Giving injecting drug users a daily pill against HIV nearly halved their risk of infection by the AIDS virus, a pioneering study published on Thursday said.

The four-year research strengthens convictions that antiretroviral drugs can prevent HIV infection, rather than simply treat the virus after someone has been infected, it said.

A 10-year-old American girl whose dire need for a lung transplant catapulted her into the political spotlight underwent potentially life-saving surgery Wednesday after a donor was found.

"We are thrilled to share that Sarah is out of surgery. Her doctors are very pleased with both her progress during the procedure and her prognosis for recovery," said the child's mother, Janet Ruddock Murnaghan.

Britain's Department of Health will on Wednesday unveil a new system for coordinating cancer treatment which it hopes will save thousands of lives each year, the Times reported.

Data from millions of patient records has been brought together in the biggest cancer registration database, giving specialists instant access to detailed clinical data.

Britain will urge the G8 to coordinate plans to prevent a spread of drug-resistant microbes, which it fears could cause a public health crisis, the government said Tuesday.

Science Minister David Willetts said Britain would call for a joint clamp down on the over-prescription of antibiotics and for cross-border cooperation in fighting the spread of bacterial diseases at next week's G8 summit in Northern Ireland.

Patients who successfully battled cancer during childhood face an extraordinarily high rate of chronic illness during their grown-up years, according to study published Tuesday.

The research released by the Journal of the American Medical Association (JAMA) tracked 1,700 adult survivors of childhood cancer, and found that the vast majority were combating one or more chronic ailments.

Singapore is fighting back against a rapidly worsening dengue epidemic by distributing insect repellants to every household and recruiting hundreds of disease control officers, officials said.

Two Singaporeans have died from the virus so far this year and weekly cases hit an all-time high of 820 in the period ending June 8, the National Environment Agency (NEA) said in a statement issued late Tuesday.

Apricus Biosciences Inc. said Monday that its impotence drug Vitaros has been approved in 10 European countries.

The company said Vitaros is now approved in the Netherlands, Germany, France, Italy, and the U.K., among other countries, for the treatment of erectile dysfunction. Apricus sought marketing approval for Vitaros in specific countries, and says the decentralized process was faster than seeking approval by the entire European Union.

Secretary-General Ban Ki-moon says the overall U.N. goal of halting and reversing the spread of AIDS will be met by the target date of 2015.

But the U.N. chief told the General Assembly Monday that despite the "important progress," more must be done to target AIDS in countries and communities where it is still spreading — and this will require additional funds.

Singapore is telling doctors to be more vigilant against dengue fever as the mosquito-borne disease surges this year.

The Southeast Asian city-state has had more than 9,000 cases and two deaths since January. The illnesses counted so far in 2013 are already twice the total for all of last year.

The Obama administration said Monday it would comply with a judge's order to allow women and girls of any age to purchase emergency contraception, ending its efforts to restrict the drug's availability.

The reversal on the politically sensitive issue means that anyone, including young girls, will soon be able to purchase the popular Plan B One-Step morning-after pill over the counter, without a prescription.