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Microbiology ` microbiology—Parasitology Microbiology ` microbiology—Parasitology SEcTioN ii 161

Ectoparasites
Sarcoptes scabiei Mites burrow into stratum corneum and Common in children, crowded populations
A cause scabies—pruritus (worse at night) and (jails, nursing homes); transmission through
serpiginous burrows (lines) often between skin-to-skin contact (most common) or via
fingers and toes A . fomites.
Treatment: permethrin cream, washing/drying
all clothing/bedding, treat close contacts.

Pediculus humanus/ Blood-sucking lice that cause intense pruritus Body lice can transmit Rickettsia prowazekii
Phthirus pubis with associated excoriations, commonly on (epidemic typhus), Borrelia recurrentis (relapsing
scalp and neck (head lice), waistband and fever), Bartonella quintana (trench fever).
B
axilla (body lice), or pubic and perianal Treatment: pyrethroids, malathion, or ivermectin
regions (pubic lice). lotion, and nit B combing. Children with head
lice can be treated at home without interrupting
school attendance.

Parasite hints associatioNs orgaNism
Biliary tract disease, cholangiocarcinoma Clonorchis sinensis
Brain cysts, seizures Taenia solium (neurocysticercosis)
Hematuria, squamous cell bladder cancer Schistosoma haematobium
Liver (hydatid) cysts Echinococcus granulosus
Microcytic anemia Ancylostoma, Necator
Myalgias, periorbital edema Trichinella spiralis
Perianal pruritus Enterobius
Portal hypertension Schistosoma mansoni, Schistosoma japonicum

Vitamin B 12 deficiency Diphyllobothrium latum

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