Reviewed March 2018
The Governments of Nigeria and other countries across the Lake Chad basin region (Niger, Cameroon, the Central African Republic and Chad), continue to implement a strong outbreak response following the detection of four wild poliovirus cases in August 2016, after more than two years without detection. See here for the latest information on cases, surveillance and vaccination campaigns.
The impact of the current outbreak response is constantly being evaluated. The security situation is evolving, and the programme has staff on the ground to rapidly move into newly-accessible areas and immunize at-risk children.
Additionally, the regional outbreak response is being coordinated across all countries in the Lake Chad basin region, and within the context of the broader humanitarian emergency response ongoing in parts of the region. Polio eradication teams on the ground, as well as at national, regional and global levels, are closely coordinating with governments, humanitarian emergency response teams, other UN organizations and NGOs, to maximize the impact of all available resources and ensure that polio vaccine can be delivered alongside broader health interventions to the most vulnerable and at-need populations in the region.
Thanks to this rapid response to the 2016 detection of cases in Borno, it appears that Nigeria and its neighbours have been able to prevent further spread of the disease.
However, areas of Borno State remain inaccessible and it is difficult to vaccinate all children. Efforts are ongoing to improve operations in accessible areas, where children continue to be missed.
The Lake Chad basin region is a very complex environment, with multiple conflicts, limited healthcare and high population movement. The polio programme has identified the entire basin as an area that is vulnerable to poliovirus spread from northern Nigeria.
It is important to continue an extensive and determined immunization and surveillance effort as there remain many children living in inaccessible areas of the basin who have not been immunized. The programme will not stop outbreak response until there is certainty that there is no poliovirus anywhere in the basin.
The programme will continue determined outbreak response on the Lake Chad islands until there is certainty that there is no poliovirus present. Currently, efforts are focused on getting to every island, and maintaining surveillance and immunization campaigns there. The programme is working with national governments to achieve this, as well as with multiple partners, and local groups.
Insecurity always complicates outbreak response and the ability to conduct disease surveillance and routine and campaign immunization. However, much has been learned during the programme’s history, and numerous successful campaigns have been run in conflict affected areas.
The programme’s emphasis is always on keeping polio vaccinators safe, whilst ensuring that as many children are vaccinated as possible, and that the virus is detected wherever it is present. The programme works closely with other agencies, partners, national governments, local leaders, and communities to gain access to difficult areas.
The programme aims to enter newly accessible areas as quickly as possible to ensure that every child receives polio vaccination.
Across Nigeria and in the Lake Chad basin region, the acute flaccid paralysis (AFP) reporting network is being expanded, and environmental surveillance improved. Since 2016, sensitization trainings of health workers have been rolled out, and additional laboratory support, training, supplies and equipment provided. Technical support, including data management and analysis, has been scaled up. In response to recommendations from the November 2017 Outbreak Response Assessments of the region, further action will be taken over the coming months.
These activities have not only been implemented in Nigeria and the Lake Chad basin region, but across all other countries which are affected or are at high-risk.
How will the programme know this time that the region truly is polio free, and that no cases have been missed?
Poliovirus only survives in humans; it does not survive for a significant time in the environment. This means that between 2014 and 2016, virus was circulating in populations present, or near to, the Borno region.
This time, the programme’s outbreak response and surveillance teams are taking no chances. The programme has redoubled focus on reaching every last child – whether they are migratory, in an inaccessible area, or in a community that resists vaccination. The programme is determined not to close the response until it can confidently be said that there are no pockets of Nigeria or other Lake Chad basin countries that have not been accessed with vaccines. To do this, the programme has continued to collect data on population immunity, refusals, and inaccessible areas, as well as conducting extensive environmental surveillance to search for any trace of virus. A broader and more comprehensive acute flaccid paralysis reporting network has also been implemented, which allows potential cases occurring in difficult to access, remote areas to be reported to health workers via mobile phone. The use of GIS technology has also been expanded. An Accountability Framework has been institutionalized at all levels to improve staff and programme performances, and the programme has worked to expand community based surveillance, deploy National STOP consultants and strengthen collaboration with NGOs and military forces when and where necessary. Nigeria remains on the endemic country list until there is full confidence that transmission of wild poliovirus has been stopped.
The Democratic Republic of the Congo
The Democratic Republic of the Congo (DRC) is currently facing two separate circulating vaccine-derived poliovirus type 2 (cVDVP2) outbreaks, in Haut Lomami and Tanganyika outbreak area, and in Maniema province. The Ministry of Health, supported by WHO and partners of the Global Polio Eradication Initiative (GPEI), has responded by implementing outbreak response activities to contain the virus. See here for the latest information on cases, surveillance and vaccination campaigns.
Circulating vaccine-derived poliovirus is an extremely rare strain of poliovirus, genetically changed from the original strain contained in oral polio vaccine (OPV). When children are given OPV, they shed the weakened vaccine-virus in their stools. On rare occasions, when population immunity is very low, this vaccine-virus can pass between unvaccinated children and can mutate along the way. After a long period of time, and multiple mutations, this virus strain can regain the ability to paralyse. Hence this effect is not so much due to the vaccine, but more to do with low vaccination coverage. When this paralytic virus emerges in a community it is called vaccine-derived poliovirus. If the virus is transmitted from person to person, this is called a circulating vaccine-derived poliovirus (cVDPV).
If enough children have been vaccinated against polio, they are protected against wild and also vaccine-derived polioviruses, as the vaccine-virus cannot find hosts in which to mutate.
The GPEI is actively working with countries to eradicate both wild and vaccine-derived polioviruses. The same strategies that are being used to fight wild poliovirus are also used to stop cVDPV.
As of February 2018, four monovalent oral polio vaccine (mOPV2) supplementary immunization campaigns and one mOPV2 mop-up campaign have taken place in DRC since the beginning of outbreak response.
The majority of districts in Haut Lomami and Maniema provinces were covered by all four mOPV2 campaigns, which took place in June, July, November, and December 2017. Three districts in Haut Lomami and Haut Katanga provinces were additionally covered by the mOPV2 mop-up campaign.
Three districts of Tanganyika province (Ankoro, Manono and Kiambi) were covered by the November and the December mOPV2 campaigns.
Planning is currently ongoing to decide on the date and scope of additional campaigns, in light of virus spread. The Government and programme are also working together to improve the quality of campaigns and surveillance, to strengthen the outbreak response and lower the chances of further virus circulation.
Emergence could pre-date the switch, but the programme cannot rule out continued use of tOPV in some areas. As part of the outbreak response, the programme is making the most of opportunities to conduct sweeps of health centres, to see if there is any evidence of continued tOPV use, and to further verify that indeed it has been fully withdrawn in all areas.
Insecurity always complicates both outbreak response and the ability to conduct disease surveillance. The cVDPV2 affected provinces face security issues, and the programme works to overcome this where possible. Response is complicated by the complex humanitarian emergency situation currently ongoing in DRC, which has led to an estimated 4.1 million internally displaced people, and immunity gaps in some places.
No wild poliovirus has been found in DRC since 2011. No circulating vaccine-derived poliovirus type 2 has been reported in DRC since 2012, when an outbreak occurred in what was previously Katanga province. The current cVDPV2 strains are not related to this previous outbreak.
The African Region
There have been no cases of wild poliovirusreported in the African region since 2016. The date of onset of the last wild poliovirus case was on 21 August 2016. The programme, in collaboration with GPEI partners, is operating and coordinating outbreak response in Nigeria and the surrounding area to ensure that these are the last cases. The programme is also working concertedly to close the outbreak of vaccine-derived poliovirus affecting the DRC. These efforts are aided by the immense commitment of national governments across the region, all of whom are engaged in regular immunization activities.
Africa will not be declared polio free until three years have passed following the last detected wild poliovirus, in the presence of high quality, certification-standard surveillance and high population immunity.
The Africa Regional Commission for the Certification of poliomyelitis eradication (ARCC) is an independent body appointed in 1998 by the WHO/AFRO Regional Director to oversee certification and containment processes in the African region. All the 47 countries of the African region have established a National Polio Certification Committee (NCC), and have also instituted a National Polio Expert Committee (NPEC), and a National Task-Force on poliovirus containment (NTF).
Every year, all the NCCs review and endorse a country annual progress/update report, before submitting it to the ARCC. This includes detailed evidence and data on polio eradication activities in the country. This mechanism is important to allow the commission and its secretariat to monitor the level of progress towards poliovirus eradication in each country. The certification of polio eradication is done at regional level, meaning that individual countries are not certified poliovirus free.
The ARCC will certify the African region poliovirus free only after the receipt of complete documentation from all the 47 countries of the region by the ARCC. A region is eligible for regional certification after meeting all criteria for certification, and after three years has passed without detection of any wild poliovirus in any country in that region, from any source, in the presence of high quality certification-standard surveillance.
As of January 2018, a total of 39 countries out of 47 in the region have successfully presented their complete documentation for certification, which has been validated by the ARCC. AFRO is supporting the remaining countries to strengthen their polio eradication programme performances and their documentation process, aiming towards the certification of the region.
The GPEI is the largest healthcare programme worldwide, vaccinating over 400 million children, and investigating over 100,000 cases of acute flaccid paralysis every year. In order to rapidly respond and prevent a major epidemic, the programme needs to find every child, and search the virus out, in some of the most remote and difficult to reach environments on earth. This is what drives the cost of the programme. The costs of not reaching zero is much higher – in both human and financial terms.
The GPEI has a vast infrastructure and staff on the ground which coordinates efforts with the infrastructure and staff available for broader humanitarian emergency response. The aim is to deliver polio vaccine alongside other basic healthcare to populations most at need.
Polio resources contribute to humanitarian emergency and disease outbreak response across the African region. Measles campaigns, supported by polio infrastructure, have resulted in a 50% decline in measles deaths since the start of the millennium, whilst the successful response to Ebola outbreak in Nigeria is also attributed in part to the support offered by the polio programme. The poliovirus surveillance network regularly detects and helps to respond to outbreaks of yellow fever, cholera, NNT and other diseases, and routinely offers infrastructural, logistical and personnel support to other programmes, including through distributing vitamin A and deworming medication.
The programme has also established best practice methods used by numerous healthcare programmes and has mobilized communities to engage with healthcare.
The money spent now benefits children alive today, and in the future. Soon, no child will ever again contract poliovirus.
The Global Polio Eradication Initiative, a unique public-private partnership, coordinates strategy among the world’s most respected health agencies, philanthropies and non-profits. In total, the programme vaccinates around 400 million children every year.
- WHO coordinates the major strategic planning, management and administration processes of the Global Polio Eradication Initiative. In the African region, they coordinate operational research, support ministries of health and coordinate outbreak response. WHO also serves as secretariat to the certification process, which will eventually certify Africa as polio-free.
- UNICEF works alongside WHO to strategically and operationally support countries, and procures and distributes polio vaccines for routine and supplementary immunization. Significantly, UNICEF helps countries to develop communications strategies that are vital to local acceptance of the vaccine. In Africa, this includes recruiting community mobilizers in the Democratic Republic of the Congo, and providing mobilizers in the Lake Chad basin with communications materials and training.
- The Bill & Melinda Gates Foundation provides technical and financial support to the programme. They play a large role in innovation, including helping to develop the AVADAR mobile-based acute flaccid paralysis surveillance system in countries such as Nigeria, Chad, and Cameroon.
- The US Centers for Disease Control and Prevention forms the technical backbone of the surveillance network. Each year, they analyse thousands of environmental and human stool samples from the African region for signs of poliovirus, and are instrumental in strengthening surveillance systems at a country level.
- Rotary International was the first organization to have the vision of a polio-free world, and is the driving force behind the eradication effort. Since 1985, Rotarians have raised hundreds of millions of dollars for polio eradication in Africa, and globally.