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Preventing Infection

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Immunizations for 2002

Vaccinations against childhood illnesses are arguably one of the most significant medical achievements of the twentieth century. One hundred years ago, approximately half of all children born in the United States died before the age of 5, many of them from diseases that today can be prevented by vaccines. With proper immunization, the number of cases of these diseases has been reduced dramatically.

Although no new vaccines have been added to the 2002 recommended childhood immunization schedule, this year's schedule highlights vaccines for pre-adolescents and "catch-up" vaccines for children who have fallen behind the currently recommended schedule.

In addition, due to unusual national shortages of the pneumococcal and diphtheria/tetanus/pertussis vaccines, the 2002 immunization schedule also includes a link to information from the Centers for Disease Control (CDC), which explains the necessary modifications to the recommended schedule for these vaccines. These vaccine shortages will hopefully only be temporary.

Please discuss your child's immunization history with the doctor to insure that his or her immunizations are up to date in accordance with the current 2002 Recommended Childhood Immunization Schedule, approved annually by the CDC, the American Academy of Pediatrics, and the American Academy of Family Physicians. For additional reliable and up-to-date information about vaccines and their importance, visit the National Immunization Program website at http://www.cdc.gov/nip or the American Academy of Pediatrics website at http://www.aap.org/.
April 2002 Update

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Vaccine safety: no link between thimerosal and neurodevelopmental disorders

Parents should feel confident and safe when having their children immunized. No evidence exists that proves a link between thimerosal-containing vaccines and neurodevelopemental disorders, such as autism, attention deficit-hyperactivity disorder, or speech and language delay. The Institute of Medicine recently reported these findings, consistent with the recommendations of the American Academy of Pediatrics.

Thimerosal, a mercury-containing preservative, was used for many years in vaccines to prevent contamination. Taking in a high dose of mercury is toxic to the human nervous system. But because of the increasing number of vaccines routinely recommended for infants, concern was raised in 1999 by the Food and Drug Administration that the total amount of mercury contained in the vaccinations could be exceeding the recommended mercury levels for infants.

Although there's no data to suggest thimerosal caused any harm, the American Academy of Pediatrics and the U.S. Public Health Service have requested manufacturers remove thimerosal from vaccines. As a result, most, if not all, childhood vaccines are now thimerosal-free.

The Institute of Medicine's recommendations emphasized the importance and continued safety of childhood vaccination. Parents should definitely be reassured that all routine childhood immunizations are in their children's best interests, as they clearly have been shown to prevent potentially life-threatening diseases.
November 2001 Update

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Lyme Disease Update

Can antibiotics catch Lyme disease before it develops? Do antibiotics alleviate the lingering symptoms after the infection is cured? Two recent studies published in The New England Journal of Medicine shed light on these two controversial questions.

In the first study, conducted in Westchester County, New York, an area with high rates of Lyme disease, researchers gave a single dose of either an antibiotic or a placebo to patients who were bitten by deer ticks in the previous 72 hours.

The researchers found the antibiotic doxycycline prevented the disease form developing. However, only 3.2% of the untreated patients developed the characteristic bull's eye rash around the tick bite. This suggests the risk of Lyme disease is low even in Westchester County. The study also found the infection was more likely to develop from bites by ticks in the nymph stage, and if the tick was attached for 72 hours or more.

This study suggests preventive treatment is only worthwhile in areas with a particularly high incidence of the disease or if you are bitten by a nymphal deer tick that has been attached for three days or more. You should save the tick in a jar of alcohol so it may be identified to help you and your physician make that decision.

In the second study, researchers investigated whether prolonged treatment with antibiotics reduces the fatigue, muscle and joint pain, and mood or memory disturbances that some people experience even after the infection has cleared. But the study was discontinued early when preliminary results showed prolonged antibiotic treatment was no more effective than a placebo at improving the persistent symptoms.

If you are experiencing post-Lyme disease symptoms, long-term use of antibiotics is unlikely to help. But there is hope your condition will improve — the study found symptoms improved in 36% of the untreated patients.
September 2001 Update

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Flu Vaccine and Recurrent Heart Attack Risk

Late each fall, the call goes out to remind people to get their flu vaccinations. Most healthy people equate the flu with a week of being miserable. However for the elderly or people with chronic illnesses, the complications of influenza, such as pneumonia, can be life threatening. Good enough reason to get the shot, but now research suggests the vaccination may also lower heart attack risk.

The study, conducted by researchers at the University of Texas-Houston, questioned whether getting a flu shot could reduce the risk of a second heart attack in people with coronary artery disease. Scientists have been studying a potential link between cardiovascular disease and infection, and some of their work suggests upper respiratory infections, such as the flu, might be a risk factor for heart attack.

The investigators evaluated 218 individuals with previous heart attacks who were seen in the university's cardiology outpatient clinic during the 1997-98 flu season. Of the patients who met the study criteria, 109 experienced a heart attack during the study period. These volunteers were matched with 109 controls with coronary artery disease, but had not experienced a second heart attack during the same period.

Of those who had had new myocardial infarctions, the rate of flu vaccination during the current season was 47%, versus 71% among those who did not have new heart attacks. After adjusting for differences between these groups, the researchers found the risk of heart attack was reduced by two-thirds among patients who had gotten a flu shot that season. This study showed no evidence that use of multivitamins or physical exercise changed risk for recurrent heart attack.

No one knows how flu vaccination might reduce a person's risk of heart attack. Perhaps exposure to the flu might cause atherosclerotic plaques to become less stable or the stress of this illness might dangerously increase the heart's workload for people with cardiovascular disease. Other theories include an increased tendency for blood clots during the flu or that the flu may contribute to poor blood vessel function. Whatever the cause and effect, people with coronary artery disease (and who are not allergic to the vaccine) should strongly consider getting a flu shot this season.
September 2001 Update

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Early Childcare and Communicable Illnesses

All kids get sick, but young children in day care are at increased risk for infection.

The National Institute of Child Health and Human Development recently examined rates of ear infections, gastrointestinal tract illnesses, and upper respiratory tract infections in children participating in the Institute's Study of Early Child Care. The study is following 1200 children from birth to age three in ten locations across the county. The researchers found the rates for each illness were higher for children in day care than for those reared exclusively at home during the first two years of life. But this difference disappeared by the time they were three years old.

The number of hours per week children spent in day care generally had little to do with their likelihood of getting sick. Instead, the great the number of children enrolled in a facility, the greater a child's risk of illness. But being sick more frequently didn't have developmental consequences. Some parents felt that sickly children had increased behavioral problems, but this was likely the result of increased stress.
July 2001 Update

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Meningococcal Disease Prevention for College Students

Meningococcal disease is an inflammation of the membranes that encase and protect the brain and spinal cord. When caused by a bacterial infection, meningococcal disease can be fatal. Survivors can suffer significant lifelong impairments, including permanent brain damage or hearing loss.

In recent years, the incidence of meningococcal disease has been on the rise in 15- to 24-year-olds in the United States. And the Centers for Disease Control and Prevention (CDC) has revealed that U.S. college students living in a dormitory setting are more than three times as likely to contract meningococcal disease than those in the same age group who do not live in a dormitory setting. Freshmen face the greatest risk.

Sixty percent or more of these cases could be prevented with an existing, available vaccine. Adverse reactions to the vaccine have been shown to be mild, and serious reactions are rare. Based on findings from recent studies and on input from expert committees, the American Academy of Pediatrics advises physicians to inform college-bound patients who intend to live in a dormitory of the increased risk for meningococcal disease and of the benefits and limitations of the vaccine. Physicians are also advised to make the vaccine available to those patients who then request it.

U.S. military recruits have been routinely vaccinated against meningococcal disease since 1971, in response to a high incidence of the disease in that population.
February 2001 Update

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Tamiflu (Oseltamivir) for Flu Prevention

Until recently, there wasn’t much a person could do once he or she was hit with the flu. However, the Food and Drug Administration approved two medications that could be added to the usual routine of fluids, bedrest, and fever-reducing analgesics. Both drugs interfere with an enzyme (neuraminidase) that is crucial for the flu virus to multiply. Taken within two days of symptom onset, zanamivir (Relenza) and oseltamivir (Tamiflu) can reduce the severity and duration of a bout with this winter menace. Now, the FDA has also approved Tamiflu for the prevention of influenza in adults and children 13 and older.

The FDA’s approval was based on several recent studies. One trial followed healthy, unvaccinated adults and adolescents who took 75 mg of Tamiflu or a placebo once a day for 42 days during a community outbreak of the flu. The flu rate among study subjects taking the placebo was 4.8%, while only 1.2% of the Tamiflu group came down with the virus. In a second study, researchers assigned elderly nursing home residents to either a placebo or 75 mg of Tamiflu daily for 42 days. Of the placebo group, 4.4% developed the flu, compared with only 0.4% of the treatment group. (It is important to note that in this study, 80% of the elderly population had gotten a flu shot.) A third investigation evaluated whether Tamiflu could prevent the spread of the virus within a household. Family members received either 75 mg of Tamiflu or a placebo within two days of the onset of symptoms in the flu sufferer. In placebo households, the flu rate was 12%. In the Tamiflu households, only 1%.

Note that Tamiflu is not a substitute for the flu shot and those at high risk for complications of the flu should get their yearly vaccination. None of these studies tested Relenza (zanamivir), so it is unclear whether this drug offers similar benefits. Keep in mind, both Tamiflu and Relenza are effective only against type A and type B flu viruses, and although many upper respiratory infections and severe colds caught during the winter are viral, that doesn’t mean they are "the flu."

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Symptomless Genital Herpes Infections

Recent research tested a potential vaccine against genital herpes only to find it ineffective. But study investigators did learn something very important about this infection. During the course of the trial, 63% of study volunteers who developed antibodies to the virus (indicating exposure) never developed symptoms. Women were about equally likely to develop symptoms or not.

Perhaps the most important message here is that while a newly acquired genital herpes infection may cause no symptoms, new symptoms of genital herpes may in fact result from an old infection. If you or your sexual partner develop symptoms of genital herpes, it is very possible that this is ancient history coming to light in the context of a new relationship.

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Lyme Disease Vaccine

Should you get the Lyme disease vaccine? Experience so far has shown that the vaccine, which is called LYMErix, is safe and effective. The side effects include a couple of days of soreness in the upper arm where the vaccine was injected, short-term headache, and flu-like symptoms. The largest study of the vaccine, published in the July 23, 1998, New England Journal of Medicine and the basis for its FDA approval, showed no difference in long-term, arthritis-like side effects between the treatment group and the placebo group. That finding reassures those concerned that the vaccine might provoke an autoimmune response (when a person’s immune system attacks his or her own body). The same clinical trial showed that when the full, three-shot series of the vaccine was given, it was 76% effective — that is, the people who received all three shots were 76% less likely to come down with Lyme disease than people who received three placebo shots. As with other vaccines, however, its effectiveness is probably lower among older people because as the immune system ages, it gets less responsive.

But just because it is safe and it works doesn’t mean it’s necessary. Lyme disease is transmitted by deer ticks infected with the Borrelia burgdorferi bacteria. Your risk of getting Lyme disease comes down to primarily three factors: the number of infected deer ticks in the environment; what you do in that environment; and how much of an effort you make to keep ticks off you in the first place and remove them if they do bite you.

Infected deer tick territory is concentrated in southern New England, New York, New Jersey, Pennsylvania, Maryland, and a few counties of Minnesota and northeastern Wisconsin. Even in these hotbeds, only 15–30% of ticks are infected with the disease-causing bacteria. Also, the number of ticks is very sensitive to local conditions and can vary tremendously from town to town or even from block to block. Deer ticks favor moist, bushy, leafy places — not the wide expanse of your lawn, the beach, or even grass-covered dunes. Do you need to get the Lyme disease vaccine if you’re going to Martha’s Vineyard this summer to swim, play and lounge on the beach, and shop? Probably not. But if you plan on clearing brush and doing some gardening in a high-risk area, you might be a good candidate for the Lyme disease vaccine. Even then, some doctors question whether the vaccine is warranted, partly due to lingering doubts about how long protection lasts. Booster shots may be necessary. Also, deer ticks carry other diseases that the vaccine does not protect against. People who garden in tick-infested areas can (and should) take other precautions, like wearing high rubber boots. Hikers and birdwatchers can cut down on their risk by sticking to the center of well-traveled paths.

The time of year also makes a big difference. Lyme disease season starts around May on the East Coast and in the Upper Midwest. It continues through June and July when the deer ticks are in their nymphal stage. It is not so much that these nymphs are super-infectious. Rather, they are so small that people can’t spot them easily — especially because these tiny pests favor hard-to-spot places on the body. By August, most of these young ticks have either died or satisfied their appetite. Adult ticks are still active and infected, but their size (about that of an apple seed) makes them easier to see.

About 12,500 cases of Lyme disease are reported to health authorities every year, and many more go unreported. Because they play outside, children are vulnerable, and approval of a child version of LYMErix could come later. No one questions the value of the vaccine, but it isn’t for everyone — even where infection rates are relatively high.

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Pet Reptiles and Salmonella

Between 1996 and 1998, approximately 16 state health departments reported salmonella infections in persons who had direct or indirect contact with reptiles (i.e., lizards, snakes, or turtles) to the Centers for Disease Control and Prevention.

Salmonella infection can result in severe illness and even death, particularly in infants, young children, and anyone with a compromised immune system. The CDC issued the following recommendations to reduce the chances of anyone in your family contracting this potentially deadly infection from these increasingly popular exotic pets:

  • Pet store owners, veterinarians, and pediatricians should provide information to owners and potential purchasers of reptiles about the risk of acquiring salmonellosis from reptiles.
  • People should always wash their hands thoroughly with soap and water after handling reptiles or reptile cages.
  • People at increased risk for infection or serious complications of salmonellosis (e.g., children younger than age 5 and immunocompromised persons) should avoid contact with reptiles.
  • Pet reptiles should be kept out of households where children younger than age 5 and immunocompromised persons live. Families expecting a new child should remove the pet reptile from the home before the infant arrives.
  • Pet reptiles should not be kept in childcare centers.
  • Pet reptiles should not be allowed to roam freely throughout the home or living area.
  • Pet reptiles should be kept out of kitchens and other food-preparation areas to prevent contamination.
  • Kitchen sinks should not be used to bathe reptiles or to wash their dishes, cages, or aquariums. If bathtubs are used for these purposes, they should be cleaned thoroughly and disinfected with bleach. Back to Top

 

Starve a Cold, Feed a Fever, Take a Pill for the Flu?

The height of the flu season is starting to wane, but we seem to be at the peak of print and television ads promoting new treatments. Late in 1999, the U.S. Food and Drug Administration approved two new anti-influenzal drugs zanamivir (Relenza) and oseltamivir (Tamiflu). Both work by interfering with an enzyme needed for the flu virus to reproduce. Both offer an option for treating uncomplicated cases of the flu.

In clinical trials, when taken within two days of the onset of flu symptoms, Relenza was shown to make people feel better a little (about 36 hours) sooner. This drug is administered in an inhaler twice daily for five days. Relenza has not been proved effective for people who have severe asthma or chronic breathing problems, and in fact may cause bronchial spasms in these individuals. Tamiflu comes in pill form (taken twice a day for five days) and can reduce the length and severity of flu symptoms if it is taken within two days of the onset of symptoms, but not by much.

Patients participating in two clinical trials reported feeling better about one day sooner than patients taking a placebo. The most common side effects of Tamiflu included upset stomach, vomiting, trouble sleeping, and dizziness. Neither drug can prevent people from passing the flu on to others. These medications may offer some relief to flu sufferers, but getting a flu vaccine remains the best way to minimize your chances of getting this virus in the first place. This is true for healthy people and especially for people at high risk for complications from the flu (the elderly and people with compromised immune systems or chronic lung diseases).

In fact, the safety and effectiveness of these new flu treatments are unproven in these populations. What's more, Tamiflu and Relenza are effective only against influenza types A and B, but not type C (a very common, less severe flu) and many upper respiratory infections caught during the winter are viral, and not the flu.

The bottom line is that these medications are helpful in only a handful of situations. An extra day of fluids and bed rest may be all you can do.

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