TWiP 253: Sub-Saharan Somnolence - A Case of East African Sleeping Sickness
0:24 Case Introduction: The episode focuses on a 28-year-old Tanzanian man who returned from visiting game parks, presenting with fever, malaise, headaches, body aches, and somnolence (disrupted sleep cycles).
2:51 Initial Workup: Initial blood smears for malaria were negative, but a repeat smear revealed something "extra-erythrocytic" (outside of red blood cells), leading to the diagnosis.
3:19 Patient History: The patient was HIV-negative, with no significant past medical history. Symptom onset was about a week before presentation, and 1-2 weeks after returning from the game parks.
3:44-18:33 Listener Emails: Multiple listeners correctly diagnosed East African sleeping sickness (trypanosomiasis) caused by Trypanosoma brucei rhodesiense. Clues included the game park visit, painful insect bite (tsetse fly), and the extra-erythrocytic parasite on blood smear.
18:33 Treatment advances: The discussion highlights new WHO guidelines (published in The Lancet Infectious Diseases) for treating T. b. rhodesiense human African trypanosomiasis (HAT), with expanded indications for fexinidazole and pentamidine. Fexinidazole is effective in both early and late stages.
37:07 Confirmed diagnosis: The man was diagnosed with East African Sleeping Sickness and, because of repeat blood smears, many trypomastigotes were present in the blood sample.
38:46 Tsetse Fly Control: The hosts discuss tsetse fly control methods, including traps with dark fabric and insecticide. Christina mentions attractiveness of Savannah tsetse flies to odors, and the visual attraction for riverine tsetse flies.
41:35 Sexually Transmitted Cases: The hosts briefly discuss a rare case of sexually transmitted HAT, noting it's unusual but that Trypanosoma evansi in horses is transmitted sexually.
42:34 Antigenic Variation It is explained that a possible reason for the delayed discovery of parasites in the patient's blood is the parasite's build-up of antigenic variation.
46:04 Fatal if untreated: The uniformly fatal consequence of an untreated diagnosis is contentiously discussed between the hosts.
47:13 Book Giveaway: Listener Steve from the Eastern Sierra wins an autographed copy of Parasitic Diseases.
48:10 Hero of the Episode: Christina nominates the Drugs for Neglected Diseases initiative (DNDi) as the hero. DNDi is a non-profit organization developing new treatments for neglected diseases.
51:33 DNDi's contributions They developed fexinidazole. They are also working on acoziborole, an oral single-dose treatment that entered clinical development in 2012.
54:45 New Case Presentation: A new case is presented involving a 26-year-old American woman volunteering in Guinea who presents with fever, cough, and gastrointestinal symptoms. She had tested for eggs on stool parasite screen. She has been treated unsuccessfully, and the solution is to be revealed in an upcoming episode.