Nemotods Flashcards
Basic characteristics nematod
bilaterally symetrical pseudoceolomate longitudinal muscles only (sinusoidal movement) dioecious true mouth and anus require warm moist soil for eggs.
Trichuris trichiura
whip worms DH: humans direct life cycle found in tropics because of environment eggs are infective stage transmission due to breakdown in sanitation
T. trichiura pathology, diagnosis, treatment, prevention
dysentary, bloody stool, anemia, rectal prolapse, physical and mental retardation
fecal exam for eggs
abendazole
mass treatment of children regardless of infection status
Trichinella spiralis
cosmopolitan
indirect life cycle
same host is DH and IH
infects humans, pigs, rats, and mammals
T. spiralis life cycle
DH ingests nurse cells with J1
J1 develops to adult in gut
Produces more J1
J1 migrate to muscle tissue go intracellular
Hijack gene expression to feed parasite, becomes nurse cell
DH consumes nurse cell form undercooked meat
T. spiralis domestic cycle
important to human health
pigs and rats
transmission facilitated by human practices of feeding pigs trash/ground up pigs parts
T. spiralis sylvatic cycle
tropical, temperate and arctic hosts
T. spiralis pathology
happens at three stages:
- enteric: nonspecific, misdiagnosed as food poisoning
- migratory: rupture of blood vessels, swelling. death depending on location and intensity.
- muscle: extreme muscle pain, inflammation, death depending on location and intensity
T. spiralis diagnosis and treatment
muscle biopsy
can only be treated during enteric stage. prevention is best. Cook pork all the way through!
Capillaria hepatica
DH: rodents
adults in liver
IMPORTANCE: host must die for transmission
transmitted when (1) mouse dies, rots, eggs exposed to environment and consumed by DH or (2) mouse eaten, digested, eggs released by consumer, exposed to environment and then eaten by rodent.
Dioctophyme renale
DH: mammals
adults in right kidney only
importance: host must stay alive for transmission
Strongyloides stercoralis
tropical parasite
transmitted because of sanitation breakdowns
DH: humans
RH: dogs
parasitic free-living life cycles. Autoinfection also
Treatment: Ivermectin
Diagnosis: fecal smear for J1
S. stercoralis pathology
- penetration site: pain, dermatitis
- migration from heart to lungs to gut
swelling, redness, pnuemonia-like - intestinal once adults establish infection
symptoms are intensity dependent; tissue damage, ulcers
Necatur americanus
Ancylostoma duodenale
DH: humans
cosmopolitan in tropics was in US SE.
eggs passed with feces, J3 penetrate into host
N. americanus and A. duodenale pathology/diagnosis/treatment/prevention
- penetration
- migration
- intestinal: dependent on intensity, species, and host nutritional status. characterized by high blood loss, iron deficiency anemia, protien deficiency
fecal exam for eggs (I think)
Albendazole
education and wearing shoes/using toilets
Ancyostoma caninum
Ancyostoma braziliense
general, pathology, treatment, control
affect cats at dogs in US can cause Creeping Eruptions/Cutaneous Larvae Migration in humans because of wandering worms ALbendazole cream clean up after dogs/cats
Ascaris lumbricoides
Giant Intestinal Worm cosmopolitan globally: largest global spread and most common soil transmitted helmentheis DH: humans spread by fecal contamination of soil infective stage: eggs
A. lumbricoides pathology/diagnosis/treatment
migration (pnuemonia-like, coughing) in gut (intestinal blockage) wandering worms when females searching for males fecal exam for eggs Albendazole
hookworms
N. americanus
A. duodenale
A. caninum
A. braziliense
Toxocara canis
Toxocara cali
Brayisascaris procyonis
dogs cats racoons cause visceral larva migrans in human when human ingests eggs. J3 hatches and wanders through tissue and can end up anywhere. Tx: Albendazole but difficult
Enterobius vermicularis
pin worm
cosmopolitan in temperate areas
DH: humans
monoxenous; literal hand-to-mouth transmission
E. vermicularis pathology/treatment/Diagnosis
not much
albendazole and then heat house up to kill eggs
Scotch Tape Test for eggs or just look for worms in butt
risk factors/control/clinical manifestation/diagnosis of soil transmitted helminthes
- poor sanitation of human feces leading to contamination of soil, food, and water
- sanitation and hygiene
- adverse effects of parasite in intestine (malnutrition diarrhea) and mental and physical retardation
- eggs in feces except for Strongyles
Human Lymphatic Filariasis/Elephantiatis
caused by Wuchererua bancrofti, Brugia malayi, and Brugia timori
DH: humans
IH: mosquitoes (Culex pipens in urban areas and Anopheles spp. in rural areas)
J3 is human infective stage
Periodicity
microfilariae (infective stage to IH) circulates in blood only when mosquito vectors is active and is in tissue otherwise.
Pathology, diagnosis, treatment HLF/Elephantiatis
lymphanema-massive lymph swolling, accumulate of lymph fluids in lower extremities
Hydrococle-swollen scrotum
secondary infection because of cracks/hardening skin
blood smear for microfilaria or use Card (?) test for antigens in blood
DEC in areas without river blindness, Ivermectin in river blindness endemic areas
xenomonitoring
using PCR to detect filarial worm DNA in pools of wild caught mosquitos to determine if parasite is still endemic in an area
cannot detect if mosquito is capable of transmitting disease
Lymphatic Filariasis in Egypt
W. bancrofti endemic in delta area, around Aswam high Dam
vector: Culex pipiens pipiens
dam increased prevalence because of standing water
only hydrococle no lymphanema
Lymphatic Filariasis in Papua New Guinea
all forms of lymphatic filariasis present
1 million infected, 4 million at risk with W. bancrofti
10-92% prevalence
endemic with malaria
Onchocerca volvulus
causes River Blindness
endemic in West Africa and Central/South America
DH: humans
IH: Black fly (F. simulidae and G. simulian spp.)
