N251 exam 4: lecture 5

very frequently

microscopic or near microscopic

Tongue-eating louse

Parasitic crustacean that attaches and consumes a fish's tongue and eventually replaces it.

types of parasites

Protzoans
singe celled eukaryotic organisms:
-malaria
-giardia

Anthropods
-bot fly
-tick

Worms
-hookwarms
-roundworms
-pinworms
-tapeworms

malaria

protozoa

-carried by anopheles mosquitos

-fever, chills, and flu symptoms

-sever complications can develop and lead to death

-about 1500 us cases per year: mainly from travelers and people from other countries where malaria is more common

plasmotian parasite

-pregnant women are at very high risk of dying

-10,000 travelers are reported of becoming ill with malaria after they come home

-every 60 seconds a child dies from malaria in africa

life cycle of malaria

1. anophele mosquito bites a human (parasite is in sporozoite stage)
2. enter the blood and sporozoites will head to liver
3. transform in liver and become merozites
4. leave the liver
5. infect RBC
6. form a ring in RBC
7. tropozoite then schizont forms
8. merozoits will rupture from rbc and infect others
AT THE SAME TIME
-gametocytes (part of sexual phase)- will get then taken up into another mosquito
and then female will become macrogameotcites and males microgametocites
-will join together and zygote is formed
-goes through DNA replication
-then ookinetes form and forms cysts then will release into salivary glands sperozilites to be transferred to another human host

giardia

protozoa
-in the US
-long distance hiking where water is an issue
-can be in water sources that may be on trails
-water will need to be filtered or treated to kill
-can also be on infected foods

1. human ingests the cyst that giardia forms
2. giardia emerges and goes through asexual replication (happens in GI tract) some poeple will show symptoms in this phase-diarrhea, or could have none
3. become cysts again and travel through digestive
4. come out in the feces
5. can survive for extended periods of times and can handle a lot of temps
6. can wind up in a water supply or food

Giardiasis

infection caused by a protozoa, causing vomiting, cramping, and diarrhea, gas, bloating
-close contact
-problem in day care centers
-unprotected anal sex
-untreated water

human bot fly

in south america
-only in north america if they travel with someone
-large buzzing fly
-huge

female bot fly will tackle a female mosquito and forcefully lay legs on mosquito
-eggs will sense body temp when mosquito lands and egg will hatch and crawl into the hole that the mosquito lays
-will emerge from skin
-usually tackle smaller blood sucking fly

adult human bot fly does not eat
-produce chemicals so we dont feel them

botfly removal from
-lips,
-boys head

ticks

carry several types of disease
-rocky mountain spotted fever
-lyme disease
-anaplasmosis

life cycle of deer tick: 2 year

1. typically feed in fall or get blood meal in dear in spring
2. can lay 3000 eggs
3. hatch in early august
4. become 6 legged larvae and look a small blood meal
5. larvae will remain dormant until the spring- they are very tiny
6. will molt into an 8 legged nymph
7. often come in contact with humans or dogs, often when lime disease gets spread
8. august: molt into an adult and need a third blood feeding
-females need this to produce their eggs and males need it to produce sperm-typically in fall
9. go through winter and start cycle over

babesia

tic borne disease
-protozoan
-mice are desired host
1. feed on white footed mouse
2. go through binary fission
3. will infect more blood cells
4. some will become gametocytes
5. another tic feeds on mouse and pics up gametocytes and gametogenesis happens

if it winds up in humans, will get sick but usually wont be picked up again by a tic

tic is vector

hookworms

-small worm that enters through the skin and eventually migrate to the small intestine

1. larvae will hatch and develop in the soil
2. climb up on grass and hook onto the person
3. penetrate the skin and enter the blood stream
4. larvae travel to the lungs and get into alveolar spaces and get people to cough
5. get coughed up and swallowed
6. get to small intestine and produce eggs
7. pass onto feces and then hatch and infect again

dont have them much here because of where feces gets deposited

roundworms

Ascaris lumbricoides
-large intestinal nematode or roundworm
-very common

1. eggs wind up on food (Carrots)
2. hatch in small intestine
3. larvae then released
4. penetrate intestine and get into blood stream
5. head to lungs
6. go across epiglottis and get swallowed to get to digestive
7. grow in intestines to produce eggs that get passed with feces

problems:
-can travel throughout body and climb out nose or tear duct
-can get large numbers in intestines
-they absorb nutrients and cause vitamin deficiency

pinworms

the common pinworm or threadworm
-enterobius vermicularis

most common nematode infection
-complete life cycle occurs in human host

adult=colon
female will move to child anal area and deposit eggs- causes an itching sensation and gets eggs under fingernails to another person
-often a doorknob and will move from host to host

Enterobiasis

anal itching, especially at night can led to pelvic inflammatory disease or vaginitis

tapeworms

intestinal tape worm
-echinococcus granulosus
-head is full of hooks that helps them hold on to where they want to stay
-further back from head the more mature
-want to be intestines
-dogs are a really good host

transmitted fecal-orally

THREE DOG NIGHT
-a night thats so cold that you need three dogs to keep you warm

hydatid disease

Caused by the tapeworm Echinococcus granulosus
Eggs are ingested and migrate to the liver, lungs, or brain
Develops a hydatid cyst
Can grow and hold up to 15 liters of fluid
May rupture, causing anaphylactic shock
Diagnosis with serological tests, X rays, CT, and MRI
Treatment with surgical removal or albendazole

can be mistaken for cancer