Polio virus spreads from Syria to IraqBMJ 2014; 348 doi: https://doi.org/10.1136/bmj.g2481 (Published 02 April 2014) Cite this as: BMJ 2014;348:g2481
Iraq has reported its first case of poliomyelitis for 14 years, amid concern that the disease cannot be prevented from spreading beyond Syria and throughout the Middle East.
Laboratory testing has confirmed a case of wild poliovirus type 1 (WPV1) in a 6 month old Iraqi baby living in the outskirts of Baghdad. The disease is the same strain as that in cases reported in Syria last October in a poor and largely rebel held eastern region that shares a long border with Iraq.
“It is a huge blow, because for 14 years Iraq has been polio free,” said Syed Jaffar Hussain, head of mission for the World Health Organization (WHO) in Iraq.
So far 38 cases of polio have been confirmed inside Syria, and tests have confirmed that the virus was brought into the country from Pakistan.
A single confirmed case indicates a wider problem, because for every case of polio that leads to paralysis WHO estimates that another 199 infected children are carrying the virus and spreading it undetected. On the basis of this assumption WHO has estimated that there might be 7600 infected children.
But some experts have estimated that there could be up to 1000 infected children for each child that developed symptoms, and they said that a high proportion of the 100 children in whom acute flaccid paralysis has been diagnosed could have polio.
Polio spreads through contaminated water and food and thrives in unsanitary, crowded areas and among malnourished children. Determined efforts over the past 25 years to eradicate the disease worldwide by vaccinating all vulnerable children have succeeded in making 80% of the world free of polio, the United Nations announced on 14 March. India, once renowned for having perhaps the greatest polio burden, is the latest country not to have reported a single case for three years (the requirement in order to be declared polio free).
The disease is now endemic only in three countries, Afghanistan, Pakistan, and Nigeria, in all of which vaccination programmes have been disrupted by conflict.
But the Syrian outbreak and an outbreak in the Horn of Africa threaten the progress of the campaign that began in 1988, when there were 350 000 cases of polio across 125 countries.
What makes the Syrian threat particularly frustrating is that the disease seems to have emerged as a result of government vaccination programmes collapsing in areas held by rebels.1 All 38 cases of polio officially confirmed in Syria so far have been in these areas.
Last October the UN launched the biggest ever vaccination campaign in the Middle East, aiming to give all children aged under 5 years in Syria and six other countries (Lebanon, Iraq, Jordan, Egypt, Turkey, and the Palestinian Territories) the oral polio vaccine at least three times (six in Syria). But there is concern that the campaign has not so far reached enough children in Syria enough times, because of security and logistical problems in some areas.
The European Commission has just pledged an extra €1m (£0.8m; $1.4m) to support the ongoing campaign, saying that the money would ensure that 700 000 children who had so far not been vaccinated would be protected.
A WHO spokesman said that the number of children missed so far by the campaign was probably much lower than the 700 000 claimed by the European Commission. Its regional office said that its monitoring indicated that more than 90% of under 5s in all but two districts (Damascus and rural Damascus) had been reached by the most recent vaccination round and that 80% have been reached in those districts overall.
However, the figures cannot be considered definitive, because people monitoring the campaign, like the vaccination teams themselves, cannot get to all parts of the country, and many people are on the move.
Some Syrian and foreign doctors believe the true number of cases of polio in Syria may be much higher than the official 38 confirmed. They have diagnosed around 100 cases of acute flaccid paralysis, but because this can sometimes have other causes (enterovirus 71, Japanese encephalitis, Guillain-Barré syndrome, or Chinese paralytic syndrome) WHO will not accept that they may be polio. It recognises only laboratory tested cases. A recent case of acute flaccid paralysis in Lebanon tested negative for polio.
In a recent report Save the Children warned, “Up to 90 000 children are likely to be infected by polio’s most aggressive form and are silently spreading the disease.”2 The figure was based on calculations by Annie Sparrow, a paediatrician and public health expert at the Icahn School of Medicine, Mount Sinai, in New York city, who has visited the region several times. She said that there may be 1000 undiagnosed cases for every clinically reported case of paralysis—giving a number more than 10 times WHO’s calculation of 7600.
Adam Coutts, a researcher at the London School of Tropical Medicine and Hygiene, said that probably neither figure was correct. He warned that the absence of reliable data on the humanitarian situation in Syria and refugee camps in neighbouring countries was hampering effective targeting of responses to many healthcare needs.
Pakistan, where suspicion of Western inspired vaccination campaigns has led to vaccination workers being killed,3 recently began offering to pay parents in Peshawar, the largest poliovirus reservoir in the world, 1000 rupees (£6; €7.3; $10) for each child who completed vaccinations. As of 1 March India now requires that all visitors from countries where polio is present take the oral vaccine before travelling.
Cite this as: BMJ 2014;348:g2481