With a goal of circumcising 20 million African men by 2015 as an effective measure in reducing AIDS, the answer appears to be the PrePex device, which was developed in Israel.

Without the traditional surgery, the device uses two rings and an applicator to restrict blood supply, and thus requires no anesthesia or surgeons.

According to the results of a number of new studies, circumcision is an effective measure in reducing AIDS, and PrePex, which avoids the traditional surgery and uses two rings and an applicator to restrict blood supply, appears to be the efficient method to accomplish the task.

According to a recent story in the New York Times by Donald G. McNeil Jr., the studies show that PrePex is faster, less painful and more bloodless than any of its circumcision rivals.

Circumcision, the story reports, is believed to protect heterosexual men because the foreskin has many Langerhans cells, which pick up viruses and “present” them to the immune system — which H.I.V. attacks.

“ PrePex, invented in 2009 by four Israelis after one of them, a urologist, heard an appeal for doctors to do circumcisions in Africa, was approved by the Food and Drug Administration,” several weeks ago, McNeil wrote. The World Health Organization is expected to make a decision on it soon, said Mitchell Warren, an AIDS-prevention expert who closely follows the process.

From the initial safety studies done so far, PrePex is clearly faster, less painful and more bloodless than any of its current rivals. And it relies on the simplest and least-threatening technology — a rubber band.

“ The band compresses the foreskin against a plastic ring slipped inside it; the foreskin dies within hours for lack of blood and, after a week, falls off or can be clipped off ‘like a fingernail,’ said Tzameret Fuerst, the company’s chief executive officer, who compared the process to the stump of an umbilical cord’s shriveling up and dropping off a few days after it is clamped.”

The procedure is accomplished using topical anesthetic cream, and there is usually no bleeding. The PrePex rings can be put in place and removed by nurses with as little as three days training.

In a safety study presented at an AIDS conference last month, the Times’ story said, scientists from Rwanda’s health ministry reported that they had used PrePex to circumcise 590 men. Only two had “ moderate” complications; one was fixed with a single suture, and one required a new band in a different spot.

According to Dr. Jason Reed, an epidemiologist in the global AIDS division of the Centers for Disease Control and Prevention, 2 of 590, or 0.34 percent, is a tenth the typical complication rate of surgical circumcision.

None of the men became infected.

On the 10-point pain scale, they reported on average only about 1 when the ring was placed and only 3 when it was removed.

By the end of the study, the two- nurse teams could do a procedure in three minute

PrePex’s ultimate cost is still being negotiated with donor agencies and foundations, but may end up in the $15-to-$20 range, about the same as a surgical circumcision kit.