Is Myocarditis Contagious?
Yes, some presentations of myocarditis are contagious, but it is not necessary that all forms of the disease show the given characteristics. Myocarditis is the name given to such a cardiac disease that produces inflammation of the heart walls marked by degeneration or dystrophy of the cardiac muscle. Though the very first incidence of the disease is a topic for debate yet, there is an estimation based on data submitted to national tribunal, that multiple thousand newer patients has been diagnosed with myocarditis each year in United States alone.
Patient seems to be healthy and asymptomatic until an episode of acute cardiac attack occurs. It has become a trend that myocarditis usually occurs in otherwise healthy person resulting in moderate to severe impairment of cardiac muscle or in some cases even death may occur. There is a study that proves that myocarditis has 5 to 20 percentages of all the cases of unanticipated mortality in mid-age and young adults.
Causes of Myocarditis
Myocarditis is a group of diverse pathological conditions caused by variety of infectious organisms or/with primary inflammatory condition resulting in myocardial injury. Though there are multiple causes of myocarditis have been identified, which include viral infections, environmental toxins, autoimmune diseases, adverse reactions in response to certain drugs and some other diseases yet, there are three major causes have been registered. These includes-
Infections
Bacterial- Borelli (Lyme disease), Corynebacterium diptheriae, Neisseria meningococcus.
Chlamydial- Chlamydophyla psittaci.
Fungal- Candida.
Helminths- Trichinosis.
Protozoan- Toxoplasmosis, Trypanosoma cruzi (Chaga’s disease)
Rickettsial- Rickettsia typhi, Typhus fever
Viral- Coxsackievirus, Cytomegalovirus, ECHO, HIV, Influenza.
Immune Mediated Reactions
Drug hypersensitivity- Methyldopa, Sulfonamides.
- Post streptococcal (Rheumatic fever).
- Post Viral
- Systemic lupus erythematosus.
- Transplant rejection.
Unknown
- Giant cell myocarditis
- Sarcoidosis
Most common cause of myocarditis is viral. Coxsackie virus A & B along with some other varieties of enteroviruses account for almost all viral causative factors. Depending on the etiological agent and the host factors, virus can bring out myocardial injury either by initiating a hyperactive immune response leading to damage or by direct cytopathic effect. Secondary damage may be carried out by inflammatory mediators such as cytokines which are produced as a by-product of myocardial injury. The dysfunction of cardiac muscles caused by these mediators is way out of proportion to the damage actually caused to myocytes. Other important non-viral causative agents particularly involves a protozoan named Trypanosoma, which causes Chaga’s disease has emerged as an endemic agent in some parts of South America. This type of myocarditis is rendered exclusive by parasitization of distinctive muscle fibers by trypanosome which is accompanied by an inflammatory infiltration by neutrophils, macrophages, lymphocytes and occasionally eosinophils may be found.
Recent studies have shown that it has proved fatal in 10 percent individuals during an acute cardiac attack while others developed cardiac insufficiency over a period of 10 to 20 years due to longer presenting immune-mediated inflammation. Most common helminthic disease is Trichinosis, which is caused by Trichinella spiralis and is commonly associated with myocarditis.
Other Causes of Myocarditis
Amyloidosis is a disease that developed over a long course by deposition of beta pleated sheets composed of protein fibrils and is insoluble. Heart involvement may present as a resultant of any systemic amyloidosis, but it can also be restricted to heart, especially in old age people as seen in senile cardiac amyloidosis.
Cardio toxic medication. It is generally associated with convention chemotherapeutic drugs, certain immunotherapeutic agents and tyrosine kinase inhibitors, which cause cardio toxicity. The prognosis is variable, but chronic heart failure is the major long term complication. However, both the above mentioned factors are non-contagious.
Thus, we can say that some forms of the myocarditis are contagious while some are not. But the mode of transfer of the infection varies with each type of microorganism. Restrictive cardiomyopathy and hypertrophic cardiomyopathy are the sequelae of the disease. In which former type is mainly caused by infectious form and later by amyloidosis induced myocarditis.
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