Improvements of acute flaccid paralysis and measles surveillance performances in response to outbreak of circulating vaccine-derived poliovirus (2021-2022): the case of Southwest Ethiopia Region, Ethiopia.

INTRODUCTION

following the detection of vaccine-derived poliovirus in 2019 in Ethiopia, response activities have been conducted including strengthening disease surveillance activities.

METHODS

trend analysis study design of acute flaccid paralysis and measles surveillance data for the years 2021 and 2022 for Southwest Ethiopia Region was used. The non-polio acute flaccid paralysis (AFP) rate and stool adequacy rates were used to assess the AFP surveillance. Whereas the non-measles febrile rash rate was used to assess the measles surveillance.

RESULTS

a total of 68 AFP cases in 2022 and 49 in 2021 have been reported as of week 41 and investigated for polio analysis. All cases were discarded in 2022 and 1 cVDPV was detected in 2021. The stool adequacy rate for 2022 was 96%; whereas, 94% in 2021. The annualized non-polio AFP rate was 4.8/100,000 for 2022 and 3.8/100,000 for 2021, which the former is much higher though both met the minimum expected rate in outbreak areas of 3/100,000. A total of 155 suspected measles cases in 2022 and 38 in 2021 have been investigated for IGM analysis. In 2022, 9 and 1 in 2021 Igm positive for measles were identified. The non-measles febrile rash rate for 2022 was 4.6/100,000; whereas, 1.2/100,000 for 2021.

CONCLUSION

there is an improvement in the sensitivity of AFP and measles surveillance for Southwest Ethiopia Region in 2022. Sustaining high-quality measles and AFP surveillance is suggested to maintain measles and polio-free statuses.