Child Health ALERT

Volume 15 A Survey of Current Developments Affecting Child Health Care May 1997

Safer Whooping Cough Vaccine Approved For Infants

Not that long ago, illnesses such as diphtheria and whooping cough were common causes of death in infants. Now. through the wide spread use of vaccines, we can expect children to go through their lives without fear of contracting such illnesses as diphtheria, whooping cough (pertussis), tetanus, polio, measles, mumps, rubella, and others.

Despite the remarkable successes of immunizations, there are side effects to the vaccines. One of the more troublesome immunizations was the DTP series, which provides protection against diphtheria ("D"), tetanus ("T"), and whooping cough, or pertussis ("P"). The DTP shot is given as a primary series at 2, 4, and 6 months of age, and then two "booster" shots are given, one at 15 to 18 months. and another at 4 to 6 years of age.

It is not uncommon for children receiving this combination vaccine to have high fevers or other reactions, such as persistent screaming. Very rarely, children who receive the vaccine have serious reactions such as shock or neurological complications. Most problems have been traced to the pertussis part of the vaccine, which was made from the whole cells of the bacteria that cause whooping cough.

In an effort to make the DTP vaccine safer, researchers developed a

pertussis vaccine that is not made from the whole cells of the bacterl (rather, it's made from the parts of bacteria that produce immunity), a this product is called an "acellular' vaccine. Tests showed that it did n produce as high reaction rates as t older, whole cell, vaccine, and it appeared to also produce good lev of immunity in older children. As result, the U.S. Food and Drug Administration (FDA) in 1991 and 1992 approved use of the newer, safer acellular vaccines (as part of the DTP) for use in the "booster" series for children (see CHILD HEALTHALERT, October, 1996), but the FDA didn't feel there was enough information at that time to justify its use in younger infants.

Now, announcements from the American Academy of Pediatrics (AAP) and the U.S. Centers for Disease Control and Prevention (CDC) note that the FDA has just approved the use of the newer, safer DTP vaccine for infants receiving their primary series at 2, 4, and 6 months of age. This approval was based on recent European studies that documented the effectiveness of the newer vaccine when used in infants. The AAP has also modified its immunization recommendations to include use of the acellular pertussis vaccines. (AAP Committee on Infectious Diseases, Pediatrics, February, 1997, pp. 282-288; Morbidity & Mortality Weekly Report, February 7, 1997, pp. 110-111)

COMMENT: This is good news, both because it will reduce the rate of troubling side effects following DTP and because fewer parents will avoid DTP immunization of their children out of fear of the side effects. There is no question that the newer acellular vaccines have lower rates of the uncomfortable and often disturbing reactions that follow the older whole cell-product, and most experts believe (though it hasn't been proven) that the acellular vaccines will also reduce the risk of very rare but serious neurologic conditions that have been associated with the whole-cell product.

As noted above, the acellular vaccines were developed to reduce the risk of side effects; there was little doubt that the older vaccines were highly effective in producing immunity, and it seemed that the trick was to invent a newer vaccine that was safer but still produced high levels of immunity. With that background, just about everyone was surprised by the results of studies in Italy, Sweden, and Germany. These studies found that the older pertussis vaccine was less than 50% effective, far below the 80 to 85% effectiveness that most people expected. In contrast, the newer vaccines were themselves about 80 to 85% effective. As a result, infants and children have the unexpected benefit that the newer acellular vaccines are not only safer than the ones they replace, but they also may be more effective.

INFECTIONS/ILLNESS

"Ringworm Of The Scalp": A Growing Epidemic?

Ringworm of the scalp is actually an infection caused not by a worm, but by a fungus. It can show up as relatively minor patchy areas of dandruff-like scaling with or without loss of hair, and there can be more extensive and serious infection that can be mistaken for bacteria] infections. During the 1940s and 1950s, epidemics of tinea capitis, as it is called, occurred among children throughout the U.S., but these declined in the late 1950s, partly because of the use of an antifungal agent called griseofulvin. Researchers in San Francisco noted a substantial increase in cases in the past few years, so they conducted a special study to see whether their experience reflected a larger problem.

Using data from California's Medi-Cal program (the California component of the federal Medicaid program), they studied children under the age of 10 who had received prescriptions for oral griseofulvin (the authors reasoned that since this drug is used almost exclusively for tinea capitis, tracking its . use would be a good way to identify children who had ringworm). From 1984 to 1993, they found that prescription rates had nearly doubled; rates among African- American children were almost 6 times the statewide average. Even more dramatic increases in griseofulvin prescriptions were found among children enrolled in a Northern California health plan. Since rates of prescriptions are only indirect measures of ringworm in children, the authors also looked for the diagnosis of ringworm in medical records, and found that over the same period ringworm increased by between 35 and 52%.

Previous studies have shown that ringworm can spread in households, among family members, and in schools and child-care centers. To make matters more complicated, children can carry the fungus without having any symptoms of ringworm, and this may go on for months. Close personal contact and person -to- person transmission are the most likely ways the fungus is spread, but it may also be spread through combs, brushes, bed linens, and furniture. These researchers urge that those who care for children be more alert for tinea capitis, and make sure that appropriate control measures are followed. (Lobato MN et al: Pediatrics, April, 1997, pp. 551-554)

COMMENT: Ringworm of the scalp isn't an easy diagnosis to make, as it can be confused with any number of other conditions. It is of course important to treat children who have obvious signs of infection, but other family members and household contacts also need to be examined.

Other things to consider are the following: Combs, brushes, and related items should not be shared. Children who are being treated for tinea capitis can attend school; haircuts, shaving the head, or wearing a cap during treatment are not considered necessary. As with so many conditions, early detection and implementation of effective treatment and control procedures will go a long way towards reducing the spread to others.

CHILD SAFETY

Salmonella Traced To Chicks...

During 1995 and 1996, clusters of infections due to Salmonella bacteria were found in Idaho, Washington, and Oregon. Salmonellosis, as the illness is called, most often involves diarrhea, which sometimes can be serious. In this outbreak, most of those affected were children, and many of those who were ill had been in contact with chicks. The epidemic could not be traced to any single hatchery, place of purchase, or feed source.

In an accompanying note, the U.S. Centers for Disease Control and Prevention (CDC) point out that Salmonella infections affect an estimated 2-4 million persons each year in the U.S. Most are spread by contaminated foods, but many times pets have been implicated. It's not clear how many cases of salmonellosis are associated with chicks, but many outbreaks occur during the spring, especially around Easter.

Children may be at increased risk because they are most likely to comein contact with the chicks, they tend not to wash their hands frequently, and they commonly place their hands in their mouths. Because their immune systems are less efficient, infants may be at particular risk for serious forins of Salmonella infection.

The CDC concludes that "chicks and ducklings may not be appropriate pets for children. During investigations of Salmonella infections, especially during the spring and Easter seasons, health-care workers and public health personnel should consider contact with chicks and ducklings as a potential risk factor for salmonellosis." (Morbidity & Mortality Weekly Report, March 21, 1997, pp. 237-239)

... Andiguanas

When Salmonella outbreaks are traced to pets, reptiles are the ones that are most commonly blamed for causing the epidemics. In fact, the number of reported Salmonella infections linked to pet reptiles is increasing in the U.S. Many of these have involved infants with serious complications (including meningitis and bloodstream infection, called sepsis). These infections have increased over time, along with the number of reptiles imported to the U.S. For example, importation of iguanas, the most popular pet reptile, increased from about 41,000 in 1982 to almost 600,000 in 1994.

Researchers studied a particular strain of Salmonella bacteria that is commonly found in iguanas (it's called Salmonella Marina). Among 32 cases reported in 1994, 81 % were infants under the age of 1 year; 11 patients were hospitalized, and one died. Although the vast majority of the children had been exposed to iguanas, only 14% of them touched the reptile. Parents tended not to know that iguanas could pose such a hazard--less than half of those questioned were aware that they might have been the source of infection.

The authors conclude that "pediatricians, veterinarians, and pet store owners should inform their patients and customers of the potential risks of owning reptiles and provide appropriate preventive education." (Mermin J et al: Pediatrics, March, 1997, pp. 399-402)

COMMENT: These reports reinforce that Salmonella can be spread by a number of pets. Rep-
tiles have been implicated for many years, and because the problem was so great among small pet turtles, federal legislation was passed to limit that hazard. Now the focus is on iguanas, which have become very common pets. The CDC note points out that chicks are popular during springtime, and especially around Easter.

Parents and other care providers may not realize that these animals pose a risk. Those who do know might take precautions, such as making sure that the children don't handle the pets. However, as the CDC pointed out, only a fraction of the children who had become ill from pet iguanas had touched the reptile. Because it appears that Salmonella can be spread in other ways, we need to be aware of the fact that it is difficult to prevent transmission of Salmonella from reptiles and chicks, even if precautions are taken.

ENVIRONMENT

As Lyme Disease Season Begins, Can We Predict When To Use Antibiotics For A Tick Bite?

We've heard a lot about Lyme disease in recent years. This infection is caused by bacteria that are spread through the bite of a deer tick (which are actually carried by mice), typically during the late spring and summer months. Lyme disease often begins with a red circular rash at the site of the tick bite; the rash can last a few weeks, and may be accompanied by flu-like symptoms such as headache, fever, and muscle aches.

Because the disease can be severe, many people think it is useful to give antibiotics following a tick bite to prevent the development of Lyme disease. On the other hand, there are many who argue against this practice, for a variety of reasons: First, the risk of Lyme disease following a tick bite is very small. Second, antibiotics can themselves produce side effects. And third, overuse of antibiotics leads to antibiotic resistance, a problem for the entire community.

Rather than giving antibiotics to everyone with a tick bite, researchers have looked for ways to identify people who have the greatest risk of infection, and who therefore would benefit most from antibiotics. In a recent study, researchers from New York asked people who had been bitten by a tick in the previous two or three days to remove the tick and send it to them; those who were bitten were then followed to see if they developed Lyme disease.

The authors received specimens from 312 subjects, of which only 229 (76%) were actually deer ticks. Of these, 14% carried the Lyme disease bacteria. Lyme disease occurred in 3.7% of those who were followed.

As ticks feed, the blood they draw from their human hosts swells their bodies; by examining the size of the ticks, the authors were able to estimate how long they had been attached. They found that the risk of infection was higher when the tick had been attached for more than 72 hours than when it had been attached for less than 72 hours. The authors conclude that measuring ticks to see how large they are might be a way to identify patients who would benefit most from antibiotics. (Sood SK et al: Journal of Infectious Diseases, April, 1997, pp. 996-999)

COMMENT: With Lyme disease season on its way in many regions of the country, this report serves as a useful reminder of some of the issues to consider. Once a tick has bitten, the question often asked is whether antibiotics should be given to prevent Lyme disease. Though the authors suggestions seem to offer an intriguing way to reduce the number of people who would get antibiotics, the fact is that it is very impractical to consider measuring ticks to estimate risk.

In the real world, most laypeople cannot estimate how long a tick has been attached, since they don't know when it first appeared; on the other hand, few of us can recover an intact tick to present to an expert for examination.

But this study does offer some other information of interest. First, some of the specimens thought to be ticks weren't, and of the 303 that were, almost one in four wasn't the kind of tick (a dee tick) that prompts concern. What this all means is that at least some bites are not due to the ticks that pose a risk of Lyme disease, so much of the time our worry is unnecessary. Giving antibiotics to all children who've had an undocumented "tick" bite would therefore be unnecessary.

Further, encouraging news came from a study in Connecticut last year. It found that when Lyme disease was detected early in children and antibiotics were given promptly, the outcome was far better than most people had expected (CHILD HEALTH ALERT, November, 1996). In fact, four weeks after treatment was started, 94% of the children were free of symptoms, and after two years none of the children had any objective evidence of Lyme disease. However, the key to this success was the level of skill and experience of the Connecticut physicians who made the diagnosis early--delaying treatment might result in more serious illness.

While early treatment is an important way to reduce the severity of Lyme disease, parents and others who care for children would do well to implement efforts that reduce the risk of Lyme disease in the first place--by reducing the likelihood of tick bites.

... And Avoiding Tick Bites In The First Place

The first line of defense is to try to avoid areas where the ticks are common. Second, make sure that any ticks that might have become attached are removed. There's no emergency to doing this, since it takes a couple days for the disease to be transmitted by an infected tick. The best approach is to conduct a thorough "tick check" at the end of each day. Dog ticks and other relatively large ticks should not be confused with the small ticks that carry this disease. In May and June, deer ticks are about the size and color of a poppy seed, making them difficult to find, but a good place to look is the waist and thigh areas, where they commonly attach themselves. A shower can remove those that aren't attached, and those that are attached can be removed with a tweezers by grasping the tick as close to the child's skin as possible and-gently but firmly pulling it off.

It's important to realize that not all tick bites will lead to Lyme disease. On the other hand, preventive measures are reasonably simple and highly effective, so children can enjoy being outside without being at great risk for Lyme disease.

RESOURCES

National Safe Kids Campaign Gears Up

To help parents and caregivers fight the leading killer of children ages 14 and under- -preventable injury--the National Safe Kids Campaign will unveil a new program during National Safe Kids Week, May 10- IS, 1997.

Called SAFE KIDS GEAR UP, the key to this effort is the SAFE KIDS GEAR UP Guide, an attractive, easy-to-read booklet that illustrates the safety gear and precautions families need to use to keep children safe from injury at home, in the car, and at play. For example, homes and child care settings should have both smoke and carbon monoxide detectors, latches on cabinets and drawers, window guards and stairway gates, water heaters set no higher than 120º F, and a first aid kit that includes ipecac (to induce vomiting in case of certain poisonings).

The Guide will be distributed by the Campaign and its more than 200 state and local coalitions at SAFE KIDS GEAR UP Games that will be held in communities nationwide during Safe Kids Week.

"Children continue to die and become disabled at an alarming rate from injuries that are easily preventable, " said Campaign Chairman C. Everett Koop, M.D., the former U.S. Surgeon General. "By using the Guide and participating in the Games, parents and caregivers will gain valuable information about how to stop these needless tragedies."

The Safe Kids Campaign is making available a Resource Catalog, at no cost, and the Guide, (for $2 each; make check payable to National Safe Kids Campaign); to request these materials or further information, write: National Safe Kids Campaign, 1301 Pennsylvania Avenue NW, suite 1000, Washington, DC 20004-1707. 71