Intestinal Infections MCQs

Category A bioterrorism agents are those that pose the highest risk to national security because they can be easily disseminated or transmitted from person to person, result in high mortality rates, and have the potential for major public health impact. Explanation for why not the other options: a. Vibrio cholerae: Vibrio cholerae is the bacterium responsible for causing cholera, a severe diarrheal disease. While cholera can cause significant morbidity and mortality, it is not typically considered a Category A bioterrorism agent due to its lower potential for deliberate dissemination and widespread impact compared to other agents in Category A. Reference: Park's Textbook of Preventive and Social Medicine, 27th Edition, Page no.:982

Explanation: Endemic typhus (also called murine typhus ) is caused by Rickettsia typhi . Transmission: Flea bite (commonly from rats). Clinical features: Mild febrile illness, headache, myalgia, sometimes rash. Usually self-limiting. Differentiation from epidemic typhus: Epidemic typhus → caused by Rickettsia prowazekii , transmitted by body lice , more severe. Explanation of Incorrect Options: Rickettsia prowazekii (Option A): Causes epidemic typhus , not endemic typhus. Salmonella typhi (Option C): Causes typhoid fever , a bacterial enteric fever, not a rickettsial infection. Orientia tsutsugamushi (Option D): Causes scrub typhus , transmitted by chiggers , not fleas.

Explanation: Shanchol is a bivalent oral cholera vaccine given in 2 doses This refers to a vaccine that targets two different strains of Vibrio cholerae and requires two doses for complete immunisation. The Shanchol vaccine is bivalent, meaning it covers two different strains of Vibrio cholerae (01 and 0139) and typically requires two doses for full protection.

Ans. is 'a' i.e., > 300 [Ref Park 21"/e p. 221] Below 200 → Hookworm infection is not much of significance 200 - 250 → Potential danger 250 - 300 -- Minor public health problem Above 300 → Important public health problem

Explanation: Dengue Hemorrhagic Fever (DHF): Caused by dengue virus (Flavivirus). Clinical features: High-grade fever with chills Macular rash, often starting on the neck and chest Positive tourniquet test (capillary fragility) Hemorrhagic manifestations in severe cases Lab findings may include thrombocytopenia and hemoconcentration . The positive tourniquet test is a classic sign of capillary fragility in DHF . Explanation of Incorrect Options: Malaria (Option A): Fever with chills is common, but rash and positive tourniquet test are absent. Filariasis (Option B): Chronic infection with lymphedema and elephantiasis ; acute fever is rare. Typhoid (Option D): Presents with prolonged fever, rose spots , and gastrointestinal symptoms, but tourniquet test is not positive .