POLIO ERADICATION EPI (SA) FACT SHEET

1. GOALS AND OBJECTIVES

Following the success of the eradication of smallpox, poliomyelitis was resolved to be the next disease to be eradicated at the World Health Assembly in 1988. The goal was set for the global eradication of polio by the year 2000, however had to be changed to 2005.

A Global Certification Commission was established and criteria for the Certification of the Eradication of Poliomyelitis include:

• there will be no cases of clinical poliomyelitis associated with wild polio viruses;
• there will be no wild polio virus identified anywhere in the Southern African region, the process of independent certification of polio-free status may be initiated at national and sub-regional levels, leading to full regional certification within 3 years starting from 2002.

To date, progress made in attaining these goals in South Africa are as follows:

• Last virologically confirmed case of polio was in 1989
• Acute Flaccid Paralysis (AFP) notifiable since 1994
• Case investigation surveillance instituted in 1995
• The coverage reached in the polio mass immunisation campaigns are shown in table 1.

2. RATIONALE FOR POLIO ERADICATION

Polio can be eradicated for the following reasons:

• Polio affects only humans, no animal reservoir
• Effective, safe and inexpensive vaccine is available
• No long term carriers
• Immunity is life long
• Polio virus survives only for a short time in the environment, outside the human body.

3. STRATEGIES

Polio eradication is based on four strategies:

High routine coverage with oral polio vaccine (OPV):

Routine immunisation coverage for OPV-3 is sub-optimal and must be increased to 90%. Available information indicates OPV-3 coverage to be 71.5% (1994 vitamin A coverage survey) and 72.1% (1998 district health survey) and 85% according to the routine system in 2001.

Mass immunisation campaigns:

Mass immunization campaigns were initially conducted to facilitate implementation of the polio eradication strategy. The campaigns in 1995-2000 were conducted to rapidly interrupt the chains of polio transmission. All children 0-59 months of age, irrespective of immunisation history, were immunised with two doses of oral polio vaccine (OPV) during two rounds (see Table 1).

"Mopping-up" campaigns

Mopping-up is the house-to-house vaccination of all children 0-59 months within a high-risk geographic area or population with two doses of OPV regardless of previous immunisation history.

Table 1: Doses given (in millions) and Coverage (% of target group), mass campaigns 1995-2000

Quality AFP surveillance

The primary purpose of AFP surveillance is to -

• Find / detect cases of polio due to wild polio virus if the were to occur;
• show that if wild polioviruses existed, it would be found; and
• achieve the gold standard for polio-free certification.

4. CRITERIA FOR ACHIEVING POLIO-FREE CERTIFICATION

• A minimum AFP detection rate of 1 per 100 000 children under 15 years of age (with good geographical distribution of cases)
• At least 80% of AFP cases have 2 stool specimens taken within 14 days after onset of paralysis, within 24 to 48 hours apart AND reach the WHO accredited laboratory on ice within 3 days.
• At least 80% of AFP cases without adequate stool collected should have a follow up examination after 60 days.
• At least 80% of routine reports (including zero-reports) received

5. PROGRESS WITH AFP SURVEILLANCE

Performance with AFP surveillance in South Africa during 1997-2001 is illustrated below.

Graph 1. AFP Stool Collection: SA, 1997-2000

Graph 2. AFP Case Detection Rate 2001

Although SA reached the detection target, it is expected of each province to reach all criteria.

6. DISEASE

Polio is a highly infectious disease caused by poliovirus. The virus mostly affects children below the age of five years, however any person who does not have immunity to polio, may be affected.

The virus causes paralysis, which is irreversible in many cases. The disease follows infection with any of the three related entero-virus, which are poliovirus type 1, type 2 and type 3.

The virus enters through the mouth and multiplies inside the throat and intestines.

Poliovirus is shed intermittently in faeces for several weeks. Person-to-person transmission of poliovirus is high, especially in areas with poor hygiene and sanitation, or at any environment where children are not yet toilet trained. It can also be spread when food or drinks is contaminated by faeces containing the virus.

The initial signs and symptoms of polio include fever, fatigue, headache, vomiting, constipation or less commonly diarrhoea, neck stiffness and pain in the limbs.

In most severe cases, poliovirus attacks the motor neurons of the brain stem, reducing breathing capacity and causing difficulty in swallowing and speaking. Without adequate respiratory support, this form of polio, called bulbar polio, can result in death.

Polio cannot be cured but it can be prevented. Five doses of Oral Polio Vaccine (OPV) will protect a child for life.

7. ROLE OF CLINICIANS & COMMUNITIES

Health workers and communities can assist:

• By reporting every case of Acute Flaccid Paralysis even if he/she is so convinced that the paralysis is not caused by a poliovirus
• By ensuring that 2 stool specimens are collected within 24-48hours apart from each case, within 14 days of onset of paralysis, and send on ice to the National Institute for Communicable Diseases (NICD) previously the National Institute of Virology (NIV)

8. ROLE OF MEDIA & COMMUNITIES

• The media is the most influential advocacy vehicle and play key roles in mobilising public support. Issues around immunisation reach the public widely through radio, television and newspapers.
• Parents and the community can assist by reporting any child younger than 15 years, with sudden weakness or paralysis in the leg(s) and /or arm (s) that was not caused by injury.
• All parents and caregivers must take their children for oral polio vaccine at the correct ages.

FOR FURTHER INFORMATION CONTACT:
EXPANDED PROGRAMME ON IMMUNIZATION
DEPARTMENT OF HEALTH
PRIVATE BAG X828
PRETORIA 0001
Tel: 012 312 0099 Fax NO: 012 321 9882