|Spring 2010||Volume 25, Number 2||Findings Magazine|
Global Children's Health
1. Preterm birth rates are rising worldwide and many scientists suspect that air pollution is one of the causes. With funding from the U.S. National Institute for Environmental Health Sciences, SPH investigator Marie O’Neill and colleagues are studying 1,000 pregnant women in Mexico City to learn whether inflammatory responses to air pollution can affect the outcome of pregnancy. In addition to monitoring each woman’s air pollution exposure, the researchers will collect information on infection, inflammation and maternal nutrition, development of the baby and genetic differences that may influence the risk of preterm birth.
2. It’s well-known that exposure to lead is dangerous for young children, but less is known about the long-lasting effects of fetal lead exposure on older children and adolescents. In this pilot study of 200 mothers and children in Mexico City, SPH researchers Karen Peterson, Dana Dolinoy, and Brisa Sanchez want to learn whether women with high lead levels during pregnancy are more likely to have children who are overweight or whose physical maturation lags behind their peers. The researchers will analyze DNA from children’s stored cord blood samples to study the effects of prenatal lead exposure on genes that regulate growth and development.
3. SPH environmental health scientist Howard Hu and colleagues at Harvard University and the National Institute of Public Health in Mexico are continuing their 17-year-long ELEMENT study to determine how fetal exposure to toxic metals, especially lead, in the environment affects a child’s future health, behavior and ability to learn. The investigators want to understand how individual differences in gene activity, diet and lifestyle make some children more susceptible than others to the effects—like aggression, ADHD and learning disorders—of toxic metal exposure.
4. Inadequate nutrition is a growing public health threat with long-lasting consequences for children in developed and developing countries. In ongoing research with thousands of Colombian schoolchildren, SPH investigators Eduardo Villamor and Ana Baylin are studying how a poor diet makes children more susceptible to disease and affects their growth and development. They also focus on interactions between genes and diet and how they increase the risk of obesity, cardiovascular disease and diabetes.
6. In a study for the World Health Organization’s EURO region, SPH policy expert Gary Freed and colleagues surveyed immunization program managers in 53 member states in Europe, Eastern Europe and the former Soviet Union to determine how the decision to approve a new childhood vaccine was made and factors that influenced these decisions—especially for hepatitis B and haemophilus influenza, type b (Hib) vaccines. Factors most commonly cited as reasons for their decisions were the current burden of disease in the country and cost of the vaccine.
8. In one of the first epidemiology studies of pediatric brain tumors to be conducted in Africa, SPH epidemiologist Amr Soliman, SPH student Leana May, and colleagues from Morocco reviewed medical records of 542 children diagnosed with primary brain tumors from 2003 through 2007 at hospitals and clinics in the two largest cities in Morocco. Medulloblastoma was the most common type of tumor documented in the study, with brain tumors in general being slightly more common in boys than in girls. The study confirmed that the epidemiology of pediatric brain tumors in Morocco is the same as seen in other countries.
9. Can childhood exposure to chemicals found in plastics—like BPA and phthalates—alter normal gene activity and increase the risk for breast cancer later in life? To find the answer, SPH faculty members Dana Dolinoy, Laura Rozek, Maureen Sartor, and Amr Soliman are studying girls in Gharbiah, Egypt, where breast cancer is three to four times more common in urban women than in rural women. SPH investigators are comparing DNA from girls living in industrial areas with those from rural areas to determine if environmental chemicals interact with genes in ways that affect breast development during puberty.
10.Children in Nigerian cities have the highest rates of malaria and lead poisoning in Africa. In a recent study, SPH investigator Jerome Nriagu found an intriguing association between high blood levels of lead and fewer bouts of malaria in Nigerian children. Researchers know that children with sickle cell disease are less likely to get malaria. Could lead’s damaging effects on red blood cells somehow be protecting these children against malaria parasites as well? The issues are complex, but Nriagu plans to keep working until he finds answers.
11. Malaria kills at least one million people every year–the vast majority of them in Africa and primarily children under age five. In their survey of Malawi households, SPH epidemiologists Mark Wilson and Don Mathanga found that using insecticide-treated bed nets reduced by 50 percent episodes of malaria in young children. They also found that children in households with the lowest incomes were least likely to use bed nets and most likely to have anemia and malaria parasites in their blood. The researchers affirmed that providing free nets to poor families could help reduce the epidemic of childhood malaria in Africa. In Malawi, all mothers who attend antenatal clinics now receive free bed nets, along with instructions for their use.
12. In 2005, 11.2 percent of sexually active 15–24-year-olds in the Western Cape province of South Africa tested positive for HIV, the virus that causes AIDS. To understand what motivates young people to seek HIV testing, SPH researcher Rachel Snow and colleagues examined data from the Cape Area Panel Study. They learned that women were far more likely than men to be tested for HIV, especially if they have been pregnant. To slow the spread of the HIV virus in South Africa, the study concludes it is important to increase rates of HIV testing in young men and young women who have never been pregnant.
13. Since 2001, SPH environmental health scientists Tom Robins and Stuart Batterman with partners at the University of KwaZulu-Natal have conducted extensive research with South African schoolchildren to study the effects of ambient air pollution. Early research in Durban—one of South Africa’s most industrialized and polluted cities—found that children living in highly industrialized parts of the city were more likely to have decreased lung function and asthma. Currently, the researchers are starting a new study of Durban children with specific genetic variations that increase their sensitivity to air pollution.
14. Vaccines have eradicated polio in most parts of the world, but not in parts of northern India where more than 733 new cases were diagnosed in 2009. In a study to inform the World Health Organization, SPH epidemiologist Jim Koopman is modeling the dynamics of transmission in this part of India to learn why current vaccination programs aimed at children under age five have failed to stop the spread of disease. His conclusion: Transmission is so high in this region that in order to stop polio from spreading, some adults should be vaccinated.
15. Exposure to lead is a serious environmental health problem in India, where lead is commonly used in manufacturing and was still added to gasoline until 2001. SPH Professor Howard Hu and colleagues in Chennai are studying elementary schoolchildren to determine how lead exposure is related to IQ, behavior, and brain development. This project is the first formal study of the impact of lead toxicity on children to be conducted in India.
16. There’s no cure for asthma – a chronic and potentially life-threatening disease that affects 300 million people worldwide and often develops during childhood. Health behavior and health education faculty Noreen Clark and Molly Gong developed and tested the Open Airways self-management program to help children learn how to avoid disease triggers, prevent asthma attacks and hospitalizations. The Open Airways program has been adapted for use in schools around the world—most recently in Beijing and Tianjin, China. With the assistance of SPH researchers, Chinese doctors and educators are using Open Airways to help children from 20 Tianjin elementary schools learn about asthma’s symptoms and triggers and what to do during an asthma attack.
17. Public health officials in China are worried about recent outbreaks of measles, especially in major cities like Tianjin. More than 100,000 cases were diagnosed nationally in 2008, many in children under one. Working with the Tianjin CDC, SPH epidemiologist Matthew Boulton and colleagues hope to organize and direct large-scale case-control studies to identify segments of the Tianjin population most at risk for infection. The researchers also want to create a laboratory testing program for blood samples to determine how many people in the city have already been exposed to measles and now carry protective antibodies against the disease. A successful control effort in Tianjin will help the national Chinese CDC learn how to manage outbreaks of measles nationwide.
By Sally Pobojewski.