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Flu Hospitalization Rates Are the Highest in Years. Here’s Why. This Flu Season Is Now the Worst in Years. Here’s Why.
(7 days later)
Updated on Feb. 2, 2018. Updated on Feb. 9, 2018.
As of February 2, infection rates for the 2017-2018 flu season were still rising, higher than those in any year since 2009, when the swine flu was pandemic, according to the Centers for Disease Control and Prevention. It is now as bad as any flu season since the Centers for Disease Control and Prevention adopted stringent surveillance methods in the early 2000s. The infection rate is now 7.7 percent, which equals the peak of the 2009 “swine flu” pandemic. (The rate is a measure of what percentage of all patients visiting doctors in a particular week had flulike symptoms, including a fever of at least 100 degrees.)
Even more worrying, the hospitalization rate is the highest that the C.D.C. has ever recorded at this point in the season. It has just surpassed that of the lethal 2014-2015 season, during which 710,000 Americans were hospitalized and 56,000 died. Even more worrying, the hospitalization rate is the highest that the C.D.C. has ever recorded at this point in the season. It has now substantially surpassed that of the lethal 2014-2015 season, during which 710,000 Americans were hospitalized and 56,000 died.
“It is possible that this season will exceed that,” said Dr. Daniel B. Jernigan, director of the C.D.C.’s influenza division. “I wish there were better news this week,” said Dr. Anne Schuchat, acting director of the C.D.C., “but almost everything we’re looking at is bad news.”
More than 7 percent of all doctor’s visits reported to the C.D.C. are for flu-like symptoms, and a total of 53 children have died. Large numbers of Americans have fallen ill, and 48 states are still reporting “widespread” flu activity, one state fewer than last week. Hawaii has not reported it yet, and only in Oregon has the infection rate faded a bit. “We are on track to break some recent records,” she added. (History’s worst influenza pandemics — 1918, 1957 and 1968 — all occurred before the C.D.C.’s new surveillance standards were rolled out in the early 2000s and modified in 2010.)
H3N2 is the most dangerous of the four seasonal flu strains, but it is not new nor uniquely lethal. A typical season mixes two Type A strains — H1N1 and H3N2, and two Type B strains — Victoria and Yamagata. (The B strains normally arrive later and are rarer.) As of Jan. 20, about 77 percent of all samples genetically sequenced have been H3N2, according to the C.D.C. That strain first emerged in Hong Kong in 1968 and killed an estimated 1 million people around the world that year. But it has circulated ever since, constantly undergoing small mutations. Many people have had it, and an H3N2 strain is a component of every season’s flu shot. It is too early to know how many will ultimately die, but 10.1 percent of all deaths being recorded now are from flu or pneumonia, and a total of 63 children have died thus far.
About 7.1 percent of all Americans seeking medical care now have flu symptoms, and the number is still rising. That is tracked by the C.D.C.’s Outpatient Influenza-like Illness Surveillance Network, to which about 2,000 doctors’ offices and clinics around the country report weekly how many of their patients have fevers of at least 100 degrees plus a cough or sore throat. The 2014-15 season peaked at close to 6 percent. By contrast, the mildest recent season, 2011-2012, barely surpassed 2 percent. In 2009, during the H1N1 “swine flu” pandemic, almost 8 percent of visits were flu-related, but they peaked in October, not in January. That never happens in seasonal flu but is typical of pandemic flus. Health officials from all states except Oregon and Hawaii are reporting “widespread” flu activity. By a different measure, flu activity is now rated “high” throughout most of the country, including all the Mid-Atlantic states and northeastern states except for Maine. Those regions were the last in the country to be reached by the virus.
Not universally across the country, but in some places — including Southern California, Pennsylvania and central Texas — some hospitals have seen so many flu patients that they had to set up triage tents or turn other patients away. Local shortages of antiviral medications and flu vaccines have been reported, and the C.D.C. said patients may have to call several pharmacies to find shots or to fulfill prescriptions. H3N2 is the most dangerous of the four seasonal flu strains, but it is not new nor uniquely lethal. A typical season mixes two Type A strains — H1N1 and H3N2, and two Type B strains — Victoria and Yamagata. As of Feb. 3, about 74 percent of all samples genetically sequenced have been H3N2, according to the C.D.C. That strain first emerged in Hong Kong in 1968 and killed an estimated 1 million people around the world that year. More B strain flus are now being detected. Scientists have not yet found any genetic changes in the H3N2 virus that would account for its severity this year, Dr. Schuchat said.
This year’s outbreak began in Louisiana and Mississippi, then spread to California and up the West Coast. The C.D.C. believes it has peaked there; California reported four times as many people hospitalized with flu as were seen three years ago. The flu is now widespread across the Midwest and South, and intensity is still increasing in the Northeast, including in New York City. About 7.7 percent of all Americans seeking medical care now have flu symptoms. That is tracked by the C.D.C.’s Outpatient Influenza-like Illness Surveillance Network, to which about 2,000 doctors’ offices and clinics around the country report weekly how many of their patients have fevers of at least 100 degrees plus a cough or sore throat. The latest percentage equals the mark set in 2009 “swine flu” pandemic, but that was a completely new H1N1 virus containing bird and pig genes for which no one had immunity. (That year’s infection rate peaked in October, not midwinter. Out-of-season peaks are common only for pandemic flus.) The previous high mark for seasonal flu was the 2003--2004 season, which peaked at 7.6 percent; that year’s dominant strain was a mutated variant of H3N2 that proved particularly lethal to children. It prompted the C.D.C. to begin recommending that all children over 6 months old get flu shots.
An experimental new measure, produced by Kinsa from 35,000 daily readings a day uploaded by its internet-connected thermometers, indicates that the highest percentages of people now reporting fevers are in Missouri, Kansas, Iowa and Georgia, and numbers rising in the Mid-Atlantic states and the Northeast. Not universally across the country, but in some places — including Southern California, Pennsylvania and central Texas — some hospitals have seen so many flu patients that they had to set up triage tents or turn other patients away. Local shortages of antiviral medications and flu vaccines have been reported, and patients may have to call several pharmacies to find shots or to fulfill prescriptions. Nationally, Dr. Schuchat said, the commercial supply of oseltamivir still exceeds demand and there has not yet been any need to use the national strategic stockpile; but suppliers are struggling to keep all pharmacies supplied.
Hospitalization rates have risen sharply, and those presage high death rates. As happens every season, some apparently healthy people have died. They include a 21-year-old fitness buff in Latrobe, Pa., a mother of three in San Jose, Calif., and a 10-year-old hockey player in New Canaan, Conn. The latest C.D.C. figures indicate that 53 children and teenagers have died of flu and its consequences, including pneumonia, meningitis and sepsis. In 2014-2015, 148 children died by flu season’s end. The C.D.C. does not recommend that oseltamivir be used to prevent infections, except under certain circumstances. These would include, for example, to stop an outbreak in a nursing home, or when a highly vulnerable individual, such as one with a compromised immune system, has been exposed to someone known to have flu.
Even in a mild year, flu kills about 12,000 Americans, the C.D.C. estimates. In a bad year, it kills up to 56,000. Most of those deaths are among the elderly, but flu also kills middle-aged adults with underlying problems like heart or lung disease, diabetes, immune suppression or obesity. It is also dangerous for pregnant women, children under age 5 and children with asthma. This year, Americans aged 50 to 64 — part of the baby boom generation — are being hospitalized at unusually high rates, for reasons that are still unclear. This year’s outbreak began in Louisiana and Mississippi, then spread to California and up the West Coast. It is now widespread across the Midwest and South, and intensity is still increasing in the Northeast, including in New York City.
An experimental new measure, produced by Kinsa from 35,000 daily readings a day uploaded by its internet-connected thermometers, indicates that the highest percentages of people now reporting fevers are in Georgia, South Carolina and the southeast. It indicates the Plains states are leveling off and numbers are still rising in the Mid-Atlantic states and the Northeast.
Hospitalization rates have risen sharply, and those presage high death rates. As happens every season, some apparently healthy people have died. They include a 21-year-old fitness buff in Latrobe, Pa., a mother of three in San Jose, Calif., and a 10-year-old hockey player in New Canaan, Conn. The latest C.D.C. figures indicate that 63 children and teenagers have died of flu and its consequences, including pneumonia, meningitis and sepsis. In 2014-2015, 148 children died by flu season’s end.
Even in a mild year, flu kills about 12,000 Americans, the C.D.C. estimates. In a bad year, it kills up to 56,000. More than 80 percent of those deaths are usually among the elderly, but flu also kills middle-aged adults with underlying problems like heart or lung disease, diabetes, immune suppression or obesity. It is also dangerous for pregnant women, children under age 5 and children with asthma. This year, Americans aged 50 to 64 — part of the baby boom generation — are being hospitalized at unusually high rates, for reasons that are still unclear. In 2014-2015, flu hospitalization rates for that age group were 35 per 100,000 people; they are now at 63 per 100,000.
Its H3N2 component is a bad match for the circulating strain. Australia just had a severe flu season with many deaths, and the vaccine there had the same mismatch. Experts estimated that the vaccine prevented infection only 10 percent of the time. The shot’s efficacy here has not yet been calculated because the virus is still spreading, but experts believe it to be about 30 percent. In Australia, vaccination failed partially because it is urged for only the most vulnerable, while in the United States millions of healthy people are vaccinated.Its H3N2 component is a bad match for the circulating strain. Australia just had a severe flu season with many deaths, and the vaccine there had the same mismatch. Experts estimated that the vaccine prevented infection only 10 percent of the time. The shot’s efficacy here has not yet been calculated because the virus is still spreading, but experts believe it to be about 30 percent. In Australia, vaccination failed partially because it is urged for only the most vulnerable, while in the United States millions of healthy people are vaccinated.
Experts say yes, because even when the shot does not prevent you from catching the flu, it may save you from dying of it. Its effectiveness against H1N1 and B strain flus is higher. And while getting the vaccine in October is best, because it takes about two weeks to build immunity, now is still not too late, because the virus persists into spring. Because some doctors and pharmacies are out of vaccine, the C.D.C. suggests consulting vaccinefinder.org.Experts say yes, because even when the shot does not prevent you from catching the flu, it may save you from dying of it. Its effectiveness against H1N1 and B strain flus is higher. And while getting the vaccine in October is best, because it takes about two weeks to build immunity, now is still not too late, because the virus persists into spring. Because some doctors and pharmacies are out of vaccine, the C.D.C. suggests consulting vaccinefinder.org.
Yes, to the extent that they ever do. Of all the samples tested so far by the C.D.C., only 1 percent were resistant to oseltamivir, zanamivir, and peramivir, the ingredients in Tamiflu, Relenza and Rapivab. But to be effective, these medicines must be taken as early as possible after symptoms appear. (Rapivab is given intravenously, usually in hospitals.) Yes, to the extent that they ever do. Of all the samples tested so far by the C.D.C., only 1 percent were resistant to oseltamivir, zanamivir, and peramivir, the ingredients in Tamiflu, Relenza and Rapivab. But to be effective, these medicines should be taken within 48 hours after symptoms appear.