SEATTLE, USA - A polio outbreak was reported in Papua New Guinea. This is the first time polio has been seen in the country in nearly two decades, and an especially poignant occurrence as polio is extremely close to eradication around the world.
Polio is a dangerous virus spread through food, water and contact with infected people. Those who do not have access to adequate sanitation are especially vulnerable to the virus.
Polio multiplies in the intestines but can move to other parts of the body through the bloodstream and affect the nervous system. This can lead to paralysis. The poliovirus has no cure once contracted, so the only route to the end of polio is through vaccination and other methods of prevention.
There are two forms of vaccination against the polio virus, but oral poliovirus vaccines are the vaccine predominantly used across the world today. These vaccines are inexpensive, at a maximum of 60 toea for countries supplied by UNICEF in 2016.
They also are easy-to-use as they are administered orally. Such facility means that the vaccine does not need trained healthcare personnel or sanitized syringes for application.
The strain of polio in Papua New Guinea is known as vaccine-derived poliovirus type 1. This form of poliovirus is caused by a mutation of the weakened version of the polio virus used in the oral vaccine.
The weakened version of the virus stays inside the person who has received the vaccine for several weeks. During this period of time, the body excretes the virus.
In areas with poor sanitation, the vaccine virus can be transferred from person-to-person and can also pass on a passive immunization to others in the community. However, if there is low immunisation in a region, the virus can continue transferring for an extended period of time.
This spread can lead to mutations in the virus and, in extremely rare cases, the virus can become neuro-virulent again in what is called a vaccine-derived poliovirus.
Within the Morobe Province — the region where the virus outbreak was found — only 61% of the children had received the three doses of the oral polio vaccine recommended by the World Health Organiszation (WHO). This lack of immunisation in conjunction with the lack of adequate sanitation increases the spread of the virus and the danger of the outbreak.
WHO, the PNG Department of Health, the Global Polio Eradication Initiative and other groups are working alongside the government of PNG to contain the virus. Since the confirmation of an outbreak of polio in PNG, several large-scale measures have been put into place to prevent any further spread of the disease.
These measures include extensive immunization of those in the region where the virus has been detected, especially for children under the age of 15, and increasing surveillance measures in order to detect any new cases of polio. Plans have also been established to employ more immunization campaigns in the coming weeks.
Global efforts to eradicate the polio virus were launched in 1988. Since that time, polio incidence has dropped by 99% across the world. The wild poliovirus only remains endemic in three countries: Afghanistan, Pakistan and Nigeria. In 2017, there were 22 cases of wild poliovirus and 96 cases of vaccine-derived poliovirus.
This dangerous disease is close to global eradication; however, the outbreak of polio in Papua New Guinea shows that the virus remains a danger in areas with insufficient sanitation and lack of adequate vaccinations.
Organisations across the world continue to fight to keep everyone safe and to end the poliovirus once and for all.