What illness could she have?
Our patient had an illness caused by the Bourbon virus. This is a tick borne illness discovered in 2014 and named after Bourbon County in eastern Kansas where a man developed the index case after being bitten by ticks. He presented with a flu-like illness and later died. Our patient removed two ticks from her body several weeks before she was admitted to the hospital with somnolence, fevers, myalgias and a rash.
Rocky Mountain spotted fever map above. .
Lyme disease map above.
Tick borne diseases in Missouri also include Rocky Mountain spotted fever , tularemia,,heartland virus, Ehrlichia, and lyme disease. Where Rocky Mountain spotted fever had been reported most often in the southeast; there were 229 cases reported in Missouri in 2017. The number of cases of Erhlchia is also rising with 149 reported cases. Tularemia is not only found in ticks but also in rodents and rabbits. It can be aerosolized with reported illness in a person who ran over a dead rabbit with a lawn mower. ( Francisella tularensis is very infectious with 10-50 organisms causing disease and is a candidate for possible weaponization) If contaminated animals inhabit a site, even a lawn, there have been cases of tularemia reported after mowing the lawn. Of the 200 or so cases reported each year, Arkansas, Missouri, Kansas and Oklahoma claim the most cases.
Heartland virus was discovered in Missouri at Heartland hospital near St. Joseph in 2009 when two farmers were infected and did not respond to doxycycline. Their sera was sent to the CDC and a new virus was confirmed.
None of the reported incidence of tick borne disease is likely to be accurate since most people have a mild illness and do not seek medical attention. It is a good thing that tick borne illness is often mild since ticks are a world wide vector of disease. Two cases of Crimean- Congo hemorrhagic fever were reported from near Madrid in the July 13, 2017 New England Journal of Medicine. This is a particularly virulent tick borne illness in which the first patient presented with fever and malaise, developed a coagulopathy and died. The second case reported was the nurse who assisted with the intubation and central lines of the first patient. She developed fever and coagulopathy. She was treated with ribavirin and developed hemolytic anemia but eventually recovered after 22 days.
Our patient had a complicated course . Her past history included follicular lymphoma which had been treated. She developed encephalopathy, mouth ulcers, acute respiratory failure, hemophagocytic lymphohistiocytosis, pancytopenia and shock. She died three weeks after admission.
Feldman KA, Enscore RE, Lathrop SL, et al. an outbreak of primary pneumonic tularemia on Martha’s Vineyard. N Engl . J Med 2001. 345(22): 1601-6.
Negredo A, de la Celle-Prieto F, et al. Autochthonous Crimean-Congo Hemorrhagic Fever in Spain. NEJM 2017 377;2: 154-161.