True about measles are all EXCEPT?
**Core Concept**
Measles is a highly contagious viral infection caused by the measles virus, leading to symptoms such as fever, cough, runny nose, and a characteristic rash. The measles virus primarily affects the respiratory system and the immune system, causing a range of complications.
**Why the Correct Answer is Right**
Measles virus infection triggers an immune response characterized by the production of IgM antibodies, which can be detected in the blood of infected individuals. The measles virus also affects the lymphoid system, causing atrophy of the lymphoid tissues and a decrease in the number of lymphocytes. This immune suppression makes individuals with measles more susceptible to secondary bacterial infections, such as pneumonia and otitis media.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is a true statement about measles. Measles is indeed a highly contagious viral infection, and the measles virus is primarily spread through respiratory droplets.
**Option B:** This option is incorrect because it is a true statement about measles. Measles virus infection does indeed cause a characteristic rash, which typically appears 3-5 days after the onset of fever.
**Option C:** This option is incorrect because it is a true statement about measles. Measles virus infection can cause a range of complications, including pneumonia, otitis media, and encephalitis.
**Clinical Pearl / High-Yield Fact**
The measles vaccine is a live, attenuated vaccine that provides long-term immunity against measles. It is usually administered in combination with mumps and rubella vaccines as the MMR vaccine.
**Correct Answer:** D