Wiping out polio, country by country

Updated 1622 GMT (0022 HKT) October 24, 2014
Boy with polio in AfghanistanBoy with polio in Afghanistan
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To date, smallpox is the only human infection to have been eradicated worldwide. Here, we look at efforts to eradicate polio. Could the world be free of this virus by 2018?
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Poliomyelitis (Polio) is an infectious disease caused by three wild types of the poliovirus (WPV1, WPV2 and WPV3) with WPV1 being the main virus present among affected populations today.

The disease mainly affects young children, causing symptoms such as fever, fatigue and limb pain. Once the virus replicates in the intestine, it can enter the nervous system and cause permanent paralysis. Polio is transmitted through contact with infected human feces and contaminated food or water and there is no cure.

The only prevention is through immunization.
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In 1988, the Global Polio Eradication Initiative was launched to rid the world of polio by 2000. The target date was not met but the number of cases has fallen from affecting 350,000 people in 125 countries endemic with the disease in 1988, to 206 cases in three endemic countries as of 14 October 2014.

Polio continues to be imported and has caused outbreaks in six countries, where 19 people have been reported to be infected in 2014. The new target date for a world free of polio is 2018.
Courtesy FAROOQ NAEEM/AFP/Getty Images

The main strategy to eradicate polio has been global delivery of three doses of the oral polio vaccine (OPV).

However, OPV uses a live, but less infectious, form of the polio virus to stimulate an immune response in the body. In very rare cases this can cause paralysis (1 case per 2.4 million doses administered, according to the WHO). As polio numbers fall worldwide this risk is slowly outweighing the benefit.

Today's strategy involves the eventual replacement of OPV with the injectable Inactivated Polio Vaccine (IPV). This has already taken place in 75 countries.

2014 cases, as of 14 October: 206.
Most Recent Case: 22 September 2014.
Polio immunization coverage: 75%.

Pakistan is the biggest focus of attention for the Global Polio Eradication Initiative as 84% of all known polio infections have occurred here so far in 2014.
Insecurity in the country hinders immunization programs from reaching children in need of vaccination, particularly in the Federally Administered Tribal Areas (FATA).
Courtesy UNICEF

No. cases in 2014, as of 14 October: 10.
Most recent case: 18 September 2014.
Polio immunization coverage: 71%.

Polio remains in the population in the eastern region of the country, mainly due to cross-border transmission from Pakistan
Nationwide immunization programs continue to try to ensure enough people are protected to stop the spread of the virus, known as "herd immunity." For polio, this is 80-86% of the population and Afghanistan is yet to reach this threshold.
Courtesy WAKIL KOHSAR/AFP/Getty Images

No. cases in 2014, as of 14 October: Six.
Most recent case: 24 July 2014.
Polio immunization coverage: 59%.

Nigeria could be approaching its final days of polio, with a consistent decrease from 122 cases of polio in 2012 to 53 cases in 2013, and this year just six, as of the beginning of October.
The remaining cases in the country reside in the country's north-eastern states of Kano, Borno and Yobe, where militant group Boko Haram is active. Despite the threat of insecurity, numbers remain low, with the last case recorded on 24 July 2014.
Courtesy UNICEF

No. cases in 2014, as of 14 October: Five.
Most recent case: 11 August 2014.
Polio vaccination coverage: 47%.

Somalia sits on the "wild polio virus importation belt" of Africa, where recurrent importation of poliovirus leads to continuous transmission.
Infections often occur among nomadic populations living in Somaliland -- a self-declared autonomous state in the north-east -- where communities are hard to reach. Vaccination coverage is also low in the conflict-affected regions in the south.
Courtesy UNICEF

No. cases in 2014, as of 14 October: Five.
Most recent case: 3 May 2014.
Polio vaccination coverage: 39%.

Immunization coverage in Equatorial Guinea is chronically low, which puts people at risk if the virus is imported into the population. The five infections this year are the first to occur in the country since 1999 and came into the country from an ongoing outbreak in neighboring Cameroon.
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No. cases in 2014, as of 14 October: Five.
Most recent case: 9 July 2014.
Polio vaccination coverage: 85%.

An outbreak of Polio in 2013 led to four cases in the country that year, which were the first reported cases since 2009. The ongoing outbreak meant five more infections occurred in 2014 and the WHO is not ruling out that more unknown infections may have occurred.

Cameroon has led seven supplementary nationwide immunization campaigns, which are also being escalated in Central African Republic to prevent further spread.
Courtesy Reinnier KAZE/AFP/Getty Images

No. cases in 2014, as of 14 October: Two.
Most recent case: 7 April 2014.
Polio vaccination coverage: 70%.

Iraq has not had an indigenous case of polio since 2000, but this year there were two infections imported and reported in children. The form of the virus originates from Pakistan. A rapid and national supplementary immunization campaign is underway to ensure people in Iraq and neighboring countries are immunized.
Courtesy SABAH ARAR/AFP/Getty Images

No. cases in 2014, as of 14 October:
One. Most recent case: 21 January 2014.
Polio vaccination coverage: 52%.

Syria has not had an endemic case of polio since 1999, but an outbreak in October 2013 resulted in 35 cases of the disease that year and one additional infection in 2014.

The ongoing conflict in the country has lowered immunization coverage among the population from 75% in 2013 to 52% this year. This reduces the potential for herd immunity and puts people at risk from imported viruses.
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2014 cases, as of 8 October: One.
Most recent case: 5 January 2013
Polio vaccination coverage: 70%

Ethiopia has had only one case of polio in 2014, down from nine cases in 2013. The country also sits on the "wild polio virus importation belt," meaning it is recurrently at risk of polio importation and re-infection. The solitary infection occurred in the Somali region of the country, where cases also occurred last year.

Nomadic tribal populations reside in the affected region, making them hard to reach with immunization programs. However, the sole case occurred on 5 January 2014, and no further infections have since been reported.
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No. cases in 2014, as of 14 October: Zero.
Most recent case: 14 July 2013
Polio vaccination coverage: 82%.

There have been zero cases of polio in Kenya in 2014. However, the country had an outbreak mid-2013, where 14 people were infected and a rapid outbreak response was initiated across the country.

The 2013 outbreak occurred in eastern Kenya, close to the border with Somalia, where refugee camps are situated. Resulting campaigns have included use of both oral polio vaccine and the injectable Inactivated Polio Vaccine for increased immunity. No cases have occurred in 2014.
Courtesy UNICEF