Parasitic Infections, by Organ System and Signs/Symptoms | |||
| ORGAN SYSTEM, MAJOR SIGN(S)/SYMPTOM(S) | PARASITE(S) | GEOGRAPHIC DISTRIBUTION | COMMENTS |
|---|---|---|---|
| Skin | |||
| Serpentine rash | Hookworm | Worldwide | Can cause anemia in heavy infections |
| Strongyloides | Moist tropics and subtropics | Disseminated infection in immunocompromise | |
| Toxocara (animal roundworm) | Tropical and temperate zones | Cutaneous or visceral larva migrans | |
| Itchy skin rash | Onchocerca | Mexico, Central/South America, Africa | Larvae detectable in skin snips and nodules |
| Painless ulcers | Leishmania | Tropics and subtropics | Amastigotes detectable in biopsies; may cause destructive mucocutaneous infection; AIDS-defining infection |
| Skin nodules | Onchocerca | Mexico, South America, Africa | Large nodules of adult worms |
| Loa loa (African eye worm) | Western and central Africa | Migratory nodules | |
| Gnathostoma | Southeast Asia and China | Migratory nodules with eosinophilia | |
| Painful nodules, especially involving feet | Dracunculus (Guinea worm) | Africa | Nearly eradicated |
| Central nervous system | |||
| Somnolence, seizures, coma | Plasmodium falciparum | Subtropics and tropics | Cerebral malaria, especially in children |
| Trypanosoma brucei rhodesiense | Sub-Saharan eastern Africa | Painful chancre from tsetse fly bite; death in weeks to months | |
| Space-occupying lesions, seizures | Acanthamoeba | Worldwide | Immunocompromised individuals |
| Balamuthia | Americas | Indolent meningoencephalitis with brain mass | |
| Toxoplasma | Worldwide | Reactivation disease in immunocompromise; ring-enhancing lesions; AIDS-defining infection | |
| Taenia solium | Mexico, Central/South America, Africa | Cysticercosis; variable sized or calcified larval cysts on CT | |
| Schistosoma japonicum | Far East | Aberrant eggs can form brain or spinal cord masses. | |
| Schistosoma mansoni | Africa, Central/South America | Aberrant eggs can form brain or spinal cord masses. | |
| Pyogenic meningitis | Naegleria | Worldwide | Motile trophozoites in fresh cerebrospinal fluid; rapid death |
| Eosinophilic meningitis | Angiostrongylus (rat lung worm) | Southeast Asia, Pacific, Caribbean | Most common cause globally; spontaneous resolution |
| Gnathostoma | Southeast Asia and China | Migratory nodules | |
| Eyes | |||
| Painful corneal ulcers | Acanthamoeba | Worldwide | Freshwater and brackish water; corneal trauma; long-wear contact lenses |
| Corneal opacification | Onchocerca | Mexico, Central/South America, Africa | Immune response to microfilaria in cornea |
| Congenital or adult visual loss | Toxoplasma | Worldwide | Primary infection in pregnancy and subsequent primary or reactivation infection |
| Retinal mass | Toxocara | Worldwide | Ocular larva migrans |
| Visible roundworm in eye | Onchocerca | Mexico, Central/South America, Africa | Worms may cross eye during migration. |
| L. loa | Western and central Africa | Worms may cross eye during migration. | |
| Pain, possible vision loss | Gnathostoma | Southeast Asia and China | Migratory skin nodules, eosinophilia |
| Lungs | |||
| Pulmonary nodule/abscess | Paragonimus | Far East, Africa, Americas | Ectopic migration to abdomen or central nervous system |
| Cough, transient infiltrates, eosinophilia | Migrating helminths | Worldwide | Loeffler's syndrome from migrating Ascaris, hookworm, Strongyloides |
| Heart | |||
| Pulmonary edema | P. falciparum (complication) | Tropics and subtropics | End-organ damage from severe malaria |
| Cardiomegaly, arrhythmias | Trypanosoma cruzi | Mexico, Central/South America | Late amastigote infection of myocardium; AIDS-defining infection |
| Gastrointestinal tract | |||
| Hepatosplenomegaly | Malaria (multiple episodes) | Tropics and subtropics | Splenomegaly with anemia and recurrent fever are hallmarks of malaria. |
| S. mansoni | Africa, Central/South America | Portal obstruction with cirrhosis and late varices | |
| Leishmania donovani complex | Tropics and subtropics | Visceral leishmaniasis; AIDS-defining infection | |
| Hepatomegaly | Entamoeba histolytica | Tropics | Acute with fever, right-upper-quadrant pain; or chronic with enlarged liver; hypoechoic abscess(es) on ultrasound or CT |
| Echinococcus | Sheep-raising areas | Characteristic cysts of liver > lung | |
| Fasciola | Sheep-raising areas | Eosinophilia | |
| Cholangitis | Clonorchis | China, Southeast Asia | Recurrent cholangitis and late cholangiocarcinoma |
| Microsporidia | Worldwide | AIDS | |
| Cryptosporidium | Worldwide | AIDS-defining infection | |
| Bloody diarrhea | E. histolytica | Tropics | Less fever than in diarrhea of bacterial etiology |
| S. mansoni | Africa, Central/South America | Only in heavy, acute infection with fever and eosinophilia | |
| S. japonicum | Far East | Only in heavy, acute infection | |
| Watery diarrhea | Cryptosporidium | Worldwide | Severe in immunocompromised pts |
| Giardia | Worldwide | Foul-smelling stool with steatorrhea | |
| Isospora belli | Worldwide | Fever, abdominal pain, chronic diarrhea | |
| Microsporidia | Worldwide | Chronic diarrhea with AIDS | |
| Capillaria | Southeast Asia, Egypt | Malabsorption, wasting | |
| Passage of large roundworm (>6 cm) | Ascaris | Worldwide | Pts may confuse the roundworm with an earthworm. |
| Small roundworms visible around anus | Pinworm | Worldwide | Anal itching; eggs rarely detected by ova and parasite (O&P) exam |
| Trichuris | Worldwide | Rectal prolapse with heavy infection in children | |
| Passage of tapeworm segments | T. solium or Taenia saginata | Worldwide | Usual reason for seeking medical care |
| Diphyllobothrium latum | Worldwide | Pernicious anemia in genetically predisposed Scandinavians | |
| Genitourinary system | |||
| Itchy discharge | Trichomonas vaginalis | Worldwide | Common sexually transmitted disease of both sexes |
| Hematuria | Schistosoma haematobium | Africa | Hematuria with negative cultures, urinary tract infections, and late bladder cancer |
| Muscular system | |||
| Myalgias, myositis | Trichinella | Worldwide | Palpebral swelling; high-level eosinophilia |
| Bloodstream | |||
| Fever without localizing symptoms | Plasmodium | Tropics and subtropics | Consider in any pt from a malarious area. |
| Babesia | New England, United States | Geographically limited; worse with splenectomy | |
| T. brucei rhodesiense, T. brucei gambiense | Sub-Saharan Africa | Limited to tsetse fly range; painful chancre; adenopathy and cyclical fevers; early (rhodesiense) or late (gambiense) central nervous system involvement | |
| Filariae | Asia, India | Periodic fever with eosinophilia, adenolymphangitis, chronic lymphangitis | |
| L. donovani complex | Tropics and subtropics | Hepatosplenomegaly, fever, wasting; AIDS-defining infection | |