On 25 August 2020, the region of Africa was awarded a wild poliovirus (WPV) free certificate by the World Health Organisation (WHO). Over the past decades, all African countries, except Nigeria, had successfully eliminated Poliomyelitis, an infectious viral disease that invades the nervous system causing irreversible paralysis often leading to death. In 1988, WHO, in collaboration with Centers for Disease Control and Prevention (CDC), the UNICEF and the financial support of Rotary International, later joined by Bill and Melinda Gates Foundation, launched an extensive campaign to eradicate this disease. At that time, there were over 350,000 polio cases yearly and polio was endemic in 135 countries. On the African continent, there were over 75,000 cases in 1996, when, at an African Union meeting in Cameroon, Nelson Mandela pressed on all African leaders to ‘kick polio out of Africa.’ It was a success. However, polio persisted in the northern region of Nigeria, difficult to reach because of insurrections and terrorist attacks. Vaccinators, through tremendous efforts, were able to bring the vaccine to those remote zones. Finally, the last case in Nigeria was recorded in 2016, and since there has not been any case for the next three years, the African region, made up of 47 countries, was awarded a wild poliovirus-free certificate. This is a major landmark in the history of infectious diseases on the African continent. Now that the campaign against polio is over, the trained personnel is being re-directed to fight new diseases such as Ebola and the prevailing one, COVID-19.
Poliomyelitis, an ancient disease, has plagued humanity for centuries. Until recent times, it was widely distributed throughout the world, in both tropical and temperate zones, in developed and developing countries. During the 20th century, there were serious outbreaks in the US, northern Europe, Malta and the African region; there was a desperate attempt to find a vaccine. In the US President Franklin Roosevelt, himself a polio victim, encouraged research and the development of a vaccine. In the African region, the Poliomyelitis Research Foundation (PRF) was set up in Johannesburg. Scientists in different countries struggled to find vaccines for polio and other infections, against the backdrop of cold war and arms race.
Polio cases, in Mauritius, were first reported in February 1945, in Rose Hill, Beau Bassin, and Quatre-Bornes. By May, more cases were recorded in rural areas, the disease having affected about 1000 people, in a total population of about 420,000. Isolation wards were created in hospitals until a polio hospital was set up at Mangalkhan, Floreal. As no vaccine existed, patients were treated with penicillin and even with drugs related to malaria. A few ventilators, known as iron lungs, received from England, helped polio patients suffering from acute respiratory problems.
Since the majority of cases were children, the government enforced precautionary measures to prevent the spread of infection. Schools were closed for several weeks and children under 15 were not allowed to travel by bus or train, go to cinema and attend public gathering and church service. Teachers were required to visit pupils in their homes and report any problem to medical authorities. Drs. R. Lavoipierre and J. Seegobin, on radio at the Mauritius Broadcasting Service, recommended parents to adopt sanitary precautions at home and restrict the travels of their infants. The main symptoms were influenza-like, bouts of fever, headache, and bodily pains, but there could be asymptomatic cases too. In April, a group of experts led by Dr. H. J. Seddon, professor of orthopaedic surgery at Oxford University, arrived on an official mission. A thorough island-wide survey was carried out. At first, there were several speculations about the cause; for example it was believed that houseflies could be transmitting vectors. This idea was dismissed after it was found that monkeys inoculated with the suspension of flies were not affected by polio. Dr. Seddon gave talks at the Teachers Training College and on radio, advising parents to send affected children to the Floreal Hospital, where a personnel consisting of a medical officer from Tanganyka (Tanzania), a matron from Uganda, a physiotherapist from England, and nurses recruited from the local branch of the Red Cross looked after patients.
Dr. Seddon also advised parents to encourage affected children to wear calipers, devices made of wood, metal and straps to protect paralyzed muscles. Through his initiative, the government of Malta sent 400 calipers to Mauritius; more of these were made at the Government Prisons. The Floreal Hospital closed down when the Princess Margaret Orthopaedic Centre opened at Candos. When a polio epidemic broke out at Rodrigues in 1949, patients were isolated in a government school building and Dr. A. Bathfield was sent to supervise their treatment.
After the 1945 epidemic, other outbreaks followed in November 1948-February 1949, March-June 1952, and June-September 1959. A survey carried out in 1955 by Dr. J. Gear (PRF) recorded only few cases among adults. It was argued that polio cases have occurred in 1892 and 1927 and that adults could have developed immunity from exposure to an endemic infection on the island. Polio was a notifiable disease since 1925.
The first vaccine was developed by Jonas Salk in the US in 1952. It is an inactivated poliovirus vaccine, (IPV) administered by injection. After clinical trials, vaccination campaigns started in 1955. Another American scientist, Albert Sabin, developed a live attenuated or weakened vaccine, given orally (OPV). Although the cold war was at its peak, Russia accepted to test the Sabin vaccine. It was first used in the US in 1962. Both polio vaccines were major medical breakthroughs and have since been used worldwide, especially the OPV type, easy to administer and cheap. It has also been established that polio is transmitted from one person to another by oral ingestion of matter infected by the faeces of a polio victim. The polio outbreak in Mauritius occurred at a time when sanitary conditions were low. Apart from a sewage system in Port Louis, the rest of the island depended on a latrine system, which was not efficient.
In Mauritius, the Salk vaccine campaign started in September 1957, it did not reach the whole infant population, when another epidemic broke out in 1959. On the advice of experts from PRF, the Sabin vaccine was introduced in August 1959, when it was still undergoing trials in other countries. In 1960, Dr. B. Teelock published a detailed study with tables and statistics of both Salk and Sabin vaccination campaigns in Mauritius in the British Medical Journal. He analysed the impact of the vaccines, he compared previous outbreaks and their incidence as per districts and ethnic groups. The new Central Health Laboratory carried out distribution operations of the vaccine, while, samples of blood and stools were analysed at the former Réduit laboratory. More samples were sent to PRF, Johannesburg for more research. Vaccination was very effective in Mauritius, the last case was notified in 1967. Between 1945 and 1967, there were 2,258 cases and 117 deaths.
The colonial government made notable efforts to encourage physically handicapped children to lead a normal life. A workshop for woodwork was created at Floreal hospital for handicapped children who stayed for a long time at the hospital. Those who returned home were encouraged to go back to school and attend normal classes. Needlework and other skills were taught to girls at the Social Welfare Centres. Catholic charitable institutions also organized the education of children affected by polio. In Le Mauricien, 17 May 1990, L. Ah-Choon paid tribute to educationalists such as Yolande Thomasse and Ena Mestry, who with the support of catholic charitable institutions and the Red Cross organized the uplift of polio-affected children in the 1950s and 1960s. (Y. Martial, L’Express, 5 June 2015)
The battle against polio is not over. Poliovirus still exists in Afghanistan and Pakistan. As often repeated by WHO experts regarding all pandemics, ‘no country is safe unless all countries are safe.’ Routine immunization and surveillance should be maintained worldwide, as imported cases can enter any country. Moreover, a major disadvantage of OPV is that it can cause vaccine-derived poliovirus VDPV, especially in communities where the level of vaccination coverage is low and sanitation is poor. For this reason, some Western countries have reverted to IPV.
So close to the finish line, it is hoped that the world eradication of polio is not far. It would be the eradication of the second infectious disease after smallpox. Other diseases are also awaiting eradication, measles, mumps, Hepatitis B…
Most past pandemics have lessons to offer to communities that are ready to learn, whether it is regarding the importance of international scientific cooperation, the free exchange of information and data, the need for solid surveillance systems, the education of communities, and more…
Boodhoo, Raj – Infectious Disease and Public Health ELP 2019.
Teelock, B. – Poliomyelitis epidemic in Mauritius and the effect of vaccination BMJ Oct 1960.