2025 – PAGE 318 – INFECTIOUS DISEASES
(DOUBLE TAKE) TRICHOMONAS VAGINALIS
Trichomonas vaginalis is a protozoa. Look for yellow-green discharge, bubbly, frothy, motile flagella, and a pH > 4.5. This can be intensely pruritic. A classic sign is a strawberry cervix. Treat with metronidazole. It can also cause nongonococcal urethritis.
MNEMONIC: Imagine two girls having this conversation: “Can you believe that dirty old man TRICKED MONA, our favorite BUBBLY stripper, into putting a STRAWBERRY into her va-jay-jay?!? Gross! I heard it still had a long green STEM on it!” Sorry for the gross mnemonic, but hopefully it helps you associate the stem with the motile TAIL/FLAGELLA of Trichomonas.
BABESIOSIS
Babesiosis is unlikely to be tested. It’s caused by a protozoan (Babesia) and is usually asymptomatic or causes only mild fevers. In a severe case, it can look like malaria with high fevers, chills, and a hemolytic anemia. Mild or severe cases can cause sudden death. The key will be to look for a non-autoimmune hemolytic anemia and a smear with the classic “Maltese Cross” finding. It is transmitted by the Ixodes tick (same as Lyme disease and ehrlichiosis). Treat with quinine and clindamycin.
IMAGE: www.pbrlinks.com/BABESIOSIS1
IMAGE: www.pbrlinks.com/BABESIOSIS2
MNEMONIC: Imagine a “babe” (baby) with a CROSS on her chest which represents the “Maltese cross”.
CRYPTOSPORIDIUM
Cryptosporidium is a protozoan. It causes watery diarrhea lasting a LONG time (7 days to a month!) and is spread by fecal-oral transmission. Outbreaks can occur through contaminated water. Look for cysts in the stool, do direct fluorescence antibody (DFA) testing, or do PCR for diagnosis. Treatment is primarily supportive for immunocompetent patients, but nitazoxanide should be given to immunocompromised patients or to anyone with severe symptoms.
MALARIA
Malaria is rare in the U.S. and so is not commonly tested. Look for travel to an endemic area or migrant status. Symptoms will include cycles of feeling cold, then having harsh chills (rigors), and then high fever with diaphoresis (all within a 6-hour period). Patients can have hepatosplenomegaly and a hemolytic anemia. Diagnose with a blood smear (even if a rapid antigen test is positive). Each of the four species has a characteristic appearance on the THIN AND THICK BLOOD SMEARS/FILMS you would request. Plasmodium vivax and ovale can relapse, so perhaps those would be the ones tested. Falciparum and malariae do not.
MNEMONIC: Vivax & Ovale can relapse. “V.O.dka goes to the LIVER and hides. No wonder they can relapse!”