A Quantitative Risk Assessment to Evaluate the Efficacy of Mitigation Strategies to Reduce Highly Pathogenic Avian Influenza (HPAI) Virus, Subtype H5N1 (HPAI H5N1) in the Menoufia Governorate, Egypt

Abstract BackgroundThe poultry industry in Egypt has been suffering from endemic highly pathogenic avian influenza (HPAI) virus, subtype H5N1 since 2006. However, the emergence of H9N2, H5N8, and H5N2 in 2011, 2016, and 2019 respectively, has aggravated the situation. Our objective was to evaluate how effective are the mitigation strategies by a Quantitative Risk Assessment (QRA) model utilizing daily outbreak data of HPAI-H5N1stratified by different epidemic waves from 2006 to 2016 are in Egypt. ResultsUtilizing the epidemiologic problem-oriented approach methodology, a conceptual scenario tree was drawn based on the knowledgebase. Monte Carlo simulations of QRA parameters were ran utilizing @Risk software. In poultry farms, the likelihood of poultry still having a high Prevalence Rate (PR) after failure of mitigation strategies such as vaccination, passive, and active surveillance, in 90% of the time, these mitigations will fail 48% of the time. Failure of efficacy of these mitigations will raise PR to 70% with missed vaccination, while failure in detection by surveillance will raise it to 99%. In backyard poultry, the likelihood of still having a high HPAI-H5N1 PR in three different poultry types due to failure of passive and active surveillance varies between domestic, mixed and reservoir. In mixed poultry, the probability of HPAI-H5N1 not detected by surveillance was higher with a mean and a SD of 16.8 x 10-3 and 3.26 x 10-01 respectively. The sensitivity analysis ranking for the likelihood of HPAI-H5N1 in poultry farms due to missed vaccination, failure to be detected by passive and active surveillance was examined. In poultry farms, increasing vaccination by 1 SD will decrease the PR by 14%, in active surveillance by 12% and in passive surveillance by 6%, respectively. while in backyard, the active surveillance had high impact in decreasing the PR by 16% in domestic poultry. Whereas the passive surveillance had less impact in decreasing PR by 14% in mixed poultry and 3% in domestic poultry. ConclusionIt could be concluded that the applied strategies were not efficient in controlling the spread of the HPAI-H5N1 virus. Public health officials should take into consideration the evaluation of their control strategies in their response.