Please enable JavaScript.
Coggle requires JavaScript to display documents.
Intestinal Nematodes (ii) (Stronglyoides stercoralis (complicated…
Intestinal Nematodes (ii)
Stronglyoides stercoralis
tropics + subtropics
SE Asia, SSA, Latin America, Caribbean
rarely in temperate climates
affects 30-100 million worldwide
common in institutions
v small - female adults 2 mm
infective filariform larvae penetrate (burrow through) intact skin to blood
go to alveoli (lung maturation phase)
move up trachea + get swallowed
females mature in SI, penetrate intestinal mucosa
rhabdatidiform larvae passed in stool (usually non-infectious, no eggs)
autoinfective cycle: larvae in stool become infective
Independent life cycle in soil
infection persists for decades
larva currens
cut condition
serpiginous wheel (wavy red lesion) with surrounding flare
comes + goes in a few hrs
itchy
incubation period = 1 month
small bowel pathogen
often asymptomatic
primary infection
rash for 3 wks
resp symptoms during larval migration
abdo discomfort
diarrhoea
chronic strongyloidiasis
may persist for decades
has classic symptoms
mild non-specific GI upset
abdo pain (epigastric + RUQ)
weight loss
complicated infection
usually in debilitated patients
sprue-like syndrome
steatorrhoea
protein losing enteropathy (low albumin, oedema)
abdo pain
vomiting
diarrhoea
sepsis-like picture
obstruction/ileus (lack of movement leading to buildup)
Pul syndrome
SOB
cough
wheeze
pneumonitis
pul abscess
neuro complications
can ruin transplants - screen
hyperinfection syndrome
overwhelming infection in immunodeficient/suppressed
steroids
drugs
post-transplant
chemo
HTLV1
malnutrition
rare with HIV
screen all @ risk patients
severe + bloody diarrhoea
bowel inflamm
micro-perforations
gram -ve sepsis (salmonella)
meningitis/encephalitis (bacterial)
Pul exudates, haemoptysis, effusions
Tx with antihelminthics + directed tx
Dx
clinical
diarrhoea
abdo pain
urticaria
larva currens (pathognomonic)
lab
eosinophilia (rare in hyper infection)
serum IgE raised
culture on charcoal medium
serology - ELISA
Tx
Ivermectin 200ug/kg/day for 3 days (once off may also work)
albendazole 400mg/d or 400mg/BD for 3 days (7 days if chronic)
thiabendazole 5 mg/kg BD for 3 days
Hookworms
acylostoma duodenale
necator americanus
non-infectious eggs passed in stool (NB safe sewage disposal system) + hatch in warm damp soil (24-32 degrees) as rhabditoform larvae
filariform larvae penetrate human skin on contact, esp in poorer countries where people don't wear shoes outside
lung stage: filariform larvae travel to lung following piercing of skin
have mouth, teeth/cutting plates, pharynx, oesophagus, anus
suction - adults attach to mucosa of SI
primary infection
ground itch @ site of entry - often expats
lung stage @ 1-2 wks: dry cough, wheeze, fever, eosinophilia
self-limiting 2-3 months
may be followed by abdo pain
adult worms
blood suckers
symptoms related to Fe-deficient anaemia
nutritional hypoproteinaemia
may lead to high output cardiac failure
children + pregnant women @ highest risk
A duodenale eats 0.15-0.26 ml/day
N Americanus eats 0.03 ml day
lay 9000-30000 eggs/day
<25 worms is insignificant, 500-1000 worms gives disease
eosinophilia
eggs in stool on microscopy (conc methods may be needed)
Tx
single dose albendazole (400mg)
mebendazole 100 mg BD x 3 days
tx fe deficient anaemia