On October 25th 2013, the New York Times published an article that seemed more fitting as a headline 30 years ago than it did today. A polio epidemic, an idea almost unimaginable to a generation shielded by vaccines, was looming in war-torn Syria. Most of us probably don't even remember what polio does unless we tie it to a U.S. history lesson on President Roosevelt. We can reason that this is an unfortunate setback for the global eradication of polio, but what warrants such detailed coverage from the New York Times? The newspaper has since published four more articles specifically on this polio outbreak. With Syria over 5,000 miles away, why should we worry about this vaccine-preventable virus specifically when there are bigger concerns at home like the economy?
The tricky part about viruses is their incredible stealth. While we can use border control and metal detectors to screen for weapons, viruses like polio can easily pass unnoticed -- and with borders becoming more porous with the influx of each new wave of refugees, controlling disease spread is almost impossible. Polio is notorious for its deception. Almost 95 percent of polio infections are "silent," meaning a person may have little to no symptoms when infected. For every one person who is paralyzed by polio, there are anywhere from 200 to 1000 people who are contagious for up to a month. A person can seem perfectly healthy while the virus multiplies in their intestines and is subsequently shed in their stool.
It's the reason why the strain of polio isolated in Syria has also been found in the sewage of the Palestinian territories, Israel and Egypt. Its original sources trekked all the way over from Pakistan with the infected people unknowingly spreading the virus while remaining symptom-free. Prior to this, the entire Middle East was considered polio free with the last reported case in Syria being 14 years ago. Historically, Syria boasted some of the highest immunization rates in the region with over 90 percent of its population vaccinated. The recent turbulence created the perfect storm for the virus's reintroduction: the country's immunization rate fell below 68 percent, with much of the affected population children under the age of five who inevitably missed vaccinations after becoming refugees.
But Syria is a unique problem with a substantial amount of civil unrest!
Syria's neighboring countries have been working hard to keep immunization rates high enough to prevent a regional polio epidemic in spite of the influx of Syrian refugees to these countries. However, immunization programs aren't perfect, and the disease burden rests heavily on those too young to have been completely vaccinated. In response to this new problem, the World Health Organization (WHO) plans to supersaturate the entire Middle East with the polio vaccine regardless of prior immunization status to rid the region of polio's presence entirely. It's a monumental task requiring the vaccination of 23 million children against polio in Syria and neighboring countries as part of WHO's mass polio vaccination campaign.
Fine, it's a big deal across the Atlantic, but the Middle East is still so far away from me. Why should I care?
The reality is that polio anywhere in the world can be reintroduced into the U.S. The movement to eradicate polio was on the brink of completion with less than 250 cases reported worldwide in 2012, compared to over 350,000 worldwide cases in 1988 (WHO). Even 300 cases a year, with 285 of those cases being silent carriers, allows polio plenty of opportunity to migrate to new areas and seek out vulnerable populations. To add insult to injury, it could take up to one year of silent transmission in a new area before someone infected with polio develops paralysis and an outbreak is recognized.
The U.S.'s standard routine immunization regimen still covers polio, meaning most of us are still protected from the virus. This not only helps those immunized, but also increases protection for America's remaining vulnerable population by disrupting the chain of infection and decreasing the likelihood of interaction with an infectious person. Two populations in the U.S. are exceptionally vulnerable to polio: those who abstain from vaccinations and those with compromised immunity, as they have a sub-optimal response to the vaccine. The U.S. already has a precedent for outbreaks of viruses in communities with a high number of abstainers. Just this past August, an outbreak of measles in Texas was tracked down to a person who had recently been overseas. Over 20 unimmunized people contracted measles from the infected person, following a national rise in a virus that had essentially disappeared after the development of vaccines.
So what comes next?
The World Health Organization has recently announced that over 20 million children need to be vaccinated throughout the Middle East. The one-time vaccination campaign will take anywhere from six to eight months to complete and will require over 50 million doses of vaccine. This complex task, only complicated by the regional strife, stands as the only solution to preventing the spread of this crippling disease. The ultimate goal is to ensure that this preventable disease does not ravage the future of the Middle East by paralyzing the future of the youth. And with countries like India reaching a milestone of 3 years since the last reported case of polio, we are hopeful that eradication of this disease is within reach.
The authors are thankful for the mentorship and input of Dr. William Schaffner, Immediate Past-President, National Foundation for Infectious Diseases and professor of infectious disease at Vanderbilt University School of Medicine.