A virus that starts off like the common cold could be responsible for leaving more than 100 children with paralysis. Last summer, more than 1,000 children and teens across the country were hospitalized with symptoms that appeared to be caused by a particularly nasty strain of enterovirus. While some of the children showed only minor symptoms of the virus - such as runny nose, sneezing and coughing - others suffered weakness of the limbs to complete paralysis . Doctors caring for the sick children  connected the illness early on to a pathogen called enterovirus  D-68. A new study published on Monday has strengthened the connection between enterovirus D68 and the sudden paralysis of more than 100 children in the last year . A new study published Monday in the journal Lancet Infectious Diseases backed those initial opinions, after following the progress of 25 children in California and Colorado who experienced paralysis. Enteroviruses are a type of virus that use a single strand of RNA to replicate themselves inside the cells of mammals. Among other enteroviruses are polio, the virus that causes Hand Foot and Mouth disease along with others that cause a range of respiratory illnesses. Enterovirus D-68 is among the most recently idenfitied and was first spotted in California in 1962. It can cause mild to severe respiratory illness and is likely to be spread by inhaling virus particles when an infected person coughs, sneezes, or touches a surface. In previous years only small numbers of EV-D68 infections have been reported but that has increased during 2014, according to the US Centre for Disease Control and Prevention. It has caused severe illness in a number of children and has even been implicated in some deaths. The incidence of infections has fallen off considerably since October but public health officials warn that infections seem to spike during the late summer and autumn. Researchers now suggest that the children were infected with a mutated form of D-68, which first appeared four years ago. B1 has five to six coding differences that make it different from other strains commonly found in the U.S., and that these differences cause nerve-damaging symptoms similar to polio. And like polio, the nerve damage appears to be permanent - since none of the children have fully recovered. 'This is starting to look more like polio unfortunately where the paralysis appears to be permanent or semi-permanent. This is why there is such an urgency for more research to investigate this' researcher Charles Chiu, an associate professor at the University of California, San Francisco, said according to the Washington Post. However, the study has not definitely proved the connection between B1 and the paralyzed children, since researchers could not find the strain in the patients' spinal fluid. The researchers however, theorized that that was because the samples were taken too late. 'This is a virus that causes the common cold,' Chiu told NBC News. 'Parents don't bring their kids in until they are really sick. By that time, typically, the viral levels may be very, very low or undetectable.' They looked for other viruses, bacteria, fungi and parasites that also could have caused the symptoms but none were present. Researchers were also not able to answer another mystery of the enterovirus - why some children only came down with minor symptoms and others lasting paralysis. Included in the study were two siblings that both came down with an 100 per cent genetically-identical strain of the virus in the past year. One of the siblings experienced  paralysis while the other only suffered upper respiratory symptoms. With enterovirus season just a few months away in late summer, researchers are saying it's extremely important that more work be done to unravel the B1 mystery and make grounds to develop a vaccine to fight the dangerous virus. The Children's Hospital Colorado continues to monitor the patients infected with enterovirus, and have even set up a special clinic for the victims.
Researchers now believe mutated strain of enterovirus D-68 caused more than 100 children to suffer sudden paralysis in the last year . The B1 strain first popped up four years ago and has coding differences that make it similar to polio . None of the children monitored in the new study have fully recovered - suggesting the paralysis is permanent .