Sickle cell disease.

Sickle cell disease (SCD) is a group of inherited disorders caused by mutations in HBB, which encodes haemoglobin subunit ß. The incidence is estimated to be between 300,000 and 400,000 neonates globally each year, the majority in sub-Saharan Africa. Haemoglobin molecules that include mutant sickle ß-globin subunits can polymerize; erythrocytes that contain mostly haemoglobin polymers assume a sickled form and are prone to haemolysis. Other pathophysiological mechanisms that contribute to the SCD phenotype are vaso-occlusion and activation of the immune system. SCD is characterized by a remarkable phenotypic complexity. Common acute complications are acute pain events, acute chest syndrome and stroke; chronic complications (including chronic kidney disease) can damage all organs. Hydroxycarbamide, blood transfusions and haematopoietic stem cell transplantation can reduce the severity of the disease. Early diagnosis is crucial to improve survival, and universal newborn screening programmes have been implemented in some countries but are challenging in low-income, high-burden settings.

Regional and sociodemographic variation of breastfeeding in the United States, 2002.

With use of data from the Ross Mothers Survey (RMS), rates for breastfeeding in the hospital and at 6 months of age were evaluated within 4 geographical regions of the United States. Odds ratios for determinants of breastfeeding were also calculated. Regardless of sociodemographic characteristics, breastfeeding in the hospital and at 6 months of age was most common in the West and least common in the South. College education and not participating in the Women, Infants, and Children (WIC) program were the strongest predictors of breastfeeding in the hospital. Not working outside the home and not participating in WIC were the strongest predictors of continued breastfeeding to 6 months of age. Region of residence is important in considering how to develop programs targeted to populations with lower breastfeeding rates.