Adverse events following immunization: Knowledge and experience of mothers in immunization centres in Enugu State, Nigeria

Abstract

Background : The rapid improvement in immunization services has resulted in significant decline in infant and childhood mortality and morbidity associated with vaccine preventable disease. However, because these diseases have become less visible, the public tends to be more concerned with adverse events following immunization (AEFI) than with the threat of the disease itself. Aim : To asses the knowledge of AEFI among mothers and also to determining the prevalence, the most common antigen associated with AEFI and mother’s responses to the adverse reactions. Method : This is a descriptive cross-sectional study of the mothers who brought their children for immunization in three randomly selected immunization centers in Enugu Urban. A systematic sampling method was used to select 331 mothers. An informed consent was obtained from each participant. Data was collected using a pre-tested, semi-structured, interviewer-administered questionnaire with open and closed ended questions. Data was entered and analyzed using Epi-info version 3.3 software package. Results : Two hundred and seventy-three (82.5%) studied knew that fever is a possible adverse event. Pain and swelling at the site of injection was identified by 77 (23.3%), rash 10.3%, convulsion 3.9% boils 3.0% paralysis / weakness of limbs 2.7% and ulcers 0.6%. Among the 331 mothers, 220 (66.5%) had experienced adverse reactions following immunization of their children. The most commonly reported adverse reaction by these mothers were fever 199 (90.4%), pain / swelling 61 (27.7%), rashes and convulsion 6 (2.7%) each. Ulcer was reported by 2(0.9%) while collapse and paralysis were reported by 1(0.5%) each. Two hundred and five (93.2%) of these reactions out of the reported 220(66.5%) occurred within 24 hours. The antigens responsible as identified by the mothers were DPT 176(80.0%), HBV 37(16.8%), BCG 36(16.4%), OPV 21(9.5%), measles 12(5.5%), yellow fever 10(4.5%) and CSM 7(3.2%). About 190(57.4%) of the mothers responded to these reactions by giving the child paracetamol, 31(21.1%) stopped further immunization temporarily, while 43(19.5%) took the child to hospital. Two (0.9%) of the mother each either took their children to native doctors or gave native mixtures. Sixty-two (88.6%) of those temporarily stopped immunization re-started after a while. Conclusion : The mothers had a fair knowledge of the possible adverse reactions following immunization and actions to take when such occurs. The most reported reactions were associated with DPT and occurred within 24hours of vaccination. Some of the women subsequently did not complete immunization of the affected children. Therefore, health education should be regularly organized for these women on the appropriate actions to be taken when adverse reactions uccur to dispel false rumours, emphasizing the fact that immunization programmes are still one of the safest and most effective health intervention.