Bourbon virus infection overview

# Overview
Bourbon virus infection is caused by Bourbon virus, a type of Thogotovirus, which belongs to Orthomyxoviridae family. A tick bite is usually responsible for Bourbon virus infection. The virus is transmitted by arthropods like tics and replicates in both arthropods and vertebrate hosts. Bourbon virus infection must be differentiated from other diseases that may cause arthralgia, fever, and skin manifestations with the history of exposure to ticks. Only 5 cases of Bourbon virus infection have been confirmed in the United States since its disovery in 2014. The most potent risk factor in the development of Bourbon virus infection is a tick bite. Other risk factors include traveling, residing or working in the endemic regions will increase chances of infection. If left untreated patients with Bourbon virus infection, may develop hemophagocytic lymphohistiocytosis and eventually death. Complications that can develop as a result of Bourbon virus infection are meningitis, encephalitis and multiorgan failure. A detailed history and physical exam is very helpful in the diagnosis of Bourbon virus infection. Infected individuals are treated with symptomatic therapy since a specific treatment has not yet been established. Preventing bites from ticks and other insects is the is helpful in the prevention of Bourbon virus infection.

# Historical Perspective
In 2014, Olga Kosoy, from the Centers for Disease Control and Prevention isolated Bourbon virus for the first time from a blood sample of an infected person in Bourbon County, Kansas, United States.

# Classification
Bourbon virus infection can be classified under tick-borne diseases.

# Pathophysiology
Bourbon virus is a negative sense segmented RNA virus belonging to the genus Thogotovirus, family Orthomyxovirida. It is transmitted by insects and replicates in both arthropods and vertebrate hosts. The negative sense RNA virus replicates within the nuclei of the host cells. Thogoto virus Infection induces a sustained type 1 interferon response in the host until the adaptive immunity takes effect. Microscopically, bourbon viruses are 80-120nm in diameter with a genome size of approximately 10Kb.

# Causes
Bourbon virus infection is caused by a type of thogotovirus, which belongs to Orthomyxoviridae family. It is a  single-stranded, negative-sense RNA virus, which is segmented and exists in two different morphologies.

# Differentiating Bourbon virus infection from other Diseases
Bourbon virus infection must be differentiated from other diseases that may cause arthralgia, fever, and skin manifestations with the history of exposure to ticks. The differential diagnosis of Bourbon virus disease includes Lyme disease, ehrlichiosis, anaplasmosis, Rocky Mountain spotted fever, leptospirosis, and influenza.

# Epidemiology and Demographics
Only 5 cases of Bourbon virus infection have been confirmed in the United States since its disovery in 2014. 

# Risk Factors
The most potent risk factor in the development of Bourbon virus infection is a tick bite. Other risk factors include traveling, residing or working in the endemic regions will increase chances of infection.

# Screening
According to CDC, there is insufficient evidence to recommend routine screening for Bourbon virus infection.

# Natural History, Complications and Prognosis
If left untreated patients with Bourbon virus infection, may develop hemophagocytic lymphohistiocytosis and eventually death. Complications that can develop as a result of Bourbon virus infection are meningitis, encephalitis and multiorgan failure. From 2014 to 2017 only 5 cases of Bourbon virus infection have been reported and all have resulted in death.

# Diagnosis

## History and Symptoms
The patient with bourbon virus infection has a typical history of exposure to ticks or travel to endemic areas. A history of multiple tick bites is also common in individuals suspected of Bourbon virus infection. The patient of Bourbon virus infection may present with nausea, weakness, and diarrhea. Furthermore, symptoms such as fever, anorexia, chills, headache, myalgia, and arthralgia may develop.

## Physical Examination
The physical examination findings of bourbon virus infection may present with several tick bites and maculopapular rash on the trunk. The patient may appear as very weak, hypertensive and dyspneic.

## Laboratory Findings
There are no specific laboratory findings associated with Bourbon virus infection. Laboratory findings in bourbon virus infection may reveal leukopenia and thrombocytopenia.

## X ray
There are no specific X-ray findings associated with Bourbon virus infection. A chest X-ray may reveal findings of pulmonary venous congestion and interstitial edema.

## CT scan
There are no CT  findings associated with bourbon virus infection. Contrast CT scan of the chest, abdomen, and pelvis may show trace pleural effusions, bibasilar atelectasis, and multiple prominent abdominal lymph nodes. 

## MRI
There are no MRI findings associated with bourbon virus infection.

## Ultrasound/Echocardiography
There are no ultrasound findings associated with Bourbon virus infection. Echocardiogram of bourbon virus infection, may show global hypokinesia. 

## Other Imaging findings
There are no other imaging findings for Bourbon virus infection.

## Other Diagnostic Studies
There are no other diagnostic studies for Bourbon virus infection.

# Treatment

## Medical Therapy
There is no specific treatment, cure, or vaccine for Bourbon virus infection. Early diagnosis, hospitalization, and supportive therapy are fundamentals of treatment.

## Surgery
Surgical intervention is not recommended for the management of Bourbon virus infection.

## Primary Prevention
There is no vaccine or drug to prevent Bourbon virus disease. Therefore, preventing bites from ticks and other insects is the best way to prevent infection.

## Secondary Prevention
Secondary preventive measures for Bourbon virus infection are similar to primary prevention.