Polio Returns to Nigeria: CDC Responds to New Cases | 2016 Update

A Setback in the Polio Eradication Effort: Two Cases Confirmed in Nigeria

Health officials have confirmed two new cases of wild poliovirus in Nigeria, marking a setback in the global effort to eradicate the disease. The cases, detected in Borno State, represent the first confirmed instances of polio in the country in over two years. While a disappointing development, public health experts emphasize that this does not negate the significant progress made toward polio eradication worldwide, and that ongoing efforts will be redoubled.

Polio, or poliomyelitis, is a highly infectious viral disease that primarily affects young children. The virus invades the nervous system and can cause irreversible paralysis, and even death. Before the development of effective vaccines, polio was a widespread threat, causing thousands of cases of paralysis annually. The Global Polio Eradication Initiative (GPEI), launched in 1988, has dramatically reduced the incidence of polio, with wild poliovirus now endemic in only a few countries. You can learn more about the history of polio and the eradication efforts at Make Polio History – Nigeria.

Borno State: A Challenging Environment for Eradication

The two recent cases were identified through the Nigerian polio surveillance system in Borno State, a region facing significant security challenges. The volatile situation in this area can hinder both disease surveillance and vaccination campaigns, making it difficult to reach all children with the polio vaccine. This underscores the importance of access and security in successful public health interventions.

Nigeria faced significant hurdles in its polio eradication journey. In 2006, vaccination coverage with the oral polio vaccine was only 36.7%, leading to over 1,100 cases of paralysis across the country. Still, a concerted, multi-sectoral effort involving health workers, community leaders, and government officials ultimately led to Nigeria being declared free of wild polio in 2016. This progress demonstrates the power of sustained commitment and collaboration.

What Does This Mean for Polio Eradication?

The re-emergence of polio in Nigeria serves as a stark reminder that eradication is not a linear process. Setbacks are inevitable, and sustained vigilance is crucial. As the CDC statement notes, this is not the first time eradication efforts have faced challenges, drawing parallels to the smallpox eradication program, which also encountered numerous obstacles before achieving success.

The key to overcoming these setbacks lies in strengthening surveillance and immunization activities. Robust surveillance systems are essential for detecting cases quickly and responding effectively. High vaccination coverage rates are critical for preventing the spread of the virus. UNICEF highlights that over 270 million vaccines are administered yearly in Nigeria to sustain its polio-free status. You can find more information on Nigeria’s polio journey on the UNICEF website.

Understanding Poliovirus and Vaccination

Poliovirus is transmitted through contaminated water and food, and through direct contact with an infected person. There are three serotypes of poliovirus (types 1, 2, and 3). The oral polio vaccine (OPV) contains weakened forms of all three serotypes, providing immunity against all three. However, in rare cases, the weakened virus in OPV can mutate and cause vaccine-derived poliovirus (VDPV), which can also cause paralysis. This is why many countries are transitioning to using inactivated polio vaccine (IPV), which does not carry the risk of VDPV.

The Role of International Collaboration

The fight against polio is a global effort, requiring collaboration between governments, international organizations, and local communities. The CDC has a long history of working with the Nigerian government and partners like the World Health Organization (WHO), UNICEF, Rotary International, and the Bill and Melinda Gates Foundation through the GPEI. The CDC will continue to provide technical and scientific support to Nigeria and the global polio eradication initiative.

What Comes Next: Strengthening Surveillance and Response

The immediate priority is to contain the outbreak in Borno State. This will involve conducting supplementary immunization activities (SIAs) to reach all children in the affected area, strengthening surveillance to detect any further cases, and investigating the source of the virus. A retrospective review of AFP surveillance performance and polio-compatible cases in Nigeria between 2006 and 2016 was conducted by the World Health Organization Country Office, as detailed in this study published in BMC Public Health. This ongoing analysis helps to refine strategies and improve effectiveness.

Beyond the immediate response, It’s crucial to address the underlying factors that contribute to the spread of polio, such as insecurity, limited access to healthcare, and vaccine hesitancy. Building trust with communities and ensuring that all children have access to life-saving vaccines are essential for achieving and sustaining polio eradication.

The commitment to eradicating polio remains unwavering. As the CDC statement emphasizes, perseverance and commitment are critical elements for success. The world has made remarkable progress in the fight against polio, and this setback will not deter efforts to achieve a polio-free future.