Managers of Guatemala's biggest hospital have declared the facility to be in a state of emergency due to a massive supply shortage.

"There are no sutures, bandages, gauze, laboratory tests or X-rays, so we have decided to declare a state of calamity," Roosevelt Hospital's board president Arnoldo Lopez told reporters late Wednesday.

Ever since the popular painkiller pill OxyContin became harder to crush into powder two years ago, many U.S. drug abusers have turned to heroin instead, researchers said Wednesday.

The formula change did not appear to stop people from snorting or shooting up, but rather caused them to switch to a dangerous street drug that mimics the same high, said a letter to the editor in the New England Journal of Medicine.

Various trials examining the use of anti-retroviral drugs in healthy heterosexuals as a way to prevent HIV have shown drastically different results, research showed Wednesday.

The findings of three major studies in Africa, published in the New England Journal of Medicine, raise many questions about which groups would likely benefit and how to manage such treatments in the future, doctors said.

Rich nations and the Bill and Melinda Gates Foundation said they had pledged more than 2.6 billion dollars towards family planning in developing countries at a summit in London Wednesday.

The aim of the summit was to secure new funding pledges to give an additional 120 million women and girls access to contraception by 2020.

Children who are solely breast-fed in the first six months of life are at increased risk of developing a nut allergy, new research showed Thursday.

A study by The Australian National University, published in the International Journal of Pediatrics, investigated the link in primary school children in the Australian Capital Territory, of which Canberra is the capital.

Worries about a link between depression and the amount of time spent on Facebook or other social media sites are probably unfounded, a U.S. study said this week.

The University of Wisconsin School study found no basis to support the theory outlined in a study last year by the American Academy of Pediatrics that suggested exposure to Facebook could lead to depression among adolescents.

Quitting smoking leads to an average weight gain of four to five kilograms (nine to 11 pounds) in the first year -- "significantly" more than previously thought, a study said Wednesday.

Most of the pounds are piled on in the first three months, a team of medical researchers wrote in the online journal bmj.com, as another group stressed that the health benefits of quitting far outweighed the risks of putting on weight.

Officials have slain 2.5 million birds at poultry farms in western Mexico over the past three weeks in an attempt to contain a bird flu outbreak, the agriculture ministry said Tuesday.

The virus responsible for Mexico's current bird flu outbreak, H7N3, has occasionally caused human disease in various parts of the world, according to the United Nations, but has not shown itself to be easily transmittable between humans.

Shaken awake by police on a park bench, a 12-year-old boy from Prague was so drunk he could neither walk nor talk -- grim evidence of an unparalleled alcohol scourge affecting underage Czechs.

The boy was one of seven whom police found falling-down drunk in the Czech capital on the last day of school in late June.

Laws that criminalize gay behavior create a host of legal tangles that waste resources and hinder an effective response to HIV/AIDS worldwide, an independent commission reported on Monday.

The report by the Global Commission on HIV and the Law also pointed to laws that make sex work a crime, laws that prevent interventions with injecting drug workers, and legislation that denies youths access to sex education.