Rogue antibody linked to severe second dengue infections

Study probes connection between disease and low platelet count The playground ditty “first the worst, second the best” isn’t always true when it comes to dengue fever. Some patients who contract the virus a second time can experience more severe symptoms. A rogue type of antibody may be to blame, researchers report in the Jan. 27 Science. Instead of protecting their host, the antibodies are commandeered by the dengue virus to help it spread, increasing the severity of the disease. Four closely related viruses cause dengue, a mosquito-transmitted disease marked by fever, muscle pain and other flu-like symptoms. When a previously infected person contracts a second type of dengue, leftover antibodies can react with the new virus. Fewer than 15 percent of people with a second infection develop severe dengue disease. Those who do may produce a different type of antibody, says Taia Wang, an infectious diseases researcher with the Stanford University School...