• Study suggests too many invasive heart tests given
• Panel: Women need chance to avoid repeat C-section
• CDC uses shopper-card data to trace salmonella
• Hoped-for drop in childbirth deaths not happening
• Researchers: AIDS virus can hide in bone marrow
• Brazil's Silva quits smoking after 50 years
• WHO: over 85M African kids get polio vaccination
• Gene test claims to show what diet works best