A person returns to Delhi from Bangladesh after 2 days and has diarrhoea. Stool examination shows RBCs in Stool. The likely organism causing is ?

Ans. is 'd' i.e., Shigella Dysentriae . The person is suspected to have traveller's diarrhoea. . The most common cause of traveller's diarrhoea is E.coli , but the strains of the E.coli (Enterotoxigenic & Enteropathogenic) given in the choice do not produce invasive illness i.e presence of blood in stool. . It is a feature of Enterohemorrhagic E.coli . Now the choice is between Salmonella & Shigella diarrhoea are . Both these organisms produce invasive disease i.e dysentery or inflammatory diarrhoea . But Shigella & Salmonella can be differentiated on the basis of incubation period. i) Shigella (1-2days) ii) Salmonella --)0. (10-14 days)