Experts say weather helps
INFLUENZA was responsible for the deaths of 146 Californians between October 2014 and late January 2015. When the flu season ended that year, over 400 people had died of the infection—an outbreak the state rated “moderately severe.”
Last year, California faced a huge improvement in the flu situation, when the season’s death toll plummeted to 78, reported the Los Angeles Times.
Since October, there were three reported flu-related deaths in California, and health experts are saying the weather could be part of the reason.
Between El Niño’s unusually warm temperatures and the weekend’s winter storm “Jonas” blizzard, much of the country has been experiencing unusual bouts of weather.
December 2015 was, on average, the country’s hottest and wettest December on record, according to the National Centers for Environmental Information. Health experts said the weather created conditions least conducive to the spread of the flu.
As of mid-January, flu cases were minimal or low in 47 states, according to new data from the Centers for Disease Control and Prevention. Around the same time last year, activity was minimal or low in 17 states.
Fewer patients are showing up with the flu, said Helen Macfie, who monitors emergency room visits at Southern California’s six MemorialCare Hospitals. Even at Long Beach Memorial Medical Center, which runs one of the busiest ERs in Los Angeles County, flu visits have lessened.
“We’re really seeing very little uptick so far, so mostly more common colds and those sorts of things,” she said. “Definitely slower than in prior years.”
Nevertheless, public health officials are warning that flu outbreaks are “unpredictable,” and that the country could still be hit hard in the coming weeks. “The flu season often peaks in February, though the past three seasons did so in December,” said Lynnette Brammer, an epidemiologist for the CDC.
“We seem like we’re back on a more normal pattern actually,” she said. “Because recent ones were unusually early, it feels like this one is abnormal.”
She also pointed to CDC data that show flu activity going up from the first week of January to the second week. “It may peak in February, it may be a little bit later. I don’t know, but we’re definitely seeing a true increase in flu activity,” Brammer added.
“Large numbers of people probably aren’t falling sick from the flu because most of the strains circulating are the same as last year’s. That means that people who were infected last year still have some immunity against the virus,” said Sadina Reynaldo, an epidemiologist with the Los Angeles County Department of Public Health.
In Los Angeles County, 456 people had tested positive for the flu as of two weeks ago, according to county. During last year’s flu season, there had been around 1,405 flu diagnoses.
According to the CDC, people have been infected this season by other viruses including H3N2, H1N1 and some B viruses. Though experts say H3 viruses can cause bad flu seasons, with more hospitalizations and deaths, researchers found that the strains circulating match those included in the current available vaccine—meaning that this year’s flu shot is likely providing strong immunity for those who got vaccinated.
Reynaldo also encouraged everyone to be vaccinated against the flu, even those who are healthy and likely to recover. “It’s not for you; you don’t want to spread it to someone else who may not be so fortunate if they get sick,” she stressed.
James Tamerius, a professor at the University of Iowa who studies the environment’s effect on human health, said this year’s mild season could be due to the warmer temperatures seen in December. “I don’t think it’s the sole reason, but it could be delaying it a bit,” he told the Times.
Forecasts show that the warmer weather will continue in many parts of the country. According to the National Weather Service Climate Prediction Center, both the whole northern half and the West Coast will experience unusually warm temperatures into late April, largely because of El Niño’s tropical conditions.
“It was once believed that the flu was transmitted more in cold weather because people spent more time indoors in closer proximity, making it easier for germs to jump from person to person. However, there isn’t much scientific evidence to back that up,” said Tamerius.
The accepted theory now is that the influenza virus thrives in low humidity, and is “therefore more likely to infect somebody who comes into contact with it,” he added. “It’s also possible that spending time in cold, dry air makes humans more susceptible to catching the virus.”
“There definitely seems to be a link.”
Influenza spreads easily in cold, drier conditions—and statewide, California has experienced a largely warm fall and winter season, punctuated by heavy El Niño rains.