More helminths and ectoparasites Flashcards
How to treat crusted scabies?
Topical pemethrin daily for 1 week then twice weekly
PLUS
ivermectin 1,2,8,9,15 (maybe 22 and 29)
treatment for normal scabies?
Permethrin apply for 8 hours then repeat 1 wk later
OR
malathion apply for 24 hours then repeat 1 week later
What causes larva currens?
Diagnosis?
Treatment?
strongyloides stercoralis
Diagnosis: enterotest (string test/duodenal aspirate) coz stool microscopy notoriuously insensitie (<50%)
Tx: ivermectin stat x2
or albendazole 400mg bd 3-7 days
What causes hookworm infection?
treatment?
Ancylostoma duodenale/necator americanus
Tx: albendazole stat/mebendazole 3 days
What causes cutaneous larva migrans?
How to differentiate it clinically from larva currens?
treatment?
Ancylostoma braziliense/ancylostoma caninum
Cutaneous larva migrans is slower (1cm/hr) whilst larva currens is faster (1cm/5min)
Tx: ivermectin
What causes visceral larva migrans?
Treatment?
Toxocara canis/toxacara cati
Tx:albendazole BD for 2 weeks
if pulmonary/cns/cardiac, add steroids
What causes ocular toxocariasis?
How does it present?
treatment?
toxacara canis/toxocara cati
Presentation: child/adult w puppy exposure, visual impairment and white elevated granuloma on eye
(may have uveitis/papilitis/endophthalmitis)
Tx: albendazole+steroids
What is the scientific name for pinworm?
where does it reside?
Treatment?
Enterobius vermicularis
resides in caecum & colon
Tx; albendazole/mebendazole stat, repeat at 2 weeks
(used to get it at Bangi)
The roundworms are generally treated with albendazole.
Very few are treated with ivermectin - which are
these?
Which ones are for DEC?
The few roundworms treated with ivermectin are
onchocerciasis and all the ones with ‘larva’ in their name:
- larva currens (strongyloides)
- cutaneous larva migrans (ancylostoma braziliense, ancylostoma caninum)
- visceral larva migrans (toxocara canis/cati)
DEC: lymphatic filiriasis, loaisis
What is the treatment for trichuris trichiura?
Where does it reside in humans?
Albendazole 3 days
Lives in Caecum or colon
What causes trichinosis?
Clinical manifestations?
Treatment?
Trichinella (roundworm group) from pigs/rats
cysts disseminate in blood stream and seed skeletal muscle
Tx: usually mild and self-limiting
if cns/cardiac/pulmonary=albendazole bd for 2wks+steroids
pt with lymphatic filiriasis on blood smear taken between 10pm to 2am.
<2500 loa-loa microfilariae/ml
How to treat?
DEC daily for 12 days
plus doxycycline 4-6wks
pt with lymphatic filiriasis on blood smear taken between 10pm to 2am.
>2500 loa-loa microfilariae/ml
How to treat?
doxy 4-6 weeks
or
albendazole 21 days
(albendazole affects adult worms only, not microfilariae)
What causes Calabar swellings?
Loa-loa worm
pt with lymphatic filiriasis, also got con-comitant onchocerciasis.
How to treat?
ivermectin first,
then DEC+doxy for LF
Which transmits Loa loa?
Treatment?
Chrysops fly (tabanid, horse or deer fly)
Tx: DEC 21 days to kill microfilariae
(doesn’t kill adult worms, have to wait for adult worms to die).
Treatment for Onchocerca volvolus?
ivermectin (kills microfilaria and adult worms)
plus
DOXYCYCLINE (due to Wolbachia)
Treatment for taenia solium/saginata intestinal infection
stat praziquantel or stat niclosamide
pt has operculated egg isolated from stool. reports dizziness, salt craving. has megaloblastic anaemia.
Japanese who loves seafood.
Possible causative organism?
Treatment?
Diphyllobothrium latum (fish tapeworm)
treatment: stat praziquantel or niclosamide
Which is the only tapeworm that can be transmitted from human-to-human?
Treatment?
Hymenolepsis nana (dwarf tapeworm)
diagnosed by eggs (which have characteristic double membrane)
Tx: praziquantel higher dose 25mg/kg stat
or niclosamide daily for 1 week
Schistosoma intercalatum. Which area?
what does it cause?
Treatment?
Central and West Africa
Intestinal schistosomiasis
stat praziquantel
chinese liver fluke. What’s the causative organism?
Ingested at which stage?
How to treat?
Clonorchis sinensis.
adult worms inhabit bile capillaries, deposit eggs,
which are released into water and eggs ingested by snails. Inside snail, eggs hatch into miracidia. miracidia multiply into cercariae that pass into water, encyst on fish as metacercariae. HUMANS INGEST METACERCARIAE.
Tx: high-dose praziquantel 25mg/kg tds for 2 days
Which Opisthorcis species is associated with cholangiocarcinoma in Thailand?
Opisthorcis viveriini
(dog liver fluke)
Pt likes to eat pickled crabs. One day, she reports fever, pleuritic chest pain, cough productive of brown sputum, intermittent haemoptysis. cough showed below. A few days later she developed lung abcess.
What is the diagnosis? How to treat?
Paragonimus westermaani (lung fluke).
Adults live in lungs, eggs are released which are coughed up/swallowed and enter feces. In water,eggs release miracidia which infect intermediate snail host. after 3-5 months, snail releases cercaria which infect crustaceans (crabs&crayfish) and encyst in their tissue.
Tx: praziquantel tds for 2 days, or biothonol
Which two intestinal flukes are due to metacercaria encysted onto aquatic plants?
Treatment for each?
Fasciola hepatica - triclabendazole stat
fasciolopsis buski - praziquantel tds for 1 day
Child in South America presents with symptoms mimicking appendicitis, with eosinophilia. house has rats. eats from family farm contaminated with slugs.
Which fluke,and what treatment?
Rat lung worm = angiostrongylus cantonensis
Tx: laparatomy to remove infected tissue
OR DEC with tiabendazole
Anisakiasis. pt presents with symptoms of gastric anisakiasis (abdo pain, nausea, vomitting) 48 hours after ingestion. What causative agent, and how to treat?
Phocanema
treatment: usually improve spontaneously.
may be faster if worms removed endoscopically.
Causes of eosinophilic meningitis
Rat Gnawed Pig Shit To Coccyx
(Ratlungworm,Gnathostomiasis, neurocystercicosis, schistosomiasis, toxocariasis, coccidiodomycosis-paracoccidiodomycosis)
Furunculoid Myiasis is caused by….
Ophthalmomyiasis is caused by…
Wound myasis is caused by…
Furunculoid myiasis
- Tumbu fly (africa) - cordylobia anthropophaga
- botfly - Latin America - dermatobia homin
Ophthalmomyiasis - Oestrus ovis (sheep botfly)
Wound myiasis - C.hominivorax (new world screwworm) or C.bezziana (old world screwworm)
3 diseases caused by human lice (pediculosis) and their treatment.
- Epidemic typhus - R.prowazekii - doxycycline7days (even if kid given mortality)
- Trench fever - Bartonella quintana - fever, rash, splenomegaly/endocarditis. tx: 4-6wks macrolide+doxy. if endocarditis:surgery and very prolonged Ax.
- Relapsing fever- Borrelia recurrentis - stat doxy
The flukes are generally treated with praziquantel, except few (at least 3). Which are these?
- Fasciola hepatica - triclabendazole stat
- Capillaria philippinensis (capillariasis) - mebendazole
- Eosinophilic meningitis due to rat lung worm (angiostrongyliasis cantonensis) = steroids/albendazole 14days +-therapeutic LP
How do anti-helminthics work?
Disrupting tegument and intestine by preventing microtubule formation. this affects glucose uptake by adult and larval stages.
what is tropical pulmonary eosinophilia?
Treatment?
hypersensitivity reaction to lymphatic filiriasis worms (Wucheria bancrofti and brugia malayi)
often seen in visitors to areas (NOT LOCALS)
Treatment: DEC. consider steroids if on-going alveolitis/fibrosis (exclude strongyloides first)
What is Loeffler’s syndrome?
Treatment?
Transient respiratory illness associated with blood eosinophilia and respiratory shadowing.
caused by larval migration of worm through resp tract (Ascaris, hookworm, strongyloides)
tx; as per individual species. if results negative, empirically albendazole for 3 days.
How to treat katayama fever?
stat praziquantel, then rpt at 6-8weeks. initial serology may be negative. diagnosis is clinical.
Schistosomiasis - which species to which snail?
S.haematobium - bulinus
S.japonicum - oncomelania
S.mansoni - biomphalaria
