Polio: This Close
by Kenneth Lyen
The campaign “End Polio Now” was initiated by the Rotary Club in 1985, when, according to the World Health Organization, there were 269,000 new reported cases in 125 countries, the vast majority (60%) coming from South-East Asia.
They were joined by the World Health Organization (1988), US Centers for Disease Control and Prevention (CDC)(1988), the United Nations Children’s Fund (UNICEF)(1988), and the Bill and Melinda Gates foundation (2007) and together they have been the main players in the mission to wipe out polio.
In 2019, only three countries have reported new cases of polio: Afghanistan, Pakistan, and the Philippines. Nigeria has not had any new cases for the past 3 years, and was recently declared polio-free.
This year (2020), the combined Rotary Clubs of Singapore, of which I am proud to be a member of Singapore North, are currently top-ranked worldwide in terms of support for the End Polio campaign!
Since the year 2000, some 10 billion doses of oral polio vaccine have been given worldwide. This year, 2018, there have been a total of 109 new cases of polio, from seven countries. This is an drop of 99.99% since 1985 when the campaign was launched. I am proud to be a member of the Rotary Club of Singapore North, and to be part of this worldwide effort to eradicate polio. We are this close to ending polio.
It was almost two centuries after Edward Jenner declared his hope that vaccination could annihilate smallpox, in 1801. On May 8, 1980, the 33rd World Health Assembly officially announced the world to be free of this disease. The eradication of smallpox is indeed one of the highest achievements in international public health. We hope to follow suit with polio.
My Experiences
About 30 years ago, I was on call when a young boy who had flown from Sri Lanka was admitted to hospital in Singapore. He had some pain and weakness in the legs which was preceded a week earlier by some vomiting. My differential diagnosis included Guillain-Barre Syndrome, a condition in which the body’s immune system attacks the nerves and can cause paralysis. The other possibility I thought of was an inflammation of the muscles due to an infection. Then I forgot about the case until a few weeks later when I received a phone call from the Ministry of Health asking where this child was. I told the caller that the boy had already flown back home to Sri Lanka. I was then informed that this boy’s stool sample had tested positive for polio. I left it to the Ministry to handle the follow-up management of this case. I then informed my medical colleagues and ward nurses of the polio. That was my first and only patient with polio that I had looked after throughout my medical career.
Dr William Tan
I have been a friend of Dr William Tan for many years. I had wanted to write a musical based on his life but sadly I could not raise enough funds to stage the production. He developed polio when he was two years old, and was unable to walk. In kindergarten and school he was bullied by his peers.
Academically William was a highflyer. He studied at Raffles Institution, did an undergraduate science degree at the National University of Singapore, followed by a Masters in Physiology, and a PhD in neuroscience. He was awarded a Harvard University Fulbright Scholar and an Oxford University Chevening Scholar, and became a neurosurgical research fellow at the renowned Mayo Clinic in the United States. It was there that he was inspired by a wheelchair-bound Chief of Neurology to rekindle his dream of becoming a doctor. He went to the University of Newcastle in Australia to study medicine, graduating in 2005.
In the early 2000s, when he was the Chevening Scholar at Oxford University he entered the London Marathon. This first taste of wheelchair marathons would change his sporting career spectacularly. It opened up a whole new sporting universe for him. In 2005 he set a world record by being the first paraplegic to finish 10 marathons in seven continents in 70 days, In the past thirty years, he has completed more than 100 wheelchair marathons, using them as a means of charity fundraising. He has also competed in over 60 ultra marathons (more than 42.2 km) around the world, and he holds six endurance marathon world records, including the “fastest time to complete three marathons in three consecutive days in three countries". As if this were not enough, in 2007, William became the first person in the world to accomplish a marathon in a wheelchair in the North Pole in 21 hours and 10 minutes, facing hazardous terrain and freezing temperatures of -25 degrees Centigrade. Altogether, William has raised more than $18 million for Singapore and international charities, including Operation Smile that provides cleft lip and palate operations to children worldwide. And he has also raised funds for PolioPlus to eradicate polio worldwide.
In 2009, halfway through a Paris marathon, he felt weak and exhausted. Immediately upon returning to Singapore he had his blood checked, and he was diagnosed to have Stage 4 leukaemia. He was told that he had only 9 months to 1 year to live. This was absolutely devastating news. Having to combat polio, he now had to battle leukaemia. Each year passed by uneventfully, and he is now in remission for nearly 10 years. What an incredible fighter!
Earlier this year in February 2018, against medical advice, William took part in his last 31-hour long ultramarathon celebrating the 31st anniversary and fundraising for Bizlink, a non-profit organization dedicated to serving disadvantaged individuals, in particular persons with disabilities, through training and employment in Singapore. This is his swansong, the last ultramarathon he will take part in. I take my hat off to William!
What is Poliomyelitis?
The term “poliomyelitis” originally referred to any paralytic disease. Currently it refers to an infection due to the poliovirus.
Initial symptoms may be quite mild, including fever, sore throat, headache, neck stiffness, and aches and pains in the arms and legs. Later there may be weakness especially in the legs, and difficulty walking. The legs may not be symmetrically involved, sometimes weaker on one leg than the other. Less commonly the arms are affected. Some patients do not have any symptoms at all when they are originally infected by the poliovirus, but years later, they may slowly develop muscle weakness. Patients who have had polio for several years may have a shorter and thinner affected leg. About 20% or a fifth of patients with paralytic polio may have the virus spreading to both the brain and spinal cord. This is the most severe form of polio because it may cause paralysis of the diaphragm, making it impossible for the person to breathe without a mechanical ventilator. There may be additional paralysis of both the arms and legs, swallowing difficulties, and the heart may also be affected.
How is polio spread?
If one goes to the toilet to defaecate and fails to wash one’s hands thoroughly, the virus may contaminate the food and utensils, so sharing of food and drinks can spread the virus. Close contact with persons who are infected with the virus can also spread the infection. The infected person can infect others for up to six weeks, even if they themselves have no symptoms.
How is polio diagnosed?
Poliovirus can be cultured from stool sample, a swab from the pharynx, from the blood and cerebrospinal fluid. Antibodies to the poliovirus can be detected in the blood. Currently there is a polymerase chain reaction test that can detect the RNA of the poliovirus.
Treatment of Polio
Current treatment of polio is rather limited. Analgesics like non-steroidal anti-inflammatory drugs can alleviate pain. Physiotherapy to prevent muscle wasting and limb contractures are helpful. Orthopaedic surgery can help correct limb deformities. If there is difficulty breathing, a portable ventilator may be necessary, and chest physiotherapy can help clear the lungs of phlegm. The antiviral antibiotic, pocapavir is a capsid inhibitor and preliminary clinical trials have found it to be safe and effective.
Prevention of Polio
The cardinal method of preventing polio is by vaccination. The inactivated polio vaccine is given by an intramuscular or subcutaneous injection. In the USA, this is the only type of vaccine available.
In Singapore we can still give the oral polio vaccine. Five doses of the vaccine are given: at 2, 4, 6, and 18 months, with a further booster at 10-11 years of age.
Other preventive measures include washing hands with soap and water, especially after going to the toilet or changing diapers, before preparing food and eating. You can also use an alcohol-based handwashing solution.
What is the poliovirus?
This is an RNA virus that belongs to a family called Picornaviridae, and it is protected by a protein coat or capsid.
Like all RNA viruses, in order to get the host cell’s nucleus to do the replication on behalf the invaders, the virus hijacks a cellular enzyme to design and create replication factories on the cell’s membrane filled with P14P lipids. These lipids, in turn, allow the RNA viruses to attract and stimulate the enzymes they need for replication.
Historical Aspects of Polio
This Egyptian stone carving dates back 3,000 years ago, and shows a priest with a walking stick a shortened thin right leg and foot deformity characteristic of polio.
The disease was given its first clinical description in 1789 by the British physician Michael Underwood, in his book “A Treatise on the Diseases of Children”. It was recognised as a separate condition by Jakob Heine in 1840. The growth of cities during the industrial revolution led to overcrowding, but hygiene and sanitation were undeveloped, hence fueling the first modern epidemics.
The poliovirus was first isolated in 1909 by Karl Landsteiner and Erwin Popper. They obtained the cerebrospinal fluid from a patient who had died of polio, and carefully filtered it, thus trapping the bacteria. They then injected the filtered bacteria-free fluid into monkeys. When the monkeys developed polio, they realized that the infectious particles were smaller than bacteria, and concluded that polio was due to a virus. It was not until the 1950s when the electron microscope was developed that allowed scientists to visualize the actual poliovirus.
In 1921 the American president Franklin Delano Rooselvelt at the age of 39 became paralyzed by an illness which was initially thought to be polio, but some think it may have been Guillain Barre Syndrome. Rooselvelt established the March of Dimes in 1938 to combat polio.
Polio Vaccines
The first polio vaccine was developed by Jonas Salk in 1955 and a killed poliovirus was injected into the subject. Six years later, Albert Sabin developed an oral polio vaccine, which was the predominant method of vaccination until around 1997, when the number of new cases of polio in the USA had fallen to 3. To prevent vaccination-associated paralysis which occurred at the rate of 1 per 1.4 million vaccine doses, the US switched to a vaccine regimen consisting of two doses of injectable polio and one dose of oral polio vaccine. In 2000, the US switched to injectable polio vaccine exclusively.
Bulbospinal and Bulbar Polio
Respiratory failure due to paralysis of the diaphragm was perhaps the most devastating effect of polio. This was due to bulbospinal and bulbar polio, and it affected about 21% of cases of paralytic polio. Until the introduction of the iron lung this carried a mortality rate ranging from 25% to 75%.
The Iron Lung
The first clinical use of a negative pressure respirator was in Boston Children’s Hospital in 1928 on an 8-year old girl who nearly died from diaphragmatic paralysis due to polio. The encasement was made of iron, and hence the term “iron lung” was adopted. In 1959 there were 1200 patients using the iron lung, and most only required it for up to a week, because the majority of paralytic polio victims could breathe again. But some patients were not so lucky and were in the iron lung for decades.
When I was a medical student in England in the 1970s, I saw one patient who had been in an iron lung for many years. I was shown how the portholes on the sides were used by the nurses to wipe the body, and to remove urine and faeces. Over the head of the patient was a book but the nurse had to be called each time the patient wanted the pages turned. Sometimes the patient requested to have either a television, or a mirror so they could see their visitors.
By the 1950s. positive pressure ventilation had grown in popularity and the negative pressure iron lungs were gradually replaced.
Hiccup
Just as we were about to celebrate the near eradication of polio, we have a hiccup.
On 20 August 2019, the World Health Organisation (WHO) declared Nigeria to be polio-free, not having any new cases for the past 3 years.
However, one month later, on 20 September 2019, the WHO confirmed that there were 2 new cases of polio in the Philippines. The vaccination rate in the Philippines has decreased to below 70%. According to the WHO, it is estimated that 2.6 million Filipino children under the age of 5 years are not protected from preventable infectious diseases.
There have been 42 new cases of polio reported in Afghanistan, and 62 new cases from Pakistan, in 2019.
Malaysia had been polio-free for 27 years, but on 31 December 2019, one new case of polio was announced. The strain of polio is known as a circulating vaccine-derived poliovirus (cVDPV) strain, a rare mutation of the poliovirus used for oral polio vaccination. This mutated virus is excreted in the orally-vaccinated child's faeces. However, vaccination can protect against both this mutated strain (DVDPV} together with the wild type of poliovirus. Therefore the occurrence of a new case of polio reflects a gap in vaccination rates in Malaysia.
Conclusions
The new cases of polio in 2019 tells us that we cannot be complacent and let our guard down. We are so close to achieving a polio-free world, that we need to put in that extra effort to realize our dream.
The total eradication of paralytic polio will stand as one of the major achievements in the history of medicine.
The above photo shows the Rotary Club of Singapore North organising a Polio walk to raise funds to "End Polio Now"
I am a perpetual optimist, and I remain confident that we will succeed in putting an end to polio in the not too distant future!
References
Poliomyelitis Wikipedia: https://en.wikipedia.org/wiki/Poliomyelitis
Poliomyelitis eMedicine: https://emedicine.medscape.com/article/1259213-overview#showall
Our World in Data: https://ourworldindata.org/polio
Global Eradication: http://polioeradication.org/polio-today/polio-now/this-week/
Incidence of Polio: http://www.who.int/features/2004/en/gallery1_popup.htm
Malaysia new case of polio: https://www.thestar.com.my/lifestyle/health/2019/12/31/the-return-of-polio
Written by Kenneth Lyen
13 Nov 2018, updated 4 Sept 2020
%20a.jpg)
The above video is an excellent overview of polio. It can also be viewed online:
https://www.youtube.com/watch?v=ycOXWGr5Dag
Creative Commons CC BY-SA 4.0