National Geographic News
A polio victim living in Uganda.

A Sudanese refugee and polio victim living in an orphanage in Uganda.

Photograph by Stephen Alvarez, National Geographic

Diane Cole

for National Geographic

Published August 14, 2013

The finish line for eradicating polio worldwide can seem like a weary marathoner's mirage.

The distance traveled is immense: The disease is now endemic in only three countries around the globe—Afghanistan, Nigeria, and Pakistan—and its incidence has decreased by more than 99 percent from an estimated 350,000 cases in 1988. (Endemic is the term used to describe countries with an ongoing incidence of the disease.)

But we're not quite there yet, as this year's spring outbreaks in previously polio-free Somalia and Kenya reminded us. In addition, the discovery of sewage samples containing poliovirus in Israel has led to a countrywide campaign to offer oral polio vaccines to children between the ages of four months and nine years, as a precaution.

No cases have appeared in Israel. And the numbers of those affected in Somalia and Kenya are small—110 as of August 7—with 177 reported cases worldwide so far this year, according to data from the Global Polio Eradication Initiative, an international group spearheaded by the World Health Organization (WHO). In April the group issued a detailed strategic plan to eliminate polio "for all time" by 2018. Fully funded, the comprehensive vaccination and monitoring and surveillance plan would cost about $5.5 billion.

But in the meantime, this highly infectious nerve disease persists, potentially causing lifelong paralysis in the young children it most often targets.

Why has the end remained elusive, and what is being done to protect against future setbacks?

Polio in Perspective

It's important to remember there is no cure for polio; it exists only in humans, and it can only be prevented by vaccination, points out Dr. Jay Wenger, director of the polio eradication program at the Bill and Melinda Gates Foundation. Put those factors together and it means that "to eradicate polio we essentially have to vaccinate enough children so that the poliovirus has no place to go," he says.

In the United States, effective vaccine campaigns have kept the population polio free since 1979. But as recently as the late 1940s and early 1950s—before the anti-polio vaccines were developed—the disease disabled approximately 35,000 people, many of them children, here each year.

By contrast, between 1988 and today, the number of polio-endemic countries has gone from 125 to just 3, and in 2012 only 223 cases were recorded worldwide.

Given that larger picture, "it's important to put the issue of setbacks into the context of the program and recognize that progress continues," says Dr. Hamid Jafari, director of the WHO's Global Polio Eradication Initiative. Or, as Dr. Wenger puts it: "These outbreaks highlight the importance of eliminating the virus" in the remaining endemic countries.

Logistics, Logistics, Logistics

Vaccines are the answer. The challenge lies in identifying, locating, and then reaching people of all ages who have not yet been vaccinated. For example, highly mobile groups, such as Nigeria's nomadic livestock herders, may spread the disease as they travel from place to place. (According to the WHO, the polio strains affecting residents of the Horn of Africa originated in West Africa.)

At the same time, armed conflict, political unrest, and what Dr. Jafari calls "complex geopolitical situations" can make access by vaccine workers at times dangerous or difficult, if not impossible. Such conditions are present in parts of all three countries where polio still exists, making different pockets or areas insecure for efficient vaccine delivery at different times. Public health infrastructure can also be spotty, if it exists at all.

Because each area can present a distinct set of obstacles, detailed and tailored strategies need to be worked out for each situation, including partnerships with local authorities, community groups, traditional leaders, and non-governmental organizations (NGOs), says Dr. Jafari.  "Fundamental commitment to the program from the top of the government down to the local authorities" is needed if everyone is to be vaccinated.

Resistance, Distrust, and Violence

Mistrust of outsiders is another major obstacle, brutally dramatized by the targeted killings of polio vaccine workers in Nigeria and Pakistan over the past year. In Pakistan's North and South Warziristan, the Taliban have banned vaccination since June 2012, leaving children without immunity and at high risk for the disease.

Dr. Jafari is stoic, but not despairing. "As long as there are authorities on the ground and mothers who want to protect their children," there is a way to make progress, he says. "That is why, despite the shootings, the people come out with their children to get them vaccinated ... and these brave men and women are going out in their communities to vaccinate" the children.

Environmental Vigilance

Beyond vaccination, surveillance and monitoring the presence of the virus in the environment are essential to eradicating polio. It's not known how the virus was carried to Israel, which detected poliovirus in sewage samples starting in February 2013. According to the WHO, the strain in Israel is related to the South Asian cluster of wild poliovirus currently circulating in Pakistan, which had recently also been detected through environmental sampling in Egypt.

The current oral vaccine campaign in Israel—which is polio free and has a very high rate of immunization—is a safeguard, a direct response to the detection of poliovirus in its sewage. The goal of Israel's vaccine campaign is to boost immunity levels even in children who have already received the injected vaccine, as well as to protect against further spread to anyone traveling in or out of Israel.

Setbacks on the Radar

Against the backdrop of all these issues, the setbacks in Kenya and Somalia show how quickly and far poliovirus can travel, and demonstrate the importance of maintaining high immunity levels within populations and the need for strong surveillance to halt its spread.

According to Dr. Jafari, such setbacks will happen "as long as the virus is alive and people are moving with the virus, and it will spread as people move. And when it lands in places where immunization and sanitation are not in place, that is where the setbacks will take place."

The key is being prepared to deal with them, while continuing to move forward. "We're on track, and we'll deal with these outbreaks. They are not obstacles; they are part of the course."

Sally Edelstein
Sally Edelstein

Aging boomers still have childhood memories of a summer time fear of polio when sun drenched summer was open season for the dreaded disease. Read more about pools, polio and a mid century miracle


Samaila Mera
Samaila Mera

It is myopic to generalise and target Islam as the sole reason why the world is still battling with the scourge of poliomyelitis , resistance to vaccination exists the world over including in the most advanced countries . To accept or reject a vaccine is an individual decision ,the religion of Islam supports and encourages prevention as the best form of cure. It also preached that for every disease their is a cure except old age some through preventive measures (vaccinations..etc)and others through consultations with people God has blessed with the knowledge of a cure. Please don't comment on issues you have no knowledge about many Muslims are working hard to eradicate the virus from our planet and feel strongly about what they do.

Johnnie Dorman
Johnnie Dorman

I am one of those 35,000 kids that caught the polio virus, my infection occurred in 1955, I was only ten months of age. My family lived in Southern California at the time, and lucky for me, it only paralyzed my right arm and shoulder before my body finally managed to overcome it. This is one of the reasons I despise fools like those that are part of the Taliban. There is no evil worse than the enabling of a disease like Polio. I personally give thanks to Dr. Sulk, who discovered the inoculation, and Shriner's Hospital for crippled children here in Los Angeles and in Shreveport Louisiana. Shriners Hospitals and their doctors gave me back the use of my right arm. Their doctors are, and always have been, geniuses.

ED Roche
ED Roche

In large part the great success we've had in minimizing Polio has been due to Rotary International's funding of global erradication programs, joined more recently by Bill Gates. Rotary International's deep involvement for decades should have been investigated and reported on.

Barm Krauesen
Barm Krauesen

Be honest.  The statement "Mistrust of outsiders is another major obstacle, brutally dramatized by the targeted killings of polio vaccine workers" is a total lie of omission.  It is exclusively Islamic communities that are behaving this way.  If it wasn't for Islamic policies, polio would have already been eradicated.  Sects of muslims want polio to infect children.  At this point in time, polio should be a disease synonymous with Islam.  It is one of the only things Islam is providing to the world.

Barm Krauesen
Barm Krauesen

@Samaila Mera The Taliban executed 6 aid workers in Afghanistan yesterday.  Doctors Without Borders just had to exit Somalia because they were being executed by muslims.  It may not be all Islamic countries; but you can't seriously be claiming that Islam is all about vaccinations while Islamic groups run about executing all people in their region offering vaccinations.

Johnnie Dorman
Johnnie Dorman

@Barm Krauesen I agree with you, Barm. Makes me wish each of those Taliban (explicative) fools would get a good dose of the disease. Ignoramus creeps. Some place below hell is where they belong.


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