The Crown Jewels of Prevention
Elimination and Eradication
A new vaccine against malaria, known as the R21/Matrix-M, has been developed. Recently, the Central African Republic has acquired 43,000 doses. In October of last year, the World Health Organization first recommended it. Intended for children aged 5 to 36 months as a routine immunization, the vaccine is poised to make a significant difference in Africa, where malaria's harm is particularly high. Over two and a half years ago, the first vaccine, RTS,S was unveiled. However, its supply cannot keep up with the demand.
The combination of these vaccines is expected to save tens of thousands of children's lives every year. In places with strong seasonal transmission and malaria chemoprevention, both vaccines prevent about 75% of malaria episodes. The R21/Matrix-M is expected to reduce the amount of disease that mosquitoes can transmit, ensuring protection for both vaccinated and unvaccinated children. By deploying this vaccine, the World Health Organization hopes to reach its goal of eliminating malaria in at least 30 countries by 2030.
Eradication and Elimination
Disease eradication is a global permanent achievement, while elimination refers to a specific geographic area. Eradication removes the agent that caused the disease, while elimination reduces to zero the incidence of a specified disease in a defined geographical area through deliberate efforts. Continued actions are required to prevent re-establishment.
In the ongoing fight against infectious diseases, prevention has proven to be our most effective strategy. By focusing on preventive measures, we can stop diseases before they spread, protecting individuals and communities alike. The ultimate method for prevention is eradication. And if not eradication, then at least elimination.
Eradication Successes
Disease eradication relies heavily on robust prevention strategies. Here are some landmark achievements:
1. Smallpox - The global eradication of smallpox in 1980 is a milestone in public health, achieved through a comprehensive vaccination campaign. The strategic use of the smallpox vaccine, coupled with surveillance and containment efforts, led to its end.
2. Rinderpest - This cattle disease was eradicated in 2011 through sustained vaccination programs. The end of rinderpest has had profound implications for food security and livelihoods, particularly in developing countries.
Elimination Successes
While eradication is a global goal, elimination focuses on reducing disease cases to zero in specific geographic areas, necessitating continued preventive measures to maintain this status. The United States has seen success in eliminating several diseases, thanks to vigilant prevention efforts:
1. Polio - The U.S. has maintained its polio-free status since 1979 through rigorous vaccination programs. Continued immunization efforts are critical to preventing the reintroduction of the virus.
2. Measles - Eliminated in 2000, measles prevention relies on high vaccination coverage. Outbreaks linked to imported cases highlight the need for sustained immunization and public awareness.
3. Rubella - Eliminated in 2004, rubella prevention involves vaccination of children. Also, women of childbearing age are vaccinated to prevent congenital rubella syndrome and protect future generations.
The Future of Eradication and Elimination
Looking forward, the role of prevention in public health cannot be overstated. Continued investment in preventive measures will be crucial in addressing both existing and emerging health threats.
1. Global Polio Eradication - Efforts continue worldwide to eradicate polio. Vaccination campaigns and surveillance are essential to eliminate the remaining pockets of the virus.
2. Malaria - Advances in malaria prevention, including new vaccines and vector control strategies, are making significant strides towards the potential elimination of this deadly disease.
3. HIV/AIDS - Prevention through education, safe practices, and treatments like antiretroviral therapy and pre-exposure prophylaxis (PrEP) are transforming the effort to eliminate HIV/AIDS.
4. Neglected Tropical Diseases (NTDs) - Targeted prevention efforts, such as mass drug administration and improved sanitation, are paving the way towards the elimination of diseases like lymphatic filariasis and trachoma.
Guinea worm disease is a parasitic infection caused by the Guinea worm or Dracunculus medinensis. A person becomes infected by drinking water contaminated with Guinea worm larvae that reside inside copepods (a type of small crustacean). Guinea worms leave the digestive tract after stomach acid digests the copepod. Around a year later, the mature female migrates to an exit location, generally the lower leg, causing a painful blister from which the worm emerges. This period of emergence disables the sufferer for three to ten weeks.
In the 1980s, the World Health Assembly adopted a strategy for control and elimination of Guinea worm and committed to global eradication in 1991. This strategy involves behavior change, health education, filter distribution, vector control, safe water provision, and case containment. These methods, led by the Carter Center, have had considerable success. In 1986, there were an estimated 3.5 million cases in 20 countries; Eradication of Guinea worm disease remains in sight with only 14 provisional human cases reported worldwide in 2023, preceded by 13 cases in 2022 and 15 in 2021.
Conclusion
Prevention is the “Queen” of public health, with elimination and eradication as its crown jewels (with apologies to Carl Friedrich Gauss)*. The successes achieved through preventive measures highlight the importance of continued vigilance, innovation, and investment in public health strategies. Disease eradication is an ongoing process.
The International Task Force for Disease Eradication (ITFDE) lists eight potentially eradicable diseases - Guinea worm (dracunculiasis), poliomyelitis, mumps, rubella, lymphatic filariasis, cysticercosis, measles, and yaws. The World Health Organization currently suggests polio and Guinea worm disease are eradicable, while other diseases could be eliminated from some parts of the world. As science advances and researchers develop new ways to tackle diseases, the world may change its perspective on which goals are feasible now and which are not yet. As we move forward, a collective commitment to prevention will be essential in safeguarding the health of future generations.
*Mathematics is the queen of science and number theory is the queen of mathematics”