As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From Lise in Quebec:

How are you protecting yourself from AIDS while trying to help people in Haiti? I know AIDS was already prevalent there.

Answer:

Lise, thank you for the question. Whenever possible, all medical professionals here in Haiti are following normal medical hygiene protocols; we wear gloves and make sure medical instruments are sanitized even if in some cases that’s done with alcohol.

Just to be clear, HIV, the virus that causes AIDS, is not easily spread. In fact according to the Centers for Disease Control and Prevention, the chances of a health care worker becoming infected with HIV from an open cut or even an open wound is no higher than approximately .3 percent.

We asked Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, about the AIDS problem in Haiti during this crisis and he said that “(AIDS) is the very least of the problems that health care workers will face in Haiti. The prevalence of HIV in Washington, D.C., is higher than that in Haiti and so you can make the case that an emergency room health care personnel who sees a lot of trauma in a general hospital in D.C. is at an even greater risk of getting stuck with a contaminated needle…than is a health care worker in Haiti”

In recent years, Haiti has shown some improvement in infection rates and antiretroviral use. As of the United Nations’ last report, Haiti has lower HIV/AIDS prevalence than the Bahamas. According to the World Health Organization, two thirds of HIV infections are in sub-Saharan Africa.

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From Annette in Washington D.C.:

“I would like to know if the full body screening proposed for all our airports presents any health hazards – more specifically harmful radiation that could lead to long term problems, especially for frequent fliers.”

Answer:

Annette, you are not alone in your concern about these new scanners. We’ve received many e-mails like yours. So we talked with a radiologist and a physicist whose job it is to make sure people are safe when they’re getting treated with radiation. Those experts say these scans are completely safe.

I should point out that the TSA is using two types of screening machines. One, the millimeter wave imaging machine, uses radio frequency energy to image the body. According to the TSA these deliver 10,000 times less energy than your cell phone. The other type of machine, backscatter X-ray, is what has people talking because these units rely on X-ray technology.

These X-rays are very low level, they bounce radiation off the skin and back to the machine. This is how authorities can scan for dangerous items under someone’s clothes. But this also means the radiation is at very low levels. It's bouncing off the skin, not penetrating it or your organs. This is unlike a medical X-ray which is a higher level radiation penetrating the skin to see bones and other tissue.

Medical professionals working around these levels of radiation are required to wear a badge that measures radiation. Dr. Wayne Olan, director of neuroradiology and MRI at Suburban Hospital Johns Hopkins Medicine sent us a picture of such a badge explaining that he and his co-workers are required to submit their badges every month to ensure they have not been overexposed. He tells us the max whole-body dose of radiation is 5,000 millirem per year. To put these scans in perspective, it would take you 125 thousand trips through these scanners to max out.

In fact, passing through this backscatter X-ray scanner actually exposes you to a hundred times less radiation than a flight from say Boston to Los Angeles. When you fly you are exposed to cosmic rays so the backround radiation is higher at higher altitudes. This is is the same reason people in Denver are exposed to more radiation per year than, say, folks living in Miami, because Denver is at higher altitude.

The American Cancer Society told us that because the radiation levels being reported are low, its experts don’t see this being a serious issue for infrequent travelers.

The bottom line: Every expert we talked to said these were safe even if you're a frequent flier. The radiation just won't add up but the TSA says you do have the option of a pat-down if you're concerned.

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From Scott, Oregon

“After suffering through the H1N1 flu for almost a week, I feel completely healthy, save for a lingering cough. There is not much if any mucous involved, it's just a sensation that makes me constantly want to clear my throat. I am a healthy 33 year old male with no chronic illness; no allergies and I have never smoked.”

Answer:

You are not alone, Scott. Persistent, nagging cough is a common complaint among people who contract the H1N1 virus, even healthy non-smokers like you. Some say that the cough lasts for days – sometimes weeks – after other overt symptoms like fever, nausea, fatigue and congestion go away.

It's sort of like having a house guest who has worn out their welcome.

So why does the cough stick around for so long? The H1N1 virus causes inflammation in the respiratory tract, which includes the back of the throat and bronchial tubes that branch out in the lungs. The virus attacks that lung tissue, causing irritation. So although you are not suffering from the flu any longer, irritation in the mucus membranes lining your respiratory tract is still healing, and that is manifesting as a cough you cannot shake.

Unfortunately, the best thing for you to do is wait it out. Your cough could be a bothersome symptom for another two or three weeks, but it should dissipate as your respiratory tract heals. There are some effective cough medicines out there available over the counter, and even stronger ones in prescription form, but the good news: this is likely to get better on its own.

Incidentally, residual cough is common with most flu, including seasonal strains. As long as you are fever-free and otherwise feel well, there is little chance that your cough is spreading the H1N1 virus. The incubation period for H1N1 – the time during which you are most infectious to others – is between one and seven days.

Of course if several weeks go by and the cough has not subsided, you may decide to visit your doctor.

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From the Paging Dr. Gupta blog, Terry asks:

"I would love some advice on choosing a heart rate monitor."

Answer:

Well, it turns out, Terry; our folks at CNN.com gave some great advice on this. Advice that I paid attention to since I’ve been working hard this year to get in better shape and am now training for a triathlon as a part of CNN’s Fit Nation Challenge.

As I train, something I've been focusing on is heart rate target training. It's actually pretty simple to do. First of all, calculate your maximum heart rate. The way that you do that, you subtract your age from the number 220. So, mine would be 180. Now, you calculate a range between 60 percent and 70 percent of that number. Mine would be from 108 to 126. Try and keep your pulse rate in that range while you work out. A heart rate monitor is a simple device to help you calculate your target heart rate and keep track of your workouts so you can measure your progress.

So Terry here is a rundown of heart rate monitors depending on what you’re looking for and how much you want to spend. There are a lot of monitors out there. New monitors are equipped with GPS, speed calculating shoe sensors and data analysis tracking every detail of your performance over time.

So, the experts CNN.com quoted said the new Garmin Forerunner 310XT is the optimal choice, but it is very expensive. It's almost $350. It does work anywhere in the world and you can get your heart rate, measure movement, elevation, distance and speed. Now, if you're looking for something more affordable, like a lot of people, Nike offers a slim watch size unit called the Nike Plus Sport Band. It runs about $59 and displays your distance, pace and calories burned. It holds about 30 hours worth of workout data. Check out more options at CNN.com/technology.

Keep in mind the longer your keep your body at that target heart rate I talked about, the more efficient your cardiovascular system will become, and overall, the fitter you will be. Good luck Terry hopefully tracking your heart rate will help you make your workouts even better.

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From Cyrus in Pittsburgh:

“Can obesity be linked to Alzheimer's disease? And can physical activity help ward off the disease?”

Answer:

There are two important questions here. The quick answer, of course, is yes. But obesity, as you might imagine, is just one part of the whole puzzle. First, most things that are bad for your heart are often bad for your brain as well. That’s one way to think about it. You see, it's all about blood flow. So what impedes or affects blood flow to the heart is generally going to cause the same in the brain. Elevated blood pressure, high triglycerides, and high cholesterol all affect blood flow and all increase your chances of developing Alzheimer's disease later in life.

The good news, to the second part of your question, is we know a lot about what we can do to prevent or delay the onset of this disease. Being physically active has been shown to improve mental function and to keep your brain healthier as you age. It's also essential for maintaining good blood flow and encouraging the growth of new brain cells. Studies show exercise that raises your heart rate for a minimum of 30 minutes several times a week seems to be the key. And exercise does so much more: It significantly reduces the risk of heart attack, stroke and diabetes. So stay active to keep your body and brain healthy for those later years.

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

CNN blogger, Beata, asks:

"Of those who have lived long lives, what is the common thread? What's the one thing I can do today that can make me live longer?"

Answer:

For well over a decade I've been investigating the answer to this question. The good news is there are actually a lot of small lifestyle changes you can make today that will add years to your life. For instance, flossing can add a year to your life – a whole year – just by adding to your daily routine. Turns out there's a pretty clear link between gum disease and heart disease. Flossing is your best bet at stopping that.

Here are a few more: A low-dose aspirin a day could add two years, and limiting your coffee intake to two cups a day could add another year. Simply checking blood pressure regularly could add one and a half years, and exercising three times a week could add three years. Cut work hours down to a manageable 40-50 hours a week and you add another one and a half years. Add it all up – and you have added a decade of functional life.

I will be the first to admit, it isn't always easy to practice what I preach, especially when it comes to the work-hour issue. But, we do know stress affects just about every part of our bodies. Our bodies simply start to shut down and become unable to tolerate the assault being placed on them every day.

Earlier this week I sat down with anti-aging expert Dan Buettner. He explores the world searching for longevity hotspots, known as blue zones, and looks for the lessons we can learn from them. One thing Buettner points out is that the people who live long lives in blue zones around the world are stressed out too. Yet they are still living disease free and often to 100 years old. The difference is they don't internalize their stress as most of us do. They all practice simple techniques to de-stress including praying, napping, even happy hour. Also meditating, which I have started, for 20 minutes every day and taking time for yourself every day can help.

In case you missed it, click here to hear more of my conversation with the world's leading anti-aging experts and get more tips to live a longer, healthier life.

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From Connie in California:

"My family will be flying for the holidays. Should we be concerned about being in an enclosed space for five hours?"

Answer:

Connie, more than 2 million people are expected to be flying over this holiday weekend and many have the same concern as you. The Centers for Disease Control and Prevention points out there are not many studies about the spread of flu on airplanes, but anytime people are in close quarters the chance for germs spreading is much higher.

If you are sitting next to someone who is coughing excessively or seems ill, that’s when you are most at risk. According to researchers at Purdue University, you’re most likely to get sick from the people sitting in your row or the row behind you. They actually developed an animation showing how germs move around an airplane. If you’re in this situation, there are things you can do to lessen your risk of getting sick. Point the air vent away from yourself and towards the sick person – that may help push the germs back at that person. Also, turn your body away from the person who seems ill and as we’ve been saying – don’t touch your face. Dr. Julie Gerberding, the former director of the Centers for Disease Control and Prevention, adds that you could ask a flight attendant whether a mask could be given to that person or if that person or you could be moved to another part of the plane. Gerberding also points out that the air on planes is circulated through a HEPA filter, so if you are several rows away from a sick person you’re unlikely to catch his or her germs.

Keep in mind, you can go a long way in protecting yourself by taking some simple steps. I know we talk about this all the time, but wash your hands frequently with soap and water. If soap and water aren't available, you can carry those alcohol-based hand sanitizers. Cover your nose and mouth with a tissue while sneezing and encourage people around you to do the same thing and avoid touching your eyes, nose and mouth. We touch our hands to our faces a lot. In addition, some people might consider carrying a disposable mask, especially if you're feeling sick yourself. Finally, the CDC recommends that you get vaccinated, if you can. That’s sometimes harder than it sounds. For more information, check out flu.gov and CNN’s special report on H1N1.  Have a safe trip, Connie

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From Elaine in New Jersey:

I attended a clinic this weekend for the H1N1 shots, and they administered the nasal spray to my 14-month-old! According to the CDC website it should NOT be administered to children under 2 years of age! I contacted the pharmacy where the clinic was held, and they took my contact info and said we will get back to me. Can you tell me is my child at risk?? I also have a call into my pediatrician. I also contact the CDC and was told they are not medical professionals.

Answer:

Elaine, it is easy to sense dismay and concern from your e-mail, and as a father I can certainly relate.

The reality is – yes – the nasal spray version of the H1N1 vaccine, which contains a weakened live flu virus, should be given only to people ages 2 to 49. We also know that children with conditions such as asthma may not be eligible for the live flu vaccine.

In order to ease your mind a bit, unless he or she has asthma, chances are very good that your 14-month-old will be fine.

The primary reason children younger than 2 do not get the nasal spray H1N1 vaccine is that it has not been tested in, and therefore is not licensed for, that age group. It is that simple. You need solid data to submit to the Food and Drug Administration before a medication can be approved for use in a particular population – that data do not exist for children younger than 24 months.

To ease your mind a bit more, rare complaints among adults and children taking the nasal spray form of the H1N1 vaccine are runny nose, sore throat, and sometimes fever. These symptoms usually go away within a couple of days. If they do crop up for your 14-month-old, you should not be too concerned, but if the symptoms get worse or your instinct tells you to, do see your pediatrician.

On the bright side of your predicament, your son or daughter is now vaccinated against H1N1. There are many parents who are still waiting to have their children vaccinated, so count yourself among the fortunate. Your child should soon have a second H1N1 vaccine dose – this time with the injectable form of the vaccine. And if you have not yet been vaccinated, you should do so – as the caregiver for your baby, you are eligible for these early doses of vaccine.

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From Kali in Florida:

My 4-year-old daughter has egg and peanut allergies. Can she still take the H1N1 vaccine? If not what are her choices. I've been getting conflicting answers.

Answer:

Kali thanks for writing in. We’ve received several questions like yours since the H1N1 vaccine became available. Let me start by saying that if your daughter has a true egg allergy, and not just a sensitivity, then she can not have the H1N1 or the seasonal flu vaccine. The two types of H1N1 vaccine, the shot and the nasal spray, are made with eggs so it is not recommended for people with severe egg allergies.

However, allergists we spoke with said people with mild reactions to eggs can get vaccinated. Keep in mind that the amount of egg protein in a vaccine is often less than you would find in most baked goods. So if your daughter has been able to eat bread or cake, she may have a more mild allergy.

Consider going to an allergist and ask about getting a skin-prick test. The allergist will have a diluted and non-diluted version of the vaccine. Their first step will be to do the skin-prick test with the undiluted version. If your daughter does not break out in hives or have a strong reaction, then she can have a stronger test with a small, diluted injection. If your child doesn’t have a strong reaction to that test, then her allergy may not be severe and your allergist may give her a flu shot.

If your child does have a strong reaction and your doctor believes she shouldn’t get the flu shot, then talk with your health care provider about strategies for keeping her healthy. These steps are basic hygiene, such as washing hands for the count of singing the “Happy Birthday” song twice and staying away from sick friends plus, avoid wiping your eyes and touching your face if possible.

I hope this helps and your daughter has a flu-free season

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From Robert in Kansas:

“I heard this week that the H1N1 virus has now turned up in pigs. Does this mean it can get into our food supply and I’ll get sick if I eat it?”

Answer:

Great question. The U.S. Department of Agriculture did recently announce that a commercial herd of pigs tested positive for swine flu. The USDA continues to stress that you will not infected with the HIN1 virus from eating pork. In fact, the infected pigs in Indiana weren’t destroyed. Once they recover from the flu, they will go to slaughter according to the USDA. Officials experimentally infected pigs earlier this year to see whether their blood and meat also became contaminated. They concluded that the H1N1 virus stayed contained in the respiratory tract of infected pigs and the virus did not infect the meat. The World Health Organization and World Organization for Animal Health have also concluded that humans can not be infected with the H1N1 virus from consuming pork. For more information about H1N1 and food safety, click here.

From Cheryl:

“While at my doctor's office, I asked about the H1N1 vaccine. I was told it will be very expensive, like $300. Since I do not have health insurance, the expense of the H1N1 vaccine will factor into whether I get it.”

Answer:

$300 is an excessive amount to pay for a free vaccine! That’s right – it’s free. The federal government has purchased the H1N1 vaccine and is shipping it out to states free of charge. They’re even picking up the tab for the syringes, needles, sharps containers, and alcohol swabs. Centers for Disease Control and Prevention has also stated private clinics may not charge patients a co-pay or other out-of-pocket charges for the vaccine. The only thing you should be paying is perhaps an administrative fee for your office visit but in many cases that fee is being waived as well. I would double check with your doctor again on the price. If the office still attempts to charge you $300, I would decline and instead contact your state’s health department to locate public clinic administering the vaccines near you. You can also track the vaccine’s shipments in your state through the CDC’s Web site. Check it out by clicking here.