Porcine Parainfluenza Virus 1 (PPIV-1)

We all know that pigs are an efficient reservoir for all sorts of viruses. New stains of influenza frequently originate in pigs and the animals function as a ‘mixing vessel’ where different versions of existing viruses mix and evolve. But influenza is not the only family of potentially lethal viruses that pigs can harbour.

A recent study[1] describes a novel parainfluenza that has been identified in 12 of 386 dead pigs from Hong Kong. The novel parainfluenza virus has been given the name porcine parainfluenza virus 1 (PPIV-1).

Human Parainfluenzaviruses (HPIVs) are the cause of a number of known human diseases. There are four distinct types of HPIVs and two subtypes that circulate at different times of the year. HPIV-1 infections often cause croup in children. There are usually more cases in the fall of odd-numbered years. HPIV-2 infections can also cause croup. HPIV-2 infections occur more commonly in the fall. It is less frequently detected than HPIV-1 and HPIV-3. HPIV-3 infections usually occur in spring and early summer months each year. However, HPIV-3 infections can occur throughout the year, particularly when HPIV-1 and HPIV-2 are not in season. HPIV-4 (subtypes 4a and 4b) seasonal patterns are not as well characterized.

[Image: www.drugline.org]

According to an interview in the South China Morning Post[2], researchers believe this novel parainfluenzavirus has been circulating in pigs for some time. Dr. Yuen: “The new virus is closely related to some human influenza viruses. We should watch for possible cross-species transmission from pigs to humans, just as in the case of [human] swine influenza H1N1”.

The scientific article states that this novel porcine virus is most closely related to human parainfluenza virus 1 (HPIV-1) and the Sendai virus (SeV), which primarily affects mice, but can also infect hamsters, guinea pigs, rats, and (rarely) pigs.

Nature is playing Macbeth: Round about the cauldron go; In the poison'd entrails throw.

[1] Lau et al: Identification and characterization of a novel paramyxovirus, porcine parainfluenza 1 virus, from deceased pigs in Journal of General Virology - 2013
[2] Article in South China Morning Post here.