Murine Parainfluenza Virus-1 (MPIV-1)

Murine Parainfluenza Virus-1 (MPIV-1) is perhaps better known as Sendai Virus (SeV). The virus is closely related to other parainfluenza viruses, such as Human Parainfluenzavirus-3 and Bovine Parainfluenzavirus-3. It is responsible for a highly transmissible respiratory tract infection in mice, hamsters, guinea pigs, rats, rabbits and occasionally pigs and monkeys[1].

The infection passes from one animal to the other through both air and direct contact routes. The virus can be detected in mouse colonies worldwide, generally in suckling to young adult mice. In laboratories around the world, infection in mice is perpetuated by the introduction of susceptible animals, which will become infected by the animals in the colony that are already infected. Infections of mice are usually associated with a high mortality rates, while surviving mice have long-lasting immunity.

Human Parainfluenzavirus-3 causes several respiratory diseases in humans, but no signs of disease were detected in experimentally infected mice. Murine Parainfluenza Virus-1 has never been reported to cause humans disease, in spite of abundant human exposure to infected mice and mouse colonies. The virus might never have infected human, but the fact remains that these viruses have adapted to different host ranges but they may recombine in the near future to create a novel virus and nobody knows when and where that will happen. Or how lethal it may become.

In 2008 a novel subtype of Murine Parainfluenza Virus-1 was discovered[2]. Research indicated that the Tianjin strain represented a new evolutionary lineage of MPIV-1. As Sherlock Holmes would say: 'The game is afoot.'

[1] Skiadopoulos et al: Sendai Virus, a Murine Parainfluenza Virus Type 1, Replicates to a Level Similar to Human PIV1 in the Upper and Lower Respiratory Tract of African Green Monkeys and Chimpanzees in Virology - 2002
[2] Shi et al: A new paramyxovirus, Tianjin strain, isolated from common cotton-eared marmoset: genome characterization and structural protein sequence analysis in Archives of Virology - 2008