Suspect it when doxycycline does not work

Heartland virus is a Bandavirus, first identified as a cause of human
illness in 2009 in Missouri. It is an RNA virus **transmitted by the lone
star tick** (Amblyomma americanum), and is most similar to **severe fever
with thrombocytopenia syndrome (SFTS) virus**, found in Asia and also
tick-borne.

As of November 2022, more than 60 cases had been identified, in eastern,
south-eastern and south-central states. Cases have been in adults, mostly
with illness onset during May–September, and **most patients reported tick
exposure in the two weeks before onset.**

The diagnostic clue

Initial symptoms are very similar to ehrlichiosis — fever, fatigue,
anorexia, nausea and diarrhoea — along with leukopenia, thrombocytopenia,
and mild to moderate elevation of liver transaminases.

Both are tick-borne. Both present the same way. The difference is what happens
next:

**Heartland virus disease should be considered in patients being treated for
ehrlichiosis who do not readily respond to treatment with doxycycline.**

Ehrlichiosis is bacterial and responds to doxycycline. Heartland is viral and
does not. The failure of the treatment is the signal — which means the
diagnosis is often made by a clinician noticing that a patient is not getting
better on a drug that should be working.

Severity

Heartland virus infection has rarely been associated with severe disease,
including haemophagocytic lymphohistiocytosis, and death — in patients
with immunocompromising conditions or multiple comorbidities.

Testing

Molecular and serologic testing can diagnose it. **Contact your state or
local health department for assistance with diagnostic testing** — and note
that some tests are not currently available at the CDC, so check the test
directory for what can be performed.

For a disease with about sixty recorded cases, testing is not something a
hospital laboratory will have to hand, and the health department is the route
to it.

Source: Centers for Disease Control and Prevention.