Northwest Health | FALL 2009 By Julia Vouri

Ever wonder how you caught that last cold or flu? Think back about three days and consider the possibilities. Perhaps you opened doors, used a public toilet, handled money, saw a friend who was feeling under the weather, endorsed a check with the bank's pen, sliced raw chicken on a cutting board, repotted a plant, or changed Frisky's litter box. And throughout that day you scratched your nose, rubbed your eyes, and grabbed a quick snack — without washing your hands.

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Some infectious diseases, such as the common cold, just make you miserable and slow you down for a few days. Others, like H1N1 and avian flu, are unpredictable, scary, and can be serious. To protect yourself, it's important to understand the causes of these diseases, how they spread, and what you can do to protect yourself.

The Science Behind the Sickness

Causes of infectious diseases

Tenacious microscopic organisms are the culprits, including:

Bacteria. These one-celled organisms exist virtually everywhere, and most of them are beneficial. For example, we live in harmony with millions of bacteria that reside inside our digestive tracts, where they help us absorb food properly. The remaining few, however, can wreak havoc.

Infectious bacteria enter the body through the mouth, nose, or other orifices, or cuts in the skin. Some produce toxins that cause illnesses such as strep throat and urinary tract infections. Others, such as the antibiotic-resistant superbug, Methicillin-resistant Staphylococcus aureus (MRSA), are spread through skin-to-skin contact or by touching a contaminated surface.

Viruses. Unlike bacteria, viruses must invade the cells of a living host to reproduce. They latch onto people, plants, and animals, attacking and destroying the host's cells. Once a virus enters a living cell, it begins to produce more virus particles and becomes an infection. Viruses cause many diseases, from colds and flu to measles, smallpox, and HIV infection.

Fungi. There are good fungi, such as mushrooms, the mold that makes blue cheese, yeast that makes bread rise, and yeast that thrives in our intestinal tracts. And there are good fungi that go bad. An overgrowth of yeast in the intestinal tract — caused by antibiotic overuse or an impaired immune system — can cause thrush, vaginal yeast infections, and skin problems such as athlete's foot. Some fungal infections invade the body and cause systemic infection, such as Valley Fever (coccidioidomycosis).

Protozoa. One of three major types of parasites, protozoa are one-celled organisms that are both independent and parasitic. Some live out their days harmlessly in our intestinal tracts, but others can cause infections such as giardia or amebic dysentery if they enter our body after we eat or drink food or water that's been contaminated with feces. They are also transmitted through the bites of mosquitoes or sand flies.

How germs are spread

Most infectious diseases, both bacterial and viral, are spread through direct contact — person to person, animal to person, or mother to unborn child — or indirect contact, such as touching something that has been contaminated.

For example, flu and cold viruses can live on a surface from a few seconds to 48 hours; E. coli for a few hours to a day; the stomach flu for days or weeks; and hepatitis for weeks or months. Some bacteria, like Bacillus anthracis (anthrax), can form protective spores and survive hundreds of years.

Cold and flu droplets from a cough or sneeze can be carried 3 to 6 feet. Other bacteria and viruses such as tuberculosis and chickenpox are spread through airborne transmission and can remain suspended in the air for 2 hours or more.

Some germs hitch rides on mosquitoes, lice, mites, ticks, and other pests. Flies track germs in on their feet, and other insects transmit them through a bite. Mosquitoes spread malaria and West Nile virus, and ticks can carry Lyme disease and Rocky Mountain spotted fever.

Food and water can carry germs that may result in food poisoning. Common examples are E. coli and salmonella, bacteria found in undercooked meats, untreated water, unpasteurized milk or fruit juices, or unwashed raw fruits or vegetables. According to the Centers for Disease Control and Prevention (CDC), about 76 million Americans experience foodborne illnesses each year, often thinking it's the flu.

The spread of viruses — particularly influenza — can be complex. For example, people contract West Nile virus from the bite of a mosquito that has previously bitten a bird that carries the virus. Pigs can also provide an influenza link from birds to humans. Avian flu is unique because it's spread from chickens to people, rather than first through pigs.

"Even though the avian flu is particularly virulent, the risk to humans is low because it doesn't move easily between humans," says Robert L. Thompson, MD, infectious disease specialist and chair of Group Health's Infection Control Committee.

Why we get sick

Lucky for us, our bodies are built for battle. Most germs are repelled by our skin, tears, mucous membranes in our nose and throat, even the fine hairs in our nose. If we've had a vaccination for a certain disease or have had the disease itself (such as chickenpox), antibodies rise to our defense.

Some germs that sneak by our first line of defense can gain access to our bloodstream and deeper tissue. When this happens, our white blood cells (macrophages) swarm in to devour them. This natural defense system explains why it's not always wise to suppress our symptoms. A fever helps the body fight infection, sneezing expels bacteria, and coughing can oust phlegm from the lungs.

However, in any battle, the good guys don't always win, and infections and disease may prevail. The challenge then is to diagnose, treat, and control the infections.

How to Outsmart Disease-Causing Germs

Stay on top of your family's vaccinations

Thanks to immunizations, we no longer see many cases of such devastating diseases as polio, pertussis (whooping cough), diphtheria, measles, meningitis, rubella, or mumps. But while parents are usually diligent about keeping their children on schedule until the age of 2, well-child preventive care visits drop off significantly through the teenage years. And these diseases will resurface if children aren't vaccinated.

"When immunization rates went down in Japan in the mid-1970s, the number of pertussis cases jumped from 400 and no deaths a year to 13,000 cases and 400 deaths," says Tim Seppa, MD, a pediatrician at our Riverfront Medical Center in Spokane. "When immunizations rose again, the disease rates declined."

"Most vaccines are given in childhood, from birth through the teenage years, and it's important to stay on track during that time," says Lisa Jackson, MD, MPH, senior investigator in vaccine studies at the Group Health Research Institute. "Adults are also routinely immunized to prevent illnesses such as the flu, shingles, and tetanus."

Traveling abroad? If you plan to travel outside the country, call our Travel Advisory Service at least two months before you leave to find out if you need any vaccinations. Parasites are particularly problematic in some foreign countries. Vaccinations specifically for travel are usually not included in coverage benefits.

Simple Steps to Protect Yourself

Wash your hands and avoid touching your eyes, nose, and mouth. Alcohol-based sanitizers are best — the CDC recommends products containing at least 60 percent alcohol, such as Purell. But good old soap and warm water or antimicrobial wipes or towelettes are also effective. Steer clear of antibacterial soaps and detergents, which enable stronger germs to survive and become resistant.

Cover your nose and mouth with a tissue when you cough or sneeze, even when you're alone in a room. Then toss the tissue into a wastebasket and wash your hands. If you don't have a tissue, cough or sneeze into the crook of your arm (elbow), not your hands.

Don't be embarrassed to wear a mask if you're infectious or in a setting where others might be. Masks are available to wear at our medical centers.

Use antibiotics wisely. Antibiotics are for bacterial infections, not viral infections like colds and flu. Overuse and misuse have led to antibiotic-resistant bacteria.

Keep open cuts and wounds covered — no matter how small — with clean bandages.

Don't share personal items such as toothbrushes, razors, deodorant, towels, clothing, eating utensils, and drinking glasses.

Take precautions at the gym. Bring your own yoga mat, wear workout gear that covers your skin, and avoid walking barefoot on surfaces to avoid fungal infections.

Minimize humidity in your home. Moisture attracts mold and fungus.

What Group Health Is Doing to Protect You

Your personal physician can diagnose and treat most infectious diseases, and can readily consult our infectious diseases specialists when questions about MRSA or other complex infections arise.

As a precaution for everyone, alcohol-based sanitizer is placed throughout our medical centers, including in every waiting room and exam room, for patients and staff to use.

"Special precautions are taken with patients who have MRSA or other infectious diseases," says Janie Garris, RN, MN, Group Health's director of Infection Control and Prevention. "Depending on their disease, patients may be placed in private rooms and staff may wear gloves, gowns, and masks when caring for them."

Though it may sound deceptively simple, Dr. Thompson stresses the importance of hand washing (and sanitizer use) in every setting — home, office or workplace, and public spaces. "Hand washing is the single most effective way to prevent the movement of viruses from one person to another," he says.

As a major health care provider in the region, Group Health is prepared to handle diseases such as H1N1, which was declared a pandemic in June by the World Health Organization. H1N1 is a respiratory disease that spreads from person to person and is similar to seasonal flu.

"By spring 2009, the severity of the symptoms associated with H1N1 was similar to those of seasonal flu in recent years," says David Grossman, MD, preventive care chief and co-leader of Group Health's pandemic response team. "Most believe it will be back again this fall, but we have no way of predicting the severity of the next round of infections."

Group Health is working with state, local, and federal agencies to understand and limit the spread of the H1N1 virus. "Here at Group Health, we have antiviral medication on hand and we're helping to test the new H1N1 vaccine at our Group Health Research Institute," says Dr. Thompson. The Institute is also testing a vaccine for avian flu, and new vaccines for preventing pneumonia in seniors.