HELMINTHS Flashcards
Chronic infection with this hookworm constitutes an important cause of anemia worldwide
Ancylostoma duodenale
-leads to Fe-DEFICIENCY ANEMIA because each worm consumes as much as 0.25 ml blood/day
Most common helminth infection in humans worldwide
Ascardis lumbricoides
-as much as 1/4 OF THE WORLD POPULATION is infected; infection causes GI OBSTRUCTION, granulomas of the biliary tree, liver abscesses, and HYPERSENSITIVITY PNEUMONITIS
Infection is associated with damage to the biliary tract and the development of cholangiocarcinoma
Clonorchis sinensis
-associated with consumption of INFECTED FRESHWATER FISH
Infection can be associated with megaloblastic anemia
Diphyllobothrium latum
-this enormous fish tapeworm absorbs dietary vitamin B12, resulting in B12 DEFICIENCY in the host
Removal of this nematode is traditionally accomplished by slowly twisting it around a stick to remove it from beneath the skin
Dracunculus medinensis
-infection is acquired by consuming water contaminated by the INTERMEDIATE HOST, the CYCLOPS, a microscopic crustacean
Larvae form large space-occupying hydatid cysts in the liver and lung, and leakage of fluid can result in anaphylaxis
Echinococcus granulosus (dog tapeworm)
-because herbivoers such as SHEEP are usually an INTERMEDIATE HOST for the dog tapeworm, infection commonly presents in the context of a SHEEP FARMER with many SHEEPDOGS
Causes perianal pruritus, with diagnosis confirmed by recovery of eggs from the anus with scotch tape
Enterobius vermicularis (pinworm)
-MOST COMMON HELMINTH INFECTION IN THE US and often associated with DAY-CARE INSTITUTIONS
Infection can result in subcutaneous “caliber” swellings and can be seen migrating across the eye beneath the conjunctiva
Loa loa
-infection is transmitted by the bite of the MANGO FLY, Chrysops
Endemic to africa, especially along river basins, infection can result in River blindness
Oncocerca volvulus
-transmitted by the BLACKFLY, this nematode also causes loss of elasticity of the skin with significant dependent edema [i.e., HANGING GROIN]
Infection of the bladder is associated with the development of squamous cell carcinoma of the bladder
Schistosoma hematobium
-endemic to EGYPT AND SUDAN and associated with wading through MOIST SOIL WHILE BAREFOOT; diagnosis is confirmed by finding SPHERICAL EGGS with a TERMINAL SPINE in the URINE
The smallest of all intestinal nematodes, high worm burden is possibly the result of autoinfection
Strongyloides stercoralis
-it is the only intestinal nematode capable of COMPLETING ITS LIFE CYCLE WITHIN THE HUMAN HOST
One of the most common cestode infections in the US and associated with the consumption of improperly cooked contaminated beef
Taenia saginata (beef tapeworm)
-usually results in vague abdominal pain, although the tapeworm can grow to SEVERAL METERS IN LENGTH
Infection with the larval form of this tapeworm from feces-contaminated water can lead to cyticercosis
Taenia solium (pork tapeworm)
-results in the growth of the larvae in the brain, resulting in a SWISS CHEESE APPEARANCE of the cerebral hemispheres
Accidental transmission of these nematodes from pet feces (in sandboxes or on sandy beaches) results in Visceral larva migrans
Toxocara canis and Toxocara cati
-symptoms include eosinophilia, pneumonitis, and VISION LOSS
Infection is acquired by consuming cysts in undercooked contaminated pork
Trichinella spiralis
-infection results in flu-like symptoms, diarrhea, MYALGIAS, and PERIORBITAL EDEMA
