Diagnosing, treating strep throat key to preventing rheumatic heart disease

Accurately diagnosing and treating strep throat is the key to preventing rheumatic fever and subsequent rheumatic heart disease, according to an updated American Heart Association scientific statement published in Circulation, journal of the American Heart Association.

Rheumatic fever is an inflammatory disease that can affect many of the body’s connective tissues, especially those of the heart, joints, brain or skin. When the heart valves are damaged by rheumatic fever it leads to rheumatic heart disease which can last a lifetime. Rheumatic fever is caused when a particular strain of strep throat (group A β-haemolytic streptococcus, or GAS pharyngitis) is left untreated. Rheumatic fever/rheumatic heart disease continues to be the leading cause of cardiovascular death during the first five decades of life in the developing world.

A throat culture, taken by swabbing the back of the throat, is considered the “gold standard” for identifying this strep infection. The culture and good clinical judgment are the best ways to diagnose strep throat, said Michael A. Gerber, MD, lead author of the scientific statement.

“It’s important to know that while strep throat is most common in children five to 15 years old, most sore throats in this age group are not caused by this particular type of strep,” said Gerber, Professor of Paediatrics in the Division of Infectious Diseases at Cincinnati Children’s Hospital Medical Center in Ohio. “In fact, most are caused by viruses which do not raise the risk of rheumatic fever and are not treatable with antibiotics.”

The update of the American Heart Association’s 1995 scientific statement gives healthcare providers here and abroad the most recent evidence for preventing rheumatic fever, including specific diagnostic instructions and antibiotic treatment.

Preventing initial episodes of rheumatic fever (primary prevention) requires accurate diagnosis and proper antibiotic treatment of GAS pharyngitis. Patients who have had an attack of rheumatic fever are at very high risk of developing recurrences if they have another case of strep throat. They need continuous antibiotics to prevent recurrences (secondary prevention). Patients who have had rheumatic carditis (inflammation of the heart or area around the heart) should also receive preventive antibiotic therapy well into adulthood and perhaps for life. Penicillin is the agent of choice for secondary prevention, but there are other antibiotics that are acceptable alternatives for people allergic to penicillin.

Recurrent episodes of rheumatic fever can worsen rheumatic heart disease or, less frequently, cause rheumatic heart disease in people who didn’t develop it during their first infection.

Signs of GAS pharyngitis include (but are not limited to):

• Sudden-onset of sore throat
• Pain on swallowing
• Fever, usually 101–104
• Headache
• Abdominal pain, nausea, and vomiting may also occur, especially in children.

These signs can occur with other upper respiratory tract infections, and it can be difficult even for an experienced healthcare provider to tell GAS pharyngitis from other types of pharyngitis, so the throat culture is important for accurate diagnosis.

Symptoms of rheumatic fever vary widely, but may include:

• Fever 
• Painful, tender, red, swollen joints 
• Pain in one joint that migrates to another one
• Heart palpitations
• Chest pain
• Shortness of breath
• Skin rashes
• Small, painless nodules under the skin

Rheumatic fever is rare in children younger than 3 years of age in the US. Among adults, initial attacks of rheumatic fever are rare, but do occur. Overall, the progression from strep throat to rheumatic fever is rare in the United States, but a few localised acute rheumatic fever outbreaks in civilian and military populations were reported in the 1980s.

“This reappearance of acute rheumatic fever reminds physicians, parents and others about the importance of continued attention to prevention of rheumatic fever in the United States and in other developed countries,” said Gerber.

(Source: American Heart Association: Circulation: March 2009)