In anticipation of the special exhibition Countdown to Zero: Defeating Disease, we highlight significant milestones in eradication campaigns.
Guinea Worm Disease
Disease Agent
The parasitic worm Dracunculus medinensis
The Threat
The number of cases has decreased by more than 99 percent since the 1980s, to 148 cases in 2013.
How Infection Spreads
Through drinking water, which contains microscopic crustacean hosts that carry worm larvae.
Defeating the Disease
A concerted effort spearheaded by The Carter Center—educating and engaging communities in solutions to avoid contracting and spreading the disease, plus making available water-filtering tools—has brought the disease within sight of eradication.
Eradication Potential
Poised for eradication.
Lymphatic Filariasis
Disease Agent
Three species of nematode worm: Wucheria bancrofti, Brugia malayi, and Brugia timori
The Threat
About 120 million people are currently infected, with nearly 1.4 billion people in 73 countries under threat.
How Infection Spreads
Through mosquito bites, which transmit these worms’ larvae. The worms damage the lymphatic system, causing painful, disfiguring, and disabling swelling.
Defeating the Disease
Drug treatment and bed nets can prevent transmission.
Eradication Potential
Identified by the World Health Organization (WHO) as a candidate for eradication.
Malaria
Disease Agent
Plasmodium parasites
The Threat
Though preventable and curable, malaria continues to infect hundreds of millions annually across about 100 countries in Africa, Asia, and Latin America.
How Infection Spreads
Through the bites of female Anopheles mosquitoes; there are numerous species of Anopheles around the world.
Defeating the Disease
Widespread use of insecticidal bed nets has been successful in stopping transmission, and vaccines are in development. Genetically engineering mosquitoes is another approach that is being considered.
Eradication Potential
Malaria has been eliminated in certain regions, while for others, control may be the most effective short-term approach.
Polio
Disease Agent
The poliovirus
The Threat
Polio infections fell by more than 99 percent from 1988 to 2013
How Infection Spreads
From person-to-person contact or through contaminated food or water.
Defeating the Disease
Two vaccines—the Oral Polio Vaccine and Inactivated Polio Vaccine—have been in use for over 50 years, helping bring the number of cases world wide to all-time low in 2012.
Eradication Potential
Eradication is possible, but only if vaccination programs are not compromised by regional instability or opposition to vaccines.
River Blindness
Disease agent: Onchocerca volvulus worms
The Threat
Occurs mainly in tropical areas; more than 99 percent of infected people live in sub-Saharan Africa.
How Infection Spreads
Through the bites of black flies. Worms reproduce under the skin, producing thousands of offspring that inflame the skin and cause blindness.
Defeating the Disease
Drug treatment is critical; killing fly larvae in their breeding places also helps interrupt transmission.
Eradication Potential
Successful elimination efforts in Latin America offer models for tackling the disease in sub-Saharan Africa.
Smallpox
Disease Agent
The variola virus
The Threat
First-ever disease to be eradicated; the smallpox virus exists only in secure labs.
How Infection Spreads
From person-to-person contact, through the air, and from contact with infected bodily fluids and objects such as bedding or clothing.
Defeating the Disease
The smallpox vaccine, discovered by Edward Jenner in 1796, was the world’s first vaccine. A global immunization effort began in the mid-20th century, led by the World Health Organization (WHO).
Eradication Potential
Declared eradicated in 1980.
The full story appears in the Winter issue of Rotunda, the Member magazine.