Why is flu more common in winter? The answer can help protect you

 

 How do these sneeze droplets differ in winter? Read on!

Photo courtesy of www.dost-dongnai.gov/vn 

This year's flu season is expected to be one of the worst the US has seen in 10 years, according to the the Centers for Disease Control and Prevention. Said Dr. Joseph Bresee, "There's flu all over the country right now...there's widespread disease in most states and high levels of disease in most states...the country has lots of flu."

Most of the US is nearing a "moderate to severe" flu season, and it has not yet peaked.

Flu outbreaks are worse in cold weather

All flu outbreaks tend to be worse in winter. In the Northern Hemisphere flu season is November to March. But seasons are reversed in the Southern Hemisphere - the cool weather of autumn starts in May, and flu season there is May to September.

Why is winter worse?

I had always heard that flu spreads in winter because we're all cooped up together indoors. But that's not it, apparently.

Dr. Peter Palese of Mount Sinai School of Medicine and his colleagues have studied the transmission of flu between guinea pigs, which can get infected with human flu viruses. Palese's results indicate that spending more time together inside is not a factor in the timing of flu outbreaks.

Sneezed droplets have longer hang time in winter air

Palese says flu viruses are more stable (and last longer, presumably) in colder, drier conditions. What's more, the droplets of fluid that people spew into the air with sneezes and coughs are much smaller at lower temperatures and lower humidity, so the droplets carry much farther and stay suspended in the air longer. The smaller droplets can be inhaled more deeply into the respiratory passages and lungs, Palese says. The opposite is true at warmer temperatures and higher humidity, when the droplets become much bigger and sink to the floor, reports Palese. These influences are so pronounced that "at 75 to 80 degrees, we don't see any transmission" of flu viruses.

In cold dry air, inhaled particles cling to membranes

Palese and his colleagues also report that colder, drier air makes mammals' respiratory tracts more vulnerable to infection by airborne viruses. In cold air, "the mucous is much more viscous," Palese explains. Sticky mucus clogs up the cilia, or tiny hairs, that normally move in waves to expel virus-laden particles from the breathing passages. So in cold weather, inhaled flu viruses tend to stay where they land, reproducing and infecting the unfortunate victim.

What can you do?

If you have the flu, stay home. When you sneeze or cough, cover your nose and mouth. If you don't have a cloth or tissue, use the inside of your elbow. If you're touching doorknobs or anything else an infected person may have touched, wash your hands frequently and avoid touching your nose, mouth, or eyes.

If you don't have the flu:
1) Get a flu shot. It's not too late.
2) Try to avoid breathing the air within 6 feet of an infected person who's sneezing and coughing.
3) If you're touching doorknobs or anything else an infected person may have touched, wash your hands frequently and avoid touching your nose, mouth, or eyes.

Sources for Palese's research and for flu prevention

Richard Knox. Flu heads south for the winter. NPR Morning Edition.
How Flu Spreads. The Centers for Disease Control

GMOs threaten Monarch Butterflies

 

Adult Monarch on milkweed I planted in my yard. Photo: Sally Kneidel

I was very sad that California’s Proposition 37 failed to pass in the Nov 6 election. The proposition would have required labeling of all genetically-modified foods and would have prohibited "all-natural" labeling of such foods. We desperately need government action regarding GMOs and I was hopeful this was the beginning. Well, it is a beginning in a way, because 46.9% of California voters voted to pass the Proposition. It probably would’ve passed, if not for the fact that the corporations profiting from genetic engineering spent five times more money on the vote than those who support labeling. Those corporations (e.g.Monsanto, Dow) spent about a million dollars a day, from early October until election day, on a media blitz of false and misleading claims directed at voters.

70% of our processed foods contain GMOs

The U.S. is one of the very few industrialized nations that hasn't either banned GMOs or required labeling. It’s a symptom of the control that corporations have over our government, through lobbying and campaign contributions. Because of this financial and political clout, the corporations behind GMOs are able to keep U.S. shoppers in the dark about the contents of the food on our grocery store shelves. Up to 85% of U.S. corn, 91% of soybeans, and 95% of sugar beets are now genetically modified. According to the Center for Food Safety, 70% of processed foods in supermarkets now contain genetically-modified ingredients, yet are not labeled as having them. Human-health risks from GMOs include immune suppression and cancer.

Wild plants and animals threatened

Risks to the planet are even more frightening for me. The uncontrolled dispersal of the engineered genes in agricultural plants threatens wild plant and animal species with contamination of their own genetic material and possible extinction. This sounds dramatic, but if you doubt it, read the Center for Food Safety’s “Monsanto vs. U.S. Farmers".
Anyway – the problems with genetically-modified foods are not new. I’ve known about GMOs and the corporate control of their development and proliferation for some time. I’ve known about the industry’s appalling disregard of anything other than corporate profits. My daughter Sadie and I wrote about that topic in our 2008 book, Going Green.

But I almost choked when I heard...

I just recently learned something new about an unexpected victim of the genetic-engineering industry. Monarch butterflies. Last summer, while researching a 2^nd edition of my book "Creepy Crawlies and the Scientific Method", I began talking to monarch experts who are involved in the conservation of this magnificent butterfly, a species that weighs less than a paper clip but migrates 2000 miles every autumn! They migrate farther than any other insect, farther than many migratory birds. Through this research, I learned that monarchs are declining, and when I found out why, I almost gagged. Monsanto!!! Monsanto has wiped out much of the milkweed in the Midwest that these butterflies lay their eggs on. Not intentionally, but as a by-product of Monsanto's widely used agricultural herbicide “Round-Up.” Milkweed grows best in disturbed areas, such as in and around crop-fields. Farmers can and do now spray Round-Up directly on their maturing crops. Before, herbicides had to be used sparingly and before crops sprouted, because herbicides killed crops as well as unwanted plants.
But since Monsanto has genetically modified a huge proportion of crop seeds used in the U.S. to withstand  their own herbicide, Round-Up, those GM crops are now immune to this particular herbicide. So Round-Up is sprayed in abundance, throughout the growing season.  It kills all other plants in the vicinity, including milkweed.
And scientists say this is the primary reason monarchs are declining, due to loss of their "host plant" milkweed, which they must have for egg-laying and caterpillar growth.
It's very disturbing. And yet Monsanto marches on, squashing Proposition 37 and any other opposition to their dangerous domination of American agriculture.

What's to be done?

Write your legislators about GMOs and Monsanto.  Will it do any good?  I don't know.  Contact the Center for Food Safety and ask what you can do.

One thing you can do for sure is to plant milkweed.
Several monarch scientists and educators have created monarch websites for teachers, students, and citizens who’d like to get involved in monarch conservation, by planting milkweed and nectar plants and by monitoring, tagging, reporting data to monarch scientists, and more.  These are great websites, great projects - for families, classrooms, individuals.  Check them out!
Journey North
Monarch Watch
Monarch Larva Monitoring Project
Monarch Teacher Network