The community strain of methicillin-resistant Staphylococcus aureus behind an explosion in nasty skin infections across the country is now causing ear and sinus infections and neck abscesses in children nationwide, a new study has found.
Of 21,000 pediatric staphylococcus infections from 2001 to 2006, 22% were the aggressive community MRSA strain known to scientists as USA300.
Moreover, the six-year review of data from more than 300 hospitals revealed an "alarming nationwide increase" in these infections, from just under 12% of in 2001 to 28% in 2006, according to the study published Monday in Archives of Otolaryngology -- Head and Neck Surgery.
"Because of the proximity of the head and neck to important areas like the brain, the eyes and the chest, [these infections] need to be taken very seriously and treated aggressively," said Dr. Steven E. Sobol, a pediatric otolaryngologist at Emory University School of Medicine and one of the authors of the study.
As with the skin infections, some children seem to be more at risk than others for the ear, nose and neck infections. Living in crowded conditions, often because of poverty, is one risk factor. (Skin infections also have plagued football teams, wrestlers, gym rats and others who engage in sweaty, skin-contact sports.)
But Sobol said that he has seen ear, sinus and neck infections caused by USA300 in children who didn't appear to live in crowded conditions or have other risk factors.
The average patient infected was between 6 and 7 years old, an age at which immune systems aren't fully developed and children tend to catch infections easily, he added.
Infectious disease experts say that the increase in USA300-caused infections is not surprising. About one in three of us harbor staph on our skin or in our noses as part of our normal bacterial flora. Since the USA300 strain first appeared in the 1990s, it has been spreading across the nation and the world, pushing out other strains to become the dominant one.
Which is not to say that the spread isn't alarming. As long as staph stays where it's supposed to stay --on the outside -- it does little harm. But when it becomes invasive, slipping into a part of the body where it shouldn't be, any strain can cause severe infections of bones, joints, blood and lungs. And USA300 is particularly virulent, or capable of causing disease.
Sobol and co-authors Dr. Iman Naseri of Emory and Dr. Robert C. Jerris of Children's Healthcare of Atlanta at Egleston are completing a series of studies that look at how children who contracted these infections fared, how the germs spread and what makes USA300 infections so severe.
Sobol stressed in a phone conversation that parents shouldn't panic, but they and their pediatricians should be aware of the seriousness of these infections. For prevention, he recommended hand washing and avoiding overuse of antibiotics, which can both encourage further resistance and create a niche for bad bugs by destroying other ones.
-- Mary Engel