Poliomyelitis eradication
Encyclopedia
The global eradication of poliomyelitis is a public health
Public health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals" . It is concerned with threats to health based on population health...

 effort to eliminate all cases of poliomyelitis
Poliomyelitis
Poliomyelitis, often called polio or infantile paralysis, is an acute viral infectious disease spread from person to person, primarily via the fecal-oral route...

 (polio) infection around the world. The global effort, begun in 1988 and led by the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

, UNICEF and The Rotary Foundation, has reduced the number of annual diagnosed
Diagnosis
Diagnosis is the identification of the nature and cause of anything. Diagnosis is used in many different disciplines with variations in the use of logics, analytics, and experience to determine the cause and effect relationships...

 cases from the hundreds of thousands to around a thousand. If polio is the next disease to be successfully eradicated, this will represent only the third time this has ever been achieved, after smallpox
Smallpox
Smallpox was an infectious disease unique to humans, caused by either of two virus variants, Variola major and Variola minor. The disease is also known by the Latin names Variola or Variola vera, which is a derivative of the Latin varius, meaning "spotted", or varus, meaning "pimple"...

 and rinderpest
Rinderpest
Rinderpest was an infectious viral disease of cattle, domestic buffalo, and some other species of even-toed ungulates, including buffaloes, large antelopes and deer, giraffes, wildebeests and warthogs. After a global eradication campaign, the last confirmed case of rinderpest was diagnosed in 2001...

. The goal of eradicating of worldwide polio has attracted attention, but since 2001 there has been no further reduction in annual cases despite extensive efforts, which has led to getting rid of the last 1% being described as "like trying to squeeze Jell-O to death."

Factors influencing eradication

Eradication of polio has been defined in various ways—as elimination of the occurrence of a poliomyelitis even in the absence of human intervention, as extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...

 of poliovirus
Poliovirus
Poliovirus, the causative agent of poliomyelitis, is a human enterovirus and member of the family of Picornaviridae.Poliovirus is composed of an RNA genome and a protein capsid. The genome is a single-stranded positive-sense RNA genome that is about 7500 nucleotides long. The viral particle is...

, such that the infectious agent no longer exists in nature or in the laboratory, as control of an infection to the point at which transmission
Transmission (medicine)
In medicine and biology, transmission is the passing of a communicable disease from an infected host individual or group to a conspecific individual or group, regardless of whether the other individual was previously infected...

 of the disease ceased within a specified area, and as reduction of the worldwide incidence of poliomyelitis to zero as a result of deliberate efforts, and requiring no further control measures.

In theory, if the right tools were available, it would be possible to eradicate all infectious diseases which only reside in a human host. In reality there are distinct biological features of the organisms and technical factors of dealing with them that make their potential eradicability more or less likely. Three indicators however, are considered of primary importance in determining the likelihood of successful eradication: that effective interventional tools are available to interrupt transmission of the agent, such as a vaccine
Vaccine
A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe or its toxins...

; that diagnostic tools, with sufficient sensitivity and specificity
Specificity
Specificity may refer to:* Being specific * Specificity , the proportion of negatives in a binary classification test which are correctly identified...

, be available to detect infections that can lead to transmission of the disease; and that humans are required for the life-cycle of the agent, which has no other vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...

 reservoir
Natural reservoir
Natural reservoir or nidus, refers to the long-term host of the pathogen of an infectious disease. It is often the case that hosts do not get the disease carried by the pathogen or it is carried as a subclinical infection and so asymptomatic and non-lethal...

 and cannot amplify in the environment.

Strategy

The most important step in eradication of polio is interruption of endemic transmission
Transmission (medicine)
In medicine and biology, transmission is the passing of a communicable disease from an infected host individual or group to a conspecific individual or group, regardless of whether the other individual was previously infected...

 of poliovirus. Stopping polio transmission has been pursued through a combination of routine immunization
Immunization
Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an agent ....

, supplementary immunization campaigns and surveillance of possible outbreaks. The four key strategies outlined by the World Health Organization for stopping polio transmission are:
  1. High infant immunization coverage with four doses of oral polio vaccine
    Polio vaccine
    Two polio vaccines are used throughout the world to combat poliomyelitis . The first was developed by Jonas Salk and first tested in 1952. Announced to the world by Salk on April 12, 1955, it consists of an injected dose of inactivated poliovirus. An oral vaccine was developed by Albert Sabin...

     (OPV) in the first year of life in developing and endemic countries, and routine immunization with OPV and/or IPV elsewhere.
  2. Organization of “National immunization days” to provide supplementary doses of oral polio vaccine to all children less than five years of age.
  3. Active surveillance for wild poliovirus through reporting and laboratory testing of all cases of acute flaccid paralysis among children less than fifteen years of age.
  4. Targeted "mop-up" campaigns once wild poliovirus transmission is limited to a specific focal area.

Vaccination

Oral polio vaccine is highly effective and inexpensive (about US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

0.10 per dose, or US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

0.30 per child.) and its availability has bolstered efforts to eradicate polio. A study carried out in an isolated Eskimo
Eskimo
Eskimos or Inuit–Yupik peoples are indigenous peoples who have traditionally inhabited the circumpolar region from eastern Siberia , across Alaska , Canada, and Greenland....

 village showed that antibodies produced from subclinical wild virus infection persisted for at least 40 years. Because the immune response to oral polio vaccine is very similar to natural polio infection, it is expected that oral polio vaccination provides similar lifelong immunity
Immunity (medical)
Immunity is a biological term that describes a state of having sufficient biological defenses to avoid infection, disease, or other unwanted biological invasion. Immunity involves both specific and non-specific components. The non-specific components act either as barriers or as eliminators of wide...

 to the virus.

Contact immunity
Contact immunity
Contact immunity is the property of some vaccines, where a vaccinated individual can confer immunity upon unimmunized individuals through contact with bodily fluids or excrement...

 to polio can occur when attenuated poliovirus derived from the oral polio vaccine is excreted, and infects and indirectly vaccinates unvaccinated individuals.

Herd immunity

Polio vaccination is also important in the development of herd immunity
Herd immunity
Herd immunity describes a form of immunity that occurs when the vaccination of a significant portion of a population provides a measure of protection for individuals who have not developed immunity...

. For polio to occur in a population, there needs to be an infecting organism (poliovirus
Poliovirus
Poliovirus, the causative agent of poliomyelitis, is a human enterovirus and member of the family of Picornaviridae.Poliovirus is composed of an RNA genome and a protein capsid. The genome is a single-stranded positive-sense RNA genome that is about 7500 nucleotides long. The viral particle is...

), a susceptible human population, and a cycle of transmission
Transmission (medicine)
In medicine and biology, transmission is the passing of a communicable disease from an infected host individual or group to a conspecific individual or group, regardless of whether the other individual was previously infected...

. Poliovirus is transmitted only through person-to-person contact and the transmission cycle of polio is from one infected person to another person susceptible to the disease, and so on. If the vast majority of the population is immune to a particular agent, the ability of that pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...

 to infect another host is reduced; the cycle of transmission is interrupted, and the pathogen cannot reproduce and dies out. This concept, called community immunity or herd immunity, is important to disease eradication because if the number of susceptible individuals can be reduced to a small number through vaccination
Vaccination
Vaccination is the administration of antigenic material to stimulate the immune system of an individual to develop adaptive immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by many pathogens...

, the pathogen itself can also be eliminated.

When many hosts are vaccinated, especially simultaneously, the transmission of wild virus is blocked, and the virus is unable to find another susceptible individual to infect. Because poliovirus can only survive for a short time in the environment (a few weeks at room temperature, and a few months between 0–8° Celsius
Celsius
Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...

 (32–46° Fahrenheit
Fahrenheit
Fahrenheit is the temperature scale proposed in 1724 by, and named after, the German physicist Daniel Gabriel Fahrenheit . Within this scale, the freezing of water into ice is defined at 32 degrees, while the boiling point of water is defined to be 212 degrees...

)) without a human host the virus dies out.

Herd immunity is an important supplement to vaccination. Among those individuals who receive oral polio vaccine, only 95 percent will develop immunity. That means 5 of every 100 given the vaccine won’t develop any immunity and will be susceptible to developing polio. According to the concepts of herd immunity this population whom the vaccine fails, are still protected by the immunity of those around them. Herd immunity can only be achieved when vaccination levels are high. It is estimated that 80-86 percent of individuals in a population must be immune to polio for the susceptible individuals to be protected by herd immunity. If routine immunization were stopped, the number of unvaccinated, susceptible individuals would soon exceed the capability of herd immunity to protect them.

Obstacles

Among the greatest obstacles to global polio eradication are the lack of basic health infrastructure, which limits vaccine distribution and delivery, the crippling effects of civil war and internal strife, and the sometimes oppositional stance that marginalized communities take against what is perceived as a vertical (top down) intervention. Another challenge has been maintaining the potency
Potency
Potency may refer to:* Potency , a measure of the activity of a drug in a biological system* Virility* Potency is a measure of the differentiation potential of stem cells...

 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.

An independent evaluation of obstacles to polio eradication requested by the WHO and conducted in 2009 considered the major obstacles in detail by country. In Afghanistan and Pakistan, they concluded that the most significant barrier was insecurity; but that managing human resources, political pressures, the movement of large populations between and within both countries, inadequately resourced health facilities, also posed problems, as well as technical issues with the vaccine. In India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, the major challenge appeared to be the high efficiency of transmission within the populations of Bihar
Bihar
Bihar is a state in eastern India. It is the 12th largest state in terms of geographical size at and 3rd largest by population. Almost 58% of Biharis are below the age of 25, which is the highest proportion in India....

 district and Uttar Pradesh
Uttar Pradesh
Uttar Pradesh abbreviation U.P. , is a state located in the northern part of India. With a population of over 200 million people, it is India's most populous state, as well as the world's most populous sub-national entity...

, set against the low (~80% after three doses against type 1) seroconversion response seen from the vaccine. In Nigeria, meanwhile, the most critical barriers identified were management issues, in particular the highly variable importance ascribed to polio by different authorities at the local government level, although funding issues, community perceptions of vaccine safety, inadequate mobilisation of community groups, and issues with the cold chain also played a role. Finally, in those countries where international spread from endemic countries had resulted in transmission becoming re-established - namely Angola
Angola
Angola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...

, Chad
Chad
Chad , officially known as the Republic of Chad, is a landlocked country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon and Nigeria to the southwest, and Niger to the west...

, and South Sudan
South Sudan
South Sudan , officially the Republic of South Sudan, is a landlocked country located in the Sahel region of northeastern Africa. It is also part of the North Africa UN sub-region. Its current capital is Juba, which is also its largest city; the capital city is planned to be moved to the more...

, the key issues identified were underdeveloped health systems and low routine vaccine coverage, although low resources committed to Angola and South Sudan for the purpose of curtailing the spread of polio and climatic factors were also identified as playing a role.

Two additional challenges are found in unobserved polio transmission and in vaccine-derived poliovirus. In 99% of infections, polio is a mild condition that causes very few symptoms and most infected people are unaware that they carry the disease, allowing polio to spread widely before cases are seen. And since 2000, there have been a number of outbreaks of circulating vaccine-derived poliovirus, following mutations or recombinations in the attenuated strain used for the oral polio vaccine, which have raised the necessity of eventually switching to the more expensive inactivated polio vaccine.

Progress

International Polio Cases and Countries reporting Cases by Year
Year Estimated Recorded Countries
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
2001 - 483 15
2002 - 1,918 9
2003 - 784 15
2004 - 1,258 18
2005 - 1,979 16
2006 - 1,997 17
2007 - 1,315 12
2008 - 1,651 18
2009 - 1,604 23
2010 - 1,294 20
References:


Following the widespread use of poliovirus vaccine in the mid-1950s, the incidence of poliomyelitis declined rapidly in many industrialized countries. Czechoslovakia
Czechoslovakia
Czechoslovakia or Czecho-Slovakia was a sovereign state in Central Europe which existed from October 1918, when it declared its independence from the Austro-Hungarian Empire, until 1992...

 became the first country in the world to scientifically demonstrate nationwide eradication of poliomyelitis in 1960. In 1962 — just one year after Sabin
Albert Sabin
Albert Bruce Sabin was an American medical researcher best known for having developed an oral polio vaccine.-Life:...

's oral polio vaccine (OPV) was licensed in most industrialized countries — Cuba
Cuba
The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...

 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. The Pan American Health Organization (PAHO), under the leadership of Ciro de Quadros
Ciro de Quadros
Dr. Ciro de Quadros is a leader in the field of Public Health, in particular, the area of vaccine preventable diseases.-Eradication of polio:Dr. de Quadros played a critical role in developing the strategies now used worldwide in the eradication of polio....

, launched an initiative to eradicate polio from the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

 in 1985.

Much of the work towards eradication was documented by Brazilian photographer Sebastião Salgado
Sebastião Salgado
Sebastião Salgado is a Brazilian social documentary photographer and photojournalist.-Biography:Salgado was born on February 8, 1944 in Aimorés, in the state of Minas Gerais, Brazil. After a somewhat itinerant childhood, Salgado initially trained as an economist, earning a master’s degree in...

, as a UNICEF Goodwill Ambassador, in the book The End of Polio: Global Effort to End a Disease.

1988–1991

In 1988, the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

, together with Rotary International
Rotary International
Rotary International is an organization of service clubs known as Rotary Clubs located all over the world. The stated purpose of the organization is to bring together business and professional leaders to provide humanitarian service, encourage high ethical standards in all vocations, and help...

, UNICEF, and the U.S. Centers for Disease Control and Prevention
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...

 passed the Global Polio Eradication Initiative, with the goal of eradicating polio by the year 2000. The Initiative was inspired by Rotary International
Rotary International
Rotary International is an organization of service clubs known as Rotary Clubs located all over the world. The stated purpose of the organization is to bring together business and professional leaders to provide humanitarian service, encourage high ethical standards in all vocations, and help...

's 1985 pledge to raise $120 million toward immunising all of the world's children against the disease. The last case of wild poliovirus poliomyelitis in the Americas was reported in Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

, August 1991.

1994–2000

On 20 August 1994 the Americas were certified as polio-free. This achievement was a milestone in efforts to eradicate the disease.

In 1994 the Indian Government launched the Pulse Polio
Pulse Polio
Pulse Polio is an immunisation campaign established by the government of India in 1995-96 to eradicate poliomyelitis in India by vaccinating all children under the age of five years against polio virus...

 Campaign to eliminate polio. The current campaign involves annual vaccination of all children under age five.

In 1995 Operation MECACAR
MECACAR
Operation MECACAR is a multi-national immunization program launched in 1995 by the World Health Organization to coordinate polio vaccination efforts...

 (Mediterranean, Caucasus
Caucasus
The Caucasus, also Caucas or Caucasia , is a geopolitical region at the border of Europe and Asia, and situated between the Black and the Caspian sea...

, Central Asian Republics and Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

) were launched; National Immunization Days were coordinated in 19 Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

an and Mediterranean countries. In 1998, Melik Minas of Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

 became the last case of polio reported in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

. In 1997 Mum Chanty of Cambodia
Cambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...

 became the last person to contract polio in the Indo-West Pacific
Indo-West Pacific
The Indo-West Pacific, or IWP, is a zoogeographical region spanning the entire Indian Ocean including the Red Sea and the Pacific Ocean as far as the Caroline Islands but short of the Marshall Islands...

 region. In 2000 the Western Pacific Region (including China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

) was certified Polio-free.

In October 1999, the last isolation of type 2 poliovirus occurred in India. This type of poliovirus appears to have been eradicated.

Also in October 1999, The CORE Group -- with funding from the United States Agency for International Development
United States Agency for International Development
The United States Agency for International Development is the United States federal government agency primarily responsible for administering civilian foreign aid. President John F. Kennedy created USAID in 1961 by executive order to implement development assistance programs in the areas...

 (USAID) -- launched its effort to support national eradication efforts at the grassroots level. The CORE Group initiated this initiative in Bangladesh
Bangladesh
Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...

, India and Nepal
Nepal
Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...

 in South Asia, and in Angola
Angola
Angola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...

, Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...

 and Uganda
Uganda
Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...

 in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

.

2001–2004

By 2001, 575 million children (almost one-tenth the world's population) had received some 2 billion doses of oral polio vaccine. The World Health Organization announced that Europe was polio-free on June 21, 2002 in the Copenhagen
Copenhagen
Copenhagen is the capital and largest city of Denmark, with an urban population of 1,199,224 and a metropolitan population of 1,930,260 . With the completion of the transnational Øresund Bridge in 2000, Copenhagen has become the centre of the increasingly integrating Øresund Region...

 Glyptotek
Ny Carlsberg Glyptotek
The Ny Carlsberg Glyptotek is an art museum in Copenhagen, Denmark...

.

In 2002, an outbreak of polio in India occurred. The number of planned polio vaccination campaigns had recently been reduced, and populations in northern India, particularly from the Islamic background, engaged in mass resistance to immunization. At this time, the Indian state Uttar Pradesh
Uttar Pradesh
Uttar Pradesh abbreviation U.P. , is a state located in the northern part of India. With a population of over 200 million people, it is India's most populous state, as well as the world's most populous sub-national entity...

 accounted for nearly two-thirds of total worldwide cases reported. (See the 2002 Global polio incidence map.) However, by 2004, India had adopted strategies to increase ownership of polio vaccinations in marginalized populations, and the immunity gap in vulnerable groups rapidly closed.

In August 2003, rumors spread in some states in Nigeria, especially Kano
Kano
Kano is a city in Nigeria and the capital of Kano State in Northern Nigeria. Its metropolitan population is the second largest in Nigeria after Lagos. The Kano Urban area covers 137 sq.km and comprises six Local Government Area - Kano Municipal, Fagge, Dala, Gwale, Tarauni and Nassarawa - with a...

, that the vaccine caused sterility in girls. This resulted in the suspension of immunization efforts in the state, causing a dramatic rise in polio rates in the already endemic country. On June 30, 2004, the WHO announced that after a 10-month ban on polio vaccinations, 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. By 2006, this ban would be blamed for 1,500 children being paralyzed and had cost $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
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...

 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).

2005

Reported Polio Cases in 2005
Country Cases Transmission
Status
Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...

 
830 endemic
Yemen
Yemen
The Republic of Yemen , commonly known as Yemen , is a country located in the Middle East, occupying the southwestern to southern end of the Arabian Peninsula. It is bordered by Saudi Arabia to the north, the Red Sea to the west, and Oman to the east....

 
478 importation
Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

 
303 importation
Somalia
Somalia
Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...

 
185 importation
India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 
66 endemic
Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

 
27 endemic
Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...

 
27 re-established
transmission
Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...

 
22 importation
Angola
Angola
Angola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...

 
10 importation
Niger
Niger
Niger , officially named the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east...

 
10 importation
Afghanistan
Afghanistan
Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...

 
9 endemic
Nepal
Nepal
Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...

 
4 importation
Mali
Mali
Mali , officially the Republic of Mali , is a landlocked country in Western Africa. Mali borders Algeria on the north, Niger on the east, Burkina Faso and the Côte d'Ivoire on the south, Guinea on the south-west, and Senegal and Mauritania on the west. Its size is just over 1,240,000 km² with...

 
3 importation
Chad
Chad
Chad , officially known as the Republic of Chad, is a landlocked country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon and Nigeria to the southwest, and Niger to the west...

, Eritrea
Eritrea
Eritrea , officially the State of Eritrea, is a country in the Horn of Africa. Eritrea derives it's name from the Greek word Erethria, meaning 'red land'. The capital is Asmara. It is bordered by Sudan in the west, Ethiopia in the south, and Djibouti in the southeast...

,
Cameroon
Cameroon
Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...

 
1 ea. importation


There were 1,979 cases of wild poliovirus (excludes vaccine
Vaccine
A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe or its toxins...

 derived polio virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

es) in 2005. Most remaining polio infections were located in two areas: the Indian subcontinent
Indian subcontinent
The Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...

 and Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...

.

Eradication efforts in the Indian sub-continent have met with a large measure of success. Using the Pulse Polio
Pulse Polio
Pulse Polio is an immunisation campaign established by the government of India in 1995-96 to eradicate poliomyelitis in India by vaccinating all children under the age of five years against polio virus...

 campaign to increase polio immunization rates, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 recorded just 66 cases in 2005; down from 135 cases reported in 2004, 225 in 2003, and 1,600 in 2002.

Yemen
Yemen
The Republic of Yemen , commonly known as Yemen , is a country located in the Middle East, occupying the southwestern to southern end of the Arabian Peninsula. It is bordered by Saudi Arabia to the north, the Red Sea to the west, and Oman to the east....

, Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

 and Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...

, countries which had been declared polio-free since before 2000, each reported hundreds of cases - probably imported from Nigeria. On May 5, 2005, news reports broke that a new case of polio was diagnosed in Java, Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

 and the virus strain was suspected to be the same as the one that has caused outbreaks in Nigeria. New public fears over vaccine 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.

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
Darfur
Darfur is a region in western Sudan. An independent sultanate for several hundred years, it was incorporated into Sudan by Anglo-Egyptian forces in 1916. The region is divided into three federal states: West Darfur, South Darfur, and North Darfur...

; 78,654 children were immunized and 20,432 more in southern Sudan (Yirol and Chelkou).

In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 on September 29, 2005 the Minnesota Department of Health identified the first occurrence of vaccine derived polio virus (VDPV) transmission in the United States since OPV vaccinations were discontinued in 2000. The poliovirus type 1 infection occurred in an unvaccinated, immunocompromised infant girl aged 7 months (the index patient) in an Amish
Amish
The Amish , sometimes referred to as Amish Mennonites, are a group of Christian church fellowships that form a subgroup of the Mennonite churches...

 community whose members predominantly were unvaccinated for polio.

2006–2009

In 2006 only four countries in the world (Nigeria, India, Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

 and Afghanistan
Afghanistan
Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...

) were reported to have endemic poliomyelitis. Cases in other countries are attributed to importation. A total of 1,997 cases worldwide were reported in 2006; of these the majority (1,869 cases) occurred in countries with endemic polio. Nigeria accounted for the majority of cases (1,122 cases) but India reported more than ten times more cases this year than in 2005 (676 cases, or 30% of worldwide cases). Pakistan and Afghanistan reported 40 and 31 cases respectively in 2006. Polio re-surfaced in Bangladesh
Bangladesh
Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...

 after nearly six years of absence with 18 new cases reported. "Our country is not safe, as neighbours India and Pakistan are not polio free", declared Health Minister ASM Matiur Rahman. (See: Map of reported polio cases in 2006)

In 2007 there were 1,315 cases of poliomyelitis reported worldwide. Over 60% of cases (874) occurred in India; while in Nigeria, the number of polio cases fell dramatically, from 1,122 cases reported in 2006 to 285 cases in 2007. 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. Local governments and clerics allowed vaccinations to resume on the condition that the vaccines be manufactured in Indonesia, a majority Muslim country, and not in the United States. Turai Yar'Adua
Turai Yar'Adua
Hajiya Turai Umar Musa iar'Adua is the widow of former Nigerian President and former Katsina State Governor Umaru Yar'Adua. She served as the First Lady of Nigeria from 2007 until the death of her husband, President Yar'Adua, on May 5, 2010....

, wife of recently-elected Nigerian president Umaru Yar'Adua, made the eradication of polio one of her priorities. Attending the launch of immunization campaigns in Birnin Kebbi
Birnin Kebbi
Birnin Kebbi is a city located in northwestern Nigeria. It is the capital city of Kebbi State and headquarters of the Gwandu Emirate. As of 2007 the city has an estimated population of 115,547....

 in July 2007, Turai Yar'Adua urged parents to vaccinate their children and stressed the safety of oral polio vaccine.

One factor in the failure of polio immunization programs has been opposition by Muslim
Muslim
A Muslim, also spelled Moslem, is an adherent of Islam, a monotheistic, Abrahamic religion based on the Quran, which Muslims consider the verbatim word of God as revealed to prophet Muhammad. "Muslim" is the Arabic term for "submitter" .Muslims believe that God is one and incomparable...

 fundamentalists. This opposition has varied and is linked mostly to local political will rather than any religious orthodoxy. In Pakistan and Afghanistan, the Taliban have issued fatwa
Fatwa
A fatwā in the Islamic faith is a juristic ruling concerning Islamic law issued by an Islamic scholar. In Sunni Islam any fatwā is non-binding, whereas in Shia Islam it could be considered by an individual as binding, depending on his or her relation to the scholar. The person who issues a fatwā...

s
against polio vaccination, while Saudi Arabia
Saudi Arabia
The Kingdom of Saudi Arabia , commonly known in British English as Saudi Arabia and in Arabic as as-Sa‘ūdiyyah , is the largest state in Western Asia by land area, constituting the bulk of the Arabian Peninsula, and the second-largest in the Arab World...

 has supported the eradication effort by demanding that all pilgrims to the Haj
Háj
Háj may refer to:* Háj in Turčianske Teplice District, Slovakia* Háj in Košice-okolie District, Slovakia...

 that originate from polio endemic countries receive vaccination upon arrival. But even with the express support of political leaders, polio workers have been kidnapped, beaten, and assassinated. 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. In July 2007, a student traveling from Pakistan imported the first polio case to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 in over 20 years. Other countries with significant numbers of wild polio virus cases include the Democratic Republic of the Congo
Democratic Republic of the Congo
The Democratic Republic of the Congo is a state located in Central Africa. It is the second largest country in Africa by area and the eleventh largest in the world...

 which reported 41 cases, Chad with 22 cases, and Niger and Myanmar
Myanmar
Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....

, each of which reported 11 cases.

In 2008, 19 countries reported cases and the total number of cases was 1652. Of these, 1506 occurred in the four endemic countries (146 elsewhere). The largest number were in Nigeria (799 cases) and India (559 cases): these two countries contributed 82.2% of all cases. Outside endemic countries Chad reported the greatest number (37 cases).

In 2009, a total of 1606 cases were reported in 23 countries. 1256 of these were in the four endemic countries, with the remaining 350 in 19 sub-Saharan countries with imported cases or re-established transmission. Once again, the largest number were in India (741) and Nigeria (388). All other countries had less than one hundred cases: Pakistan had 89 cases, Afghanistan 38, Chad
Chad
Chad , officially known as the Republic of Chad, is a landlocked country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon and Nigeria to the southwest, and Niger to the west...

 65, Sudan 45, Guinea
Guinea
Guinea , officially the Republic of Guinea , is a country in West Africa. Formerly known as French Guinea , it is today sometimes called Guinea-Conakry to distinguish it from its neighbour Guinea-Bissau. Guinea is divided into eight administrative regions and subdivided into thirty-three prefectures...

 42, Angola 29, Côte d'Ivoire
Côte d'Ivoire
The Republic of Côte d'Ivoire or Ivory Coast is a country in West Africa. It has an area of , and borders the countries Liberia, Guinea, Mali, Burkina Faso and Ghana; its southern boundary is along the Gulf of Guinea. The country's population was 15,366,672 in 1998 and was estimated to be...

 26, Benin
Benin
Benin , officially the Republic of Benin, is a country in West Africa. It borders Togo to the west, Nigeria to the east and Burkina Faso and Niger to the north. Its small southern coastline on the Bight of Benin is where a majority of the population is located...

 20, Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...

 19, Niger
Niger
Niger , officially named the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east...

 15, Central African Republic
Central African Republic
The Central African Republic , is a landlocked country in Central Africa. It borders Chad in the north, Sudan in the north east, South Sudan in the east, the Democratic Republic of the Congo and the Republic of the Congo in the south, and Cameroon in the west. The CAR covers a land area of about ,...

 14, Mauritania
Mauritania
Mauritania is a country in the Maghreb and West Africa. It is bordered by the Atlantic Ocean in the west, by Western Sahara in the north, by Algeria in the northeast, by Mali in the east and southeast, and by Senegal in the southwest...

 13 and Sierra Leone
Sierra Leone
Sierra Leone , officially the Republic of Sierra Leone, is a country in West Africa. It is bordered by Guinea to the north and east, Liberia to the southeast, and the Atlantic Ocean to the west and southwest. Sierra Leone covers a total area of and has an estimated population between 5.4 and 6.4...

 and Liberia
Liberia
Liberia , officially the Republic of Liberia, is a country in West Africa. It is bordered by Sierra Leone on the west, Guinea on the north and Côte d'Ivoire on the east. Liberia's coastline is composed of mostly mangrove forests while the more sparsely populated inland consists of forests that open...

 both had 11. The following countries had single digit numbers of cases: Burundi
Burundi
Burundi , officially the Republic of Burundi , is a landlocked country in the Great Lakes region of Eastern Africa bordered by Rwanda to the north, Tanzania to the east and south, and the Democratic Republic of the Congo to the west. Its capital is Bujumbura...

 2, Cameroon
Cameroon
Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...

 3, the Democratic Republic of the Congo
Democratic Republic of the Congo
The Democratic Republic of the Congo is a state located in Central Africa. It is the second largest country in Africa by area and the eleventh largest in the world...

 3, Mali
Mali
Mali , officially the Republic of Mali , is a landlocked country in Western Africa. Mali borders Algeria on the north, Niger on the east, Burkina Faso and the Côte d'Ivoire on the south, Guinea on the south-west, and Senegal and Mauritania on the west. Its size is just over 1,240,000 km² with...

 2, Togo
Togo
Togo, officially the Togolese Republic , is a country in West Africa bordered by Ghana to the west, Benin to the east and Burkina Faso to the north. It extends south to the Gulf of Guinea, on which the capital Lomé is located. Togo covers an area of approximately with a population of approximately...

 6 and Uganda
Uganda
Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...

 8.

2010

According to figures updated in June 2011, the World Health Organization reports that there were 1,349 cases of wild polio in 20 countries in 2010. Reported cases of polio are down 95% in Nigeria (to a historic low of 21 cases) and 94% in India (to a historic low of 42 cases) compared to the previous year, with little change in Afghanistan (from 38 to 25 cases) and an increase in cases in Pakistan (from 89 to 144 cases). 457 cases (34% of the global total) were reported from an acute outbreak in Tajikistan
Tajikistan
Tajikistan , officially the Republic of Tajikistan , is a mountainous landlocked country in Central Asia. Afghanistan borders it to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east....

, which was associated with a further 18 cases across Central Asia (Kazakhstan
Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...

 and Turkmenistan
Turkmenistan
Turkmenistan , formerly also known as Turkmenia is one of the Turkic states in Central Asia. Until 1991, it was a constituent republic of the Soviet Union, the Turkmen Soviet Socialist Republic . Turkmenistan is one of the six independent Turkic states...

) and the Russian Federation, with the most recent case from this region being reported from Russia the 25th September. These were the first cases in the WHO European region since 2002. 441 cases (30% of the global total) were reported from an outbreak in the Republic of Congo (Brazzaville
Brazzaville
-Transport:The city is home to Maya-Maya Airport and a railway station on the Congo-Ocean Railway. It is also an important river port, with ferries sailing to Kinshasa and to Bangui via Impfondo...

). At least 179 deaths have so far been associated with this outbreak, which is believed to have been an importation from the ongoing type 1 outbreak in Angola (33 cases in 2010) and the Democratic Republic of the Congo (100 cases).

2011

Up to the end of April 33 cases were reported in Pakistan, eight in Nigeria and only one in both India and Afghanistan.

To the end of June 2011 241 cases globally have been reported (216 wild poliovirus type 1 and 25 wild polio type 3). This compares with 456 cases reported to the end of May in 2010 (399 type 1 and 57 type 3). Cases have been reported in the four endemic countries -- Pakistan, Afghanistan, Nigeria and India -- as well as in the Democratic Republic of Congo, Chad, Angola, Mali, Cote d'Ivoire, Burkina Faso
Burkina Faso
Burkina Faso – also known by its short-form name Burkina – is a landlocked country in west Africa. It is surrounded by six countries: Mali to the north, Niger to the east, Benin to the southeast, Togo and Ghana to the south, and Côte d'Ivoire to the southwest.Its size is with an estimated...

, the Republic of Congo (Brazzaville), Niger and Gabon
Gabon
Gabon , officially the Gabonese Republic is a state in west central Africa sharing borders with Equatorial Guinea to the northwest, Cameroon to the north, and with the Republic of the Congo curving around the east and south. The Gulf of Guinea, an arm of the Atlantic Ocean is to the west...

. Over 80% of all cases seen this year come from three countries: Chad, the Democratic Republic of the Congo and Pakistan. In India, only 1 case of wild poliovirus has been reported this year--a remarkable feat in a country that in many recent years has had a plurality or majority of the world's polio cases.

Since the start of 2010 there have been 14 outbreaks of polio. Several are continuing into 2011. To June 2011 Chad has reported 80 cases; the Democratic Republic of the Congo has reported 59; and Pakistan has reported 54. Polio transmission has recurred in Angola, Chad and the Democratic Republic of the Congo. The number of cases reported in Pakistan is double the number reported over the same period in 2010. 16 cases have been reported in Nigeria. Although the situation in Northern Nigeria has improved, concerns exist about further outbreaks there because of its central location. On the basis of current trends it would appear that Pakistan will be the be last place of Earth where wild polio will survive.

Up to the end of August there have been 364 cases reported (308 type 1 and 56 type 3). Up to the same date in 2010 there were 641 cases (574 type 1 and 67 type 3). Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...

 has reported its first case since 2009. China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 has reported four cases - the first cases since 1994. Côte d'Ivoire has reported 34 cases of type 3 polio as part of an ongoing outbreak. Afghanistan has reported 18 cases (all type 1). Chad has reported 109 cases. India has reported no case since January.

The situation in Pakistan is complex. The lowest number of cases reported in one year was 32 in 2007. In the first six months of 2011 there were 69 cases (compared with 37 in the same period in 2010). The remaining focuses lie in three parts of Pakistan: Balochistan Province, Karachi
Karachi
Karachi is the largest city, main seaport and the main financial centre of Pakistan, as well as the capital of the province of Sindh. The city has an estimated population of 13 to 15 million, while the total metropolitan area has a population of over 18 million...

 and the Federally Administered Tribal Areas. About 25% of children in Karachi are unvaccinated against polio; in Balochistan ~50% are unvaccinated. In contrast in Afghanistan the unvaccinated rate is ~10%. The difficulty in Pakistan appears to be a lack of trust in the health workers trying to vaccinate the children.

Up to the end of September there have been 429 cases - 370 due to type 1 and 59 due to type 3. 36 have been reported in Afghanistan. Chad has reported 111 cases. 10 have been reported in China: all have occurred in the Xinjiang Uygur - 9 in Hotan prefecture

See also

  • Eradication of infectious diseases
    Eradication of infectious diseases
    Eradication is the reduction of an infectious disease's prevalence in the global host population to zero. It is sometimes confused with elimination, which describes either the reduction of an infectious disease's prevalence in a regional population to zero, or the reduction of the global prevalence...

  • Population health
    Population health
    Population health has been defined as “the health outcomes of a group of individuals, including the distribution of such outcomes within the group.” It is an approach to health that aims to improve the health of an entire population. One major step in achieving this aim is to reduce health...

  • Mathematical modelling of infectious disease
  • Transmission risks and rates
    Transmission risks and rates
    Transmission of an infection requires three conditions:*an infectious individual*a susceptible individual*an effective contact between themAn effective contact is defined as any kind of contact between two individuals such that, if one individual is infectious and the other susceptible, then the...

  • The Final Inch
    The Final Inch
    The Final Inch is a short documentary about the effort to eradicate polio. It was directed by Irene Taylor Brodsky and focuses on health workers who are on the front lines of the fight to eliminate the disease....


External links

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