Worldwide cases of the new H1N1 swine flu virus are spreading so fast that overwhelmed global health officials have stopped counting and officials with the U.S Centers for Disease Control and Prevention say they'll soon follow suit.
But that's likely only a preview of what will happen in the fall — or even sooner — when a surge of new cases is likely to emerge as families resume more normal schedules after the summer break.
"We don't know the extent of the challenges that we'll face in the weeks and months ahead," said Dr. Anne Schuchat, director of the National Center for the Immunization and Respiratory Diseases, adding later: "I'm expecting when school reopens and kids are all back together, in some communities at least we may seen an increase."
Schuchat did not elaborate on how the CDC would inform the public about the extent of the outbreak, which has been confirmed in more than 40,600 people and implicated in 263 deaths in the United States. WHO had reported nearly 95,000 cases including 429 deaths worldwide. But the numbers are outdated, with Britain estimating it had 55,000 new cases last week alone.
However, she urged families and communities to start thinking now about alternate plans if the virus disrupts daily life — and if planned vaccines are delayed or available only to targeted groups. Schuchat added, however, that production of an H1N1 vaccine remains on schedule.
"We're really on track and not concerned about meeting expectations," she said.
WHO stops tracking individual cases
Earlier Friday, WHO officials said tracking individual swine flu cases is too overwhelming for countries where the virus is spreading widely. WHO will no longer issue global totals of swine flu cases, although it will continue to track the global epidemic.
WHO says countries should look for signs the virus is mutating, such as changes in the way swine flu is spreading, surges in hospital visits or more severe cases.
“We agree that the idea of the individual case count probably is not the way to track what’s going on,” said Dr. Anne Schuchat, director of the National Center for Immunization and Respiratory Diseases.
The virus, which has been declared a pandemic, is causing severe disease and deaths in older children and younger adults in the Southern Hemisphere, just as it has in the United States, Schuchat said.
The new virus, which officials estimate has infected millions of people, is thriving in spite of the heat and humidity of summer in the U.S., Schuchat noted. Usually respiratory viruses such as flu do not circulate well in summer months.
Schuchat said this was probably because so many people do not have immunity to H1N1, and not because the virus has some unusual biological properties.
Pregnant women also often have more serious symptoms and are more likely to die, just as with seasonal flu, Schuchat said. The same pattern is being seen in Southern Hemisphere countries like Argentina, she said.
The virus has spread fast, Schuchat said. "We have seen this virus reach every country in a matter of weeks and months and not years," she said.
Thursday, Baxter International, one of the companies making H1N1 vaccine for the U.S. market and four other countries, said Thursday it could not take any more orders.
But Schuchat said she was not worried.
Four other companies make flu vaccines for the U.S. market — GlaxoSmithKline Plc, Novartis AG, Sanofi-Aventis SA and AstraZeneca, through its MedImmune unit.
Some companies have said they are not able to make as much vaccine as they had hoped because of the way the virus grows in eggs.
"Based on what has been described to us so far, it has been in the range of our planning assumptions, but that doesn't mean we won't see more surprises," Schuchat said.
WHO has said new samples of virus are being sent to companies to see if they grow better in eggs.
Trials set to begin
Tests of the new H1N1 vaccine are likely to get underway in August and Schuchat and other officials stressed that these tests in people will be crucial to knowing how much vaccine will be needed — and available.
"We do not know how effective an H1N1 vaccine will be in different populations," Schuchat said.
Most people infected with H1N1 are never tested, so any count of confirmed cases only represents a fraction of the true infections.