infectious diseases
Chagas Disease
Symptoms and Signs of Chagas Disease
T. cruziinfection has 3 stages: Acute Chronic indeterminate Chronic Acute infection is followed by a latent (chronic indeterminate) period, which may remain asymptomatic or progress to chronic disease. Immunosuppression may reactivate infection, causing high parasitemia and in some people skin or brain lesions. AcuteT. cruziinfection in endemic areas usually occurs in childhood and can be asymptomatic. When present, symptoms start 1 to 2 weeks after exposure. An indurated, erythematous skin lesion (a chagoma) appears at the site of parasite entry. When the inoculation site is the conjunctiva, unilateral periocular and palpebral edema with conjunctivitis and preauricular lymphadenopathy are collectively called the Romaña sign. Acute Chagas disease is fatal in a small percentage of patients; death results from acute myocarditis with heart failure or meningoencephalitis. In the remainder, symptoms subside without treatment. Primary acute Chagas disease in immunocompromised patients, such as those with AIDS, may be severe and atypical, with skin lesions and, rarely, ring-enhancing brain lesions. Congenital infectionsare mostly asymptomatic, but in 10 to 40% of cases nonspecific manifestations occur, including prematurity, low birth weight, fever, hepatosplenomegaly, anemia, and thrombocytopenia. Rarely, death can result from fulminant disease. Signs of acute infection resolve even without therapy in the majority of congenital infections. Patients with chronic indeterminate infection have parasitologic and/or serologic evidence ofT. cruziinfection but have neither symptoms, abnormal physical findings, nor evidence of cardiac or gastrointestinal involvement as assessed by ECG and rhythm strip, cardiac ultrasonography, chest x-ray, or other studies. Many infected patients are identified by screening enzyme-linked immunosorbent blood assay (ELISA) and confirmatory radioimmunoprecipitation assay (RIPA) when they donate blood. Chronic Chagas disease develops in 20 to 30% of patients after the chronic indeterminate phase, which may last years or decades. The parasites are probably present in chronic disease; an autoimmune reaction also may contribute to organ damage. The main effects are Cardiac Gastrointestinal usually manifests with conduction abnormalities including right bundle branch block or left anterior fascicular block. Chronic Dilated Cardiomyopathy often follows with flaccid enlargement of all chambers, apical aneurysms, and progression of lesions in the conduction system. Patients may present with heart failure, syncope, sudden death due to manifests with symptoms resembling Achalasia or 