Microbiology and Parasitology Review

Medical Parasitology

• Parasitism: an organism (parasite) gains food and shelter from another (host) which suffers from the relationship
• Endoparasite: inside the body, connotes infection
• Ectoparasite: outside the body, connotes infestation
• Obligate parasite: type of parasite that requires host
• Facultative parasite: may exist as free living or parasitic within host
• Vector: living invertebrate carrier that transmits pathogen

Cutaneous/ Mucocutaneous Leishmaniasis

• Causes skin ulcers, visceral leishmaniasis, spiking fevers, hepatosplenomegaly, and pancytopenia
• Tx: Amphotericin B, sodium stibogluconate
• Key Terms: Oriental sore, Espundia, Kala-azar

Babesiosis

• Transmission: bite of Ixodes tick
• Disease: Babesiosis, fever and hemolytic anemia, predominantly in northeastern and north central United States
• Key Terms: Maltese Cross
• Treatment: Atovaquone + Azithromycin

Plasmodium spp. (Malaria)

• Transmission: bite of Anopheles mosquito
• Disease: Malaria, cyclic fevers, headache, anemia, splenomegaly, and hypoglycemia in severe disease
• Key Terms: Trophozoites, Cyst, Flagellated, Nonflagellated
• Treatment: Chloroquine (if sensitive), mefloquine, doxycycline, or atovaquone/proguanil (if resistant)

Toxoplasmosis

• Transmission: ingestion, transplacental
• Disease: Congenital toxoplasmosis
• Key Terms: Heterophil-negative mononucleosis

Naegleria fowleri

• Transmission: swimming in warm freshwaters, enters CNS through olfactory nerve via cribriform plate
• Disease: Rapidly fatal meningoencephalitis
• Key Terms: Acid fast oocysts, Prevention (e.g., filtering), nitazoxanide

Trypanosoma cruzi (Chagas disease/American Trypanosomiasis)

• Transmission: feces of reduviid bug/triatomine insect on bite
• Disease: Dilated cardiomyopathy with apical aneurysm, megacolon, megaesophagus

Nematodes

• Routes of infection:
  • Ingested: Enterobius, Ascaris, Toxocara, Trichinella, Trichuris
  • Mnemonic: You’ll get sick if you EAT These Things!
• Examples: Taenia solium, Taenia saginata, Diphyllobothrium latum

Comprehensive review of microbiology and parasitology, including medical parasitology, definition of terms, and types of parasitism.