The uncertainty of the number of cases of myocarditis stems from an inability to readily detect the disease. Dilated cardiomyopathy, however, is often associated with signs of a failing heart. Of these cases, about 25 percent, or about 13,000 people in the U.S., are thought to be associated with CVB each year. Unfortunately, most of these cases remain undiagnosed. There are six different types, known as serotypes or species, of coxsackie B viruses and probably at least two types of adenoviruses that cause heart disease in humans, Dr. Tracy said.
Coxsackieviruses are enteroviruses, common human viruses that usually do little harm.
Infections with coxsackieviruses are common and most young adults have had at least one or two such infections. Adenovirus is another common human virus that is generally associated with upper respiratory symptoms in humans. Natural infection is the only way by which a person becomes immune, as there are no commercially-available vaccines available against these viruses. The researchers, who have been studying these viruses for 18 years, published the results of their study in the May issue of the Journal of Virology. CVB induces a vigorous immune response in the person who is infected.