Lead poisoning in children. The ramifications and the road to prevention.

Environmental lead poisoning is easier to prevent than to treat, and it can be destructive or deadly if ignored. Dr Schlenker, medical director of the Milwaukee Health Department, shares his approach to screening young children for potentially dangerous blood lead levels, educating the community about prevention of lead poisoning, and eradicating environmental sources of lead.

Primary prevention of childhood lead poisoning through community outreach.

BACKGROUND: The prevalence of childhood lead poisoning has substantially decreased in Milwaukee, Wisconsin over the past decade. Nevertheless, by the mid 1990s, 30% of children were still found to have elevated blood levels. OBJECTIVE: To extend the reach of the Milwaukee Health Department (MHD) to previously underserved families in 1 inner city neighborhood with extremely old housing, the Sixteenth Street Community Health Center (SSCHC) implemented, in 1995, the Community Lead Outreach Project (CLOP). Going door-to-door, CLOP attempted to identify children 6 months to 6 years old with elevated blood lead levels (BLL), referring those > or = 20 micrograms/dL to MHD and enrolling those with BLLs 10-19 micrograms/dL in a program of prevention education and environmental clean-up with the specific aim of preventing BLLs increasing to 20 micrograms/dL and above. METHODS: A team of community outreach workers led by a nurse-coordinator visited, over a 4-year period, families in their homes in 13 census tracts surrounding the SSCHC. During the home visits, capillary blood samples for BLLs were drawn, environmental assessments and scoring were conducted, lead poisoning prevention education provided and repair and cleaning of household lead hazards demonstrated. For control and comparison, BLL data for the entire city by ZIP Code and provider were obtained from the Milwaukee Health Department. Odds ratios for changes in the proportions of children screened > or = 10 micrograms/dL were calculated and compared for the years 1996 through 1999. The odds ratios of changes for various populations were compared for significant differences using tests of homogeneity. To control for age confounding, proportions of elevated BBLs for all groups and for all years were age-standardized, using the direct method. RESULTS: Over the entire study, 20.9% of the children screened had BLLs > or = 10 micrograms/dL and 3.0% were > or = 20 micrograms/dL. For 395 children with BLLs 10-19 micrograms/dL enrolled in the CLOP follow-up program, the mean BLL was 12.9 micrograms/dL. Mean levels at the first, second and third follow-up visits were 10.8, 10.3 and 9.8 micrograms/dL respectively, showing an overall decline of 3.1 micrograms/dL or 24%. At the first follow-up visit, 97% of the children tested were < 20 micrograms/dL while 76% were < 10 micrograms/dL. By the second follow-up visit, 100% were < 20 micrograms/dL. Initial environmental scores averaged 24.7, declining to 19.0 at first, 17.8 at second and 14.8 at third follow-up visits. For the entire CLOP population, the proportion of children testing > 10 micrograms/dL declined each year from 46.3% in 1996 to 22.5% in 1999. The geographic area in which CLOP operated recorded the highest screening penetration rate in the city: 61%. The odds ratio for CLOP clients to have elevated blood lead levels at the end of the study period, in contrast with the beginning, was 0.34 compared to 0.55 for the entire city and 0.75 for private physicians serving the same general population. Comparison of odds ratios showed the CLOP target population enjoyed a decrease in rate of elevated BLL 1.6 times that of the city-wide average, p-value = 0.016 and more than double that of the patients of area private providers. CONCLUSIONS: We conclude that the Sixteenth Street Community Health Center Childhood Lead Outreach Project has successfully accessed populations of children with high rates of lead poisoning who had escaped more traditional screening venues and effectively intervened to reduce their BLLs to < 10 micrograms/dL. Moreover, CLOP produced impressive and unanticipated primary prevention benefits in the community at large. The demonstrated ability of community outreach workers to access high-risk populations and reduce exposure to lead hazards suggests the potential of this strategy for extension to other geographic areas, to the patients of private physicians and to address other prevalent, urban health problems like asthma, injuries and violence.

Collaborating with private sector physicians: the example of childhood lead poisoning prevention.

Collaboration between public and private health sectors to achieve public health goals can be difficult. The experience of childhood lead poisoning prevention programs in two cities where private practitioners dramatically increased blood lead screenings is used as an example of how successful collaborative relationships can be constructed. Seven action steps toward effective collaboration are offered: establish a rationale, document the problem, attend to logistics, clarify reimbursement, make known available support, build demand, and demonstrate leadership.

The impact of health care financing on childhood immunization practices.

OBJECTIVE: To examine the impact of patient insurance status and third-party payment methods on physician immunization practices. DESIGN: Family practice physicians and pediatricians were surveyed to determine whether differences existed in office immunization practices for five childhood vaccines across insurance and payment classes. SETTING: Milwaukee, Wis. PARTICIPANTS: Of 202 Milwaukee area physicians who administer immunizations routinely, 161 (79.7%) returned the questionnaire. RESULTS: Physicians reported immunizing uninsured patients in their offices less often than patients with insurance. When insurance does not pay for immunizations, most physicians (81.6%) said that they left the decision of whether to pay for private immunizations or seek free immunizations from the city health department to the family. Physicians estimated that approximately half of their uninsured patients decline private immunizations. Some physicians (20%) who treat patients receiving Medicaid reported that they immunize patients with Title 19 coverage less often than patients with other types of insurance. No significant differences in frequency of immunization were reported for patients insured by capitated-payment health maintenance organizations, fee-for-service health maintenance organizations, or traditional insurance covering immunizations. CONCLUSIONS: Physicians reported that they do not immunize uninsured and underinsured children as frequently as insured children. Further research is recommended to evaluate the impact of Medicaid enrollment on access to immunization and to develop innovative financing arrangements to ensure that no children leave their physicians' offices without being immunized.

Emergency department vaccination of preschool-age children during a measles outbreak.

STUDY OBJECTIVE: To determine the effectiveness of an emergency department vaccination program for preschool-age children during a measles outbreak. DESIGN: Cross-section study. SETTING: Urban pediatric ED with an annual census of 24,000. PARTICIPANTS: Children, 12 to 59 months old, who presented to our ED between April 1 and April 30, 1994. INTERVENTION: Staff trained in rationale for and protocol of ED vaccination offered measles-mumps-rubella (MMR) vaccine, free of charge, to all eligible children. RESULTS: Of the 541 children seen, 7% lacked measles vaccination; MMR vaccination status could not be determined in 10%. From history it was determined that all the others had been vaccinated. Of the vaccination-eligible children, 25% were vaccinated in the ED. Of the eligible children who were not vaccinated, parents declined in half of the cases and physicians did not offer vaccination in the other half. Eligible children with physical injury were more likely to be vaccinated, and those with upper respiratory tract infections were less likely to be vaccinated than were eligible children with other diagnoses (P < .05). CONCLUSION: During a measles outbreak, few children receiving care at a busy pediatric ED were definitively identified as vaccination eligible. Only a few children identified as eligible for vaccination were vaccinated. Significant logistic barriers to effective ED vaccination exist.

Oxygen consumption at rest and during exercise in pregnancy.

The oxygen consumption (Vo2) of 12 normal women was measured at monthly intervals during pregnancy and 2, 6 and 12 weeks and 6 months postpartum. At each study session measurements were made sitting at rest, during standard steady-state exercise on a bicycle ergometer, and for 10 minutes of recovery. A significant increase in exercise Vo2 was observed in late pregnancy when compared to paired postpartum values. The oxygen debt incurred by standard exercise was also greater in late pregnancy than 12-14 weeks postpartum.

Measles herd immunity. The association of attack rates with immunization rates in preschool children.

OBJECTIVE: To examine the association between incidence of measles and immunization coverage among preschool-age children. DESIGN: An ecological study in which measles incidence was compared with immunization coverage among census tracts. The independent effects of race and population density were controlled for. SETTING: A recent measles outbreak in Milwaukee, Wis. Immunization coverage data were estimated from a retrospective, school-based survey of Milwaukee grade school students. PATIENTS: One thousand eleven persons (less than or equal to 17 years) who had confirmed measles from September 1989 through June 1990. MAIN OUTCOME MEASURES: Confirmed measles cases grouped by census tract, corresponding census tract preoutbreak immunization coverage, racial breakdown, and population density. RESULTS: Census tracts stratified into four levels, with mean immunization rates of 50.4%, 60.2%, 69.9%, and 81.0%, had respective median attack rates of 11.6, 5.0, 1.7, and 0.0 cases per 1000 persons (P less than .01). The association between immunization coverage and measles attack rate remained significant even after controlling for race and population density. CONCLUSIONS: Modest improvements in low levels of immunization coverage among 2-year-olds confer substantial protection against measles outbreaks. Coverage of 80% or less may be sufficient to prevent sustained measles outbreaks in an urban community.

Screening for pediatric lead poisoning. Comparability of simultaneously drawn capillary and venous blood samples.

OBJECTIVE: To determine the ability of capillary blood lead levels to accurately reflect true blood lead levels in children at risk for lead poisoning. DESIGN: A correlation study in which lead levels of capillary blood specimens obtained by four different methods were compared with lead levels of simultaneously drawn venous blood specimens. SETTING: A central-city pediatric primary care clinic and door-to-door home visits in one central-city neighborhood. PATIENTS: Two hundred ninety-five children at high risk for lead poisoning aged 6 months to 6 years. MAIN OUTCOME MEASURES: Blood lead levels of simultaneously drawn capillary and venous blood specimens. RESULTS: Lead levels of all four capillary sampling methods were highly correlated (correlation coefficient > or = 0.96) with matched venous blood lead levels, with mean capillary-venous differences less than 0.05 mumol/L (1 microgram/dL). CONCLUSIONS: Capillary sampling is an acceptable alternative to venipuncture for lead-poisoning screening in young children.

Sources of infection among persons with acute hepatitis A and no identified risk factors during a sustained community-wide outbreak.

CONTEXT: Hepatitis A is a common vaccine-preventable disease in the United States. Most cases occur during community-wide outbreaks, which can be difficult to control. Many case-patients have no identified source. OBJECTIVE: To identify foodborne and household sources of hepatitis A during a community-wide outbreak. DESIGN: Serologic and descriptive survey. SETTING: Salt Lake County, Utah. PARTICIPANTS: A total of 355 household contacts of 170 persons reported with hepatitis A during May 1996 to December 1996, who had no identified source of infection; and 730 food handlers working in establishments where case-patients had eaten. MAIN OUTCOME MEASURE: Prevalence of immunoglobulin M antibodies to hepatitis A virus (IgM anti-HAV) among household and food service contacts. RESULTS: Overall, 70 household contacts (20%) were IgM anti-HAV-positive, including 52% of children 3 to 5 years old and 30% of children <3 years old. In multivariate analysis, the presence of a child <3 years old (odds ratio [OR]: 8.8; 95% confidence limit [CL]: 2.1,36) and a delay of >/=14 days between illness onset and reporting (OR: 7. 9; 95% CL: 1.7,38) were associated with household transmission. Of 18 clusters of infections linked by transmission between households, 13 (72%) involved unrecognized infection among children <6 years old. No food handlers were IgM anti-HAV-positive. CONCLUSION: During a community-wide outbreak, HAV infection among children was common, was frequently unrecognized, and may have been an important source of transmission within and between households. Transmission from commercial food establishments was uncommon. Ongoing vaccination of children may prevent future outbreaks.