A mystery virus has provoked reports in California, in what appears to be a cluster of cases of viral paralysis, caused possibly by Enterovirus, which appears to have effects similar to poliomyelitis, or Polio, namely paralysis, in some cases in all four limbs.
The Polio virus, or Paralytic Poliomyelitis virus, is one of several Enteroviruses, and these attack and infect up to 50 million people every year in the United States of America, most frequently causing mild symptoms. However, more chronic conditions can appear and remain in the body for years.
The Enterovirus is small, can be highly contagious and is composed of Ribonucleic Acid (RNA) and protein. This, the cousin of Poliomyelitis, is the most likely cause of the disease identified in California, which t o date has affected around 20 people.
While doctors agree that the number of cases does not point towards a generalized outbreak and stress that the risk of infection is rare, it is also true that the American Academy of Neurology has been informed of some more serious cases, in which patients have lost the use of all four limbs and do not respond to treatment.
The new infections in California have appeared over the last eighteen months and have mainly affected children. Analysis of five cases shows the presence of Enterovirus-68 - and all of the children had received the Poliomyelitis vaccination. The cluster of infections is restricted, to date, to an area 160 kilometres (100 miles) in diameter. There have been similar cases registered in Asia.
Curiously, Enterovirus-68 was isolated in California in 1962, from four patients (children) with respiratory illness. The number of cases has been extremely rare since then: 12 additional cases from 1989 to 2003. Enterovirus-68 has common biological features with enteroviruses and rhinoviruses.