On Tuesday November 19th, Dr. Stan Houston, adjunct professor at the U of A’s School of Public Health helped put the global efforts to eradicate polio into perspective by comparing its progress with efforts to eradicate other diseases. He also gave a brief history on clinical awareness of the disease and shared some facts and figures regarding it’s toll on society and the victories and challenges involved in achieving eradication.
The following are some key takeaways from his presentation:
- In 1980 Smallpox became the first disease to be successfully eradicated. At its peak in the 1950’s smallpox was responsible for 4 million deaths a year.
- The only other disease to be eradicated was Rinderpest, which targeted cattle and similar species of animals. An extremely deadly virus, rinderpest outbreaks were virtually 100% fatal. The Global Rinderpest eradication programme initiated in 1994 was highly effective, with the last reported case of the disease occurring in 2001.
- Guinea Worm, an invasive parasite, has nearly been eradicated. It’s impact has been reduced from 3.5 million cases in 1986 to about 30 cases reported annually over the last few years.
- While eradication of hookworm has stalled out incidents are drastically reduced in areas where proper water, sanitation and footwear are available.
- Yaws, a bacterial infection that targets the skin, bones and joints has seen recent efforts at eradication with antibiotics.
- Yellow Fever is highly preventable with vaccination but a reservoir of infection in monkey populations will make eradication of the disease unlikely.
- Efforts to eradicate Malaria have so far been ineffective.
- Polio became commonly recognized as a disease roughly 200 years ago. Ironically, the adoption of sanitation measures which greatly improved the health and life expectancies of the global population deprived infants of antibodies to the disease from their mothers upon early exposure.
- Two of the three strains of polio appear to have already been eradicated.
- Less than 1% of individuals infected by the polio virus will fall victim to the disease. This necessitates a herd immunity resulting from proper vaccination.
- proof positive that polio can be eradicated exists in India. A thorough vaccination program, including events where as many as 127 million children were treated in one day, earned India polio-free status in 2014
- The only two countries remaining where incidents of the disease occur are Afghanistan and Pakistan, accounting for about 100 cases this year between them.
- Distrust of the motives behind any form of western aid has occaisonally been a barrier to thorough immunization in some countries. This distrust was exacerbated by an incident where a CIA operative posed as a doctor screening for Hepatitis in Pakistani villages. The blood test involved was used to screen for DNA linking to Osama Bin Laden to aid in his discovery and elimination. It became extremely risky for legitimate health care workers in the area to do their jobs for some time after this operation was exposed.
- The ongoing risk to delaying the total eradication of polio is that the vaccine itself can cause the disease in immunodeficient individuals.
Many thanks to Dr. Houston for a highly informative discussion.