What is the Difference Between Orthomyxovirus and Paramyxovirus?

Orthomyxoviruses and Paramyxoviruses are two groups of RNA viruses that cause respiratory tract infections. The key differences between them are:

1. Genome Structure: Orthomyxoviruses have a segmented RNA genome, with 8 RNA pieces, while Paramyxoviruses have a non-segmented RNA genome.
2. Size: Orthomyxoviruses are smaller (80 to 120 nm in diameter), while Paramyxoviruses are larger (150-300 nm in diameter).
3. Virion Surface Spikes: Orthomyxoviruses have Hemagglutinin (H) and Neuraminidase (N) in different spikes, while Paramyxoviruses have both H and N activities in the same spikes.
4. Reproduction: Orthomyxoviruses are replicated in the nucleus, while Paramyxoviruses are replicated in the cytoplasm.
5. Antigenic Variation: Orthomyxoviruses undergo antigenic shift (through genetic reassortment), while Paramyxoviruses do not.

Some examples of Orthomyxoviruses include Influenza A, B, and C viruses, while Paramyxoviruses include Human and animal parainfluenza viruses, Measles, Mumps, and Respiratory Syncytial Virus (RSV). Both groups of viruses are enveloped and have a helical-shaped protein capsid. They transmit via aerosols and cause similar respiratory tract infections.

Comparative Table: Orthomyxovirus vs Paramyxovirus

Here is a table comparing the differences between Orthomyxovirus and Paramyxovirus:

Orthomyxovirus and Paramyxovirus are both single-stranded RNA viruses that cause respiratory tract infections. The key difference between them is that the genome of Orthomyxovirus is segmented, while the genome of Paramyxovirus is non-segmented. Additionally, Orthomyxovirus is smaller in size compared to Paramyxovirus.