KOTA KINABALU, Dec 11 — Malaysians were left reeling after the Ministry of Health confirmed this week the first case of polio in the country in close to three decades despite previously being eradicated.

The last known case of polio in Malaysia was recorded in 1992, and the country was declared polio-free along with other Western Pacific region nations in 2000.

The news was particularly shocking because vaccinations, thought to eliminate 99 per cent of the risk of contracting polio, are widely available at all Malaysian government hospitals.

What happened?

Health director-general Datuk Dr Noor Hisham Abdullah confirmed on Sunday that a three-month-old Malaysian infant from Tuaran, Sabah tested positive for polio last Friday after being admitted to hospital with a fever and muscle weakness.

Health Minister Datuk Seri Dzulkefly Ahmad said the baby started showing symptoms of the virus infection before getting his second vaccination shot.

It was then suspected that the virus infecting the boy was brought into Sabah from the Philippines, as the infant’s family had not travelled overseas.

The ministry said it had tested 661 people in the surrounding areas up to December 7, and found that 25 out of 214 children between two and 15 years of age in the area had not received the polio vaccine.

The baby is reportedly stable and receiving care.

What is polio?

Polio or poliomyelitis is an extremely contagious disease where the virus attacks the nervous system. It starts out as a fever or cold, but then the infection can spread to the spinal cord and cause paralysis and death in the most severe cases.

However, most people with polio do not display any symptoms or become noticeably sick. When symptoms do appear, they differ depending on the strain.

Symptomatic polio can be broken down further into a mild form, called non-paralytic or abortive polio. Meanwhile, a severe form called paralytic polio only occurs 1 per cent of the time.

Many people with non-paralytic polio make a full recovery if treated, but those with paralytic polio can become permanently paralysed and end up with misshapen limbs.

The World Health Organisation (WHO) and United Nations Children’s Fund (Unicef) have since confirmed the instance in Sabah to be a rare strain of the virus that is spreading in southern Philippines, called circulating vaccine-derived polio (cVDPV) Type 1.

They said confirmation of the type of virus was based on testing conducted by the WHO’s Regional Polio Reference Laboratory in Melbourne, Australia between December 6 and 10 after the Sabah boy developed fever and paralysis.

Why is polio dangerous? 

Based on a report by the United States Centres for Disease Control and Prevention, 25 per cent of people infected with polio will have flu-like symptoms such as a sore throat, fever, headache, stomach pain and nausea which usually last two to five days before going away.

The major indicator appears to be a fever, but also a sore throat, headache, vomiting, fatigue, back and neck pain, arm and leg stiffness, muscle tenderness and spasms and meningitis. 

Seven-two per cent of those infected with the virus will not show any visible symptoms but can still transmit the virus to those around them.

Paralytic polio affects only a small percentage of those infected with polio and the effects are much more serious and can lead to a loss of muscle reflexes, severe muscle pain and spasms, and loose or floppy limbs that are often worse on one side of the body. 

Patients can end up paralysed in one or several parts of the body, usually the limbs, but can go on to lead relatively normal lives.

There are some rare cases where patients have suffered from paralysis and eventual death. However, children below five years old are at the highest risk for contracting the disease.

To be sure of a polio diagnosis, doctors look for symptoms such as neck and back stiffness, abnormal reflexes, and trouble with swallowing and breathing. A doctor who suspects polio will perform laboratory tests that check for poliovirus by examining throat secretions, stool samples, or cerebrospinal fluid.

How can one get polio?

Polio can spread easily from person to person contact and only infects humans. The virus is typically transmitted through the stools of the infected person, or mouth, water and food. 

It enters the body through the mouth and spreads through contact with the faeces of an infected person or coughs and sneezes. It then lives in an infected person’s throat and intestines.

An infected person may spread the virus to others immediately before and about one to two weeks after symptoms first appear. The virus can live in an infected person’s faeces for many weeks. It can contaminate food and water in unsanitary conditions.

People who do not have symptoms can still pass the virus to others and make them sick.

Poor hygiene contributes to the spread of the virus, so it is usually found in areas where sanitation is lacking.

Where is polio still found? 

For the most part, the world has eliminated the disease through vaccination. 

Ever since a global effort to eradicate polio in 1988, the number of cases has reportedly gone down by 99.9 per cent — from around 350,000 cases in 1989 to merely 483 cases in 2001.

WHO aims is to eradicate polio completely and, if this happens, it will be only the third disease to have been beaten in this way, after smallpox and rinderpest.

As at 2018, Nigeria, Pakistan and Afghanistan are the three countries where polio has not successfully been stopped. The reach and spread, however, has been reduced in these areas over time.

On September 20, 2019, the Philippines recorded its first polio cases after a 19-year absence, joining a number of cases involving circulating vaccine-derived cases.

An outbreak of polio was detected in Lanao Del Sur and Laguna, two provinces in the Philippines with eight cases confirmed.

Based on tests, the child in Malaysia was infected by the very same strain that has genetic links to the one in the Philippines.

When should one start protecting against polio? 

Polio is preventable by way of vaccination. In Malaysia, it is not mandatory to vaccinate a child against polio. However, some 95 per cent of parents do vaccinate their children.

Public health departments provide free vaccination in public schools. All government hospitals and clinics also provide shots. 

But still, there exists a small but rising movement of anti-vaccination parents who are acting based on misguided religious or health concerns, that inevitably puts the rest of the population in danger.

Deputy Health Minister Dr Lee Boon Chye warned in March that the inoculation rate for measles-mumps-rubella (MMR), for example, has dropped to 89 per cent from the 95 per cent required for mass protection.

Furthermore, WHO and Unicef also pointed out that circulating vaccine-derived cases only occurs if a population is seriously under-immunised.

There is no known cure for polio and once it is contracted, the only treatment available is supportive care which can prevent further deformation or fitting with crutches or braces. 

Early detection and diagnosis is believed to be able to reduce the severity of symptoms.