Polio Response in Africa to Be Fast, Difficult and Possibly Dangerous
The counterattack against resurgent polio in Africa will be rapid, logistically difficult and potentially dangerous, involving millions of doses of vaccine, thousands of vaccinators and the health ministries and militaries of five countries, experts from the World Health Organization and other groups say.
Stopping the disease in Africa is crucial to the high-stakes effort to eradicate it from the world, a campaign that has been pressed for almost 30 years and has consumed billions of dollars.
After two years with no cases in Africa, experts were elated at the imminent taste of victory on the continent, considered the toughest front in the fight against infectious diseases. Those hopes were dashed this week when two new cases were discovered. Now Nigeria rejoins Pakistan and Afghanistan on the list of countries where the disease has not been completely eliminated.
To contain the virus before it spreads out of Borno State in Nigeria, where both paralyzed children were found last month, a first round of vaccinations will begin as early as next week. Five more rounds will take place over the coming months in ever-widening circles that ultimately encompass the entire Lake Chad basin in Nigeria, Chad, Niger, Cameroon and the Central African Republic.
“Although this is a setback and a disappointment, polio eradication is still absolutely feasible and on track,” said Michel Zaffran, the new World Health Organization chief of polio eradication. He acknowledged, however, that “it is still very tricky in some areas.”
Veterans of the polio eradication effort expressed confidence that the disease’s spread in Africa would ultimately be halted because northeast Nigeria is gradually becoming safer and because outbreaks in other treacherous regions, including Somalia and Syria, have been suppressed in recent years.
Although only two paralyzed children were found, the fact that families in separate towns, Jere and Gwoza, each had a strain of the virus last identified in Borno State five years ago suggests that it has circulated the whole time and that there may be many more hidden cases. Only about one infection in 200 produces paralysis, and other disabled children may have been overlooked in the fighting and panicky flights of people in northeastern Nigeria for some years.
The effort faces several major obstacles, experts said.
Until recently, the threat of ambushes by Boko Haram, the vicious Islamic fundamentalist militia that has massacred and kidnapped hundreds, made about 80 percent of Borno’s roads too dangerous for vaccination teams, except for sporadic “hit and run” efforts targeting individual villages during periods of relative calm.
Now, after a long and bloody campaign by the Nigerian Army in cooperation with the militaries of neighboring states, almost all Borno villages can be reached — sometimes routinely, sometimes at least briefly with military escorts, said Dr. Tunji Funsho, the head of Nigeria’s Rotary International polio committee, which helps coordinate the campaign.
Areas that have been off limits to vaccinators for several years are thought to have once contained about 200,000 children under age 5, said Michael Galway, head of polio operations in Nigeria for the Bill and Melinda Gates Foundation. Those children may have never had a single vaccine dose.
There is no accurate estimate yet of the number of children in the vast areas the campaign hopes to sweep through in the next four months, Mr. Zaffran of the W.H.O. said.
Also, while most of Borno State is populated by the Kanuri people, who are historically sedentary, engaging in farming, fishing, salt-processing and trade, many hundreds of thousands of residents were displaced by Boko Haram raids. Now, after living for months or years in camps for people uprooted by the violence or in the state’s better-protected major cities, people are starting to head back home in some areas. Mobile populations are hard to vaccinate, experts said, and protecting a child against polio takes several doses spaced three or more weeks apart.
Also, the region is crossed by the nomadic Fulani people, who drive their cattle hundreds of miles and across multiple borders in search of water and grass; they rarely visit health clinics and are even harder to track.
To reach people on the move, the campaign uses several techniques. Some teams with refrigerated supplies of vaccine are permanently on call, ready to go out when migratory people congregate for cattle markets, tribal festivals or at border posts. Other vaccinators may accompany veterinarians who go out to vaccinate cattle.
Also, the campaign sets up “health camps” to attract nomads. Nurses offer prenatal medical care, vitamins, food, and shots against measles, diphtheria, tetanus and other diseases besides polio.
“It would be immoral to just offer people two drops of polio vaccine and move away,” said Dr. Elias Durry, the W.H.O. emergency adviser for polio for the eastern Mediterranean who spent years overseeing polio campaigns in Africa.
In other respects, battling polio in Borno State may be easier that it was in northwest Nigeria, the source of Africa’s last multiyear outbreak, or in Pakistan and Afghanistan.
In both those places, the campaign was crippled by widespread rumors — promulgated by some local imams — that the vaccine was a Western plot to sterilize Muslim girls, or that it contained pork products or the virus that causes AIDS. In Borno, by contrast, Dr. Funsho said, both religious leaders and average residents accept the vaccine.
The two Nigerian cases were discovered in part because of the army’s conquests, experts said. They were found in families that had returned home from unsafe areas. The hunt for paralysis cases intensified last spring after a dangerous mutant strain of the vaccine virus was found in Borno sewage samples. It was a strain that had last been seen in Chad; since many Nigerians fled across the Chad border, experts theorized that it had come back in a family that had felt safe enough to return.