Mopping up operations for poliomyelitis

A strategy developed for polio eradication involves mass vaccination with oral polio vaccine (OPV) of all children under 5 (regardless of their immunization status) within a limited area and period of time (3 days).[1,2) This widely disseminates the vaccine virus which competes with transmission of the wild virus. In areas that experience repeated importation of wild virus, this strategy can build herd immunity to a high level producing a barrier to transmission within the high risk area and to subsequent transmission to other areas.

Poliomyelitis surveillance from 1987 to 1993 revealed that 17 (85%) of all 20 virologically confirmed cases were from 7 regions: Jeddah, Makkah, Jizan, Najran, Al-Shamal (Arar), Al-Goriyat and Al-Joue.[3] All cases were in children under four years old. Of 13 cases from 1989 to 1993 (years for which data are available), 5 of the 13 cases had less than 3 OPV.

Based on these data a special mass vaccination campaign was planned for April and May of 1995. Training workshops were held in each region to review: the epidemiological situation of poliomyelitis and this special strategy, immunization procedures, record keeping, contraindication of immunization, and communication with the public and the family.

Regional organizing committees consisting of religious and community leaders, school teachers, and members of friends of primary health care committees assisted in the planning. Newspapers, radio and television participated in public education about the importance of the OPV campaign. In addition posters and leaflets were distributed. In each region the Governor administered the first dose.

Vaccination was accomplished in these seven high risk regions during March (first OPV) and April (second OPV), 1995. Each dose of OPV was administered within three days to children below 5 years of age regardless of their previous immunization status. Two person vaccination teams (3650) vaccinated 50 children per day. The total number of staff needed at the field level was 7300 persons. Each team was responsible for enumerating all children under 5 years old in their vaccination area before the vaccination campaign. In the seven regions 536,698 (97%) of the 554,883 in the target population received the two OPV doses. Coverage ranged from 96% in Jeddah and Makkah cities to 99% in Goriat and Al-Shamal regions. Cluster surveys done after the campaign yielded an estimated vaccine coverage of over 95% for each region.

The experience gained from this campaign will benefit the upcoming national immunization days planned in late 1995. The first round of OPV is planned to begin on October 29 and the second round on November 25, 1995. Each round will be given over three days. The target population will be 2,635,890 children under 5 years old from all regions of the Kingdom.