Disease Information
Poliomyelitis

Updated: July 2005

Know before you go!

Infectious diseases not necessarily common in Canada can occur and may even be widespread in other countries. Standards of hygiene and medical care may differ from those at home. Before departure, you should learn about the health conditions in the country or countries you plan to visit, your own risk of disease and the steps you can take to prevent illness.

The risk is yours

Your risk of acquiring a disease depends on several factors. They include: your age, gender, immunization status and current state of health; your itinerary, duration and style of travel (e.g., first class, adventure) and anticipated travel activities (e.g., animal contact, exposure to fresh water, sexual contact); as well as the local disease situation.

Risk assessment consultation

The Public Health Agency of Canada strongly recommends that your travel plans include contacting a travel medicine clinic or physician six to eight weeks before departure. Based on your individual risk assessment, a health care professional can determine your need for immunizations and/or preventive medication (prophylaxis) and advise you on precautions to avoid disease. We can help you locate a travel medicine clinic closest to your home.

Some facts from the experts

The information below has been developed and is updated in consultation with The Public Health Agency of Canada’s Committee to Advise on Tropical Medicine and Travel (CATMAT). The recommendations are intended as general advice about the prevention of Poliomyelitis for Canadians travelling internationally.

Disease profile

Poliomyelitis, or polio, is an acute infectious disease caused by one of three gastrointestinal viruses, either poliovirus type 1, 2 or 3. The poliovirus can attack the nervous system and destroy the nerve cells that activate muscles. As a result, the affected muscles no longer function, and paralysis that may not be reversible can occur. In severe cases, the disease may lead to death. Polio mainly affects children under 3 years of age, but can strike older children and adults as well.

Transmission

Poliovirus is spread by the faecal-oral route. The virus enters the mouth and multiplies in the intestines. Polio is contracted either indirectly through contaminated water, where sewage and drinking water supplies are not adequately treated, or directly through contact with the faecal matter of an infected individual. Person-to-person transmission is especially common among children.

Geographic distribution and incidence trends

Until 1988, polio occurred throughout the world and the virus was endemic to over 125 countries. As a result of Global Polio Eradication Initiative, the world’s largest public health initiative, polio has been eradicated in many parts of the world. Three of the six geopolitical regions of the world, have been certified polio-free: the Americas (1994), the Western Pacific (2000) and Europe (2002). While not yet certified polio-free, the Eastern Mediterranean region is presently polio non-endemic.

At this time, polio remains endemic (constantly present) in 6 countries (Nigeria, Niger, Pakistan, Afghanistan, Egypt, and India) in the regions of Africa and South East Asia. In 2003, substantial progress towards polio eradication was made in these two regions and the year ended with a total of 784 reported cases. In 2004, a total of 1,266 cases of polio were reported in 18 countries. This figure represents a 61% increase over the 784 cases reported in 2003. The increase is attributed to a decrease in immunization activity in sub-Saharan Africa.

In November of 2004, the World Health Organization reported that sub-Saharan Africa experienced epidemic levels of poliomyelitis resulting from the suspension of immunization activities in some of Nigeria's northern states. The transmission of wild poliovirus (WPV) increased within these areas, causing Nigeria to report the largest number of WPV cases globally for 2003. Eventually, poliovirus from Nigeria spread to a number of neighbouring countries with low routine immunization coverage. Consequently, 12 previously polio-free countries in Africa became re-infected. These countries include: Benin, Chad, Burkina Faso, Cameroon, the Central African Republic, Côte d'Ivoire, Ghana, Guinea, Mali, Togo, Sudan and Botswana. Polio has since become re-established (that is, continued circulation for more than 6 months) in four of these countries - Sudan, Cote d'Ivoire, Chad and Burkina Faso.

In 2005, poliovirus originating in Nigeria has continued to spread and cases have been reported in Yemen and Indonesia; both of which had been polio-free since 1996 and 1995 respectively. In the first five months of 2005, 386 cases of poliovirus were reported in the following 10 countries. Yemen, Nigeria, Sudan, Indonesia, India, Ethiopia, Pakistan, Cameroon, Niger, and Afghanistan; 229 cases were reported during the same period in 2004.

In Canada

In Canada, the last major polio epidemic occurred in 1959. However, due to the introduction of inactivated polio vaccine (IPV) in 1955 and oral polio vaccine (OPV) in 1962, the transmission of wild poliovirus (WPV) was rapidly controlled in Canada. The last significant outbreak in Canada occurred in 1978-79, when wild poliovirus was imported from an outbreak in the Netherlands. The importation was linked to an outbreak in religious communities in the Netherlands; the outbreak in Canada was limited to similar closed communities (i.e those that do not accept routine immunizations for religious reasons). Eleven paralytic cases occurred in British Columbia, Ontario, and Alberta from this outbreak.

Symptoms

The incubation period for poliomyelitis varies from 4 to 35 days. Polio infection often produces no symptoms or minor symptoms, such as fever, fatigue, headache, vomiting, constipation (or less commonly diarrhoea), stiff neck and pain in the limbs. Infected individuals can transmit the virus to others even though they exhibit no symptoms.

In severe cases, the muscles of the legs are affected with acute flaccid paralysis (AFP) that can spread to other muscle groups. In the most severe cases, the brain and respiratory system are affected, which can result in death.

Treatment

There is no specific treatment for polio. Severe cases require supportive care that may help the patient recover. .

Vaccines

Two types of polio vaccines are available in Canada: the Salk inactivated polio vaccine (IPV) and the Sabin oral polio vaccine (OPV). The IPV is delivered by injection of killed virus in three doses over six to twelve months. IPV is highly protective but not necessarily lifelong, and is extremely safe. The OPV vaccine is given orally in three doses and is formulated from live viruses of each of the three polio serotypes. In some cases, vaccine-associated polio effects have been reported following OPV use.

Canada has a high standard of childhood immunization programs, and polio vaccination is included in our national childhood immunization schedule. While both types of vaccines are licensed for use in Canada, the Public Health Agency of Canada’s National Advisory Committee on Immunization (NACI) recommends the exclusive use of IPV.

Prevention and personal precautions

As there is no cure for polio, prevention is key.

Recommendations

The Public Health Agency of Canada strongly recommends that Canadian international travellers contact a physician or travel medicine clinic prior to departure for an individual risk assessment. Based on travellers' current health status, previous immunization history and anticipated travel itinerary, their need for polio vaccination can be assessed.

Children and adults who are not immunized should receive full immunization against polio (three doses of IPV) prior to travelling to areas where polio may be a risk. Children who have received their childhood polio series are protected against polio when travelling to an area where polio may be a risk. Adults who are immunized (i.e., have received their childhood series) require a single booster dose when travelling to an area where polio may be a risk.

Some things to think about...

International travel can expose Canadians to infectious diseases, like polio, that are not frequently seen in North America. Our high standard of sanitation and childhood immunization programs may lead many adult Canadians to become complacent about keeping their routine immunizations up to date. All travellers are advised to review their immunization history with a physician well in advance of departure to confirm whether they have been properly immunized against polio.

For more information...

• For a map of polio activity worldwide, visit the World Health Organization’s Polio Eradication Web site
• To view "Immunizations recommended for travel outside of Canada"
• For more "Know before you go" information.
• To view the Committee to Advise on Tropical Medicine and Travel "Statement on poliomyelitis vaccination for international travellers".
• To view the Canadian Immunization Guide by the National Advisory Committee on Immunization.

[Information for Travellers] [Information for Travel Medicine Professionals]