“Flashblooding,” the act of injecting one heroin addict’s blood into another to share a high or ward off withdrawal, is becoming increasingly common in some African cities, the New York Times reported July 12.

The practice puts users at the highest possible risk for contracting AIDS and hepatitis, among other diseases, doctors say.

So far, flashblooding has been reported in Dar es Salaam and Zanzibar in Tanzania and Mombasa, Kenya. In Tanzania and Kenya, AIDS incidence is much higher among heroin addicts – around 42 percent – versus only three to eight percent of adults in the country overall.

“I don’t really know how widespread it is,” said Sheryl A. McCurdy, a public-health professor at the University of Texas in Houston. who published a study of the practice in the June 2010 issue of the journal Addiction. “There’s pretty circular movement in East Africa, so I wouldn’t be surprised if it’s in other cities.”

Heroin, because of its expense, has not traditionally seen high usage in Africa, but that has changed as prices have fallen and more African port cities are being used in the international smuggling trade.