Published in Panorama
Timely intervention in preventing rheumatic fever and rheumatic heart disease
Rheumatic fever is a serious inflammatory condition that can affect several parts of your body but chiefly the heart, joints and nervous system. Although rheumatic fever can occur at any age, it most frequently occurs in children between the ages of 5 and 15 years.
While the exact cause of rheumatic fever may not be very clear, it is certain that it is a multifactorial disease in which malnutrition is an important predisposing factor, reveals Dr.Naga Srinivas, Specialist Cardiologist, Zulekha Hospital, Dubai. A second important factor in the cause of rheumatic fever is overcrowding. This is particularly so in the case of children staying in hostels and people residing in overcrowded places. In such areas, it can even occur as an epidemic, says Dr.Srinivas. “It is generally a disease of the developing countries of the world because it is related to overcrowding with transmission of the condition being on a one-to-one basis. Infection is generally spread by contaminated secretions of the throat, spread by droplets. Genetic, social and environmental factors put together can predispose individuals to rheumatic fever.”
Continuing on the susceptibility to rheumatic fever, Dr.Srinivas reveals, “It occurs following an acute sore throat which is caused by a strain of bacteria, the Group A streptococci. These bacteria when they case a sore throat, they produce some kind of antibodies which cross react with different types of antigens in our body, particularly the antigens which are present in the joints, heart and in the brain. Basically, it affects each and every part of the body, but predominantly the heart, joints and the brain. Its effects on the joints and brain do not produce permanent deformity, but when it affects the heart, it produces a permanent deformity. That’s the reason we say that rheumatic fever licks the joints but it ultimately bites the heart!”
The earliest and most common manifestation of rheumatic fever is fever with joint pains or arthritis – pain and swelling that typically migrates from joint to joint. This is the most distinguishing feature of rheumatic fever. Other symptoms include tiredness, chest pain and shortness of breath. “The pain initially starts in one joint, stays there for a week or so, subsides slowly and then starts in another joint. The associated fever is usually low grade and it may be followed by even total immobility of the joints,” explains Dr. Srinivas.
Symptoms of rheumatic fever generally appear within 5 weeks after an untreated streptococcal throat infection, the symptoms of which may include fever, sore throat, headache and inflamed tonsils. This does not imply that a streptococcal throat infection will necessarily lead to rheumatic fever! In fact, even in untreated cases, only about 3% of individuals with the infection are at risk of developing rheumatic fever.
Diagnosis of rheumatic fever depends typically on the clinical factors. Physical examination would involve the doctor checking the patient for pain in the joints and inflammation, to look for rashes or lumps in the skin and listen to the heart for abnormal rhythm or murmurs. Further diagnostic measures involve taking an ECG (Electrocardiogram) and chest X Ray to see if the heart is inflamed, blood test to look for the evidence of streptococcus infection. The anti-streptolysin O (ASO) titer is a blood test that measures antibodies to streptolysin O, a protein found on the bacteria group A streptococci. A rising ASO titer level indicates a recent strep infection. Elevated ASO levels simply indicate a previous exposure to strep and does not mean the patient has. However, this, in combination with other signs and symptoms will confirm diagnosis of rheumatic fever.
In more than half of all cases, rheumatic fever may affect the heart valves and interfere with normal blood flow through the heart. Dr.Srinivas explains, “Once the rheumatic fever starts, there is simultaneous involvement of the joints and heart. In the early, acute stage of the disease, all the three layers of the heart and its valves are also affected in that they get inflamed. In this stage, the child or individual will present with features of congestive heart failure. That means they can have breathing difficulties and swelling in the legs. Once the rheumatic fever abates, these symptoms also subside, but could leave permanent scarring of the valves. With repeated episodes of rheumatic fever, the scarring continues to occur and progress, making for a permanent deformity of the valves. This deformity could take the form of either obstruction to the flow of blood in the valve or it can be an abnormal leakage of the valve due to improper blood clotting. Permanent heart damage due to rheumatic fever is known as rheumatic heart disease. In many cases, heart damage isn't discovered until years later.”
At its worst, rheumatic fever can lead to fatalities even in children, when they develop severe myocarditis. Secondly, sometimes, in the first or second episodes of rheumatic fever, the heart valves may become so much thickened that there may be severe valvular leakages which will produce an extra burden on the heart, resulting in heart failure and death, reveals Dr.Srinivas.
There's no cure for rheumatic fever. But it can be prevented by prompt and thorough treatment of a streptococcal throat infection with antibiotics. Dr.Srinivas reveals, “Once rheumatic fever is established, we cannot prevent the development of heart involvement. Absolute bed rest is very important to the treatment because if you allow the child to play or the individual to carry on with routine activities, the stress on the heart will be very much increased and there is the risk of developing myocarditis. The second important aspect of treatment is aimed at reducing inflammation. Anti-inflammatory drugs are given. Aspirin, at the rate of 75 mg per kilogram of body weight, is the most commonly used drug for this purpose. Once this treatment is started, it has to be continued for at least four to eight weeks. In cases of severe inflammation where aspirin may not suffice or if the patient is not responding to treatment with aspirin, cortico-steroids are given. Cautious use of steroids is a must, being given for the first two weeks, followed by four to eight weeks of aspirin. This will control the inflammation, but it will not prevent damage to the heart.”
The treatment thus far, is to bring symptomatic relief for the joint pain and inflammation. But this will not guarantee that the patient will not get rheumatic heart disease in the future, emphasizes Dr.Srinivas.
Can rheumatic fever be prevented? Prevention may be Primordial or Primary, and Secondary, explains Dr.Srinivas. “Primary prevention involves prevention of the development of streptococcal sources in the community. This is very important. This can be achieved by addressing the problems of overcrowding, correcting malnutrition in children and the development of a streptococcal vaccine and undertaking mass immunization of ‘at risk’ individuals, particularly school going children. Such a vaccine though it has been developed, is yet to be marketed. Also, as part of primary prevention, it is important to make a prompt and timely diagnosis of streptococcus infection and begin appropriate treatment with antibiotics, immediately. Since there is a time interval of one to four weeks before the development of rheumatic fever following infection with streptococcus, timely treatment with antibiotics will prevent the development of rheumatic fever. Penicillin is the mainstay of antibiotic treatment. However, for individuals who are allergic to penicillin, alternatives like erythromycin are used.”
The third aspect of primary prevention involves people who have already developed rheumatic fever. The important goal here is to prevent its recurrence, emphasizes Dr.Srinivas. “Recurrences are more dangerous because they can damage heart structures, producing permanent deformities. So for all patient with rheumatic fever, whether or not the heart is involved, we give a secondary prophylaxis which is in the form of intra-muscular injections, once every three weeks. After the last episode of rheumatic fever, this prophylaxis should continue for at least five years, at the once in three weeks interval.”
The prophylactic treatment is continued even in patients who undergo valvular treatment in the form of valve replacement. Dr.Srinivas explains, “Because sometimes the rheumatic fever may not be very obvious; it may be very subtle. So to prevent these subtle episodes, it is better to give the prophylaxis.”
Corrective Surgery may be performed by way of balloon valvotomy, that is by putting a balloon across the obstructed valve to restore the free flow of blood across the heart, but re-blockage can occur. Alternatively, the valve itself may be replaced with an artificial one but all these measures are only palliative, not curative, emphasizes Dr.Srinivas.
*************
No comments:
Post a Comment