Dengue virus has long presented scientists with a puzzle: an individual
who is infected with one of the four subtypes of the virus often has a more
severe illness—dengue hemorrhagic fever—the second time around.
Now, scientists from England and Thailand, whose findings were published June
15 in the online edition of Nature Medicine (http://www.nature.com/nm/), believe they have discovered why this occurs.
Stephenson J. Fortifying Food for the Poor. JAMA. 2003;290(2):184. doi:10.1001/jama.290.2.184-a