Researchers believe they have discovered why a bacterial lung infection is so lethal in the early stages, and its not what medical authorities had thought, according to research published August 23 in the journal Immunity. The study reveals for the first time that a toxin released by bacteria causes severe bleeding in the lungs by patients with pneumococcal pneumonia. It is the bleeding, the authors argue, not inflammation as once thought, which makes the infections deadly. The same study also reveals why antibiotics often fail to help prevent early death.
Also called pneumococcus, the bacteria Streptococcus pneumoniae infects the upper respiratory tracts of the elderly and young children mostly. There are 500,000 cases of pneumococcal pneumonia annually in the United States, with about 40,000 of them fatal, according to the Centers of Disease Control and Prevention. Those numbers would be worse in children younger than 2 years if not for the 2000 introduction of the pneumococcal vaccine (Prevnar), according to one report. The picture remains far more serious outside of the United States, however, where pneumococcal infections take the lives of at least one million children each year, according to the World Health Organization
Our finding provides a better understanding of what makes a major global bacterial infection deadly, and marks the beginning of realistic efforts to save lives worldwide, said Jian-Dong Li, M.D., Ph.D., professor of Microbiology & Immunology at the University of Rochester Medical Center and an author on the Immunity paper. The power of understanding this mechanism is that it not only suggests how better to treat this disease, but also that we should think twice about whether standard drug treatments are doing more harm than good, said Li, also senior and corresponding author on the paper.
A Medical Mystery
Recognizing molecules as self, versus foreign invaders to be labeled for destruction, is
|Contact: Greg Williams|
University of Rochester Medical Center