Northern nations try to hold fast against swine flu's second surge

The United States and other northern countries are bracing for a second wave of swine-flu infections that could sicken millions of people and contribute to the hospitalization and deaths of thousands, including many children and young adults.

While flu viruses are notoriously capricious, making firm predictions impossible, a second wave could hit the Northern Hemisphere within weeks and lead to major disruptions in schools, workplaces and hospitals, according to U.S. and international health officials.

"The virus is still around and ready to explode," said William Schaffner, a Vanderbilt University School of Medicine influenza expert who advises federal health officials. "We're potentially looking at a very big mess."

Since emerging last spring in Mexico, the virus, known as H1N1, has spread to at least 168 countries, causing more than 162,000 confirmed cases and playing a role in at least 1,154 deaths, including 436 in the United States, according to the World Health Organization (WHO).

"Everyone recognizes that H1N1 is going to be a challenge for all of us, and there are people who are going to be getting sick in the fall and die," said John Brennan, the U.S. deputy national security adviser for counterterrorism and homeland security. "The strategy and the effort on the part of the governments is to make sure we ... collaborate to minimize the impact."

As the first flu pandemic in 41 years spread through the Southern Hemisphere's winter in recent months, scientists have been monitoring the virus. No signs have emerged that the microbe has mutated into a more dangerous form, and most infected people seem to experience relatively mild illness.

Still, the virus has caused major outbreaks involving a disproportionate number of younger people in Australia, New Zealand, Argentina and other countries, prompting schools to close, causing theaters to shut down, and straining some emergency rooms and intensive-care units, sometimes forcing doctors to postpone other care, such as elective surgeries.

Swine flu also is spreading in South Africa, where at least two deaths have been reported and the national laboratory was overwhelmed last week. In India, a 14-year-old girl became the first person to die from the disease in that nation. Three more deaths were reported Sunday.

In Britain, meanwhile, where anxiety was running high because of high-profile cases including Harry Potter films actor Rupert Grint, health officials were trying to determine the cause of a sharp increase in reported cases in recent weeks.

"This is something that we could see here soon," said Arnold Monto, a University of Michigan infectious-disease expert who advises the WHO, the U.S. Centers for Disease Control and Prevention (CDC) and other federal agencies. "We have to be worried about our ability to handle a surge of severe cases."

Monitoring intensifies

Concern about a second wave has prompted federal, state and local officials to intensify flu-virus monitoring and make plans to distribute vaccine and antiviral drugs and other treatments, if necessary.

"There's a lot of moving parts to this," said Joseph Bresee, who heads the CDC's influenza epidemiology and prevention branch. "Hopefully we won't have a panic, but instead we'll have the appropriate level of concern and response."

The Obama administration has been updating recommendations for school closures, what parents should do if children get sick, how doctors should care for patients and how businesses should respond to large-scale absences. Officials hope to navigate a fine line, urging precautions to minimize spread, serious illness and deaths while avoiding undue alarm.

"The last time we had anything similar to this was prior to the Internet," said one senior official who asked not to be identified.

Many experts suspect the second wave could be more severe than an average flu season, which hospitalizes an estimated 200,000 Americans and contributes to 36,000 deaths. Because the virus is new, most people have no immunity against it.

"This epidemic will transmit faster than usual, because the population is more susceptible," said Marc Lipsitch, a Harvard School of Public Health professor of epidemiology who has been helping the CDC project the severity of the upcoming wave. "It's fair to say there will be tens of millions of illnesses and hundreds of thousands of hospitalizations, and tens of thousands of deaths. What we don't know is how many tens of thousands."

Perhaps more important, the virus continues to affect children and young adults much more commonly than typical flu viruses.

Most of those who have developed serious illness and died have had other health problems. But those include many common conditions, such as diabetes, asthma and obesity. Pregnant women appear to be especially at risk. And the virus can cause severe illness and death in otherwise healthy people in perhaps one-third of cases.

Concern over vaccine

The virus continued to simmer in the United States over the summer, and officials estimate more than 1 million Americans have been infected. The number of cases could increase rapidly when schools reopen and could accelerate further as cooler, drier temperatures return, possibly peaking in October.

That's much earlier than the usual flu season, and it could create confusion. People could get sick with swine flu before a vaccine is widely available and nonetheless be urged to get vaccinated against the regular flu, which will be available first. Because different groups are being given priority for different vaccines, officials are concerned it could be difficult to make sure the right ones receive the vaccine at the right time. The elderly are a priority for the regular vaccine but not the swine-flu vaccine.

The first batches of swine-flu vaccine are not expected to become available until mid-October, assuming studies indicate it is safe and effective. And officials have not answered many questions, including how many doses will be needed. If it is two, as many suspect, it could take at least five weeks after the first shot before vaccinated people are fully protected.

"There's only so much that can be done to get ready," said Eric Toner of the University of Pittsburgh's Center for Biosecurity. "Flu, like a hurricane, is a force of nature. You can't stop it. You can't make it less severe than it would be otherwise. All you can do is try to be prepared to deal with the consequences."