extremities,
  due to bugs crawling through tissue - allergic
  reaction
• Crosses eye in subconjunctival space
• Dx eosinophilia, microfilariae in blood
• Rx DEC, steroids, extraction

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Onchocerca volvulus

• Central America, Africa, NE S Am
• Vector black fly
• Definitive host humans
• Filariform injected by bite - hang out in subQ,
  mature - encased in fibrous nodules - produce
  microfilariae - migrate to eyes, skin - infect
  new black fly
• River blindness
• SubQ nodules (adults)
• Lizard skin - pruritic, papular rash (microfil.)
• Corneal ulcer, keratitis, blindness (microfil.)
• Dx skin bx - microfilariae crawl out overnight
  slit lamp
• Rx long-term Ivermectin, mass Tx

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Cestodes (tapeworms)

• Flatworms that live in intestine of host
• Head (scolex) has suckers/hooks for attachment
• Body consists of box-like segments - proglottids
• Hermaphrodites - each segment has male female
  organs autoerotica at its finest
• Distal segments are gravid (fertilized eggs -
  contain fully developed embryos)
• The take home message only one worm needed to
  have lots and lots of baby worms
• Acquire by ingestion
• Of eggs - human is intermediate host
• Of larvae - human is definitive host

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Taenia solium (pork tapeworm)

• Worldwide little in US
• human (or hog) ingests eggs (in feces) - larvae
  hatch, penetrate intestine - blood - cystecerci
  in skeletal muscle, brain
• Cysts grow slowly, begin to die after 5-10 years
• Pig/human is intermediate host
• Human eats cystecerci in hog muscle - converts
  to adult tapeworm in intestine - attaches to gut
  wall w/4 suckers hooklets, passes eggs into
  feces- eggs eaten by hog/human
• Human is (the only) definitive host
• Autoinfection eggs re-ingested by reverse
  peristalsis - cystecerci

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T. solium

• Intestinal disease
• Usually asymptomatic
• Epigastric pain, weight loss, malnutrition
• Cysticercosis
• Sx caused by inflammatory response to dead or
  expanding live larvae
• Fever, muscle pains
• In brain seizures, epilepsy, psychiatric,
  meningitis
• Dx Bx of subQ nodule, calcifications on XR,
  serology, eosinophilia w/active cysts
• Rx praziquantel for intestinal, albendazole
  steroids surgery for cysticercosis

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Hymenolepsis nana (dwarf tapeworm)

• Worldwide most common cestode in US (south)
• Humans are definitive intermediate hosts
  spreads directly by fecal - oral route
• Autoinfection (like pinworm), between kids
• Eggs develop in intestinal epithelium - hatch
  cysticercoid that re-enters lumen - attach to
  mucosa, mature, pass eggs - eggs pass in feces,
  ingested anew
• Usually asymptomatic
• Massive infection abdominal pain, diarrhea
• Dx stool OP
• Rx Praziquantel

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Echinococcus

• See where have sheepherding
• Definitive host dogs, wolves, coyotes
• Intermediate hosts humans, sheep, cattle
• Get from handling dog poo
• Eat eggs - larvae penetrate gut, get to portal
  vein - distributed throughout body, develop into
  cysts (hydatids) - Fill with fluid, brood
  capsules, daughter cysts - carnivore eats flesh
  of intermediate host - matures, lives in
  jejunum, passes eggs into feces

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Echinococcus

• Cysts cause disease by mechanical compression
• Liver - abdominal pain, jaundice
• Lung - cough, chest pain, hemoptysis
• Brain - epilepsy, blindness
• Bone - fracture
• Heart - embolic mets
• Dx CXR, ultrasound, serology little
  eosinophilia except with rupture
• Rx albendazole hypertonic saline/surgery

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Taenia Saginata (beef tapeworm)

• Worldwide
• Definitive host humans
• Intermediates cattle, llamas
• Same as T. solium, but humans dont develop
  cysticerci when they ingest eggs
• Cattle eat eggs in human feces - larvae invade
  cow gut - blood - cysticerci in cow muscle -
  humans kill cow, eat - larvae released, matures,
  lives in jejunum - pass eggs into feces
• Usually asymptomatic
• epigastric pain, weight loss, malnutrition
  impaction of appendix, cystic pancreatic ducts
  possible
• Dx stool OP - eggs, proglottids
• Rx praziquantel, cook/freeze meat to prevent

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Diphyllobothrium (fish tapeworm)

• Europe, Russia, Baltic, Africa, Florida, Great
  Lakes
• Definitive host humans
• Intermediate crustaceans, fresh water fish (vs.
  Anisakis)
• Eggs in human feces - coracidium in water -
  ingested by cyclops (crustacean) - fish eats
  cyclops - penetrates fish flesh, becomes
  plerocercoid larva- human eats fish - matures,
  attaches to ileum, passes eggs into feces for 20
  years
• Usually asymptomatic
• Abdominal pain, cramps, obstruction, pernicious
  anemia (competes for B12)
• Dx stool OP, macrocytic anemia
• Rx praziquantel, cook fish, avoid ludefisk

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Trematodes(flukes)

• All humans are definitive host
• Tissue trematodes
• Get by ingesting metacercariae
• Hermaphrodites
• 2 intermediate hosts
• Blood trematodes
• Get by penetration by cercariae
• Separate sexes
• 1 intermediate host

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Paragonimus

• Far East, Africa, Latin America
• Definitive hosts humans, dog, cat, pig, rat
• Egg embryonates in water - invades snail,
  becomes cercariae - invades crabs/crayfish,
  becomes metacercariae - humans eat raw -
  excyst in duodenum - burrows through peritoneum,
  diaphragm to lung - lays eggs, encysts near
  bronchioles - cough up eggs in sputum or
  swallow, passed in stool

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Paragonimus

• Paragonimiasis
• Most asymptomatic (why, I dont know)
• With heavy infection bronchitis, hemoptysis,
  lung abscess, pleural effusion
• Rarely, fluke gets confused and misses lungs
• Abdominal mass, dysentery
• CNS - paralysis, epilepsy, visual disturbace
• Migratory subQ nodules
• Dx eosinophilic until walled off, CXR, eggs in
  sputum/stool
• Rx praziquantel, cook your crabs

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Clonorchis

• Korea, Japan, China, Vietnam
• Definitive hosts human, dog, cat, rat, pig
• Eggs ingested by snails - penetrate fresh water
  fish, become metacercariae - humans eat fish -
  larvae released in duodenum - ascend biliary
  tract - mature, lay eggs - passed in feces
• Clonorchiasis
• Migratory phase fever, HSM, jaundice,
  eosinophilia
• Adult phase bile duct scarring, portal HTN,
  cholangiocarcinoma
• Dx eosinophilia, elevated alk phos, bilirubin
• Rx praziquantel, cook your fish

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Schistosoma

• Variable distribution by species
• Human is definitive host
• Intermediate host snail
• Egg hatches in fresh water - larvae penetrate
  snails, become cercariae, released into water -
  cercariae penetrate skin - migrate against blood
  flow to portal vein - enter mesenteric vessels,
  travel til can move no farther - deposit egg
  clusters - erode through to a lumen or are
  retained - passed in stool/urine
• Schistosomiasis
• Early phase (migration) flu-like sx, dermatitis
• Intermediate (oviposition) Katayama syndrome -
  allergic response
• Late (retained eggs) tissue damage, varies by
  spp.

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Schistosomiasis

• S. japonicum - tons of eggs depoited, worse sx
• SE Asia, Japan
• Migrates to superior mesenteric vein (small
  bowel, ascending colon - midgut derivs)
• Late sx cirrhosis, ascites, pseudo brain tumor
  (granulomas around eggs in CNS)
• S. mansoni
• S Am, Caribbean, Africa, Middle E
• Migrates to inferior mesenteric vein (colon,
  recutm)
• Late sx abdominal pain, diarrhea, melena, HSM,
  IC nephropathy, transverse myelitis
• S. haematobium
• Africa, Middle E
• Inferior mesenteric vein - through hemorrhoidal
  plexus - submucosal veins of bladder
• Late sx pyelonephritis, renal stones, hematuria,
  bladder carcinoma

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Arthropods

• Infestations, not infections
• Hymenoptera (bees, fire ants) - stings
• Recluse spiders, hobo spider
• Painless bite redness, tenderness, followed by
  eschar, ulcer
• Rarely - fever, HA, n/v, rash, hemolytic anemia,
  renal failure
• Widow spiders
• Neurotoxin - painful muscle cramps
• Lice of body, head, pubic region
• Human - human transmission
• Pruritic red papules
• Mites
• Scabies really itchy burrows papules at body
  creases, finger webbing, person - person spread
• Chiggers itchy, where clothes constrict

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What is an intermediate host for the following
parasites?

• Echinococcus
• Diphyllobothrium
• Schistosoma
• Clonorchis
• Taenia saginata

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What is an intermediate host for the following
parasites?

• Echinococcus humans, sheep, cattle
• Diphyllobothrium
• Schistosoma
• Clonorchis
• Taenia saginata

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What is an intermediate host for the following
parasites?

• Echinococcus humans, sheep, cattle
• Diphyllobothrium fish
• Schistosoma
• Clonorchis
• Taenia saginata

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What is an intermediate host for the following
parasites?

• Echinococcus humans, sheep, cattle
• Diphyllobothrium fish
• Schistosoma snail
• Clonorchis
• Taenia saginata

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What is an intermediate host for the following
parasites?

• Echinococcus humans, sheep, cattle
• Diphyllobothrium fish
• Schistosoma snail
• Clonorchis fish
• Taenia saginata

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What is an intermediate host for the following
parasites?

• Echinococcus humans, sheep, cattle
• Diphyllobothrium fish
• Schistosoma snail
• Clonorchis fish
• Taenia saginata cattle

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What is one essential test to perform on people
who are about to be immunosuppressed, who have
spent time in the developing world or the rural S
US?

• Blood smears for malaria
• Serology for Strongyloides
• Stool exam for Trichuris
• Serology for Necator

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What is one essential test to perform on people
who are about to be immunosuppressed, who have
spent time in the developing world or the rural S
US?

• Blood smears for malaria
• Serology for Strongyloides
• Stool exam for Trichuris
• Serology for Necator

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Eating raw vegetables that have been fertilized
with human feces can cause infection with all of
the following parasites EXCEPT

• Entamoeba histolytica
• Paragonimus westermani
• Trichuris trichuria
• Ascaris lumbricoides
• Giardia lamblia

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Eating raw vegetables that have been fertilized
with human feces can cause infection with all of
the following parasites EXCEPT

• Entamoeba histolytica
• Paragonimus westermani
• Trichuris trichuria
• Ascaris lumbricoides
• Giardia lamblia

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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Match the organ(s) affected by infection with the
parasite

• Plamodium falciparum skin
• Trichuris trichuria gut skeletal m.
• Taenia saginatum gut
• Trichinella spiralis gut CNS
• Leishmania mexicana blood CNS
• Ancylostoma braziliense

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All of the following cause lesions affecting the
eye EXCEPT

• Trypanosoma brucei gambiense
• Onchocerca
• Loa loa
• Toxoplasma gondii
• Acanthamoeba

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All of the following cause lesions affecting the
eye EXCEPT

• Trypanosoma brucei gambiense
• Onchocerca
• Loa loa
• Toxoplasma gondii
• Acanthamoeba

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Take a 5 minute break