Environmental Surveillance of Poliovirus and Non-Polio Enteroviruses in Iran, 2017–2023: First Report of Imported Wild Poliovirus Type 1 Since 2000 Publisher



Nejati A¹ ; Tabatabaei SM² ; Mahmoudi S³ ; Zahraei SM³ ; Tabatabaie H¹ ; Razaghi M¹ ; Khodakhah F¹ ; Yousefi M¹ ; Mollaeikandelousi Y¹ ; Keyvanlou M¹ ; Soheili P¹ ; Pouyandeh S¹ ; Samimirad K¹ ; Shahmahmoodi S¹ Show Affiliations
Source: Food and Environmental Virology Published:2024

Abstract

In Iran, which is at high risk of the Wild Poliovirus (WPV) and Vaccine-Derived Poliovirus (VDPV) importation due to its neighborhood with two polio endemic countries, Pakistan and Afghanistan, Environmental Surveillance (ES) was established in November 2017. Sistan-Balouchestan province was chosen for the ES due to its vicinity with Pakistan and Afghanistan. Five sewage collection sites in 4 cities (Zahedan, Zabol, Chabahar and Konarak) were selected in the high-risk areas. Since the establishment of ES in November 2017 till the end of 2023, 364 sewage specimens were collected and analyzed. The ES detected polioviruses which have the highest significance for polio eradication program, that is, Wild Poliovirus type 1 (WPV1) and Poliovirus type 2 (PV2). In April and May 2019, three of 364 (0.8%) sewage specimens from Konarak were positive for imported WPV1. According to phylogenetic analysis, they were highly related to WPV1 circulating in Karachi (Sindh province) in Pakistan. PV2 was also detected in 5.7% (21/364) of the sewage specimens, most of which proved to be imported from the neighboring countries. Of 21 isolated PV2s, 7 were VDPV2, of which 5 proved to be imported from the neighboring countries as there was VDPV2 circulating in Pakistan at the time of sampling, and 2 were ambiguous VDPVs (aVDPV) with unknown source. According to the findings of this study, as long as WPV1 and VDPV2 outbreaks are detected in Iran’s neighboring countries, there is a definite need for continuation and expansion of the environmental surveillance. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.