AAP Policy Statement on Lead Exposure in Children

The Committee on Environmental Health of the American Academy of Pediatrics (AAP) has released a policy statement on lead exposure in children. The statement, “Lead Exposure in Children: Prevention, Detection, and Management,” was published in the October 17, 2005, issue of Pediatrics and is available online at http://pediatrics.aappublications.org/cgi/content/full/116/4/1036.

The AAP Committee made the following recommendations for physicians with young patients:

• Anticipatory guidance should be provided to parents of all infants and toddlers about prevention of lead poisoning in their children. In particular, parents of children six months to three years of age should be made aware of normal mouthing behavior and should ascertain whether their homes, workplaces, or hobbies pose a lead hazard to their children. Parents should be informed that lead can be present in dust and can be ingested by children when they put hands and toys in their mouths.

• Physicians should ask about lead hazards in housing and child care settings, as is done for fire and safety hazards or for allergens. If a lead hazard is suspected, the child's home should be inspected; many health departments can do the inspection. Expert training is needed for safe repair of lead hazards, and physicians should discourage families from undertaking repairs on their own. Children should be kept away from remediation activities, and the house should be tested for lead content before the child returns.

• Physicians should know state Medicaid regulations and measure blood lead concentrations in Medicaid-eligible children.

• Physicians should find out if there is relevant guidance from the city or state health department about screening children not eligible for Medicaid. If there is none, physicians should consider screening all children. Children should be tested at least once, when they are two years of age; or, ideally, twice (at one and two years of age), unless lead exposure can be confidently excluded. Physicians should recognize that measuring blood lead concentrations only at two years of age, when blood lead concentration usually peaks, may be too late to prevent peak exposure. Earlier screening, usually at one year of age, should be considered where exposure is likely. A low blood lead concentration in a one-year-old child, however, does not preclude later elevation, so the test should be repeated at two years of age. Managed health care organizations and third-party payers should fully cover the costs of screening and follow-up.

• Physicians should be aware of any special risk groups that are prevalent locally, such as immigrants, foreign-born adoptees, refugees, or children whose parents work with lead or lead dust in their occupation or hobbies and those who live in, visit, or work on old buildings.

• Physicians should be aware of the work of the National Advisory Committee on Childhood Lead Poisoning Prevention and any relevant local committees. Although there is evidence that even lower blood lead concentrations may cause adverse effects in children, there is little experience in the management of excess lead exposure in these children. Most of the recommendations concerning case management of children with blood lead concentrations of 15 mcg per dL (0.72 μmol per L) should be appropriate for children with lower concentrations, although tactics that decrease blood lead concentrations might be expected to be less and less effective as they are applied to children with lower and lower blood lead concentrations.

CDC Releases Report on Preventable Measles

The Centers for Disease Control and Prevention (CDC) has issued a report on preventable measles in the United States. The report, “Preventable Measles Among U.S. Residents, 2001–2004,” was published in the August 26, 2005, issue of Morbidity and Mortality Weekly Report and is available online at http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5433a1.htm.

Although measles has been eliminated in the United States, the disease continues to be imported from other areas of the world where it is still endemic. This results in substantial morbidity and expenditure of local, state, and federal public health resources. Measles is brought into the United States by returning residents who become infected while living or traveling abroad, from contact or association with an infected traveler, or from an unknown source. Most cases of measles in the United States can be prevented by following recommendations for vaccination, including specific guidelines for travelers.

There were 251 cases of measles reported to the CDC between 2001 and 2004; 177 (71 percent) occurred among U.S. residents and 74 (29 percent) occurred among nonresidents. Of the cases among U.S. residents, 100 (56 percent) were preventable and 77 (44 percent) were not preventable.

Confirmed cases of measles that occurred among persons for whom vaccination is recommended by the Advisory Committee on Immunization Practices but who have not received one or more doses of measles-containing vaccine (MCV) were defined as preventable. Of the 100 preventable cases, 43 occurred among international travelers and 57 occurred among nontravelers. There were 17 preventable cases among travelers six to 15 months of age, 12 of which occurred among infants six to 11 months of age and five of which occurred among children 12 to 15 months of age. Among persons older than 16 months, there were 83 preventable cases; 26 were in persons who became infected during international travel and 57 were in persons infected in the United States.

Cases that occurred among persons who: (1) had received one or more doses of MCV; (2) were not vaccinated and for whom vaccination is not recommended; and (3) were born before 1957 were defined as nonpreventable. Twelve (16 percent) of the 77 nonpreventable cases occurred among international travelers; 11 had received at least one dose of MCV and the other had been born before 1957. There were 65 cases (84 percent) of nonpreventable measles reported among nontravelers.

Three or more epidemiologically linked cases of measles were defined as an outbreak. There were 14 outbreaks of measles identified between 2001 and 2004. Nine of the outbreaks involved three or more U.S. residents, seven of which originated with a U.S. resident traveler. One outbreak occurred in 10 patients in a day care center who were exposed to an unvaccinated nine-month-old day care attendee who was infected during travel abroad.

AAP Clinical Report on Infant Methemoglobinemia

The American Academy of Pediatrics (AAP) recently released a clinical report on the risk factors of nitrate poisoning in infants. “Infant Methemoglobinemia: The Role of Dietary Nitrate in Food and Water” was published in the September 17, 2005, issue of Pediatrics and is available online at http://www.pediatrics.org.

Nitrate poisoning is a continuing problem among infants in the United States. Most reported cases have been linked to the use of contaminated well water for preparation of infant formula. Approximately 15 million families in the United States receive their drinking water from unregulated wells. A survey of 5,500 private water supplies from nine Midwestern states found that 13 percent had nitrate concentrations of more than 10 mg per L or 10 parts per million (ppm) nitrate nitrogen, the federal maximum contaminant level. Estimates are that 2 million families drink water from private wells that fail to meet the federal drinking-water standard for nitrate; 40,000 infants younger than six months live in homes with nitrate-contaminated water. The problem is aggravated in urban areas by municipal wastewater treatment discharges on surrounding farmland.

It is recommended that foods with naturally occurring nitrates (e.g., green beans, carrots, spinach, squash, beets) be avoided before three months of age because an infant's intake can be at least as high as that from well water. A target concentration of nitrate nitrogen for food of less than 100 ppm is desirable for infants, and some commercially prepared infant food vegetables are monitored voluntarily by manufacturers for nitrate content. Because the target concentration level often is exceeded in spinach, this product is commonly labeled not to be used in infants younger than three months.

There is no evidence of an increased risk of methemoglobinemia in breastfed infants from maternal ingestion of water with nitrate nitrogen concentrations as high as 100 ppm. These mothers do not produce milk with high nitrate concentrations. The predominant organism (Lactobacillus species) in the gastrointestinal tract of the breastfed infant does not reduce nitrate to nitrite.

Other than cyanosis, there are few clinical signs of methemoglobinemia. Although obvious cyanosis can occur with methemoglobin concentrations as low as 3 percent in infants with low hemoglobin concentrations, symptoms are usually minimal until methemoglobin concentrations exceed 20 percent. A diagnosis of methemoglobinemia should be considered in a child who becomes acutely cyanotic and does not respond to oxygen administration.

Health care professionals who suspect that an infant has methemoglobinemia should contact the local poison control center or a toxicologist to assist in guiding management. Identification and elimination of the source of exposure are the only treatments required in an asymptomatic infant with cyanosis who has a methemoglobin concentration of less than 20 percent.

Questions about the family residence, parental occupations, drinking water, foods ingested, topical medications, and folk remedies are included in an assessment of potential nitrate exposure. Testing well water for nitrate contamination is recommended for prenatal and newborn care of patients with private wells, and water found to have high nitrate concentrations should not be ingested by the infant or used for preparation of infant formulas or food. Although in-home systems for nitrate removal are effective, they also can be expensive. Nitrates are not removed by ordinary home water softeners. Most state health departments have listings of public health laboratories that have been certified by the U.S. Environmental Protection Agency for testing water for nitrate.