Dear Doctor: Your recent column about balance was very useful. My dad is in his late 70s, and I want to help him stay on his feet. Are there specific techniques or exercises that he can do? It would be great if we could do them together.

Dear Reader: We love the idea of you and your dad working on this together. And while the focus of your letter is to help him, the truth is that you're both going to benefit. That's because research shows that balance begins to decline when we hit our 50s and 60s, years before obvious signs like stumbling or falls begin to appear.

For people who don't have specific medical issues that can affect balance, such as neurological or inner ear disorders, the main areas of focus are muscle strength, mobility and awareness. (After the balance test we're about to suggest, you'll be tempted to add endurance to the list.)

The good news is that, no matter your age -- and again, barring medical issues -- each of these areas can be improved. Because we don't want to rush the answer on this very important topic, we'll use this column to lay out the basics. In our next column, we'll follow up with some specific techniques and exercises.

Let's begin with a (deceptively) simple test: Stand on one foot.

Sounds easy, right? So let's add a level of difficulty -- stand on one foot for as long as you can. Grab a watch or smartphone, spot each other to prevent a fall (or, if you're going solo, stand by a wall or chair) and time how long each of you lasts.

Does it take a few tries to find your balance? How long before you have to make physical adjustments, like moving your arms, to remain steady? Also take note of which muscles become most fatigued. Be sure to do the test on each foot. We tend to favor one side of the body over the other. You may be surprised by how different the balance times on your left and right sides can be.

Although the goal here is one minute, many of us, no matter our age, won't make it that long. In a recent study, researchers found that for those in their 50s, the average one-foot stand lasted 45 seconds. That dropped to 40 seconds for people in their 60s, and 27 seconds for those in their 70s. People older than 80 generally managed 12 seconds of balance before the other foot came down.

The main reasons for a decline in balance are loss of muscle tone and the effects of aging. We can change the former and, to a certain degree, learn techniques to compensate for the latter. What we can't afford to do is let nature take its course and hope for the best. One-third of all adults 65 and older suffer a fall each year, many with grave consequences. With our next column, we'll offer some specifics on how to stay on your feet.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: What is rat bite fever? Just how contagious or dangerous is it? I read that a 10-year-old boy died from it after being bitten by his pet rat.

Dear Reader: Yes, that was a tragic story. A rat purchased from a pet store transmitted a bacterial infection known as rat bite fever to a young boy who later died. Although the details caused the incident to get wide media play -- we tend to think of rats as vermin rather than pets -- the Centers for Disease Control and Prevention say that rat bite fever in the United States is quite rare.

Rats have been identified as carriers of disease for thousands of years. Rat scratches, urine and feces are all potential pathways for illness. Add in the various pests and parasites that live off rats and themselves spread disease -- think fleas and the bubonic plague, which killed 50 million people in Europe in the 14th century -- and it's no surprise that these rodents have earned a bad reputation.

So what is rat bite fever? It's a full-body illness with symptoms including fever, chills, body aches, headache and vomiting. In many patients, a rash made up of either flat or raised red bumps may appear a few days after the onset of fever. In the U.S., the cause of the disease is usually a bacterium called Streptobacillus moniliformis, which is transmitted through contact with the infected rat's saliva or urine. Spirillum minus, which also causes the disease, is more commonly found in Asia.

Although rats are the main carriers, the bacteria can be present in mice and gerbils as well. Rat bite fever is fatal in about 10 percent of infected persons who go untreated. In the case of that young boy, he may have been bitten by the rat, or may have become infected through handling his pet. As to your question about whether it's contagious, there have been no reports of rat bite fever being transmitted between humans.

The bacterium is present in healthy rats, both wild and domesticated. That means it's found in lab rats, too, which puts researchers at risk. But rat bite fever tends to be most common in urban areas, where rats can easily find food and shelter, and where residents have little control over coming into contact with the rodents or their urine.

Since a single test to diagnose the disease doesn't exist, the diagnosis must be made by identifying the presence of the bacteria in blood, skin or in the fluid of the joints of lymph nodes. However, prompt treatment is important, so the CDC recommends that patients who develop the cluster of symptoms associated with rat bite fever, particularly if they occur within two days to three weeks after contact with a rat, receive a course of antibiotics. Penicillin works extremely well, and for those who are allergic, other antibiotics are also effective.

We're very happy to be able to leave you with some good news: With timely treatment, the vast majority of patients with rat bite fever recover fully.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I've been reading a lot of warnings about the recent wet weather causing an abundance of ticks and their potential to cause disease. I knew about Lyme disease, but now Powassan virus? What's that? And just how dangerous are ticks?

Dear Reader: Ticks are external parasites that, because they feed on blood, are quite efficient at transmitting disease. In each of the three life stages that a tick goes through after hatching, it needs blood to survive. Depending on the species, ticks will feed on mammals (that's us), birds, reptiles and amphibians.

A variety of ticks throughout the United States can transmit more than a dozen dangerous and sometimes deadly diseases. These include Lyme disease, Rocky Mountain spotted fever, tularemia, and Colorado tick fever, to name a few of the most commonly known. The tick picks up the disease while feeding on an infected host, and then can transmit it through its saliva during future feedings.

One of the lesser-known diseases is Powassan virus, a flulike illness that can cause inflammation in the brain. It is spread by several types of ticks found in the northeastern states and in the Great Lakes region. The disease is fatal in up to 15 percent of individuals who show symptoms. About half of those who survive face ongoing neurological difficulties.

Powassan virus was once rare, with about two reported cases per year between 1950 and the early 2000s. That number has risen to 75 reported cases in the last decade, or close to eight per year. Some experts believe this may be due to increased awareness in diagnosing the disease.

However, Lyme disease, with close to 30,000 confirmed cases each year, remains the most common tick-borne illness in the U.S. According to the Centers for Disease Control and Prevention, the total may actually be as high as 300,000 infected individuals per year, when unconfirmed cases are factored in.

While there are some species of ticks that don't carry disease, without specialized knowledge it's almost impossible to tell them apart from those that do. As a result, the best advice is to protect yourself, your family and your pets against all tick bites.

Ticks prefer areas that are moist and humid, and concentrate in wooded and grassy areas. They can't jump or fly, so they perch at the tips of grasses and shrubs, where they can easily attach to a host as it brushes by.

To avoid tick bites:

-- When in grassy or brushy areas, wear long sleeves, long pants and close-toed shoes. Tuck pants into socks. Light-colored clothing makes spotting ticks easier.

-- Insect repellents that contain 20 percent DEET may be helpful. Some experts say picaridin is even better. Reapply according to manufacturer instructions.

-- Treat clothing, boots and tents with products containing 0.5 percent permethrin, which stays effective through several washings. Pre-treated clothing and gear is also available and may offer longer protection.

-- After spending time outdoors, be sure to do a tick check. Visually scan all areas of your body, including your scalp and hair.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)