An 80-year-old man from Tennessee was the first fatal case of Heartland virus and the only case described outside of the recent cases in Missouri, according to a report in Clinical Infectious Diseases.
Heartland virus was first found in two men from Missouri who presented with nonspecific febrile illness, leukopenia, thrombocytopenia and a history of tick exposure. CDC investigations found the virus in Amblyomma americanum ticks, which were present on one of the patient’s farms. They identified six more cases, including the man from Tennessee.
The Tennessee man had a history of chronic obstructive pulmonary disease and heavy alcohol use. In July 2013, he presented to the ED reporting weakness, frequent falls, altered mental status and fevers. He worked on a farm in Tennessee and had a history of multiple tick bites. He had hyponatremia, elevated aspartate aminotransferase (AST), elevated alanine aminotransferase (ALT), leukopenia and thrombocytopenia. He was admitted to the hospital with suspected ehrlichiosis.
On the second day, he was admitted to the ICU for worsening hypoxia and tachypnea, and hypotension and persistent delirium. He was febrile and had purpura, worsening thrombocytopenia, persistent leukopenia, decreasing hemoglobin, increased creatine kinase, increased AST and ALT, elevated lactate dehydrogenase and elevated creatinine. Blood cultures showed no bacteria and serology was negative for Rickettsia species and Ehrlichia chaffeensis.
Throughout his hospital stay, he had respiratory failure and required mechanical ventilation and also had acute kidney injury and upper gastrointestinal bleeding. The patient died on hospital day 15.
The CDC performed immunohistochemistry assays that were negative for Ehrlichia, Anaplasma, Rickettsia and Leptospira species. They then performed immunohistochemistry for Heartland virus, based on the negative tests and clinical history. The test was positive in the spleen and mediastinal and mesenteric lymph nodes, but not in other organs. The finding was confirmed by detection of Heartland virus RNA in whole blood and serum using reverse transcriptase PCR.
“Heartland virus infection should be considered in patients with fever, thrombocytopenia and leukopenia occurring in spring-summer months who report recent tick exposure, following exclusion of other tick-borne diseases,” the researchers wrote. “This case suggests that older adults or persons with comorbidities might be at risk for more severe disease, but this needs to be validated with additional case finding and description.”
Disclosure: The researchers report no relevant financial disclosures.