Getting Polio Eradication Back on Track in Nigeria
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《新英格兰医药杂志》
The recent cancellation of polio-vaccination campaigns in several key northern Nigerian states where poliomyelitis is endemic1 has focused attention on this African country, which reported more cases of the disease in 2003 than any of the other six remaining countries with transmission of indigenous wild poliovirus. Nigeria is currently the country that poses the greatest risk to the achievement of the goal of eradicating poliomyelitis globally by the end of 2004. Although the current situation in Nigeria is of great concern, the country has already achieved remarkable progress toward eradication of the disease,2 demonstrating its capacity to implement high-quality eradication strategies. Standard international surveillance has been established in all states for the reliable detection of remaining chains of transmission of wild poliovirus and to monitor progress toward eradication. Repeated polio-immunization campaigns since 1996 had interrupted polio transmission throughout southern Nigeria and, most important, in the megacity of Lagos (population, more than 12 million) for nearly two years, from April 2001 to June 2003, when wild poliovirus was reintroduced from the north. Transmission was stopped in the northern state of Kaduna for six months, between October 2002 and April 2003.
However, as of November 11, Nigeria had reported 233 cases in 2003 — for the first time, more than were reported in either India (179 cases) or Pakistan (81 cases), the two other remaining major reservoirs of poliovirus. The increase in reported cases is paralleled by a renewed spread of polio into the central and southern states of Nigeria, including Lagos. Of equal concern, wild poliovirus that has been linked by genetic viral typing to northern Nigeria has reinfected the neighboring countries of Burkina Faso, Ghana, Togo, and Chad (see Figure), all of which had been polio-free for more than one and a half years, crippling 14 children and prompting the implementation of urgent, large-scale vaccination campaigns at a cost of more than $10 million. Without rapid progress, the unchecked transmission of poliovirus in Nigeria, the largest remaining reservoir of wild virus, will, at a minimum, delay the achievement of regional and global goals, add substantial additional cost, and in the worst-case scenario, put at risk all regional and global investments in polio eradication since 1988.
Figure. Confirmed Cases of Wild Poliovirus in Nigeria and Surrounding Countries in 2002 (Panel A) and from January 1 through November 11, 2003 (Panel B).
What has caused the largest public health program ever conducted in Nigeria to stumble, especially given the enormous investment that had already been made, the progress that had already been achieved, and the urgency of the need to catch up with other countries in Africa and the world? A key underlying factor, as data now demonstrate, is that many children in the northern states of Nigeria had not in fact been immunized, because of the low quality of the immunization campaigns since the beginning of the initiative. The quality and coordination of campaigns conducted in the first quarter of 2003 below the national level were compromised further by the considerable demands that the presidential and state elections placed on civil administrators. There was also, at the time, a perceived lack of ownership of the polio-eradication effort at the level of some state and local governments, as well as considerable dissatisfaction among members of the vaccination-campaign field staff in many areas, since their payment for work in previous campaigns had been delayed. As a result, the spring 2003 campaigns were largely ineffective in increasing coverage to the level needed to curb the resurgence of polio originating from the north during the second and third quarters of 2003.
An additional factor contributing to the overall low levels of immunity among young children were rumors about alleged adverse health effects associated with oral polio vaccine, which had emerged earlier in northern Nigeria and were further promoted in mid-2003 by local opinion leaders, motivated in part by political considerations or political tensions between the national and state levels. These rumors alleged that oral polio vaccine has a sterilizing effect or spreads AIDS because it is contaminated with human immunodeficiency virus. Both rumors have previously surfaced in other countries; although they are baseless and may easily be refuted on scientific grounds, these allegations have the potential to discredit and damage immunization programs. Because of the high public awareness of the allegations, important vaccination rounds planned for September 2003 in northern Nigeria — including in Kano, the state with the highest rate of endemic polio — were suspended by state governments to allow time for special commissions set up in several states to clarify the allegations and to restore public confidence in the immunization program. The final reports of these panels are pending.
At the same time, the Nigerian federal government has taken a number of important steps to regain the momentum of polio eradication and bring the country back on track toward the interruption of transmission of wild virus. The new federal minister of health has shown strong commitment, working closely with state governments to resolve critical problems — the most important of which is the confusion surrounding the rumors about vaccine safety — as a basis for restoring public confidence in the vaccine. With testing of the vaccine now completed, the ministry of health is providing objective information to all relevant groups and building consensus in order to enhance the quality of the upcoming vaccination rounds. In particular, the minister has increased the dialogue with political and traditional leaders in the north, and the president has appointed an Ambassador Extraordinaire for Polio Eradication. A month-by-month plan of action for polio eradication was established for 2004 under the direct guidance of the minister of health, addressing key issues in the areas of advocacy and political ownership at the national, state, and community levels and defining activities and goals for the improvement of the quality of campaigns, as well as logistics, communication, and social mobilization. Steps were also taken to improve full accountability at all levels in order to ensure the optimal use of financial and other resources.
The international polio partnership, led by the World Health Organization, Rotary International, the Centers for Disease Control and Prevention, and the United Nations Children's Fund, continues to give broad support to Nigeria's polio-eradication effort, providing detailed information on vaccine safety, extending considerable financial and technical assistance toward improving the quality of vaccination campaigns at the state and local levels, and conducting joint advocacy efforts.
Building on its previous experience and using its own resources, Nigeria can overcome the current problems that have led to inadequate coverage. The previously demonstrated rapid progress in southern Nigeria shows that the interruption of transmission of wild poliovirus in Nigeria by the end of 2004 is technically feasible. The key to bringing about improvement will be building strong consensus among all groups involved, regaining public confidence in the vaccine, especially in the northern states, and translating this confidence into a series of high-quality, supplementary, house-to-house immunization rounds that reach each and every child. In view of the commitment to the children of Nigeria and the world, and given the enormous investments already made in polio eradication at the national, regional, and global levels, we hope that the national and global polio-eradication goals can be reached as soon as possible.
Source Information
From the World Health Organization Office for Africa, Brazzaville, Republic of Congo (E.S.); the Noguchi Memorial Institute for Medical Research, University of Ghana Medical School, Legon, Ghana (F.N.); and the Department of Immunology and Microbiology, Faculty of Medicine, University of Yaoundé, Yaoundé, Cameroon (R.L.).
References
Kapp C. Surge in polio spreads alarm in northern Nigeria: rumours about vaccine safety in Muslim-run states threaten WHO's eradication programme. Lancet 2003;362:1631-1632.
Progress towards poliomyelitis eradication in Nigeria, January 2002 to March 2003. Wkly Epidemiol Rec 2003;78:210-215.(Ebrahim Samba, M.D., Fran)
However, as of November 11, Nigeria had reported 233 cases in 2003 — for the first time, more than were reported in either India (179 cases) or Pakistan (81 cases), the two other remaining major reservoirs of poliovirus. The increase in reported cases is paralleled by a renewed spread of polio into the central and southern states of Nigeria, including Lagos. Of equal concern, wild poliovirus that has been linked by genetic viral typing to northern Nigeria has reinfected the neighboring countries of Burkina Faso, Ghana, Togo, and Chad (see Figure), all of which had been polio-free for more than one and a half years, crippling 14 children and prompting the implementation of urgent, large-scale vaccination campaigns at a cost of more than $10 million. Without rapid progress, the unchecked transmission of poliovirus in Nigeria, the largest remaining reservoir of wild virus, will, at a minimum, delay the achievement of regional and global goals, add substantial additional cost, and in the worst-case scenario, put at risk all regional and global investments in polio eradication since 1988.
Figure. Confirmed Cases of Wild Poliovirus in Nigeria and Surrounding Countries in 2002 (Panel A) and from January 1 through November 11, 2003 (Panel B).
What has caused the largest public health program ever conducted in Nigeria to stumble, especially given the enormous investment that had already been made, the progress that had already been achieved, and the urgency of the need to catch up with other countries in Africa and the world? A key underlying factor, as data now demonstrate, is that many children in the northern states of Nigeria had not in fact been immunized, because of the low quality of the immunization campaigns since the beginning of the initiative. The quality and coordination of campaigns conducted in the first quarter of 2003 below the national level were compromised further by the considerable demands that the presidential and state elections placed on civil administrators. There was also, at the time, a perceived lack of ownership of the polio-eradication effort at the level of some state and local governments, as well as considerable dissatisfaction among members of the vaccination-campaign field staff in many areas, since their payment for work in previous campaigns had been delayed. As a result, the spring 2003 campaigns were largely ineffective in increasing coverage to the level needed to curb the resurgence of polio originating from the north during the second and third quarters of 2003.
An additional factor contributing to the overall low levels of immunity among young children were rumors about alleged adverse health effects associated with oral polio vaccine, which had emerged earlier in northern Nigeria and were further promoted in mid-2003 by local opinion leaders, motivated in part by political considerations or political tensions between the national and state levels. These rumors alleged that oral polio vaccine has a sterilizing effect or spreads AIDS because it is contaminated with human immunodeficiency virus. Both rumors have previously surfaced in other countries; although they are baseless and may easily be refuted on scientific grounds, these allegations have the potential to discredit and damage immunization programs. Because of the high public awareness of the allegations, important vaccination rounds planned for September 2003 in northern Nigeria — including in Kano, the state with the highest rate of endemic polio — were suspended by state governments to allow time for special commissions set up in several states to clarify the allegations and to restore public confidence in the immunization program. The final reports of these panels are pending.
At the same time, the Nigerian federal government has taken a number of important steps to regain the momentum of polio eradication and bring the country back on track toward the interruption of transmission of wild virus. The new federal minister of health has shown strong commitment, working closely with state governments to resolve critical problems — the most important of which is the confusion surrounding the rumors about vaccine safety — as a basis for restoring public confidence in the vaccine. With testing of the vaccine now completed, the ministry of health is providing objective information to all relevant groups and building consensus in order to enhance the quality of the upcoming vaccination rounds. In particular, the minister has increased the dialogue with political and traditional leaders in the north, and the president has appointed an Ambassador Extraordinaire for Polio Eradication. A month-by-month plan of action for polio eradication was established for 2004 under the direct guidance of the minister of health, addressing key issues in the areas of advocacy and political ownership at the national, state, and community levels and defining activities and goals for the improvement of the quality of campaigns, as well as logistics, communication, and social mobilization. Steps were also taken to improve full accountability at all levels in order to ensure the optimal use of financial and other resources.
The international polio partnership, led by the World Health Organization, Rotary International, the Centers for Disease Control and Prevention, and the United Nations Children's Fund, continues to give broad support to Nigeria's polio-eradication effort, providing detailed information on vaccine safety, extending considerable financial and technical assistance toward improving the quality of vaccination campaigns at the state and local levels, and conducting joint advocacy efforts.
Building on its previous experience and using its own resources, Nigeria can overcome the current problems that have led to inadequate coverage. The previously demonstrated rapid progress in southern Nigeria shows that the interruption of transmission of wild poliovirus in Nigeria by the end of 2004 is technically feasible. The key to bringing about improvement will be building strong consensus among all groups involved, regaining public confidence in the vaccine, especially in the northern states, and translating this confidence into a series of high-quality, supplementary, house-to-house immunization rounds that reach each and every child. In view of the commitment to the children of Nigeria and the world, and given the enormous investments already made in polio eradication at the national, regional, and global levels, we hope that the national and global polio-eradication goals can be reached as soon as possible.
Source Information
From the World Health Organization Office for Africa, Brazzaville, Republic of Congo (E.S.); the Noguchi Memorial Institute for Medical Research, University of Ghana Medical School, Legon, Ghana (F.N.); and the Department of Immunology and Microbiology, Faculty of Medicine, University of Yaoundé, Yaoundé, Cameroon (R.L.).
References
Kapp C. Surge in polio spreads alarm in northern Nigeria: rumours about vaccine safety in Muslim-run states threaten WHO's eradication programme. Lancet 2003;362:1631-1632.
Progress towards poliomyelitis eradication in Nigeria, January 2002 to March 2003. Wkly Epidemiol Rec 2003;78:210-215.(Ebrahim Samba, M.D., Fran)