Clinical Manifestations and Pathology

There are a number of different forms of the disease, which will be considered separately. In all cases, however, the prognosis is poor because there is no effective treatment. The acute form ends in death in 10 percent of the cases, and although the chronic form may last from 10 to as long as 40 years, few individuals remain asymptomatic for life.

The acute form, occurring primarily in young chil­dren, is most commonly a febrile illness; other symp­toms are normally those of generalized lymph node enlargement as well as enlargement of the liver and spleen, and edema of the face. When death occurs, it is generally due to acute inflammation of the muscu­lar walls of the heart (myocarditis) or to a complicat­ing bronchopneumonia.

The latent form of the disease is seen in patients who have recovered from the acute form, as well as others who have harbored the parasite but have not displayed symptoms of the illness. Multiple examina­tions, however, often reveal changes in esophageal and peristaltic motility as well as electrocardio­graphic changes.

The subacute form of Chagas’ disease is normally seen in young adults who suffer a rapidly progres­sive cardiac failure.

The chronic form of the illness is the leading cause of death in endemic areas. The heart becomes tre­mendously enlarged, and in about 30 percent of the cases, parasites may be found within pseudocysts in muscle fibers. Although survival may be as long as 5 years, death usually intervenes within 6 to 12 months.

The digestive form of Chagas’ disease presents as megacolon or megaesophagus in endemic areas. The afflicted suffer the degeneration and diminution of nerve cells in the muscular layers of these organs, leading to their enlargement. The condition by itself is normally not fatal, but patients often experience difficulty in swallowing because of the enlarged esophagus, and constipation that normally accompa­nies megacolon. These difficulties in turn can pro­mote other illnesses that are life-threatening.

The congenital form of the disease has long been known. The fetus is infected transplacentally, and the result can be premature fetal death or a newborn with Chagas’ disease in its acute stage.