<prompt> Romanas sign is seen in infection due to:Trypanosoma cruziTrypanosoma bruceiLeishmania donovaniOnchocerciasis  <response>: Ans. a Trypanosoma cruzi. Ref. Harrisons medicine 16th ed. 1239CHAGASDISEASE Agent and Vector:- Trypanosoma cruzi a protozoan is transmitted through infected insect feces deposited near the bite of blood- sucking insects, especially reduviid or kissing bugs; and also perinatally, through transfusion, or through parenteral injection. Incubation:- Incubation is 5-14 days for the initial lesion if present. The acute stage lasts two-four months and the chronic stage may be life-long. Acute stage - Signs and Symptoms- About 50 of patients develop either a nodular lesion or furuncle chagoma at the site of the bite.- Conjunctival contamination with the vectors feces results in unilateral painless palpebral and periorbital swelling Romanas sign and associated lymphadenopathy of nodes draining the lesion. Other symptoms include prolonged fever, tachycardia, fatigue, anemia, weakness, hepatosplenomegaly, lymphadenopathy, and myocarditis.- It lasts 4-8 weeks and in rare cases may include myocarditis or meningoencephalitis.- In severe cases temporary electrocardiogram changes are seen, especially first degree AV block. chronic stage - Signs and Symptoms- The parasites have an affinity for smooth, skeletal, and heart muscle; and the nervous system.- The heart is the most commonly effected organ, with manifestations including CHF often right sided, rhythm disturbances, thromboembolism, and cardiomyopathy.- Megaesophagus may occur, with dysphagia, odynophagia, chest pain, cough, and regurgitation. Rx:- Nifurtimox 