Circulating vaccine derived polio virus type 2 outbreak and response in Yemen, 2021–2022, a retrospective descriptive analysis
Abstract Background The outbreaks of circulating Vaccine Derived Polio Viruses (cVDPVs) have emerged as a major challenge for the final stage of polio eradication. In Yemen, an explosive outbreak of cVDPV2 was reported from August 2021 to December 2022. This study aims to compare the patterns of cVD...
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| Format: | Article |
| Language: | English |
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BMC
2024-03-01
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| Series: | BMC Infectious Diseases |
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| Online Access: | https://doi.org/10.1186/s12879-024-09215-1 |
| _version_ | 1797259502748172288 |
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| author | Mutahar Ahmed Al-Qassimi Mohammed Al Amad Ahmed Al-Dar Ehab Al Sakaf Ahmed Al Hadad Yahia Ahmed Raja’a |
| author_facet | Mutahar Ahmed Al-Qassimi Mohammed Al Amad Ahmed Al-Dar Ehab Al Sakaf Ahmed Al Hadad Yahia Ahmed Raja’a |
| author_sort | Mutahar Ahmed Al-Qassimi |
| collection | DOAJ |
| description | Abstract Background The outbreaks of circulating Vaccine Derived Polio Viruses (cVDPVs) have emerged as a major challenge for the final stage of polio eradication. In Yemen, an explosive outbreak of cVDPV2 was reported from August 2021 to December 2022. This study aims to compare the patterns of cVDPV2 outbreak, response measures taken by health authorities, and impacts in southern and northern governorates. Method A retrospective descriptive study of confirmed cases of VDPV2 was performed. The data related to cVDPV2 as well as stool specimens and environmental samples that were shipped to WHO-accredited labs were collected by staff of surveillance. Frequencies and percentages were used to characterize and compare the confirmed cases from the southern and northern governorates. The average delayed time as a difference in days between the date of sample collection and lab confirmation was calculated. Results The cVDPV2 was isolated from 227 AFP cases reported from 19/23 Yemeni governorates and from 83% (39/47) of environmental samples with an average of 7 months delayed from sample collection. However, the non-polio AFP (NPAFP) and adequate stool specimen rates in the north were 6.7 and 87% compared to 6.4 and 87% in the south, 86% (195) and 14%(32) out of the total 227 confirmed cases were detected from northern and southern governorates, respectively. The first and second cases of genetically linked isolates experienced paralysis onset on 30 August and 1st September 2021. They respectively were from Taiz and Marib governorates ruled by southern authorities that started vaccination campaigns as a response in February 2022. Thus, in contrast to 2021, the detected cases in 2022 from the total cases detected in the south were lower accounting for 22% (7 of 32) of compared to 79% (155 of 195) of the total cases the north. Conclusion A new emerging cVDPV2 was confirmed in Yemen. The result of this study highlighted the impact of vaccination campaigns in containing the cVDPV2 outbreak. Maintaining a high level of immunization coverage and switching to nOPV2 instead of tOPV and mOPV2 in campaigns are recommended and environmental surveillance should be expanded in such a risky country. |
| first_indexed | 2024-04-24T23:10:27Z |
| format | Article |
| id | doaj.art-651d360b36be40599a9c40909f0627bd |
| institution | Directory Open Access Journal |
| issn | 1471-2334 |
| language | English |
| last_indexed | 2024-04-24T23:10:27Z |
| publishDate | 2024-03-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Infectious Diseases |
| spelling | doaj.art-651d360b36be40599a9c40909f0627bd2024-03-17T12:16:54ZengBMCBMC Infectious Diseases1471-23342024-03-012411910.1186/s12879-024-09215-1Circulating vaccine derived polio virus type 2 outbreak and response in Yemen, 2021–2022, a retrospective descriptive analysisMutahar Ahmed Al-Qassimi0Mohammed Al Amad1Ahmed Al-Dar2Ehab Al Sakaf3Ahmed Al Hadad4Yahia Ahmed Raja’a5National Polio surveillance coordinator, Yemen Ministry of Public Health and PopulationDepartment of Community Medicine, Faculty of Medicine and Health Sciences, Sana’a UniversityDepartment of Community Medicine, Faculty of Medicine and Health Sciences, Sana’a UniversityGeneral Director for Diseases Control and Surveillance, Yemen Ministry of Public Health and PopulationFaculty of Medicine and Health Sciences, Sana’a universityFaculty of Medicine and Health Sciences, Sana’a universityAbstract Background The outbreaks of circulating Vaccine Derived Polio Viruses (cVDPVs) have emerged as a major challenge for the final stage of polio eradication. In Yemen, an explosive outbreak of cVDPV2 was reported from August 2021 to December 2022. This study aims to compare the patterns of cVDPV2 outbreak, response measures taken by health authorities, and impacts in southern and northern governorates. Method A retrospective descriptive study of confirmed cases of VDPV2 was performed. The data related to cVDPV2 as well as stool specimens and environmental samples that were shipped to WHO-accredited labs were collected by staff of surveillance. Frequencies and percentages were used to characterize and compare the confirmed cases from the southern and northern governorates. The average delayed time as a difference in days between the date of sample collection and lab confirmation was calculated. Results The cVDPV2 was isolated from 227 AFP cases reported from 19/23 Yemeni governorates and from 83% (39/47) of environmental samples with an average of 7 months delayed from sample collection. However, the non-polio AFP (NPAFP) and adequate stool specimen rates in the north were 6.7 and 87% compared to 6.4 and 87% in the south, 86% (195) and 14%(32) out of the total 227 confirmed cases were detected from northern and southern governorates, respectively. The first and second cases of genetically linked isolates experienced paralysis onset on 30 August and 1st September 2021. They respectively were from Taiz and Marib governorates ruled by southern authorities that started vaccination campaigns as a response in February 2022. Thus, in contrast to 2021, the detected cases in 2022 from the total cases detected in the south were lower accounting for 22% (7 of 32) of compared to 79% (155 of 195) of the total cases the north. Conclusion A new emerging cVDPV2 was confirmed in Yemen. The result of this study highlighted the impact of vaccination campaigns in containing the cVDPV2 outbreak. Maintaining a high level of immunization coverage and switching to nOPV2 instead of tOPV and mOPV2 in campaigns are recommended and environmental surveillance should be expanded in such a risky country.https://doi.org/10.1186/s12879-024-09215-1Circulating Vaccine Derived Polio Virus Type 2OutbreakYemen2022 |
| spellingShingle | Mutahar Ahmed Al-Qassimi Mohammed Al Amad Ahmed Al-Dar Ehab Al Sakaf Ahmed Al Hadad Yahia Ahmed Raja’a Circulating vaccine derived polio virus type 2 outbreak and response in Yemen, 2021–2022, a retrospective descriptive analysis BMC Infectious Diseases Circulating Vaccine Derived Polio Virus Type 2 Outbreak Yemen 2022 |
| title | Circulating vaccine derived polio virus type 2 outbreak and response in Yemen, 2021–2022, a retrospective descriptive analysis |
| title_full | Circulating vaccine derived polio virus type 2 outbreak and response in Yemen, 2021–2022, a retrospective descriptive analysis |
| title_fullStr | Circulating vaccine derived polio virus type 2 outbreak and response in Yemen, 2021–2022, a retrospective descriptive analysis |
| title_full_unstemmed | Circulating vaccine derived polio virus type 2 outbreak and response in Yemen, 2021–2022, a retrospective descriptive analysis |
| title_short | Circulating vaccine derived polio virus type 2 outbreak and response in Yemen, 2021–2022, a retrospective descriptive analysis |
| title_sort | circulating vaccine derived polio virus type 2 outbreak and response in yemen 2021 2022 a retrospective descriptive analysis |
| topic | Circulating Vaccine Derived Polio Virus Type 2 Outbreak Yemen 2022 |
| url | https://doi.org/10.1186/s12879-024-09215-1 |
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