In eastern Syria, a recent outbreak of polio has left at least 10 children paralyzed, reports NBC News.  Though a localized outbreak is a public health concern on its own, experts are more alarmed by the threat of a global epidemic.  Currently, there are large numbers of Syrian refugees fleeing the region.  As they move to Europe and other developed areas that have been polio-free for decades, they may be bringing the infection with them.

Poliomyelitis, or polio for short, is a viral disease that affects the nervous system, reports the New York Times.  Polio is caused by the poliovirus, which spreads through person-to-person contact, contact with infected phlegm or mucus, and contact with infected feces.  Between 1840 and the 1950s, polio was a worldwide epidemic, but has been largely eradicated after the development of polio vaccines.  Now, polio is endemic only to a few countries in Africa and Asia.

According to MedlinePlus, the majority of people with polio do not have symptoms.  Those that do will likely suffer flu-like symptoms.  Severe cases result in paralysis that cannot be reversed.  Polio may be fatal.  Individuals that have had polio in the past may later develop post-polio syndrome, which includes tiredness, muscle weakness, and pain in joints and muscles.  There is currently no cure for post-polio syndrome.

Given the asymptomatic nature of polio infection, only 1 in every 200 people infected are easily identified.  Without well developed surveillance and diagnosis programs, these refugees coming from Syria may be carrying and spreading the polio virus without even knowing it.  After a period of time, a paralysis case in Europe, for example, would be identified as polio. Unfortunately, it would be too late then and hundreds would already be infected and have been spreading the virus to others.

This is not the first time that polio has been associated with refugee camps.  The Washington Post reported an “explosive outbreak” of the disease in Somalia and in a Kenyan refugee camp filled with Somalis.  Health officials have limited access to children in areas of Somalia controlled by an armed Islamist group.  Since Somalia was removed from the list of endemic countries in 2001, it has had two outbreaks of polio.  Also, earlier this year, Israel launched a polio booster campaign, offering additional vaccination for children under the age of nine, reports ABC News.  The campaign was a response to a strain of the virus being found in sewage in southern Israel, causing concerns about public health.