once-deadliest diseases that have been completely eradicated

1. Smallpox

Smallpox was a highly contagious and deadly viral disease caused by the variola virus. It manifested through fever, rash, and the formation of fluid-filled lesions on the skin. With a long history of affecting human populations, smallpox was responsible for numerous epidemics and significant mortality worldwide. However, a major breakthrough in medical history occurred with the development of a highly effective smallpox vaccine by Edward Jenner in the late 18th century. Intensive global vaccination campaigns followed in the 20th century, leading to the successful eradication of smallpox in 1980—the first and only infectious disease to be eradicated through human efforts. The eradication of smallpox stands as a remarkable achievement in public health, demonstrating the impact of widespread vaccination in eliminating a once-feared and devastating disease.

2. Rinderpest

Rinderpest, a highly contagious viral disease affecting cattle and other cloven-hoofed animals, was a significant threat to global agriculture. Caused by the Morbillivirus, rinderpest led to fever, oral erosions, and severe gastrointestinal symptoms in infected animals. The disease had devastating consequences for livestock populations, resulting in economic losses and food insecurity in affected regions. Efforts to control rinderpest intensified in the mid-20th century, culminating in a coordinated global vaccination campaign led by the Food and Agriculture Organization (FAO) and the World Organisation for Animal Health (OIE). This campaign, spanning several decades, successfully eradicated rinderpest, with the last known case reported in 2001. The eradication of rinderpest not only protected livestock but also had broader implications for food security, rural livelihoods, and agricultural sustainability. This achievement showcases the effectiveness of international collaboration and vaccination programs in eliminating a significant threat to animal health and well-being.

3. Guinea Worm Disease (Dracunculiasis)

Guinea Worm Disease, caused by the parasitic Guinea worm (Dracunculus medinensis), is a debilitating affliction that primarily affects impoverished communities in regions with limited access to clean water. The life cycle begins with humans ingesting water containing tiny copepods carrying Guinea worm larvae. Once inside the body, the larvae mature into long, painful worms that eventually emerge through the skin, causing incapacitating blisters, especially on the lower limbs. This excruciating process hinders individuals from carrying out daily activities and contributes to economic hardships. Global eradication efforts have focused on promoting clean water sources, implementing water filtration practices, and educating communities about preventive measures. Organizations like the Carter Center have spearheaded these efforts, resulting in a substantial reduction in Guinea worm cases and bringing the world closer to eradicating this neglected tropical disease.

4. Poliomyelitis (Polio)

Polio, short for poliomyelitis, is a viral infection caused by the poliovirus, with the potential to cause paralysis. Transmitted through contaminated water or food, the virus primarily affects children under five years old. The disease can lead to irreversible paralysis within hours, posing a significant public health threat. Global vaccination initiatives, especially through the oral polio vaccine, have been instrumental in reducing polio cases significantly. The Global Polio Eradication Initiative, a collaborative effort involving the World Health Organization (WHO), Rotary International, UNICEF, and the Centers for Disease Control and Prevention (CDC), has made substantial progress in eradicating the disease. While polio remains endemic in a few countries, ongoing vaccination campaigns and surveillance efforts aim to achieve the ultimate goal of a polio-free world, highlighting the impact of coordinated global health initiatives in combatting infectious diseases.

5. Yaws

Yaws is a tropical infectious disease caused by the bacterium Treponema pallidum subspecies pertenue. This neglected tropical disease primarily affects impoverished communities in tropical regions with limited access to healthcare and sanitation. Yaws is transmitted through direct skin-to-skin contact, often affecting children, causing painless, raised lesions on the skin, bones, and joints. While not fatal, yaws can lead to disfigurement and disability if left untreated. Efforts to control yaws have involved mass drug administration with antibiotics, particularly azithromycin, to affected communities. These initiatives, led by organizations like the World Health Organization (WHO), have made significant strides in reducing yaws prevalence and improving the health and well-being of those at risk, illustrating the importance of targeted interventions in addressing neglected tropical diseases.

6. Onchocerciasis (River Blindness)

Onchocerciasis, commonly known as river blindness, is a parasitic disease caused by the filarial worm Onchocerca volvulus. Transmitted through the bites of infected blackflies, the larvae of the parasite can cause severe skin and eye manifestations. Afflicting communities living near fast-flowing rivers in sub-Saharan Africa, Latin America, and Yemen, onchocerciasis can lead to visual impairment and blindness. The World Health Organization (WHO) has spearheaded efforts to control the disease through mass drug administration of ivermectin, which effectively kills the larvae, preventing the progression of the disease. These initiatives have demonstrated success in reducing the prevalence of onchocerciasis, alleviating suffering in affected populations, and highlighting the significance of community-focused interventions in combating neglected tropical diseases.

7. Leprosy

Leprosy, also known as Hansen's disease, is a chronic infectious disease caused by the bacterium Mycobacterium leprae. Primarily affecting the skin, nerves, and mucous membranes, leprosy often leads to skin lesions and nerve damage. Despite being curable with multi-drug therapy, leprosy has historically carried significant social stigma, contributing to the isolation of affected individuals. Global efforts led by organizations like the World Health Organization (WHO) have focused on early detection, treatment, and reducing discrimination associated with leprosy. Although considerable progress has been made, pockets of leprosy still exist in certain regions, emphasizing the ongoing need for awareness, community-based healthcare initiatives, and the eradication of misconceptions surrounding the disease.

8. Measles

Measles, a highly contagious viral infection caused by the measles virus, manifests with fever, cough, and characteristic red rashes. It primarily affects children and can lead to severe complications, including pneumonia and encephalitis. Despite the availability of an effective vaccine, measles outbreaks continue to pose public health challenges, particularly in areas with suboptimal vaccination coverage. Vaccination campaigns led by organizations such as the World Health Organization (WHO) have played a crucial role in reducing measles-related morbidity and mortality globally. However, vaccine hesitancy and gaps in immunization programs contribute to periodic resurgences of the disease. Efforts to maintain high vaccination rates, strengthen healthcare infrastructure, and address misinformation remain essential in the ongoing battle against measles and its potential impact on public health.

9. Mumps

Mumps is a contagious viral infection caused by the mumps virus, characterized by swelling of the salivary glands, especially the parotid glands. The virus is spread through respiratory droplets and can lead to symptoms such as fever, headache, and muscle aches. While most cases of mumps are mild, complications such as inflammation of the testicles or ovaries can occur, particularly in post-pubertal individuals. The Mumps, Measles, and Rubella (MMR) vaccine has been instrumental in reducing the incidence of mumps and its associated complications. However, occasional outbreaks highlight the importance of maintaining high vaccination coverage to prevent the spread of the virus within communities. Public health measures, including routine immunization and surveillance, remain critical in controlling mumps and safeguarding overall community health.

10. Rubella

Rubella, also known as German measles, is a contagious viral infection caused by the rubella virus. It is characterized by a mild rash, fever, and swollen lymph nodes. While rubella itself is generally a mild illness, its significance lies in its potential to cause serious complications when contracted by pregnant women. If a pregnant woman is infected with rubella, especially during the first trimester, it can lead to congenital rubella syndrome (CRS), resulting in severe birth defects and developmental issues in the newborn. Vaccination, often administered as part of the Mumps, Measles, and Rubella (MMR) vaccine, has been effective in preventing rubella and its associated complications. Global immunization efforts have contributed to the control of rubella and the prevention of CRS, highlighting the crucial role of vaccination in safeguarding maternal and child health.