The swine flu outbreak began hitting home Wednesday, spreading to 11 states and closing schools amid confirmation of the first U.S. death -- a Mexican toddler who visited Texas with his family -- and the confinement of dozens of Marines after one came down with the disease in California.

Some 100 schools were closed, and more might need to be shut down temporarily, President Barack Obama said, declaring, "This obviously is a serious situation." The total confirmed cases in the U.S. rose to nearly 100, with many more suspected.

MORE: Read more on the swine flu.

The Geneva-based World Health Organization sounded its own ominous alarm, raising its alert level to one notch below a full-fledged global pandemic. Said WHO Director General Margaret Chan: "It really is all of humanity that is under threat during a pandemic."

In Indiana

A federal shipment of enough antiviral drugs to treat 238,000 people arrived Wednesday in Indiana as the state's health commissioner crisscrossed the state, including a stop in Lake County, telling residents that diligence is key to preventing a swine flu outbreak.

The shipment put Indiana among the first wave of states and cities -- New York state and New York City were the other recipients -- to get extra antiviral medication from a federal stockpile as officials brace for a possible wide outbreak.

State officials plan to distribute the new drugs today by dispatching a portion to each of Indiana's 92 county health departments.

During a stop in Gary on Wednesday, Indiana State Health Commissioner Judith Monroe stressed common sense precautions to help prevent the spread of so-called swine flu.

"We need you to play your part," Monroe said, urging frequent hand washing, covering of coughs and sneezes and other precautions.

Indiana has received 25 percent of its allocation of the government distribution of antivirals, including Tamiflu and Relenza, said Monroe, who also traveled to Jeffersonville, Fort Wayne and South Bend.

The state was one of eight in the nation to get the first distributions of the medications, which help limit the severity of flu, Monroe said.

The strain of flu, being called swine flu, has proven sensitive to the antiviral drugs, Monroe said.

There are no vaccines for swine flu, however Monroe urged resident older than 65 to be vaccinated against pneumonia, which can be a complication of the virus.

Monroe's visit came one day after Indiana's first confirmed case of the virus was identified as a student at Notre Dame.

The student has recovered from the flu and is "doing very well," Monroe said.

No other cases have been confirmed in the state.

College programs cut short

The new virus's emerging threat, meanwhile, affected at least three Indiana colleges' study programs in Mexico, where swine flu is suspected in the deaths of about 160 people.

A Valparaiso University student studying abroad in Puebla, Mexico, has returned home as a health precaution, according to a university spokesman.

The host university, like other universities across Mexico, is closed until Wednesday due to the swine flu outbreak, said Reggie Syrcle, VU director of public relations.

The other five VU students there have been offered the opportunity to return home, Syrcle said, adding they have not made a decision about returning home early. The semester ends next week and arrangements for completing academic work would be made, he said.

The student who left Mexico was potentially at higher risk for contracting the flu because the student has a weaker immune system, Syrcle said.

Concerns over swine flu have had no impact on other VU study abroad locations around the world, Syrcle said.

Indiana University suspended all of its Mexican summer study programs, a move that affects 50 to 60 IU students and 20 high school students. And the University of Notre Dame said eight students studying in Mexico will return to the U.S. early, arriving home by the end of the week.

Waiting game

As fears mounted that the swine flu virus could spark a global pandemic, state health officials awaited test results from the Centers for Disease Control and Prevention on viral samples taken from about 30 Indiana residents suspected of contracting the disease.

Despite state officials' comments, officials in Marion County -- the state's most populous county -- said at a Wednesday news conference that the CDC had informed them that two of four viral samples collected in the county were negative for swine flu.

Results on the two other samples are still pending, said John Althardt, a spokesman for the Marion County Health Department.

Elizabeth Hart, a spokeswoman for the Indiana State Department of Health, said the state agency had received only one result from the CDC -- the result on the Notre Dame student.

With the addition of Wednesday's shipment of antiviral drugs, Indiana now has enough such medication to treat 889,000 people for the new virus -- or about 14 percent of the state's 6.3 million residents.

By Sunday, the federal government said that all states will have their share of enough medication to treat 11 million people -- just in case the swine flu takes off.

Hart said that once the drug shipments to the counties are complete, the state health department still will have on hand enough antiviral medication to treat 651,000 people.