Like so many other victims of Ethiopia's hunger crisis, Usheto Beriso weighs just half of what he should. He is always cold and swaddled in a blanket. His limbs are stick-thin.

But Usheto is not the typical face of Ethiopia's chronic food problems, the scrawny baby or the ailing toddler. At age 55, he is among a growing number of adults and older children — traditionally less-vulnerable groups — who have been stricken by severe hunger due to poor rains and recent crop failure in southern Ethiopia, health workers say.

"To see adults in this condition, it's a very serious situation," Mieke Steenssens, a volunteer nurse with Doctors Without Borders, told The Associated Press as she registered the 5-foot-4 Usheto's weight at just 73 pounds.

Aid groups say the older victims suggest there is an escalation in the crisis in Ethiopia, a country that drew international attention in 1984 when a famine compounded by communist policies killed 1 million people.

This year's crisis, brought on by a countrywide drought and skyrocketing global food prices, is far less severe. But while figures for how many adults and older children are affected are not available, at least four aid groups interviewed by the AP said they noticed a troubling increase.

"We're overwhelmed," said Margaret Aguirre, a spokeswoman for the International Medical Corps, a Santa Monica, Calif.-based aid agency. "There's not enough food and everyone's starving, and that's all there is to it.

"Older children are starting to show the signs of malnutrition when normally they might be able to withstand shocks to the system," she added. "What's particularly concerning is that the moderately malnourished are soaring. It's increasing so much that it means those children are going to slide into severe malnutrition."

Ethiopia is not alone in suffering through the worldwide food crisis, which is threatening to push the number of hungry people in the world toward 1 billion. Last week, a U.N. summit of 181 countries pledged to reduce trade barriers and boost agricultural production to combat rising food prices.

But in Ethiopia, food production is hampered by drought, meaning the country has been hit with a double blow. Drought is especially disastrous in Ethiopia because more than 80 percent of people live off the land. Agriculture drives the economy, accounting for half of all domestic production and 85 percent of exports.

Sending more food is one solution, but there already is a global crunch as rising fuel prices drive up the cost of fertilizers, farm vehicle use and transport of food to market. Biofuels, which are made from crops such as sugar cane and corn, are another contentious issue, with critics saying they compete with food crops.

The problem is echoed across Africa, from Kenya and Somalia and farther west. Exacerbating the global rise in food prices, which has sparked protests and riots in several West African nations, is an annual decline in food reserves across the high desert-like region called the Sahel, just below the Sahara Desert.

The so-called "lean season" that begins around June is marked by near-empty grain stores, with the next harvest not due until around September. Locust invasions and poor rains in recent years have only worsened the condition, which leads to deadly malnutrition among young children.

Aid agencies in Ethiopia are issuing desperate appeals for donor funding, saying emergency intervention is not enough. Ethiopia receives more food aid than nearly every other country in the world, most of it from the United States, which has provided $300 million in emergency assistance to relief agencies in the past year.

But despite the international help, the country is again facing hunger on a mass scale. Part of the reason, according to John Holmes, the top U.N. humanitarian official, is the country's climate, chronic drought and the large population of 78 million people.

"The World Food Program feeds some 8 million people already, together with the others in Ethiopia," he said. "But we may need to increase that, because of drought."

The U.N. children's agency has characterized this year's food shortage — in which an estimated 4.5 million people are in need of emergency food aid — as the worst since 2003, when droughts led 13.2 million people to seek such aid. In 2000, more than 10 million needed emergency food.

Studies by the International Medical Corps in southern Ethiopia — the epicenter of the crisis — show that up to one in four young mothers is showing signs of moderate malnutrition.

Ethiopia's top disaster response official, Simon Mechale, insists that the food situation is "under control" and will be resolved within four months. But in the countryside, there are signs that drought has taken a more serious toll.

At a recent food distribution in a village some 155 miles southwest of the capital, more than 4,000 people showed up for free wheat and cooking oil, but only 1,300 rations were available.

Harried health workers picked through the impatient crowd, sorting out the sickest children. Frantic mothers proffered their withered infants, hoping the children's poor state would earn some food for the family.

Ayelech Daka said her 6-year-old son, Tariken Lakamu, has been living on one meal a day for the past three months.

"He was very fat three months ago," said his mother, Ayelech said. "He was normal."

Now, he's skin and bones; he vomits just seconds after taking a bite of a ration offered by an aid worker.

"I'm weak," the child said. "I feel sick. I don't get any food."

Another mother, Ukume Dubancho, rocked a listless infant, trying to squeeze out drops of breast milk for her children, ages 4 months and 4 years, both of whom show signs of severe malnutrition.

Villagers said they simply cannot afford the food on the market. The few mature ears of corn in the market were selling for about 11 cents an ear. Last year, when the rains were good, that money would buy six or seven ears.

"I am not able to walk, even," Ukume said. "I walk for one kilometer and I have to rest."