As preparations begin for the next sub-national Immunisation Plus’ Days (IPDs) using bivalent oral polio vaccine, Oyeyemi Gbenga-Mustapha takes a look at why the vaccine preventable polio is still endemic in Nigeria.
Nigeria is one of the three countries that is still polio-endemic, it is in this unenviable company with Afghanistan and Pakistan. Of all the three, Nigeria is the reservoir of wild polio virus, it is the only country with ongoing transmission of all three serotypes- wild poliovirus type 1, wild poliovirus type 3 and circulating vaccine- desired polio type 2. The Northern states are the main source of polio infections.
In 2009, operational improvements in these northern states led to a 90 per cent decline in cases of wild poliovirus type 1 and a 50 per cent decline in overall cases compared with 2008.
As of last week, Polio Global Eradication Initiative, a monitoring organisation of polio situation in Nigeria, reported that two new cases of wild polio virus 1 have been found in Kano and Taraba states, bringing the total number of wild polio cases for this year to 18. The case from Kano is the most recent case in the country.
According to medical experts, as long as a single child remains infected, children in all countries are at risk of contracting polio. Failure to eradicate polio from these last remaining strongholds could result in as many as 200, 000 new cases every year within 10 years. Polio has no cure but can be prevented.
In most countries, the global effort has expanded capacities to tackle other infectious diseases by building effective surveillance and immunization systems.
A delicate balance
Polio is a highly infectious disease caused by a virus. It invades the nervous system, and can cause total paralysis in a matter of hours. Initial symptoms are fever, fatigue, headache, vomiting, stiffness in the neck and pain in the limbs. According to the World Health Organisation (WHO), one in 200 infections lead to irreversible paralysis (usually in the legs). Among those paralysed, five per cent to 10 per cent die when their breathing muscles become immobilised.
According to WHO, globally, Polio cases have decreased by over 99 per cent since 1988, from an estimated 350, 000 cases to 223 reported cases in 2012. The reduction is the result of the global effort to eradicate the disease.
Nigeria is fighting to end the endemic. However, there are sundry factors militating against the actualisation of this hope.
The polio eradication programme continue to miss too many children in key geographic areas and population groups due to a mixture of operational and social factors. In 2012, going by data supplied by Polio Global Eradication Initiative, 61 children were paralyzed by polio in the first half of 2012, as opposed to 24 at the same time in 2011. In 2011, more than 95 per cent of all cases occurred in the eight persistently endemic northern states of Borno, Jigawa, Kano, Katsina, Kebbi, Sokoto, Yobe and Zamfara.
A formerly strong primary health care system in northern Nigeria has been weakened over many years due to incessant polio outbreaks and resistant of a segment of the populace over the safety of the vaccination. This has led to serious gap in the administration of the vaccine and subsequent disruption of campaigns as well as the killing of vaccinators. Now routine immunisation services are either no longer available or irregular; coupled with limited resources for health services and gaps in vaccine storage and distribution.
According to a nongovernmental organisation, PATH, Northern Nigeria has one of the lowest rates of immunisation coverage in the world. In many parts of the north, barely 10 percent of children receive all of their routine vaccines. Coverage rates for the vaccine against tetanus among women are equally low.
Misunderstood scheme
The north is rife with misperception on the effects of the contents of the vaccine on health, especially reproduction. Campaigns have been on in the north that vaccination leads to reduction of productivity, this has been countered at all levels but the impact is still there.
But in the face of sundry factors including insecurity, especially of Boko Haram, ridding the country of the polio virus can remain a mirage. Conflicts and insecurity do weaken public health systems.
For instance, attacks on health workers in Kano State have robbed vulnerable populations of basic life-saving health interventions. In the face of these, Nigeria continues to pose a significant risk to surrounding countries. In 2011, polio viruses originating from Nigeria were detected in five countries on West and Central Africa. Despite dozens of vaccination campaigns over the past years, according to Polio Global Eradication Initiative, no more than 65 percent of children have received four or more Oral Polio Vaccine (OPV) doses in Borno, Kano, Sokoto and Yobe states.
Viruses with genetic evidence of long periods of circulation without detection are still being found, indicating surveillance gaps. Sub national engagement of political leadership remains patchy. Future benefits of polio eradication are immense. Once polio is eradicated, the world can celebrate the delivery of a major global public good that will benefit all, no matter where they live. According to WHO, Economic modelling has found that the eradication of polio would save at least US$ 40 to 50 billion over the next 20 years, mostly in low-income countries. Most importantly, success will mean that no child will ever again suffer the terrible effects of lifelong polio-paralysis.
