May 2004 | Pediatric Arts Gazette, NY

Please book your camp and school physicals early. We are already doing them. As outdoor activities increase remember to have your children wear bicycle helmets and check them for ticks. We wish you all a happy Mother’s Day.

What’s All the “Whoopla” About?-----------------

A Fish Tale-----------------------------------

Fish is widely acknowledged as a high quality protein source and an important component of a heart smart diet, yet some fish species contain dangerous amounts of methylmercury. Numerous studies have shown that methylmercury is toxic to newborns, children and even adults. It is also toxic to the fetus of pregnant women and is secreted in breast milk. Methylmercury exhibits its toxic affects mainly on the brain, kidneys and immune system. In infants and young children, methylmercury toxicity may cause developmental delays and learning problems.

The only significant source of methylmercury in the general U.S. population is from consumption of contaminated fish. Fish become mercury-contaminated when airborne mercury primarily from coal burning power plants falls into surface water and is picked up by microorganisms. These microorganisms are then consumed by small fish which in turn are consumed by larger fish resulting in substantial concentrations of mercury within these fish.

Because of this, the FDA and EPA have made formal recommendations regarding fish consumption:

Pregnant women, women who might become pregnant, nursing mothers and young children (no age specified):

should not eat shark, swordfish, king mackerel or tilefish.
can safely eat up to 12 ounces (two average meals) of purchased fish and shellfish a week. Mix up the types of fish you eat and do not eat the same type of fish more than once a week.
should check local advisories about the safety of fish caught by family and friends in local rivers and streams. If no advice is available, you can safely eat up to 6 ounces per week of fish you catch but do not consume any other fish during that week.

Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish. Albacore tuna contains more mercury, so its consumption should be limited. One environmental group recommends that women of child bearing age and children under five years of age avoid canned albacore tuna completely.

Pertussis (whooping cough) received a lot of media attention during this past school year. Several cases in the Orange County school districts prompted letters home to concerned parents prompting many physician questions.

Pertussis is a bacterial infection, highly contagious, and is spread by coughing. Pertussis, without treatment, is contagious for up to 3 weeks, with contagious rates up to 90% in unvaccinated household contacts. The incubation period is from one to three weeks.

There are three phases of classic pertussis. The initial or catarrhal stage generally lasts 1-2 weeks and is similar to the common cold with cough and congestion. This stage is the most difficult to diagnose due to the lack of significant symptoms.

The second or paroxysmal stage presents as intense bouts of coughing that last up to several minutes. It is during these bouts of coughing that the classic “whoop” may be heard. This stage lasts from 2-6 weeks.

The third or convalescent stage is characterized by a chronic cough and will last for several more weeks. The total length of illness then can be as many as 10 weeks. Other symptoms include vomiting after a coughing fit but fever is usually not present. Infants younger than 6 months, and older children and adults frequently don’t have the whoop. Pertussis is most severe in infants less than 6 months of age particularly for pre-term and unimmunized infants. Pneumonia occurs in about 20% of children less than 1 year of age. The case fatality rate is about 1% in infants less than 2 months of age. Increased rates of pertussis occur every 3-5 years. As noted above, patients are most contagious during the first few weeks when diagnosis is most difficult, thereby increasing the chance close contacts will get the disease.

The best diagnostic test for pertussis is via a swab of nasal secretions. However, this test is not done by any local hospitals and even when done properly is often negative. Further, a positive test is most likely, you guessed it, in the catarrhal stage, when testing is rarely done. An elevated white blood cell count is frequently seen but this is seen in many other infections as well. Diagnosis, then, is usually made on the basis of chronic severe cough especially when accompanied by a whoop.

Treatment of infants younger than 6 months of age frequently requires hospitalization. Pertussis is treated with the antibiotic erythromycin for 14 days or similar antibiotics such as Biaxin and Zithromax. Other antibiotics are generally ineffective for treatment. Antibiotics may shorten the length of pertussis, but only when given, you guessed it again, in the catarrhal stage. Once the paroxysmal stage has begun, antibiotics are ineffective but are recommended to limit the spread of organisms to others.

Treatment of close contacts is also important. All household contacts should receive antibiotics regardless of age or immunization status because immunization with DTP (P for pertussis) vaccine is not 100% effective and immunity wanes with time. Children with pertussis may return to school if they feel well five days after initiating antibiotic therapy. Classmates of a child with pertussis do not need antibiotics unless they become symptomatic.

Vaccination with pertussis, given as part of the DTP series, is required for school entry. Vaccination is given at 2 months, 4 months, 6 months, 12-18 months and prior to kindergarten entry. Pertussis vaccine cannot be given to anyone 7 years of age and older. The vaccine is safe and effective. Since immunity wanes over time, most cases of pertussis occur in adolescents and adults who pass it on to unimmunized or not fully immunized infants. Trials are currently ongoing evaluating the effectiveness of pertussis vaccine when given to adolescents and adults. So that’s what all the whoopla is about!