Mar 10, 2008 (CIDRAP News) Friday's announcement by the Centers for Disease Control and Prevention (CDC) that influenza appears to be slowing down has left medical personnel relieved for the imminent end of a harsh flu season.
But it has also left them worried over weaknesses that the season exposed in public health's ability to anticipate flu's behavior, and over doubts raised among their patients by the flu vaccine's diminished effectiveness.
Many are concerned as well for what the bad season demonstrates about the healthcare system's lack of surge capacity, and for the lack of nimbleness in the vaccine-production system that forced distribution of a suboptimal vaccine.
Emergency departments overcrowded
The CDC has not floated any adjectives to describe this year's flu season, though the agency said Friday that 47 out of 51 jurisdictions (the states plus Washington, DC) are experiencing "widespread" flutwo fewer than the week before.
But to the dozen family and emergency physicians who spoke to CIDRAP last week, "widespread" does not begin to capture their flu season experience. "Severe" and "slammed" are more like it.
"In four weeks, we went from a ho-hum flu season to ridiculous overcrowding," said Dr. Maurice Ramirez, an emergency physician who works in several institutions in north Florida. "We have had so many people that we have them, not in beds in the hallway, but in chairs with a number taped to the wall over their heads."
"We've seen a tremendous amount of flufrom an anecdotal standpoint, a much busier season than in recent years," agreed Dr. Peter A. Lipson, a private practice internist in southern Michigan who also sees patients at a walk-in clinic.
Around the country, physicians recounted local overloads, from a 30% increase in patients at a rural Virginia emergency department to a 15% hike in call volume for a central-Colorado ambulance service, all of them due either to lab-confirmed flu or to flu-like illnesses.
The soaring demand for flu-related care is backing up entire local healthcare systems. It has added hours to the time that all patientsnot just those with suspected fluwait before receiving an emergency department evaluation or before being admitted to a hospital bed. In some areas, physicians said, rates of "elopement"patients leaving before being seenhave risen sharply; in others, it has led to increased ambulance diversions.
The doctors experiencing the influx of flu patients all said they were impressed by how sick patients have been, recounting very high fevers, frequent pneumonias, and uncommon symptoms such as stridor, a high, whistling breath sound that indicates a partially obstructed airway and is an emergency in children.
"We've admitted a lot of elderly patients to the intensive care unit," said Lipson, in Michigan. "I sent one [influenza] patient to the emergency room recently with meningitis."
The flu onslaught is not limited to healthcare institutions. Prisons around the country have experienced huge flu outbreaks, according to media reports in several states, including the California Correctional Center and High Desert State Prison, both quarantined in February, and the Albemarle-Charlottesville Regional Jail in Virginia, which last week banned visits and required staff to wear masks. On Friday, the Chuckawalla Valley State Prison in Blythe, Calif., banned movement in or out of the institution after 546 in a population of 3,147 fell ill and two died.
Many cases in vaccinees
Troublingly, many of the flu patients coming to the healthcare system received flu shots. Their illnesses represent a mismatch between the strains that were chosen for the vaccine a year ago and the strains that actually caused illness this season, a development the CDC acknowledged in early February. The mismatch has been significant: Last Friday, the CDC said that the rates of match between the current flu vaccine and flu isolates analyzed so far this winter were 77%, 14%, and 7% for the three flu strains.
Dr. Michael Sauri, an occupational and infection-control physician outside Washington DC, was so impressed by a late-January uptick in flu cases among patients who insisted they had been vaccinated that he put a post on the international disease-warning listserv ProMED.
"I got quite a bit of response from all over the United States, Egypt, Australia, the Caribbean," said Sauri, who estimates that 25% of his flu patients represent vaccine failures. In one hospital where he works, flu cases have doubled from this time last year, he said.
In some cases, physicians said, the false sense of security produced by the less-effective vaccination may have contributed to patients' illness. Because they believed they were protected against flu, they assumed their respiratory symptoms were caused by something less serious, and so did not seek help until they were beyond the 2 days in which antiviral drugs are most likely to reduce symptoms.
The possibility that this year's vaccine would not match this year's flu strains has been known to public-health insiders all year. It was a calculated risk taken by the CDC and the Food and Drug Administration's Vaccines and Related Biological Products Advisory Committee (VRBPAC) during spring 2007 vaccine-component discussions, after it became clear that a new vaccine strain could not be produced in time to insert it into the fall 2007 vaccines.
"We did not have a viable egg isolate that could be used by the manufacturers. And so it was necessary to continue to use the [existing] virus in the vaccine," Dr Nancy Cox, director of the CDC's Influenza Division, said in a Feb. 22 press briefing.
The gamble did not pay off; the circulating virus drifted far enough from the vaccine strain to cause significant amounts of illness. That ought to underline the need to forge ahead on new vaccine technologies that would confer broader protection and would not be held hostage by the current 6-month manufacturing timeline, said Dr. Arnold Monto, a noted flu researcher and professor of epidemiology at the University of Michigan.
Lessons for pandemic planning
In the meantime, however, clinicians are concerned about the impression that the vaccine mismatch and the resulting flu cases will leave. Several times over the past decade, flu-vaccine problemsmanufacturing problems, late vaccine delivery, an early-arriving seasonhave dented flu-vaccine uptake the following year.
"We will need to really clearly and plainly explain that each year, the experts make their best educated guess . . . and some years are spot-on and some years are a mismatch," said Dr. David Kimberlin, professor of pediatrics at the University of Alabama at Birmingham. "The burden is on the medical community to say that, if we do not have a complete match, you are still getting some protection, and it is better to have partial protection than none."
Some say this flu season has more lessons to teach. In Florida, emergency physician Ramirezalso a disaster-readiness consultantticked off the components: a significant flu-virus drift, a vaccine-manufacturing system that could not keep up, seriously ill patients, and an overwhelmed healthcare system.
"These are exactly the things we ought to be prepared for in an influenza pandemic, and we were not prepared," he said. "We ought to consider this flu season as a warning to healthcare and industry. This is a gunshot across our bow."
Feb 22 CIDRAP News story, "CDC says flu is widespread in 49 states"
Feb 22 CIDRAP News story, "FDA panel endorses overhaul for 2008-09 flu vaccine"
Feb 8 CIDRAP News story, "CDC says influenza B strain doesn't match vaccine"
Feb 6 CIDRAP News story, "US seeing flu strain not matched by vaccine"