Lecture 11.2 2/19/24 Flashcards
What are the characteristics of Onchocerca?
-aka nodular worm
-IH is biting flies
-DH is horses/cattle/people/dogs
-males 40 cm
-females 75 cm
-mf 250-350 um
-PPP of 1 yr
Which Onchocerca spp. are present in horses?
-O. cervicalis: infects nuchal ligament
-O. reticulata: infects connective tissue of flexor tendons/suspensory ligament of fetlock
What is the main clinical sign associated with Onchocerca spp. in horses?
pruritic dermatitis due to mf lodging in skin
What are the characteristics of Onchocerca prevention and treatment in horses?
-avoid Culicoides (active at dusk/night)
-kill adults via ivermectin/moxidectin
What are the characteristics of Onchocerca lupi?
-DH is mainly dogs, as well as cats and people
-unknown IH
-found in large granulomatous nodules in the eye
What are the clinical signs associated with Onchocerca lupi?
-conjunctivitis
-photophobia
-lacrimation
-ocular discharge
-keratitis
-retrobulbar granuloma
-exophthalmia
How is Onchocerca lupi diagnosed?
-recovery of worm
-PCR
-detection of microfilariae
How is Onchocerca lupi treated?
-surgical removal
-ivermectin
-doxycycline to control Wolbachia
Is Onchocerca lupi of human health concern?
yes, it is zoonotic
Why does Onchocerca mf in the skin not require treatment to prevent it from going to the eye?
the microfilaria cannot become infectious without going through the IH
What are the characteristics of Dracunculus?
-aka guinea worm
-IH is copepod
-DH is dogs/cats/raccoons/people/other mammals
-male 40 mm
-female 120 cm
-L1 500-760 um
-PPP 1 year
Why is it important that the guinea worm causes hosts to want to enter water?
-female will extrude repro. organs when exposed to water
-will release larvae into water, where it can infect copepod IH
What is the main clinical sign of Dracunculus?
painful lesion at emergence site
How is Dracunculus diagnosed?
lesion with protruding worm containing long-tailed larvae
How is Dracunculus prevented and treated?
-avoid contaminated water
-surgical excision
