Protozoans and Their Infections

Protozoans

• Amoebae (Entamoeba histolytica):

  • Infection route: Ingestion of contaminated water.
  • Symptoms: Asymptomatic carriage, severe diarrhea, colitis, and ulceration.
  • Prognosis/Outcome: Can lead to invasive amebic dysentery and extraintestinal amebiasis, which can be fatal.
  • Vector: Water.
  • Creepy Fact: Few cause disease. Trophozoites migrate to the large intestine.

• Amoebae (Naegleria fowleri):

  • Infection route: Inhalation of contaminated water.
  • Symptoms: Hemorrhage, coma, and usually death within 10 days.
  • Prognosis/Outcome: Very high mortality.
  • Vector: Water
  • Creepy Fact: Protozoan infects nasal mucosa, then the brain.

• Flagellates (Trypanosoma cruzi/Chagas Disease):

  • Infection route: Insect bites (Triatoma insects).
  • Symptoms: Chagomas (swellings), fever, swollen lymph nodes, myocarditis/enlargement of organs (spleen, esophagus, colon). Asymptomatic chronic stage possible. Symptomatic stage with congestive heart failure.
  • Prognosis/Outcome: Leading cause of death in Latin America due to parasite-induced heart disease.
  • Vector: Triatoma insects (kissing bugs), opossums, and armadillos serve as reservoirs.

Other Protozoans/Flagellates

• Trypanosoma brucei gambiense (African sleeping sickness):

  • Infection route: Bite from a tsetse fly.
  • Symptoms: Fever, lymph node swelling, headaches, and meningoencephalitis.
  • Prognosis/Outcome: Death in months.
  • Vector: Tsetse fly.
  • Creepy Fact: Antigenic variation makes vaccination difficult.

• Leishmania:

  • Infection route: Bite.
  • Types: Cutaneous (skin ulcers), mucocutaneous (mucous membranes), visceral (liver, spleen, bone marrow).
  • Prognosis/Outcome: Visceral leishmaniasis is fatal if untreated in 95% of cases.
  • Vector: Phlebotomus or Lutzomyia (sand fly).

• Giardia intestinalis/Giardiasis:

  • Infection route: Ingestion of cysts in contaminated food, water, or hands.
  • Symptoms: Diarrhea, pain, bloating, nausea, vomiting.
  • Prognosis/Outcome: Usually asymptomatic.

Apicomplexans

• Trichomonas vaginalis:

  • Infection route: Sexual encounters.
  • Symptoms: Vaginosis (odorous discharge, vaginal/cervical lesions pain)
  • Prognosis/Outcome: Usually treated with nitroimidazole drugs. Can be asymptomatic in men.
  • Vector: Humans.

• Plasmodium (malaria):

  • Infection route: Bite from anopheles mosquito.
  • Types: Vivax (mildest form, dormant in the liver), Ovale and Malariae (benign, restricted geographically), Falciparum (most deadly, 50% mortality).
  • Symptoms: Recurrent fever, anemia, blood cell abnormalities, kidney/liver/brain damage, black urine.
  • Prognosis/Outcome: Fatal in some cases (particularly Falciparum in 24 hours).
  • Vector: Anopheles mosquito.

• Toxoplasma gondii:

  • Infection route: Consumption of undercooked meat or contaminated soil/water. Or inhalation.
  • Symptoms: Vary, but could result in severe problems in AIDS patients or if pregnant.
  • Prognosis/Outcome: Chronic condition possible, but severe in severe cases.
  • Vector: Cats, and fluids from cats.

Helminths

• Cestodes (tapeworms):

  • Infection route: Ingestion (uncooked meat).
  • Symptoms: Cyst formation; intestinal issues.
  • Types: Taenia solium (pork tapeworm).
  • Prognosis/Outcome: Can cause intestinal blockage in some cases

• Fasciola hepatica (flukes):

  • Infection route: Eating water vegetation with metacercariae.
  • Symptoms: Episodes of bile duct obstruction and inflammation.
  • Prognosis: Chronic infection is possible.

• Ascaris lumbricoides (roundworm):

  • Infection route: Ingestion
  • Symptoms: Intestinal blockage; abdominal pain, nausea, vomiting
  • Prognosis/Outcome: Blockage possible.

• Enterobius vermicularis (pinworm):

  • Infection route: Fecal-oral.
  • Symptoms: Intense perianal itching.
  • Prognosis: Usually asymptomatic, highly infectious.

• Ancylostoma duodenale (hookworm):

  • Infection route: Larvae burrow through skin, especially feet.
  • Symptoms: Anemia, lethargy, craving for unusual foods, pica.
  • Prognosis: Can lead to severe illness.

• Trichinella spiralis (trichinellosis):

  • Infection route: Ingestion of undercooked pork/other meats.
  • Symptoms: Fever, eye swelling, gastrointestinal upset.
  • Prognosis/Outcome: Can lead to potentially fatal conditions if severe.

Explore the world of protozoans and their associated infections. This quiz covers various types of amoebae and flagellates, including their infection routes, symptoms, and outcomes. Test your knowledge on these fascinating microorganisms and their impacts on human health.