!s a change in the definition of polio from 3 days to 60 da…
!s a change in the definition of polio from 3 days to 60 days of paralysis post-Salk vaccine, implying a manipulation of statistics which led to a perceived decrease in polio incidents
Replies
search results
is this true?
Based on the provided search results, there is no evidence to support the claim that the definition of polio was changed from 3 days to 60 days of paralysis after the introduction of the Salk vaccine to manipulate statistics and show a decrease in polio incidents.
The search results focus on the development and effectiveness of the Salk and Sabin vaccines, the history of polio vaccination, and the safety and efficacy of different vaccine types. They do not mention any changes in the definition of polio that would have artificially decreased the reported incidence of polio.
For instance, the report on the 1955 Polio Vaccine Trial Announcement by Dr. Thomas Francis Jr. discusses the effectiveness of the Salk vaccine based on field trials involving over 1.8 million children, highlighting its safety and efficacy without referencing any changes in diagnostic criteria[5].
Moreover, discussions about vaccine-associated paralytic polio (VAPP) and the shift towards inactivated polio vaccines (IPV) due to the risks associated with oral polio vaccines (OPV) further emphasize the focus on vaccine safety and efficacy rather than changes in the definition of polio[1][3][4].
Therefore, the claim that the definition of polio was changed to manipulate statistics appears to be unfounded based on the provided search results. **Note**: The actual criteria for diagnosing polio (including the duration of symptoms) may have evolved over time, but there is no evidence in the provided sources to support the specific claim of a change from 3 to 60 days post-Salk vaccine.
how did it evolve? how did it start? end?
The evolution of polio (poliomyelitis) and its eradication efforts can be summarized as follows:
**Early History:**
1. **Prehistoric Times:** Polio has been present since prehistoric times, with ancient Egyptian images showing children with withered limbs, indicative of the disease[1].
2. **Clinical Recognition:** The first clinical description of polio was by British doctor Michael Underwood in 1789, and it was formally recognized as a condition in 1840 by German physician Jakob Heine[1].
**Vaccine Development:**
1. **1932:** Maurice Brodie began developing the first live virus vaccine by passing the virus through monkeys. His work, though criticized for its methods, showed promising results in field trials[2].
2. **1949:** John Enders, Thomas Weller, and Frederick Robbins successfully cultivated poliovirus in human tissue, winning the 1954 Nobel Prize for their work[1].
3. **1955:** Jonas Salk announced the success of his inactivated poliovirus vaccine (IPV), which was licensed on the same day[1][4].
4. **1961:** Albert Sabin developed an attenuated live oral poliovirus vaccine (OPV), which came into commercial use[2].
**Eradication Efforts:**
1. **1988:** The World Health Assembly passed a resolution to eradicate polio, leading to the launch of the Global Polio Eradication Initiative (GPEI)[1][3].
2. **1994:** Polio was declared eliminated from the Americas, marking the first World Health Organization region to achieve this goal[4].
3. **Early 2000s:** Polio was eliminated in Europe and significant progress was made in reducing polio cases globally[4].
4. **2014-2020:** The South-East Asia region was certified polio-free, followed by the African region in 2020[1].
**Key Milestones:**
1. **Mass Vaccination Campaigns:** Large-scale vaccination efforts in countries like China, India, and Pakistan, supported by organizations such as Rotary International and the World Health Organization, played a crucial role in reducing polio cases[1][3].
2. **Global Collaboration:** International cooperation and assistance were critical in expanding vaccine production, improving surveillance, and conducting mass vaccination campaigns[1][3].
3. **Type-specific Eradication:** Type 2 wild poliovirus was declared eradicated in 2015, and by 2021, only two cases of wild poliovirus had been recorded globally, in Afghanistan and Pakistan[1][3].
The efforts to eradicate polio continue, with ongoing challenges in a few remaining endemic countries, but significant progress has been made in reducing the disease's prevalence globally.
how did diagnostic criteria evolve?
The evolution of diagnostic criteria for polio can be summarized from the provided sources as follows, focusing on key developments and changes over time:
1. **Early Clinical Descriptions:**
- **1789:** The first clinical description of polio was provided by British doctor Michael Underwood, followed by formal recognition as a condition by German physician Jakob Heine in 1840[2][3].
- **1908:** Karl Landsteiner and Erwin Popper identified poliovirus as the infectious agent causing polio by filtering preparations of spinal cord fluid from a person who had died of polio and injecting these into monkeys, which then developed polio[1].
2. **Development of Virus Cultivation:**
- **1949:** John Enders, Thomas Weller, and Frederick Robbins successfully cultivated poliovirus in human tissue, a breakthrough that allowed for vaccine development and more precise diagnostic techniques[1][2].
3. **Identification and Typing:**
- **1931:** The existence of more than one type of poliovirus was proposed[1].
- **1949:** David Bodian identified three types of poliovirus, which was crucial for developing effective vaccines[1].
4. **Diagnostic Criteria Evolution:**
- **Pre-20th Century:** Polio was often diagnosed based on clinical symptoms such as paralysis, with limited understanding of the virus[3][4].
- **Early 20th Century:** Improved hygiene led to delayed exposure to poliovirus, causing more severe forms of the disease. Diagnosis was still largely clinical, with the use of "iron lung" machines for severe cases[3][4].
- **1950s:** With the advent of vaccines, the focus shifted to laboratory confirmation of polio, including virus isolation and serological tests[2][3].
5. **Global Eradication Efforts:**
- **1988:** The Global Polio Eradication Initiative was launched, which included robust surveillance and diagnostic protocols to detect and confirm polio cases[1][2].
- **1990s and 2000s:** Mass vaccination campaigns, improved surveillance, and diagnostic capabilities led to significant decreases in polio cases and eventual elimination in several regions[1][3][4].
### Key Points:
- **Clinical Diagnosis:** Early diagnosis was based on symptoms and epidemiological context.
- **Virological Confirmation:** Later, methods such as virus isolation and serological tests were used to confirm polio cases.
- **Global Standardization:** The Global Polio Eradication Initiative standardized diagnostic criteria and surveillance protocols globally.
- **No Evidence:** There is no evidence provided in the sources about a change in the definition of polio from 3 days to 60 days of paralysis post-Salk vaccine to manipulate statistics.
The diagnostic criteria for polio evolved from purely clinical to include virological confirmation and standardized surveillance protocols, but there is no mention of changing the duration of paralysis in the definition of polio to manipulate statistics.