Babesiosis

Reportable by Laboratories and Providers

About this Reportable Disease

Infectious agent: Babesia microti

Description of illness: Many infected with Babesia microti do not have any symptoms. Some people develop nonspecific flu-like symptoms, such as fever, chills, sweats, headache, body aches, loss of appetite, nausea, or fatigue. Because Babesia parasites infect and destroy red blood cells, babesiosis can cause a special type of anemia called hemolytic anemia. This type of anemia can lead to jaundice (yellowing of the skin) and dark urine. Those most at risk for severe disease are: people without a spleen, immunocompromised persons, have other serious health conditions (such as liver or kidney disease); or older adults.

Interactive Disease Data

Laboratory Reporting for this Disease

Blood Parasite

TEST NAME	Blood parasite
DISEASE/DISORDER
ALTERNATE NAMES
METHODOLOGY	Morphology and/or PCR
SPECIAL INSTRUCTIONS	None
ORDERING INFORMATION	Lab Web Portal

Specimen Requirements

Patient Preparation	None
Specimen Collection	Giesma stained Thick and Thin Smears *AND* EDTA blood, 3 - 5 mL
Specimen Labeling	Specimen must be labeled with at least two unique patient identifiers and match accompanying PH-4182 Clinical Submission Requisition.
Specimen Processing	Prepare Thick and Thin Smears and stain with Giesma stain prior to shipment.
Specimen Storage and Preservation	Store EDTA specimens at 2 - 8°C prior to shipment.
Specimen Transportation	Place slides in plastic or cardboard slide holder before packing for shipping. Ship specimens at 2 - 8°C. 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	Acceptable criteria for specimen testing: - Thick and thin blood smears must be sent and examined for the presence of malaria. If species level determination cannot be made based upon morphological characteristics, malaria PCR will be performed. - From a patient with a febrile illness who is strongly suspected of having malaria (regardless of blood smear result) or a species that cannot be determined after careful examination. - From donors to a patient who developed malaria following blood transfusion. - If Ebola is suspected, it should be ruled out before being sent for malaria testing. Unsatisfactory specimens include, but may not be limited to: - Specimen was broken or leaked in transit - The incorrect preservative was used - The specimen was greater than four (4) months old, if PCR testing is required. - Specimen is not indentified properly (i.e. information does not match the accompanying requisition) - Insufficient amount of specimen submitted for testing
Testing Location	Nashville

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 2025 are indicated and there are several ways laboratories can report results to TDH.

Manually report results to TDH by faxing or mailing a completed PH-1600 form to your local health department, or faxing to the state health office at (615) 741-3857
Automatically submit results to TDH via electronic laboratory reporting (ELR), which automates the process of sharing data with TDH using interoperability standards.
- See the ELR Onboarding Handbook for details on the onboarding process, checklist, frequently asked questions, business rules, message format, and vocabulary.
- To initiate the ELR onboarding process with TDH, register in the Trading Partner Registration (TPR) system TPR provides documentation for Promoting Interoperability (PI) attestation and milestone letters to document onboarding progress. 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 Healthcare Providers

Clinical Details

Most asymptomatic patients do not require treatment.
A 7- to 10-day course of two prescription medications is the standard treatment for ill immunocompetent patients.
Patients with immunocompromise may require longer treatment courses.

Clinical Links & Info

Review the case definition | CDC

Clinical Information about this disease | CDC

Clinical Care of Babesiosis | CDC

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

Babesiosis is a disease caused by microscopic parasites that infect red blood cells. A parasite is an organism (living thing) that lives on or inside another organism. Although there are many different species (types) of Babesia parasite found in animals, only a few infect people. The most common species to infect people in the United States is Babesia microti.

Signs and Symptoms

Many people with Babesiosis do not feel sick and have no symptoms. However, some people might get flu-like symptoms, such as:

Fever
Chills
Sweats
Headache
Body aches
Loss of appetite
Nausea
Fatigue

Since the parasites attack red blood cells, babesiosis can lead to hemolytic anemia. Hemolytic anemia occurs when your red blood cells are destroyed faster than they can be replaced. Babesiosis can become a serious, even life-threatening illness for certain people, especially those who:

Do not have a spleen
Have a weak immune system for other reasons such as cancer, lymphoma, or HIV
Have serious health issues such as liver or kidney disease
Are older (> 50 years old)

Symptoms, if they appear, may start around a week after infection, but usually develop over a few weeks or months, or longer.

How it Spreads

In the U.S. most Babesia infections are from blacklegged or deer tick (Ixodes scapularis) bites. Ticks are typically found in wooded, brushy, or grassy areas. Currently, most babesiosis cases occur in the Northeast and upper Midwest.

Other less common ways of getting infected with Babesia include:

Getting a blood transfusion that has the parasite in it.
If a mother has babesiosis, she might pass it to her baby during pregnancy or when the baby is born.

Babesia parasites do not spread from person-to-person like the flu or the common cold.

Diagnosis & Treatment

A healthcare provider can diagnose babesiosis by examining a small sample of your blood under a microscope. This lab test can confirm the presence of the Babesia parasites in your red blood cells.

If you have babesiosis, there is effective treatment. You usually do not need treatment if you have no symptoms or signs of babesiosis. Talk with your healthcare provider for more information.

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