L18: Blood and Tissue Nematodes Flashcards
What are filarial worms
thread like parasitic roundworms
transmitted by anthropods
cause filarisis
minor ones are: loa loa and mansoella
mostly in africa, asia south america - hot places
What is the general life cycle
all very simialr
females are oviviparious and prodiuce microfilaroa
microfili are small thread like larvae that infect the arthopods
humans blood swelling => sheathed
human tissue swelling => unseathed
can stay for years
Explain periodicity
microfilaria are in peripheal blood the numbers increase at peak biting times of insect vector
they can accumilate in vesses of lung and liver, important diagnostic factor
What are the 4 types of periodcity
- Nocturnal periodicity: Microfilariae are present in greatest numbers in the peripheral blood during night hours
- Diurnal periodicity: Microfilariae are present in greatest numbers in the peripheral blood during day hours
- Nocturnal subperiodicity: Microfilariae are present in the peripheral blood 24 hours a day, with slightly higher numbers
during night hours - Diurnal subperiodicity
Clinical Presentation of Bancroftian filariasis
males: lympatic glands of groun and epidymous swell
females: … of labial and mammary glands
disease from living/disintergrating or dead worms in regional areas they can be asymptomaitc in inhibuation, acute inflammarory of chronic obstructive
severe cases cause build of tissue called elelphantaisis and hydrocele
stopped at slide 10
What is brancroftian filariasis caused by
Prescence of living/degenerating and dead worms in regional arrays they can be asymptomatic, acute inflammatory of chronic
Severe cases may cause elphantites => secondary infection OR
Hydrocele
How do you diagnosis brancroftian filariasis/ treatment
History, microfillary during periodicity treatment with DEC or albe/ivor
Why is B.crofti unique
Only parasitic inn humans, greatest contributor to lymphatic filariasis
Burgia can also infect monkeys/cats
What is Dirofilaria immit
Vector borne filariasis nematodes associated with carnivorous hoses
Dogs/cats
Causes dog heartworm/dirofilariasis
US/Canada problem, risk during mosquito feeding times
Clinical presentation of D.immitis in Dogs vs Cats
Dog heart with worms, tired, collapsing can lead to heart failure, breathing problems, weight loss
Die faster cause not natural host, have lower burden => heart and lung failure
D.immitis in man’s
Not natural host usually larva doesn’t survive but the dead worms cause lung granulomas and nodules in other tissues
Cause ocular dirofilarires
How to diagnose and treat D.immiti
Dogs/cats: see signs, extras for humans see granules and pulmonary lesions
Treatment in dogs: Iver or Doxy
Cats: nothing
Humans: remove granules
What is onchocera volvulus
Causes river blindness, humans are only host
Infects black flies
Adult worm in onchocercomas
Microfilaria can migrate and cause other issues
What are onchocermomas
Subcutaneous nodules that form when worm becomes encapsulated in subcutaneous tissue produced from host inflammatory response
Clinical presentation of Onchocerciasis
Disease from host inflammatory response
Nodules in different body parts, firm smooth rubbery with microfiliaires
Skin disease
Allergic reaction to microfilaries, dermatites, wrinkled, depigmended cracked
Blindness
Invade cornea cause cause inflammation => fibrous tissues
Slowly become blind
What is significant about Onchocerciasis
Low socioeconomic areas, NTD
Diagnosis and treatment of Onchocerciases
Clinical signs, do skin snips to see worms
Use ivermectin to paralyse the worm so it can’t evade other places so the host immune system can kill it but if encased in ochoromoas then doesnt work
What is D.medinensis
Tissue nematode cause dranculciase / Guinea worm disease, almost eradicated
Long thin but NOT TRUE filariel
Female larger than male
Humans are definitive host but can infect mets, intermediate hosts are Copepod crustaisans
Clinical signs of Dracunculiasis
Symptoms come after a year, an ulcer forms as the worm emerges cause secondary infections like Tetanus, gangrene
If the join is involved it can become arthritic
Diagnosis and Treatment of Dracunculiasis
Pour water on ulcer so rhabidform larvae come out no species drugs just remove it
1, water
2. Use stick to wind it out without breaking it which will release larva in tissue
3. Antibiotics
4. Pain relievers
How to control Dracunculiasis
CLEAN WATER, vector control, make sure ur dogs dont bring it home
Worm filter cloth
Cope code crustacean /fish make sure dogs dont eat it
