Poliomyelitis
	Know before you go!
	Disease profile
	Transmission
	Geographic distribution
	Symptoms
	Treatment
	Vaccine
	Prevention & precautions
	Some things to think about

Poliomyelitis

Updated: October 2006

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 four to six 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 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 measles 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 three 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 the Global Polio Eradication 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, meaning poliovirus is no longer naturally present in the environment: the Americas (1994), the Western Pacific (2000) and Europe (2002). The regions of the Eastern Mediterranean, South-East Asia and Africa continue to work towards polio eradication.

Eastern Mediterranean Region
Significant progress has been made towards the eradication of polio in this region. The virus remains endemic in Afghanistan and Pakistan where wild polio virus (WPV) transmission continues to occur. Somalia and Yemen have reported cases of imported polio virus (IPV) transmission in 2006.

South-East Asia Region
Overall, the number of cases of polio in the region has declined significantly - from a reported 25 253 cases in 1988 to 303 laboratory confirmed cases in 2005. India remains the only polio-endemic country in the region. In 2006, Indonesia, Nepal and Bangladesh have each reported a small number of imported cases.

African Region
Substantial progress towards polio eradication had been made in this region; however, in 2004 sub-Saharan Africa experienced epidemic levels of polio transmission resulting from the suspension of immunization activities in a number of Nigerian states. The transmission of WPV increased within these states. Consequently, Nigeria reported the largest number of WPV cases globally for 2004. Eventually, poliovirus from Nigeria spread to a number of neighbouring countries with low routine immunization coverage resulting in the re-infection of 12 previously polio-free countries in Africa. In 2005, Nigeria again reported the largest number of WPV cases globally and virus originating from Nigeria continued to spread reaching as far as Yemen and Indonesia. Currently, Nigeria remains the only polio-endemic country in the African region and transmission continues to remain high. The following countries, although no longer polio-endemic, are considered to have active transmission of an imported virus: Ethiopia, Niger, Angola, Namibia and the Democratic Republic of the Congo.

For a current list of confirmed cases of polio by country consult the Global Polio Eradication Initiative.

In Canada
At one time, paralytic poliomyelitis was a common childhood disease in Canada. 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 major polio epidemic occurred in 1959. Canada reported its last case of indigenous wild polio infection in 1977.

Small outbreaks of wild poliovirus occurred in 1978 and 1979 in British Columbia, Ontario, and Alberta among closed communities that do not accept immunization for religious reasons. The outbreaks stemmed from wild poliovirus that was imported from the Netherlands (outbreaks had occurred in similar communities there). In 1993, another outbreak resulting from imported virus from the Netherlands occurred in the same communities.

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

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...

• To view "Immunizations recommended for travel outside of Canada", click here;
• For more "Know before you go" information, click here
• To view the Committee to Advise on Tropical Medicine and Travel ; "Statement on poliomyelitis vaccination for international travellers" , click here;
• To view the Canadian Immunization Guide by the National Advisory Committee on Immunization, click here.