California Serogroup/LaCrosse Encephalitis

Reportable by Providers and Laboratories

About this Reportable Disease

Infectious agent:  La Crosse virus (LACV) is a California (CAL) serogroup virus, in the genus Bunyavirus, family Bunyaviridae.

Description of illness: Initial symptoms include fever, headache, nausea, vomiting, fatigue and lethargy. Some develop severe neuroinvasive disease which often involves encephalitis and can include seizures, coma, and paralysis. Severe disease most often occurs in children under the age of 16. Although seizures during the acute illness are common, fatal cases are rare (<1%) and most patients seem to recover completely. Neurologic sequelae (conditions resulting from the initial disease) of varying duration have been reported in some cases. These may include recurrent seizures, hemiparesis (partial paralysis of one side of the body), and cognitive and neurobehavioral abnormalities.

Laboratory Reporting for this Disease

Arboviral Panel (IgG and IgM Antibody Assay)

TEST NAME

 Arboviral Panel
DISEASE(S)/DISORDER(S)
  • Eastern Equine Encephalitis
  • Western Equine Encephalitis
  • St. Louis Encephalitis
  • California Encephalitis (LaCrosse)
ALTERNATIVE NAME(S) None
METHODOLOGY
  • Focus Diagnostics' Arbovirus IFA IgM
  • Focus Diagnostics' Arborvirus IFA IgG
SPECIAL INSTRUCTIONS Send acute sample at time of collection; do not wait for convalescent sample to be drawn.
ORDERING INFORMATION

Lab Web Portal

PTBMIS:

Test Order Code: ARBOVRS

Test Order Description:  Arbovirus Panel

Specimen Requirements

Patient Preparation

Paired Serum Samples:

-   Acute: drawn at illness onset

                   and

-   Convalescent: drawn 7 to 14 days later

Note: Send acute sample at time of collection; do not wait for convalescent sample to be drawn.
Specimen Collection
  • Asepticallly collect whole blood in Red Top tube (no anticoaglulant).
Specimen Labeling
  • Specimen must be labeled with at least two unique patient identifiers and match accompanying test order.
Specimen Processing
  • Allow sample to clot at room temperature prior to centrifugation.
  • Aseptically transfer serum to a sterile, plastic, screw-capped vial.
Specimen Storage and Preservation
  • Store serum at 2 - 8°C.
  • If shipping is to be delayed for longer than five  (5) days, the specimen should be frozen at  (-20)°C or colder.
Specimen Transportation
  • Ship specimen at 2 - 8°C.  If specimen has been frozen,  ship on Dry Ice. 
  • Specimen must be placed in an individual biohazard bag with absorbent material and should be shipped to the laboratory on  the day of collection. 
  • All infectious substance shipments must conform to U.S. Department of Transportation (DOT) Hazardous Materials Regulations (HMR 49 C.F.R. Parts 171-180). 
Specimen Acceptability and Rejection
  • The following submissions will not be tested:

-  Specimens not properly identified with the patient's name and date of birth and                   matching the submission form.

-  Convalescent serum that is collected sooner than seven (7) days from the collection           date of the acute sample.
Testing Location
  • Knoxville

Laboratory Reporting

Reporting requirements apply to all laboratories located within Tennessee, as well as laboratories outside of Tennessee that test residents of Tennessee, including laboratories located within healthcare facilities. Healthcare providers and laboratories in the same healthcare facility both have a duty to report. The type of organisms and analytes laboratories must report to TDH for 2026 are indicated, and there are several ways laboratories can report results to TDH.

Information about this Reportable Disease for Healthcare Providers

Clinical Summary

  • Anthrax can cause severe illness and death if not treated quickly after symptoms develop.
  • Prophylactic antibiotics should be administered immediately to patients who might have been exposed to anthrax.
  • Anthrax exposure is rare in the U.S., but some activities can put people at greater exposure risk.
  • Anthrax is not contagious.

Healthcare Provider Reporting

Healthcare reporting requirements apply to all providers located within Tennessee, as well as providers whose patients reside in Tennessee.

Providers must report cases of all diseases and conditions listed through one of these methods:

• Mail or fax a completed PH-1600 form to your local health department or fax to the state health office at (615) 741-3857

• Send automatically via electronic case reporting (eCR). See this TDH webpage for more information on eCR, register at the Trader Partner Registration website, or contact MU.Health@tn.gov for assistance.

• Submit online via NBS. NBS is TDH's reportable disease system. To request an NBS account for reporting Complete this user survey to request an NBS account for reporting. 

• Blood lead levels can be sent via fax ( (615) 741-3857), entered online, or reported using the instructions at this link. 

Information about this Reportable Disease for the Public

What It Is

Anthrax is a serious infectious disease caused by Bacillus anthracis bacteria or other Bacillus-expressing anthrax toxin. It occurs naturally in soil and commonly affects domestic and wild animals around the world. People can also contract anthrax if they are exposed during a bioterrorism event.

Anthrax is not contagious, and it can cause severe illness in both people and animals. It is very uncommon for people in the United States to be exposed to and become ill with anthrax.

Types

The type of illness a person develops when they have anthrax depends on how anthrax enters the body: through the skin, lungs, or the gastrointestinal tract. All types of anthrax can eventually cause systemic illness and death without antibiotic treatment.

Signs and Symptoms

The symptoms of anthrax depend on the type of infection and can take anywhere from one day to more than two months to present. All types of anthrax have the potential, if untreated, to spread throughout the body and cause severe illness and death.

 

Treatment

Patients with serious cases of anthrax require hospitalization. They may require aggressive treatment and supportive care, including continuous fluid drainage and mechanical ventilation.

Anthrax vaccine is approved by the Food and Drug Administration (FDA) and recommended for adults 18 through 65 years of age who are at risk of exposure to anthrax bacteria. These people should get 3 doses of anthrax vaccine, followed by booster doses for ongoing protection.

Antibiotics can be used for post-exposure prophylaxis (PEP) to prevent anthrax from developing in people who have been exposed but have not developed symptoms. All types of anthrax infection can be treated with antibiotics.

Severe illness can occur if treatment is delayed because the patient didn't know they were exposed to anthrax. After anthrax toxins, which are released when anthrax spores are activated, have been released in the body, one possible treatment is to use anthrax antitoxin together with other treatment options, including antibiotics.

This Page Last Updated: March 25, 2026 at 8:53 PM