Thursday, January 22, 2015

A New Polio Case in Pakistan and an Unsolved Epidemic




Time to check in on another globe-spanning epidemic. While we were all watching Ebola, polio continues—and as long as it does, it holds the possibility of surging back over the rest of the world.
A quick refresher: Polio has been the target of a very expensive and aggressive multi-national eradication campaign since 1988. By last summer, polio was endemic—that is, transmission from one person to another has never been interrupted—in Afghanistan, Pakistan and Nigeria. Very high rates of vaccination have kept the paralyzing disease from leaking over those countries’ borders to most of the rest of the world—but every once in a while, something slips through, or a country runs out of money and lets its vaccination campaigns lapse.
As a result, last year, there was still polio in seven other countries — Cameroon, Equatorial Guinea, Ethiopia, Iraq, Israel, Somalia and Syria—and the World Health Organization declared an international emergency.
So, updates: Despite its ongoing civil strife, Syria has not had a polio case in a year. There has been no detection of polio virus in sewage in Israel or the West Bank or Gaza since March. It has been almost 6 months since the last polio case in Nigeria—extremely good news because that country has periodically re-infected other areas of Africa.
But: Pakistan remains a problem.
In 2014, Pakistan recorded its highest number of cases of any country in the world, and also the highest number since it began its eradication campaign 15 years ago. There were 297, and epidemiologists estimate that there are 200 undetected infections for every case that is diagnosed.
In addition, the country was forced to cancel its first national vaccination drive of this year, because of threats polio workers would be shot by extremists. The Taliban is opposed to vaccination, casting it as a Western intrusion into Islamic affairs; since 2012, according to the BBC, more than 60 members of vaccination teams, or their guards have been murdered.
And this morning, according to the Pakistani paper The News International, thefirst polio case of 2015 has been diagnosed in Sindh province, in a 1-year-old child.
Among the endemic countries, Pakistan is clearly now the major challenge — more of one than Nigeria was, even though Nigeria in its worst outbreaks had more cases. I say that because the barriers to vaccination in Nigeria depended on internal sectarian politics. The children who were not being vaccinated were always technically reachable by vaccinators, once local communities decided to let them in; and there was never a threat to the lives of the vaccination teams. In Pakistan, though, the conflict is bigger than one party versus another, and the areas where children are not being vaccinated are literal no-go zones.
Meanwhile, the performance of the vaccination teams remains poor, the equipment they are using seems unreliable, and there are frequent suggestions of corruption. As BBC Asia said last week, quoting a regional polio official:
In an ideal world – where all of the population is accessible, vaccinators are not cheating on numbers, a perfect cold chain is maintained and at least 90 percent of the 40 million or so children are inoculated repeatedly during five to six monthly campaigns – Pakistan can eradicate polio in half a year, says Dr Imtiaz Ali Shah, the chief minister’s focal person on polio in the province of Khyber Pakhtunkhwa.
But there’s a technical hitch. “Most of our infected children are zero-dose — children who have never had OPV drops before,” he says.
“When we are able to restrict the incidence of polio to only those children who’ve had multiple doses of OPV and were infected only due to low immunity, we can then say that we are close to victory.”
In the meantime, the WHO continues to recommend that anyone within Pakistan who is leaving the country should be required to accept a polio vaccination on the way out, or be prevented from leaving. That was the organization’s emergency recommendation last summer, and it is still in force — though it is an open question how well it is being respected, since emergencies never stay “emergent” for long. Given the other successes last year, it looks at this point as though Pakistan might be the last hold-out of polio. The country may have to ask itself whether it wants to be responsible for returning the disease to the world.

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