In January last year, Nigerian health workers knocked on Umar's door, offering her newborn daughter a free dose of polio vaccine.
Two drops of the oral polio vaccine taken at least three times as a child, the health workers told her, would protect her daughter, Zaliha, from the crippling virus for life.
But Umar turned the vaccinators away. Most of her neighbors did the same, some hiding children under their beds.
They had heard a rumor circulating through the hot, dusty villages of northern Nigeria that the vaccine had been contaminated with an anti-fertility agent that would sterilize their children or perhaps infect them with the AIDS virus, all part of an American plot to depopulate the developing world. The villagers believed it.
It didn't matter that the World Health Organization, the Nigerian government and dozens of doctors and scientists dismissed the allegations as baseless, assuring the public that the vaccine taken by 1 billion children worldwide is safe.
"We just didn't like the vaccine," says Umar.
During the following three months, vaccinators returned to Umar's neighborhood two more times to immunize the children. On both occasions, the shy 22-year-old mother politely but firmly declined their offer.
Then in June, 10-month-old Zaliha developed a fever and diarrhea. Zaliha, who had recently learned to crawl, suddenly could no longer sit up. A few days later, paralysis, polio's damning trademark, arrived, leaving her legs limp and lifeless.
Aided by rumor, fear and misinformation, polio is making a comeback in Nigeria, reinfecting polio-free regions and moving into West and Central Africa, putting 15 million children at risk and threatening the goal of a polio-free world.
The outbreak comes just as polio appeared to be backed into a corner. In 1988, when the WHO launched a campaign to eradicate the disease, there were more than 350,000 known cases in 125 countries. Today there are about 500 cases in just seven countries: Nigeria, India, Pakistan, Egypt, Afghanistan, Niger and Somalia.
Six of these countries are on track to eliminate polio by the WHO's deadline of the end of 2004. But Nigeria, with nearly half of the cases, threatens to derail the worldwide effort.
Most of the country's 286 cases have occurred in Nigeria's predominantly Muslim northern states, where anti-Western feelings intensified by the U.S.-led wars in Afghanistan and Iraq make the population suspicious of any program supported by the United States.
Radical Muslim clerics preached the dangers of the vaccine during Friday prayers. Villagers chased, threatened and assaulted vaccinators. Frustrated, some vaccination teams dumped thousands of doses of the vaccine rather than face angry villagers, WHO officials say.
In response to the outcry, three northern Nigerian states, including Umar's home state of Kano, canceled immunization campaigns last year, allowing the virus to spread and get a foothold in neighboring countries.
Nearly a dozen children were crippled last year in Burkina Faso, Ghana, Niger, Togo and Chad from a poliovirus genetically linked to northern Nigeria.
"Polio is now spreading to areas that have been polio-free for years," says David Heymann, an epidemiologist based in Geneva who is leading the World Health Organization's polio eradication campaign. "All it takes is for someone to hop on an airplane ... to start reinfecting another part of the world."
Such fears have left WHO and local health officials scrambling to contain the spread of the virus and dispel the rumors so the vaccinations can begin again.
But if there is one measure of the challenges public health officials face here, it is Umar's defiance. Standing in her doorway on a recent morning, holding her crippled daughter, she expresses no regret.
Asked if she would accept the vaccine if she could wind the clock back to that day health workers first knocked on her door, she does not hesitate with her answer.
"No," says Umar, shaking her head. "I would do the same."
Few people in the developed world think about poliomyelitis, but during the first half of the 20th century, it was one of the most feared diseases.
The highly infectious virus can strike anyone at any age, although children younger than 5 are most vulnerable. Thriving in unsanitary conditions, the virus enters the body through the mouth and multiplies in the intestine. If it invades the nervous system, it can lead to paralysis within five days.
With no known cure, polio left victims crippled for life, rolling in wheelchairs, hobbling on crutches or spending their lives in coffin-like "iron lungs," huge cylinders that helped the most severely stricken victims breathe.
In 1955 Dr. Jonas Salk discovered a polio vaccine. But it was Dr. Albert Sabin's development in 1961 of a live polio vaccine taken orally that made mass immunizations and the dream of a polio-free world possible. Simple to administer and costing pennies a dose, the oral polio vaccine could be distributed widely and inexpensively by volunteers with minimal training.
Led by the WHO, Rotary International, the U.S. Centers for Disease Control and Prevention and the United Nations Children's Fund, the anti-polio effort began in 1988 and has grown into one of the world's largest public health care initiatives, costing more than $2 billion so far.
More than 5 billion doses of the vaccine have been distributed door to door by 20 million volunteers and health workers traveling by train, helicopter, horseback, motorcycle, boat and on foot to deliver the doses to every child younger than 5.
Vaccinators persuaded soldiers battling in civil wars in Angola, Congo and Sudan to lay down their weapons for several days so that thousands of children could be protected from the disease. In parts of India, trains have not been allowed to leave their stations until all children under 5 were immunized.
Five million people who would otherwise be paralyzed are walking because they received the vaccine, according to the WHO.
But the campaign has dragged on longer than expected, missing its original deadline of 2000.
If there are further delays, health officials fear, the campaign could be undermined by donor fatigue and frustration.
If the campaign is successful, polio would be only the second disease ever to be eradicated. The first was smallpox in 1979.
No one quite knows how the rumors about the vaccine's safety began, but local officials point to the northern state of Kano, which has the highest number of polio cases in Nigeria, as the likely source.
The state capital, Kano, developed as a center for camel caravans crossing the Sahara to trade slaves, ivory and kola nuts for salt, glass beads, weapons and cowrie shells.
Enveloped in a gray, exhaust-filled haze much of the day, the city of 1 million is dominated by the emir of its walled palace and the central mosque, where as many as 50,000 worshipers gather for Friday prayers.
The dominant tribe is the Hausa, whose culture is defined by Islamic faith. Boys study the Quran in outdoor schools under trees by the side of the road. Women are rarely seen outside the mud walls of their homes. Peace and order are maintained by the state's Sharia court system.
As in much of the Muslim world, anti-American passions run high among Kano's residents. In such a climate, rumors of plots involving the polio vaccine found a receptive audience.
"What is happening in the Middle East has aggravated the situation," says Ali Guda Takai, a WHO doctor who investigates all polio cases in Kano state. "If America is fighting people in the Middle East, the conclusion is that they are fighting Muslims."
It's no coincidence, officials say, that the number of polio cases has increased sharply since the wars in Afghanistan and Iraq. There were nine polio cases in 2001, but 54 in 2002 and 74 in the first 11 months of 2003.
What makes rumors so difficult to dispel in Nigeria is that they are supported by prominent members of the community, including doctors, Muslim clerics, political leaders and college professors.
"These are highly respected people who hardly tell lies. People believe what they say," said Takai, a Nigerian who was raised in Kano.
Perhaps the most vocal critic is Ibrahim Datti Ahmed, a Kano physician and president of Nigeria's Supreme Council for Sharia Law.
Ahmed, 68, was once a strong supporter of the polio vaccine, immunizing all five of his children himself. Initially, he was skeptical about the rumors, he says, but then he searched the Internet and discovered articles questioning the vaccine's safety.
Ahmed concluded that the United States was contaminating the vaccine with anti-fertility hormones to depopulate the developing world, afraid that rapid population growth in countries like Nigeria, with 126 million people, will overwhelm the United States, where birth rates are lower.
"They are the worst criminals on Earth to sterilize children for life. Even Hitler was not as evil as that," said Ahmed, who has appeared on radio and television promoting his theory.
As far-fetched as his ideas may sound, many believe them.
"If reducing population will enhance the United States' interests, then America will go for it," says Samaila Buba. 35, a graduate student at Bayero University in Kano. "I cannot allow my child to take [the vaccine]."
Some of Kano's fears of the vaccine stem from its experience with the U.S. pharmaceutical giant Pfizer Inc., which in 1996 administered an experimental antibiotic to help control a meningitis outbreak. Eleven children died, and others suffered paralysis, deafness and blindness as a result of the drug, the victims' families alleged in a lawsuit filed against the company in New York. The case was dismissed, but a U.S. appeals court recently referred it back to court for reconsideration.
Pfizer denies any wrongdoing.
Many Nigerians are further bewildered by the WHO campaign's single-minded focus on polio when they are threatened daily by a medical textbook's worth of illnesses: leprosy, AIDS, tuberculosis, measles, diarrhea, malaria and yellow fever. While there were 286 confirmed cases of polio in 2003, as many as 300,000 Nigerians died from malaria during the same period.
"There are more killer diseases that need attention in Africa than polio. Like malaria. It's the No. 1 killer," says Bello, who was recovering from a bout of malaria himself, but received no free treatment.
The aggressive door-to-door mass immunizations that have slashed polio infections around the world also raise suspicions. From a Nigerian's perspective, to be offered free medicine is about as unusual as a stranger's going door to door in America and handing over $100 bills. It doesn't make any sense in a country where people struggle to obtain the most basic medicines and treatment at local clinics.
The WHO acknowledges that eradicating polio may not be a top priority for many developing countries. At the time the campaign began, some critics argued that it would be better to offer routine immunizations for a number of preventable diseases. But after the success in wiping out smallpox, the WHO and its partners were optimistic that another narrow, targeted campaign would work.
None of these explanations of northern Nigeria's opposition to the vaccine satisfy public health officials trying to understand what went wrong here.
Why is it that Muslims in other countries support polio immunization campaigns? Why has progress been made in other poor, disease-ridden nations? What makes Nigeria different?
The answer, local health officials say, is politics. Although Nigeria consists of hundreds of ethnic groups, the main dividing line is north-south. Northern Nigeria is mainly Muslim. The southern part of the country is predominantly Christian and animist. There lies the source of many of the country's religious and political tensions.
The election of President Olusegun Obasanjo, a born-again Christian, in 1999 after 16 years of military rule by dictators from the north, has often put northern political leaders at odds with the national government. Any federal government program run by the Obasanjo administration arouses suspicions.
Opposition parties use any effort they can to embarrass Obasanjo's government. The polio vaccination program is one.
Safety test rejected
To calm fears, the Nigerian government recently commissioned independent tests to verify the vaccine's safety. At least four series of tests were performed by laboratories in Nigeria and South Africa, all concluding there was no evidence of anti-fertility hormones or the virus that causes AIDS.
In announcing the test results last month, Nigeria's minister of health called on local leaders to join the federal government to drive polio from the country by the end of 2004.
It's unclear whether any of these pronouncements will make a difference. Even before the government declaration, Ahmed announced that the vaccine tests had found evidence of anti-fertility hormones. Anyone who said differently was part of a U.S.-orchestrated cover-up.
The WHO meanwhile pushed ahead with immunization campaigns in the areas of Nigeria that would allow them. The northern states of Kano, Kaduna and Zamfara, with some of the highest infection rates, did not participate.
In Plateau state, home to a mix of Christians and Muslims, young men and women carrying coolers containing hundreds of doses of the vaccine trudged in blistering heat to hundreds of villages and cities.
They met thousands of families willing to accept the vaccine. But there were pockets of fierce resistance, as the vaccinators discovered in the city of Wase.
A poor farming community, Wase appears almost feudal. At the highest point in the city sits the emir's whitewashed palace. Across the street, just a few feet higher is the mosque, its dome rising over the banks of the Wase River, where peasants tend rows of maize and yams.
The polio vaccine has been available in the village for a decade or more. But opposition to the vaccine has grown steadily since residents heard about the concern in the northern states.
After two years without a case of polio, Plateau state has two children paralyzed by the virus, including one just outside Wase.
Although two cases may seem to be a small number, the risks of infection are high for residents living nearby. For every polio case resulting in paralysis, an estimated 200 people carry the virus but may show no symptoms other than diarrhea.
Such risks, however, were apparently not the primary concern for residents of one neighborhood on the outskirts of Wase. When the team of health workers started knocking on doors, villagers turned them away.
The vaccinators retreated, but then sought help from Wase's traditional ward leader, who is sympathetic to immunization efforts.
"I remember when Americans brought some medicine here once and people got cured," said Albhi Sule Rabo, whose family has ruled over Wase for more than 200 years. "Because I saw this I believe in the vaccine."
Rabo agreed to accompany the vaccinators to the troublesome neighborhood. When his car came within sight, the streets suddenly emptied.
Clearly annoyed, Rabo sprang from his car, barking for the fathers to come outside with their children. He launched into a 10-minute lecture on the benefits of the vaccine and how he had ordered all of his own children to take it. He said there was no reason to believe it was not safe. "God creates medicines," he says.
"Look at this woman," he said, pointing to one of the vaccinators. "She left her husband and children to help us. Do you think she would leave them to come and harm us. Do you think that is believable?"
He focused much of his outrage on one father, a feeble-looking man who stood with his head hung low like a mischievous schoolboy caught by the principal.
"I had heard on the radio that it was dangerous," the man told the vaccination team. After Rabo's speech, he reluctantly agreed to have his child immunized.
The vaccinators pulled a vial of orange-colored liquid from the cooler box, attached a dropper to the top and called over the boy, who squirmed and wailed in his father's arms. His father and two health workers struggled to pry open his mouth.
Then two drops of the vaccine fell to his tongue. His thumb was painted with a dab of purple ink to indicate he had been immunized. The ordeal over, the boy's sobbing suddenly quieted, and his eyes darted back and forth as if to say, "Is that all?"
His work apparently done, Rabo waved goodbye, stepped into his car and drove home.
Their success, however, was short-lived. As soon as Rabo's car disappeared from view, the crowd that had gathered disappeared. The team gave doses to two other children before it encountered a fresh wave of resistance.
One man claimed the vaccine was responsible for the deaths of two of his children. An elderly grandfather sat under a tree and refused to give the whereabouts of his young grandson, who was hiding. A crowd of teen-age boys taunted a group of young women vaccinators.
"What are you going to do? Force us to accept it?" one boy said, laughing.
At the edge of the village the vaccinators approached a man sitting alone under a baobab tree. Alarmed at the sight of them, he stood, waving his arms as if he were trying to stop traffic, saying that he was not about to allow his children to take the vaccine.
"I don't want anything to do with Christians or Americans," he screamed.
Seeing a white American in the party of vaccinators, the man spread his arms as if being crucified and hollered: "Now the Americans have come to kill me. So kill me now!"