Michelle Obama lashed out in a newspaper opinion piece Thursday against Republican plans to roll back recently improved nutrition standards in American schools, one of her cherished causes as U.S. first lady.

Obama wrote in the New York Times that revamped school nutrition standards requiring less salt, sugar and fat in meals served at school have helped reverse the obesity trend among U.S. school children.

Elliot Rodger's murderous rampage near Santa Barbara has tragically exposed the limitations of involuntary-commitment laws that allow authorities to temporarily confine people who are deemed a danger to themselves or others.

Three weeks before he stabbed and shot six people to death and then apparently took his own life, the 22-year-old sometime college student was questioned by sheriff's deputies outside his apartment and was able to convince them he was calm, courteous and no threat to anyone. The officers had been sent by local health officials after Rodger's family expressed concern about him.

Hard-hit by a cholera epidemic that started in 2010, Haiti now faces a new threat in the expanding chikungunya virus, authorities said Wednesday.

"We have had 8,561 deaths from cholera since its reappearance in Haiti in 2010, while 702,892 cases have been confirmed," said Health Minister Florence Duperval.

Nearly a third of adults and a quarter of children today are overweight, according to a report Thursday that said no country has turned the tide of obesity since 1980.

Traditionally associated with an affluent lifestyle, the problem is expanding worldwide, with more than 62 percent of overweight people now in developing nations, said the report.

A woman in Sierra Leone has died from the Ebola virus, a health ministry official announced on Wednesday, the second person in the west African country to succumb to the hemorrhagic fever.

"One of the seven Ebola patients, a woman admitted at the Isolation Center in the Government Hospital in Kenema, died on Tuesday," Dr Brima Kargbo, the chief medical officer, told Agence France Presse in a telephone interview.

Omani health authorities announced Wednesday three deaths this month from the swine flu virus, the official ONA news agency reported.

The health ministry said "82 new cases of H1N1 virus have been registered in May, three of them fatal," without elaborating.

Thousands of New York City police are to be equipped with heroin antidote kits to address a surge in overdoses from the drug, city officials said Tuesday.

New York Attorney General Eric Schneiderman said 19,500 police officers would be armed with naloxone, a highly effective drug capable of reversing the effects of an opioid overdose.

A nonprescription version of Nexium, the most popular medicine for frequent, severe heartburn, has just gone on sale.

Drugmaker Pfizer Inc. said Tuesday that over-the-counter Nexium 24HR is available for online orders at www.Nexium24HR.com and will be in most retailers nationwide within three days.

Iran has recorded its first two cases of the deadly MERS virus, both among patients who had been in hospital with a pilgrim returning from Saudi Arabia, reports said Wednesday.

The two infected women are sisters and one is in a critical condition, transmissible diseases unit chief Mohammad Mehdi Gooya told the Fars news agency.

An outbreak of cholera in South Sudan has killed 23 people and infected at least 670, aid officials said Tuesday, warning the outbreak of the deadly disease could still get worse.

The cases, all in the capital Juba, have raised fears for tens of thousands of people who have sought refuge at U.N. bases from a wave of ethnic violence triggered by a civil war between President Salva Kiir and rebels loyal to former vice president Riek Machar.