Will a single dose of albendazole 200mg-10ml cause aplastic anemia or immune def to a 4.5 yrs old?

Doubtful: Although albendazole has listed in its side-effect profile 'agranulocytosis' or aplastic anemia-it actually has an extremely good track record of safety. Most of the very rare toxicity comes in with prolonged use -as in WEEKS of treatment (for various refractory parasitic infections). I highly doubt ur child developed aplastic anemia or immunodeficiency from this med. I would look for other causes