Dec 18 2013
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Where Polio Remains a Threat: Q&A with Sona Bari, World Health Organization

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While it has been decades since polio was a critical threat for much of the developed world, the disease—a virus that can spread from person to person and affect the brain and spinal cord with the potential for paralysis—still causes disease and death in the developing world. Earlier this year cases were reported in Syria, while in Israel the polio virus was found in soil likely from human waste infected with the disease, prompting a revaccination campaign among children age 5 and under. Polio has continued to spread in Afghanistan, Nigeria and Pakistan, and has been reintroduced and continues to spread in Chad and in the Horn of Africa after the spread of the virus was previously stopped. Other countries have seen small numbers of cases recently after no cases for decades.

Because even a small spread of the disease could reach the United States if infected individuals carry the virus here, the U.S. Centers for Disease Control and Prevention (CDC) several years ago made polio one focus of their Emergency Operations Center. CDC staff work with the World Health Organization and foreign health departments on vaccination campaigns aimed at fully eradicating the disease.

>>Bonus Content: View the CDC's infographic, "The Time to Eradicate Polio is Now."

NewPublicHealth spoke recently with Sona Bari, senior communications officer at the World Health Organization about the efforts underway to eradicate polio globally.

NPH: How are you able to detect polio outbreaks?

Sona Bari: We have a global surveillance system for polio and know from it that since 1988 the reduction of the disease has been over 99 percent. Polio is now endemic, which means indigenous polio virus transmission has never been stopped in parts of three countries: Nigeria, Afghanistan and Pakistan. So the surveillance is important because you can get polio down to very low levels like you do now, but it can reemerge. To completely eradicate polio you have to have an effective intervention, which is largely by vaccination. And you can be bring polio under very tight control by massive vaccination, but the virus is very good at finding children who are unvaccinated or under-vaccinated, and in Nigeria, Afghanistan and Pakistan we still have large groups of unvaccinated children. So the reason that polio transmission has not been stopped in these areas is that not enough children are vaccinated.

NPH: Why is there insufficient vaccination in those countries?

Bari: The basic reason is the quality of vaccination activities. Do these countries have decent health systems—strong routine immunization systems where children are regularly taken to a medical facility for their immunizations? When there are mass vaccination campaigns, are we reaching all children? Then there are, on top of that, layers of political complexities. In one part of Pakistan, for example, there is a ban on polio vaccinations by the local warlords. So there are access and security issues, layered on top of the difficultly of reaching all who need vaccines in countries such as Nigeria or Pakistan. That said, we know that these circumstances are not unique. They may differ from country to country, and each country does have a unique combination of the obstacles, but polio has been eradicated in countries that are far poorer than Nigeria or Pakistan, that have had worse conflict and that have perhaps much worse health systems. So it can be done.

NPH: What are some of those countries?

Bari: Bangladesh, the Democratic Republic of the Congo and El Salvador during that country’s civil war. So the question really is finding a combination of solutions that work for that country, and we’re now operating under a strategic plan for 2013 to 2018 which looks at the specificities of these countries and how we can address some of the obstacles. For example, in Nigeria we know that in the northern states health systems are very weak, and to improve vaccination rates we need to bolster that with a surge in capacity by getting greater local ownership, so the parents will demand it of their health authorities and help them become advocates in their communities to speak against people who might oppose vaccination. We also have to help make sure that donors are getting money in on time. These are all some of the ways of addressing the very last bastions of polio virus.

NPH: When polio emerges in a country, what are the mechanics of the spread?

Bari: Let me explain that using the example of Tajikistan, which is on the eastern edges of Europe in central Asia. Tajikistan, for a number of reasons, had very poor immunity, so a large number of children had not been properly vaccinated. Contributing factors were that health systems were not functioning properly once the country was plunged into a lot of turmoil after the breakdown of the Soviet Union. Polio can travel in the intestinal region of any person who’s infected, but only one in 200 people will actually be paralyzed by polio. It travels quite silently, so I might be going to Tajikistan and taking the polio virus with me and shedding it through waste and into the environment and infecting people—but I will not be affected.

Now when polio travels to a country like the United States or Australia—which it has in the past 10 years—it might cause a case or two or no cases, because these countries have very high population immunity. However, when it lands in Tajikistan or in the Congo it can devastate the population.

In Tajikistan we had 400 cases, in the Republic of Congo we had about 100 cases, and half of those who contracted it died because in the Congo the virus found and attacked adults, who have a much higher rate of mortality than children do from polio; children more commonly become paralyzed.

So when we saw that sewage in the Middle East had evidence of polio virus in the past 12 months, immediately alarm bells were rung. We issued an international health alert immediately under what we called Disease Outbreak News at the WHO, and the reason that we sounded that alarm was that if it was in the sewage it was only a matter of time before we would start seeing children paralyzed. And sure enough, Syria, located in the same region, which has had its vaccination system and its health system overall suffer the most over the past couple of years, had a large number of unvaccinated children and these are children who were infected and are now paralyzed.

While the virus landed in the sewage system in Israel, it hasn’t caused cases because they have pretty good immunity. Unfortunately in Syria that’s not the case, so it’s Syrian children who have fallen victim to this.

The virus in the Middle East came from Pakistan, and the virus in the Congo was of Indian origin, so the virus can travel quite far. We’ve had a virus of Nigerian origin with more than 400 cases in Indonesia in 2005.

NPH: Who does the WHO partner with in its efforts, particularly in cases of countries where you won’t necessarily get assistance from the government?

Bari: The most critical partner is Rotary International, the partner that launched the eradication effort. They are a service organization and funded polio vaccination campaigns in the Philippines and realized through the Philippines and other countries in the region that, in fact, transmission of the virus could be stopped entirely. So they came to the WHO and UNICEF to work together on eradication efforts worldwide. And the World Health Assembly, the governing body of the WHO which is made up of the departments of health of all the governments of the world, launched a global polio eradication effort. So Rotary is very important for a number reasons: They had the founding vision and they are the foot soldiers. There are Rotarians in almost every country in the world who actually carry out vaccination campaigns as volunteers and rally their communities at the grassroots level. But many Rotarians are also important business people. They have a voice with their governments where they can advocate with, say, the government of Nigeria or the government of India to say we need to put more resources into this because essentially polio eradication programs are carried out by governments. WHO and UNICEF are just supporting them. The workers on the ground are government workers, plans are government plans.

So you need the government behind this. Nothing can be done if the government of Chad doesn’t decide it’s going to eradicate polio in Chad, for example. The other partners in this initiative are WHO, the U.S. Centers for Disease Control and Prevention (CDC)—the CDC works very closely with WHO on technical expertise—and UNICEF. UNICEF’s role is important because they purchase vaccines for the United Nations system and work with the community to answer questions such as: Why do we need a vaccination? What are the benefits of this vaccine? How can I get my child vaccinated? We call that “social mobilization” and UNICEF supports the governments in that. Those are really the key partners, and one additional important partner in recent years has been the Bill and Melinda Gates Foundation, both as a donor and a very credible voice that vaccination is one of the best buys that you can get in public health.

NPH: What are secondary benefits of the vaccination campaigns?

Bari: There are a number of them, including disease surveillance. The polio surveillance system has been used to detect outbreaks such as measles, avian influenza and Ebola. But probably much more important to health systems is the way in which the polio eradication infrastructure has strengthened immunization systems through capacity building. Polio personnel and people trained through the polio eradication system strengthen a country’s capacity and health force, both in terms of how to manage a health system or program and how to monitor. Monitoring is an important part of what you do during a polio vaccination campaigns, so that’s a capacity that’s being built through the polio eradication system. In India, monitoring the giant workforce that was built to mobilize the country for polio eradication is now being used for routine immunization in general.

Another critical benefit is what we call micro planning in public health, which is literally the household by household’s planning of a health intervention because polio vaccination has to go door to door and it has to be delivered family to family. You need very micro-level maps of the community; you need to know where the local church or mosque is and how many houses lie to the left it and how many houses lie to the right of it, and who lives in that bog down in the valley. Those kinds of micro plans are essential to delivering any health intervention to those who are most under reached.

And that segues into what I think is the biggest benefit of polio eradication which is that in addition to eradicating a disease from the world, the process has shown us ways to reach the most vulnerable and the most unreached. The lasting legacy of polio eradication is that last nomadic child in the Lake Chad region, that religious minority in the northern Netherlands, the children who are overlooked, the populations who are not reached, who are very vulnerable to disease. Polio has shown a way to reach those people and I think that is a path that’s been laid now that can be used and hopefully harnessed for the future of global public health.

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Tags: Infectious diseases, Prevention, Q&A, Infectious disease, Global Health, Vaccines