U.S. cases of HIV-2 remain rare

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ATLANTA, July 29 (UPI) -- Human immunodeficiency virus type-2, is related to but distinct from the well-characterized AIDS retrovirus, HIV type 1, U.S. officials say.

The Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report says HIV-2 surveillance shows reported cases of HIV-2 remain rare in the United States -- an average of only 12 diagnoses per year from 2000 to 2009 -- and are largely confined to people from West Africa. Eighty-one percent of those with HIV type-2 are from West Africa.

Sixty-six percent of the cases were reported from the Northeast and 46 percent in New York City. However, some HIV-2 cases may not have been recognized because, among reported cases, nearly 60 percent were initially misclassified as HIV-1 by the Western blot -- the test most commonly used to confirm HIV infection, the report says.

"Correct identification of HIV-2 is important because many drugs used to treat HIV-1 are not effective against HIV-2 and healthcare providers and laboratories should consider specific testing for HIV-2 if tests for HIV-1 are inconsistent or inconclusive, or imply the absence of HIV infection despite clinical evidence suggesting its presence, particularly if the patient is from West Africa," the report says. "Suspected HIV-2 cases should be reported to the state or local health department, which can conduct supplemental diagnostic tests for HIV-2 or arrange for them to be done at the CDC laboratory."