Syrian polio outbreak delivers blow to eradication hopes
The World Health Organisation has warned that an outbreak of polio in war-torn Syria is likely to spread through neighbouring countries as millions flee the bloody conflict.
The WHO has confirmed the presence of wild poliovirus type 1 in 10 young children, who were part of cluster of 22 cases of acute flaccid paralysis detected in the country’s east.
It is the first appearance of the disease in Syria since 1999, and has accompanied a huge decline in immunisation rates from 81 per cent to 68 per cent since violence erupted more than two years ago.
Syrian health authorities have launched a campaign to vaccinate 1.6 million children against diseases including polio, but efforts to boost immunisation rates are being severely hampered by the country’s bloody civil war, which is estimated to have claimed the lives of at least 115,000 people and displaced millions more.
The WHO warned of a high risk that the disease will spread across the region, delivering a big blow to hopes that it was on the verge of being eradicated like smallpox.
“Given the current situation in the Syrian Arab Republic, frequent population movements across the region and subnational immunity gaps in key areas, the risk of further international spread of wild poliovirus type 1 across the region is considered high,” the WHO said. “A surveillance alert has been issued for the region to actively search for additional potential cases.”
Writing in The Conversation, Professor Michael O’Toole of the Burnet Institute said the big surprise about the outbreak is that the point of origin may be Israel.
Professor O’Toole said that since February more than 100 samples of sewage from central and southern Israel, as well as from Gaza and the West Bank, had tested positive to the polio virus.
He said a recent study suggested up to 5 per cent of Bedouin children carried the virus, but because immunisation rates in this community were high, children did not show symptoms of the disease.
But it is highly contagious, and Professor O’Toole speculated that the mobile Bedouin population may be helping spread the disease across countries in the region.
Before the latest outbreak, there were hopes the disease was well on the way to being eradicated.
The number of polio cases worldwide plunged by 99 per cent between 1988, when there were 350,000 infections, and 2012, when just 223 cases were reported worldwide.
But Professor O’Toole said the disease had made a disappointing comeback since then, with 332 cases registered so far this year – an increase of almost 50 per cent from 2012 – including 180 cases in areas of Somalia under the control of Islamic militants Al Shabab, who have banned vaccinations.
He warned that the documented reservoir of the disease in Israel posed a risk for unvaccinated people who visited the area or came into contact with people from the area, including Australian children who had not been vaccinated because of the objections of their parents.