This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
[{'content': 'All of the following statement regarding measles are true except -a) Rash appears first on legb) Koplik spot are seen on retinac) Long term complication may be seen in form of SSPEd) Caused by RNA viruse) I-P is 2-3 days \nSelect and explain. \nA. abc, B. bcd, C. cde, D. abe', 'role': 'user'}, {'content': "Answer: D \nExplanation: Measles\xa0\n\nMeasles is caused by a RNA virus of paramyxovirus.\nMeasles in also known as rubella\nThe only source of infection is a case of measles, carriers are not known to occur.\nInfective period\xa0→\xa04 days before and 5 days after the appearance of rash.\nInfective material\xa0→\xa0Secretions of nose, throat and respiratory tract\nAge group\xa0→\xa06 month to 3 years.\nImmunity\xa0→\xa0One attack of measles generally confers lifelong immunity.\xa0\nTransmission\xa0→\xa0\n\n\nDroplet infection through respiratory tract\nInfection through conjunctiva.\n\n\nIncubation period\xa0→\n\n\n10 days from exposure to onset of fever.\n14 days from exposure to appearance of rash.\n7 days for live vaccine of measles.\n\nClinical manifestations\n1) Prodromal stage\n\nBegins 10 days after the infection and lasts until day 14.\nCharacterized by fever, coryza with sneezing and nasal discharge, redness of the eyes, lacrimation and photophobia.\nA day or two before the appearance of rash, Koplik's spots appear on buccal mucosa opposite the 1st and 2nd lower molars.\nKoplik's spots are pathognonzonic of measles.\n\n2)\xa0\xa0\xa0 Eruptive phase\n\nMaculopapular rash which begins behind the ear and spread rapidly in a few hour over the face and neck extends doWn the body.\n\n3) Post measles stage\n\nWeight loss \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0\nGrowth retardation \xa0 \xa0 \xa0 \xa0 \xa0\nDiarrhea\nCancrum oris\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\nReactivation of pulmonary TB\xa0\xa0\xa0\xa0\xa0\nCandidiasis", 'role': 'assistant'}]