Poliomyelitis eradication

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Main article: Poliomyelitis

The global eradication of poliomyelitis is a public health effort to eliminate all cases of poliomyelitis infection. The global effort, begun in 1988 and led by the World Health Organization, UNICEF and The Rotary Foundation, has reduced the number of annual diagnosed cases from the hundreds of thousands to around a thousand. Should the effort be successful, the eradication of polio will represent only the second time mankind has ever completely eliminated a disease. The first such disease was smallpox, which was officially eradicated in 1979.^[1]

Contents 1 Factors influencing eradication 2 Early efforts 3 1988-1991 4 1994-2000 5 2001-2004 6 2005 7 2006-present 8 See also 9 References 10 External links

[edit] Factors influencing eradication

Poliomyelitis, is a viral paralytic disease. The causative agent, a virus, called poliovirus, enters the body orally, infecting the intestinal wall. It may proceed to the blood stream and into the central nervous system causing muscle weakness and often paralysis.

Polio is one of few diseases with potential for eradication: the virus is transmitted only through person-to-person contact, (there is no animal reservoir, insects play no role in transmission) and the virus cannot persist in the environment for long periods of time in the absence of a human host (a few weeks at room temperature, and a few months between 0–8° Celsius (32–46° Fahrenheit).^[2]

Another factor that has bolstered efforts to eradicate polio is that the oral polio vaccine is both highly effective and cheap (about $1 per dose, or $3 per child); vaccination generally provides lifelong immunity to the virus.^[3] A study carried out in an isolated Eskimo village showed that antibodies produced from subclinical wild virus infection persisted for at least 40 years.^[4] Because the immune response to oral polio vaccine is very similar to natural polio infection, it is expected that oral polio vaccination provides similar long term immunity.^[5]

Among the greatest obstacles to global polio eradication are the lack of basic health infrastructure, which limits vaccine distribution, the crippling effects of civil war and internal strife, and a philosophical objection to vaccination based on religious reasons in the remaining polio endemic countries. Another challenge has been maintaining the potency of live (attenuated) vaccines in extremely hot or remote areas. The oral polio vaccine must be kept at 2-8° Celsius for vaccination to be successful.^[3]

[edit] Early efforts

International Polio Cases by Year
Year	Estimated	Recorded
1975	-	49,293
1980	400,000	52,552
1985	-	38,637
1988	350,000	35,251
1990	-	23,484
1993	100,000	10,487
1995	-	7,035
2000	-	2,971[6]
2001	-	498
2002	-	1,922
2003	-	784
2004	-	1,258
2005	-	1,998
2006	-	1,985
References:[3][7][8][9][10]

In 1960 Czechoslovakia became the first country in the world scientifically demonstrate nationwide eradication of poliomyelitis.^[11]

In 1962, just one year after Sabin's oral polio vaccine (OPV) was licensed in most industrialized countries, Cuba began using the oral vaccine in a series of nationwide polio campaigns. The early success of these mass vaccination campaigns suggested that polioviruses could be globally eradicated.^[12]

The Pan American Health Organization (PAHO), under the leadership of Dr. Ciro de Quadros launched an initiative to eradicate polio from the Americas in 1985. ^[13]

[edit] 1988-1991

In 1988, the World Health Organization, together with Rotary International, UNICEF, and the U.S. Centers for Disease Control and Prevention passed the Global Polio Eradication Initiative, with the goal of eradicating polio by the year 2000. The Initiative was inspired by Rotary International's 1985 pledge to raise $120 million toward immunising all of the world's children against the disease.^[13]

The last case of wild poliovirus poliomyelitis in the Americas was reported in Peru, August 1991.^[13]

[edit] 1994-2000

On 20 August 1994 the Americas were certified as polio-free.^[14] This achievement was an incredible new milestone in efforts to eradicate the disease.

In 1994 the Indian Government launched the Pulse Polio Campaign to eliminate polio. The current campaign involves annual vaccination of all children under age five.^[15] Most families have allowed their children to take the vaccine.

In 1995 Operation Mecacar (Mediterranean, Caucasus, Central Asian Republics and Russia) were launched; National Immunization Days were coordinated in 19 European and Mediterranean countries.^[16] In 1998, Melik Minas of Turkey, became the last case of polio reported in Europe.^[17]

In 1997 Mum Chanty of Cambodia became the last person to contract polio in the Indo-West Pacific region.^[18] In 2000 the Western Pacific Region (including China) was certified Polio-free.^[18]

[edit] 2001-2004

By 2001, 575 million children (almost one-tenth the world's population) had received some 2 billion doses of oral polio vaccine.^[7] The World Health Organization announced that Europe was polio-free on June 21, 2002 in the Copenhagen Glyptotek.^[19]

In 2002, an outbreak of polio in India occurred after the number of planned polio vaccination campaigns was reduced, the state of Uttar Pradesh accounted for nearly two-thirds of total worldwide cases reported.^[20](See Global polio incidence map (2002).)

In the Kano province in Northern Nigeria, which operates under Sharia (Muslim religious law), the immunization campaign was suspended in September 2003 when prominent Muslim leaders claimed vaccines supplied by Western donors were adulterated to reduce fertility and spread HIV as part of a U.S.-led drive against Islam. On June 30, 2004, after a 10-month ban on polio vaccinations, the WHO announced that Kano had pledged to restart the campaign in early July. During the ban the virus spread across Nigeria and into 12 neighboring countries that had previously been polio-free.^[13] By 2006, this ban would be blamed for 1,500 children being paralyzed and having caused $450 million for emergency activities. In addition to the rumors of sterility and the ban by Nigeria's Kano state, civil war and internal strife in the Sudan and Ivory Coast have complicated WHO's polio eradication goal. In 2004, almost two-thirds all the polio cases in the world occurred in Nigeria (760 out of 1170 total).

[edit] 2005

Reported Polio Cases in 2005
Country	Cases	Transmission Status
Nigeria	727	endemic
Yemen	478	importation
Indonesia	299	importation
Somalia	154	importation
India	64	endemic
Pakistan	27	endemic
Sudan	27	re-established transmission
Ethiopia	20	importation
Angola	9	importation
Niger	9	importation
Afghanistan	7	endemic
Nepal	4	importation
Mali	3	importation
Chad, Eritrea, Cameroun	1 ea.	importation

There were 1,831 cases of wild poliovirus (excludes vaccine derived polio viruses) in 2005.^[8] Most remaining polio infections were located in two areas: the Indian sub-continent and Nigeria.

Nigeria experienced a drop in the number of polio cases of nearly a half from last year, according to the World Health Organization. Officials credit the drop in new infections to improved political control in the southern states and resumed immunisation in the north, where Muslim clerics led a boycott of vaccination in late 2003.^[21]

Eradication efforts in the Indian sub-continent have met with a large measure of success. Using the Pulse Polio campaign to increase polio immunization rates, India recorded just 66 cases in 2005; down from 135 cases reported in 2004, 225 in 2003, and 1,600 in 2002.^[9]

Yemen, Indonesia and Sudan, countries which had been declared polio-free since before 2000, each reported hundreds of cases - probably imported from Nigeria.^[21]

On May 5, 2005, news reports broke that a new case of polio was diagnosed in Java, Indonesia and the virus strain was suspected to be the same as the one that has caused outbreaks in Nigeria. New public fears over the safety, which were unfounded, impeded vaccination efforts in Indonesia. In summer 2005 the WHO, UNICEF and the Indonesian government made new efforts to lay the fears to rest, recruiting celebrities and religious leaders in a publicity campaign to promote vaccination.^[22]

The first case of the polio outbreak in Sudan was detected in May 2004. The reemergence of polio led to stepped up vaccination campaigns. In the city of Darfur; 78,654 children were immunized and 20,432 more in southern Sudan (Yirol and Chelkou).^[23]

In the United States it was reported that "on September 29, 2005 the Minnesota Department of Health (MDH) identified poliovirus type 1 in an unvaccinated, immunocompromised infant girl aged 7 months (the index patient) in an Amish community whose members predominantly were unvaccinated for polio. The patient has no paralysis; the source of the patient's infection is unknown. Subsequently, poliovirus infections in three other children within the index patient's community have been documented."^[24]

[edit] 2006-present

In 2006 only four countries in the world (Nigeria, India, Pakistan, and Afghanistan) were reported to have endemic polio. Cases in other countries are attributed to importation. Polio re-surfaced in Bangladesh after nearly six years of absence with 17 new cases reported since January 2006. "Our country is not safe, as neighbours India and Pakistan are not polio free," declared Health Minister ASM Matiur Rahman.^[25] Nigeria accounts for the majority of cases to date but India has reported more than ten times the number of cases this year as it had in 2005 (30% of worldwide cases this year). Pakistan reported 8 cases in 2006 in children despite being given the polio vaccine. A total of 1985 cases worldwide were reported in 2006 (by February 23, 2007).^[8] (See: Map of reported polio cases in 2006)

In 2007 Pakistan continued to battle polio. In tribal areas, immunization campaigns are unpopular as Muslim clerics have claimed that the immunizations are part of an American conspiracy designed to sterilize the local Muslim population.^[26] In February 2007, physician Abdul Ghani, who was in charge of polio immunizations in a key area of disease occurrence in northern Pakistan, was killed in a terrorist bombing.^[27]

[edit] See also

• Eradication of smallpox
• Population health

[edit] References

[edit] External links

• Global Polio Eradication
• Rotary International: PolioPlus