In low- and middle-income countries, where more than 90% of the world's tuberculosis cases occur, 54% of health care workers, including nurses, have latent tuberculosis infections, according to a recent review of 51 studies. The prevalence of latent infection in nurses was higher than in all health care workers, ranging from 43% to 87%, compared with 33% to 79%. Risk also increased with age, length of service, and tasks involving greater exposure to patients with tuberculosis.

In high-income countries like the United States, the annual risk of tuberculosis infection for health care workers is between 0.1% and 1.2% because policies in health care settings promote early diagnosis and treatment and provide health care workers with personal protective equipment. Many low-income countries lack the resources and personnel to implement even low-cost protective measures. Reducing the risk of nosocomial transmission of tuberculosis in low- and middle-income countries should be a priority, according to the researchers, especially in light of the emerging strains of extremely drug resistant tuberculosis. Read the full report, by Rajnish Joshi and colleagues (published on December 26, 2006) at http://www.plosmedicine.org.

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Gadolinium contrast agents and renal disease. The Food and Drug Administration (FDA) issued a public health advisory on the use of gadolinium-containing contrast agents in magnetic resonance imaging (MRI) in patients with moderate-to-end-stage renal disease. The FDA is investigating 90 cases of nephrogenic systemic fibrosis-nephrogenic fibrosing dermopathy, a progressive and sometimes fatal disease of unknown origin that causes fibrosis in the skin and connective tissues in people with renal disease. All 90 patients had undergone MRI with a gadolinium-based contrast medium. The FDA cautions against using gadolinium in patients with renal disease, but if its use is unavoidable, prompt post-MRI dialysis should be considered.

Breastfeeding coaching pays off Just one face encounter with a breastfeeding educator during pregnancy can improve a woman's breastfeeding practice for up to three months after delivery, according to a study published in the January issue of Obstetrics and Gynecology. Women at 36 weeks of pregnancy or longer in Singapore who watched an instructional video, were given an educational booklet, and had one 15-minute counseling session with a lactation counselor were twice as likely to exclusively or predominantly breastfeed their babies at three months after giving birth, compared with women who received the booklet and watched the video but did not get counseling or who received only routine care. The American Academy of Pediatrics and the World Health Organization both recommend six months of exclusive breastfeeding followed by the introduction of solid foods and continued breastfeeding for up to two years.