Fatal Case of Heartland Virus in the Mid-Atlantic Region

Abstract and Introduction

Abstract

Heartland virus (HRTV) disease is an emerging tickborne illness in the midwestern and southern United States. We describe a reported fatal case of HRTV infection in the Maryland and Virginia region, states not widely recognized to have human HRTV disease cases. The range of HRTV could be expanding in the United States.

Introduction

Heartland virus (HRTV) is a bandavirus spread by Amblyomma americanum (lone star) ticks in the midwestern and southern United States.^[1] Many cases of HRTV infection have been characterized by severe illness or death, mostly among men >50 years of age with multiple underlying conditions.^[1–7] HRTV infection in humans typically manifests as a nonspecific febrile illness characterized by malaise, myalgias, arthralgias, and gastrointestinal distress, along with thrombocytopenia, leukopenia, hyponatremia, and elevated liver transaminases.^[3] Most reported hospitalized patients recover, but deaths have occurred and have been associated with secondary hemophagocytic lymphohistiocytosis (HLH).^[4,5]

Since HRTV was discovered in 2009 in Missouri, USA, human HRTV disease cases have also been reported in Kansas, Oklahoma, Arkansas, Tennessee, Kentucky, Indiana, Illinois, Iowa, Georgia, Pennsylvania, New York, and North Carolina according to the Centers for Disease Control and Prevention (CDC; https://www.cdc.gov/heartland-virus/statistics/index.html). Studies have documented HRTV RNA in A. americanum ticks and HRTV-neutralizing antibodies in vertebrate animals in these states.^[8–13] However, the distribution of A. americanum ticks is wider and growing, possibly because of climate change, which could lead to HRTV range expansion.^[3,11] Of note, vertebrate animals with neutralizing antibodies to HRTV have been documented in states without confirmed human cases, including Texas, Florida, South Carolina, and Louisiana in the south and Vermont, New Hampshire, and Maine in the northeast.^[12,13] To date, no seropositive animals have been reported from Maryland or Virginia in the mid-Atlantic region. We describe a fatal human case of HRTV infection with secondary HLH in which initial infection likely occurred in either Maryland or Virginia.

Table. Laboratory findings in a fatal case of heartland virus disease acquired in the mid-Atlantic region, United States*
Test	Reference range	Days after symptom onset
5	7	9	11	13
Temperature, °C	35.5–38.3	36.8	38.5	38.5	39.1	36.9
Blood cell counts
Leukocyte count, × 10³ cells/μL	4.50–11.00	2.4	3.7	3.5	2.48	3.25
Absolute neutrophil count, cells/μL	1.50–7.80	ND	ND	ND	0.99	0.88
Absolute lymphocyte count, cells/μL	1.10–4.80	ND	ND	ND	1.22	1.76
Hemoglobin, g/dL	13.9–16.3	14.5	14.9	14.6	14.4	11.7
Platelets, × 10³/μL	150–350	178	106	82	59	61
Blood chemistry test results
Sodium, mmol/L	135–148	126	115	120	129	136
Potassium, mmol/L	3.5–5.1	3.7	3.3	4.2	4.4	4.4
Carbon dioxide, mmol/L	21–31	22	22	20	17	18
Anion gap, mmol/L	7–16	13	15	12	12	11
Blood urea nitrogen, mg/dL	7–22	12	12	16	26	68
Creatinine, mg/dL	0.6–1.3	1.0	1.3	1.2	1.4	4.4
Aspartate aminotransferase, units/L	≤37	45	359	434	590	617
Alanine aminotransferase, units/L	≤40	46	238	262	209	156
Alkaline phosphatase, units/L	30–120	69	64	53	67	89
Cerebrospinal fluid test results
Leukocyte count, cells/mm³	0–5	ND	2	ND	ND	ND
Glucose, mg/dL	40–70	ND	80	ND	ND	ND
Protein, mg/dL	12–60	ND	58	ND	ND	ND
Cardiac test results
Troponin I, ng/mL	<0.04	ND	ND	ND	0.21	0.38
Troponin T, high sensitivity, ng/L	0–19	14	22	30	ND	ND
Pro-BNP, pg/mL	5–125	ND	ND	ND	4,258	ND
Lipid panel test results
Cholesterol, total, mg/dL	≤200	ND	ND	ND	69	ND
Triglycerides, mg/dL	≤150	ND	ND	ND	147	ND
Other test results
D-dimer, mg/L	0.00–0.49	ND	ND	2.72	3.71	ND
Creatine kinase, U/L	24–195	ND	ND	ND	8,727	11,083
Lactic acid, mmol/L	0.5–2.0	1.6	1.8	ND	2.5	2.4
Lactate dehydrogenase, U/L	118–273	ND	ND	1,412	1,709	ND
Ferritin, ng/mL	30–400	ND	ND	ND	47,445	174,957
Fibrinogen, mg/dL	170–422	ND	ND	199	224	170
C-reactive protein, mg/dL	<0.5	ND	1.2	0.6	0.5	ND
Interleukin 2 receptor, pg/mL	532–1,891	ND	ND	ND	9,390	ND

Table. Laboratory findings in a fatal case of heartland virus disease acquired in the mid-Atlantic region, United States*

Test

Reference range

Days after symptom onset

Temperature, °C

35.5–38.3

36.8

38.5

39.1

36.9

Blood cell counts

Leukocyte count, × 10³ cells/μL

4.50–11.00

2.4

3.7

3.5

2.48

3.25

Absolute neutrophil count, cells/μL

1.50–7.80

0.99

0.88

Absolute lymphocyte count, cells/μL

1.10–4.80

1.22

1.76

Hemoglobin, g/dL

13.9–16.3

14.5

14.9

14.6

14.4

11.7

Platelets, × 10³/μL

150–350

178

106

Blood chemistry test results

Sodium, mmol/L

135–148

126

115

120

129

136

Potassium, mmol/L

3.5–5.1

3.7

3.3

4.2

4.4

Carbon dioxide, mmol/L

21–31

Anion gap, mmol/L

7–16

Blood urea nitrogen, mg/dL

7–22

Creatinine, mg/dL

0.6–1.3

1.0

1.3

1.2

1.4

4.4

Aspartate aminotransferase, units/L

≤37

359

434

590

617

Alanine aminotransferase, units/L

≤40

238

262

209

156

Alkaline phosphatase, units/L

30–120

Cerebrospinal fluid test results

Leukocyte count, cells/mm³

0–5

Glucose, mg/dL

40–70

Protein, mg/dL

12–60

Cardiac test results

Troponin I, ng/mL

<0.04

0.21

0.38

Troponin T, high sensitivity, ng/L

0–19

Pro-BNP, pg/mL

5–125

4,258

Lipid panel test results

Cholesterol, total, mg/dL

≤200

Triglycerides, mg/dL

≤150

147

Other test results

D-dimer, mg/L

0.00–0.49

2.72

3.71

Creatine kinase, U/L

24–195

8,727

11,083

Lactic acid, mmol/L

0.5–2.0

1.6

1.8

2.5

2.4

Lactate dehydrogenase, U/L

118–273

1,412

1,709

Ferritin, ng/mL

30–400

47,445

174,957

Fibrinogen, mg/dL

170–422

199

224

170

C-reactive protein, mg/dL

<0.5

1.2

0.6

0.5

Interleukin 2 receptor, pg/mL

532–1,891

9,390

Fatal Case of Heartland Virus Disease Acquired in the Mid-Atlantic Region, United States

Abstract and Introduction

Abstract

Introduction

Tables

References

Authors and Disclosures

Authors and Disclosures

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