Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home


Diagnosis can be difficult in patients with low levels of larvae in the blood. The diagnostic work-up is usually begun after someone develops eye worm, Calabar swellings, or unexplained elevated levels of eosinophils on blood tests after travel to an affected area. The diagnosis can be made in the following ways:

  • Identification of the adult worm by a microbiologist after its removal from under the skin or eye
  • Identification of an adult worm in the eye by a healthcare provider in a patient with risk factors for infection.
  • Identification of the larvae on a blood smear made from blood taken from the patient between 10AM and 2PM.
  • Identification of antibodies against L. loa. Unfortunately these tests cannot distinguish between active infection and a history of exposure or past infection and they are not widely available in the United States.
Contact Us:
  • Centers for Disease Control and Prevention
    1600 Clifton Rd.
    Atlanta, GA 30333
  • 1-800-CDC-INFO
    TTY: 1-888-232-6348
    Hours of Operation
    8am-8pm EST/ Monday-Friday
    Closed Holidays
  • Contact CDC-INFO
  • Page last reviewed: November 2, 2010
  • Page last updated: November 2, 2010 The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Rd. Atlanta, GA 30333, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC-INFO