Hematology Case Study: The Race to Save a 48 Year Old Man from a Rare Disease

A 48-year-old Caucasian male presented to a Baltimore Emergency Room complaining of fever, chills, and aches. He stated he had not been feeling well for the past week. His symptoms had progressed rapidly over the last 3 days to include night sweats, nausea and excessive somnolence. History taken in the ER revealed the patient had returned 10 days prior from a Safari in Botswana and Zambia. The patient was admitted to the ICU, in shock, with a BP of 75/50. Even though the patient had taken anti-malarial medication, the doctors suspected malaria. Blood was sent to the lab for a blood parasite exam and treatment for malaria was started while the doctors waited for the confirmation.

In the Hematology laboratory, technologists perform microscopy of thick and thin blood smears to look for malarial parasites. The thin smear is a typical Wright Giemsa stained wedge smear, and the thick smears are prepared and stained so that the red blood cells are lysed, and the sample is concentrated, making examination easier. Thorough, careful examination of the thick smear is aimed to identify whether a particular parasite is present, but they require a long drying period and take several hours to prepare and read. Thin smears can detect the parasites but also permit identification of particular species of malaria. While the thick smears were drying the technologist examined the thin smear.

The technologist who examined this patient’s thin smears saw parasites (image 1) under her microscope. She consulted with a supervisor and pathologist to confirm, and the patient’s doctor was notified that the patient did not have malaria, but instead, had Trypanosoma! This was an exciting find in the laboratory, as there have been only 40 cases seen in the US in the past 50 years.

tryp1
Image 1. This slide shows the parasite, in dark blue. The parasite causes
African trypanosomiasis, also known as sleeping sickness
(Courtesy of Greater Baltimore Medical Center).

The race for diagnosis and treatment did not stop there, as there are 2 types of African trypanosomiasis, or African sleeping sickness, and effective and appropriate treatment must be started in a timely fashion. Both types look identical on a blood smear and both are considered universally fatal, if not treated. West African trypanosomiasis and East African trypanosomiasis are caused by the tsetse fly, which only lives in rural Africa. The patient stated he did remember being bitten by tsetse flies, and because there had been such a short span of time between being bitten and the onset of symptoms, doctors concluded that the patient had the rarer and fast-acting East African trypanosomiasis, which can kill within months.

Epidemiologists at CDC were contacted, who then consulted other infectious disease specialists at CDC. There are 2 treatments depending the stage of the disease. Surinam is the first line of defense, but melarsoprol, which is arsenic-like and very toxic, must be used if the parasites have reached the central nervous system. Because of the urgent need to start treatment, emergency shipments of both drugs were flown to Baltimore. The patient was started on Surinam to reduce the number of parasites in his blood to a level low enough to allow a spinal tap to be performed. After confirming that the CSF showed no signs of the parasite, treatment with surinam was continued and the patient was discharged a week later and has made a full recovery.

Because of the excellent work done by the medical technologists who made the first discovery, the speed with which the critical calls were made, the actions of the doctors involved, and the cooperation of the CDC, this patient received his first dose of Surinam a little over 24 hours after his blood was sent to the lab. This case shows the importance of a thorough medical and travel history in differential diagnosis. It also illustrates the importance of the competency evaluations and surveys in which all laboratory professionals are required to participate. None of the technologists, doctors or scientists involved had ever actually seen a case of African Trypanosomiasis, they had only read about it in books and seen it on competency assessments.

This case is based on an actual case from 2016. My coworker, Gail Wilson, was the technologist who first saw the Trypanosoma on the slides. Many thanks to Gail for her keen eye and attention to detail!

tryp2
Image 2: L&R: Trypanosoma brucei in thin blood smears stained with Giemsa. Center: A close up of a tsetse fly. Credit: DPDx

 

References 

  1. Jon E. Rosenblatt Barth Reller Melvin P. Weinstein.pages 1103-1108, Laboratory Diagnosis of Infections Due to Blood and Tissue Parasites Clinical Infectious Diseases, Volume 49, Issue 7, 1 October 2009; retrieved March 2018 from https://academic.oup.com/cid/article/49/7/1103/316703
  1. Ivo Elliott, Trupti PatelJagrit Shah, and Pradhib Venkatesan. West-African trypanosomiasis in a returned traveller from Ghana: an unusual cause of progressive neurological decline BMJ Case Rep. 2014; 2014: bcr2014204451. Published online 2014 Aug 14.doi: 1136/bcr-2014-204451; retrieved March 2018 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4139564/
  1. Lena H. Sun. Medical Detectives raced to save a man from a rare, ‘universally lethal’ disease; retrieved March 2018 from https://www.washingtonpost.com/news/to-your-health/wp/2016/12/22/medical-detectives-raced-to-save-a-man-from-a-rare-universally-lethal-disease/?utm_term=.16d7b136bc47
  1. Parasites – African Trypanosomiasis (also known as Sleeping Sickness). Retrieved March 2018 from https://www.cdc.gov/parasites/sleepingsickness/
  1. DPDx- Laboratory Identification of parasites of Public Health Concern; retrieved March 2018 from https://www.cdc.gov/dpdx/

 

Socha-small

-Becky Socha, MS, MLS(ASCP)CM BB CM graduated from Merrimack College in N. Andover, Massachusetts with a BS in Medical Technology and completed her MS in Clinical Laboratory Sciences at the University of Massachusetts, Lowell. She has worked as a Medical Technologist for over 30 years. She’s worked in all areas of the clinical laboratory, but has a special interest in Hematology and Blood Banking. When she’s not busy being a mad scientist, she can be found outside riding her bicycle.

 

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