BACKGROUND: The environmental surveillance has proven to be a useful tool to identify poliovirus circulation in different countries and was started in Pakistan during July 2009 to support the acute flaccid paralysis (AFP) surveillance system. METHODS: Sewage samples were collected from 27 environmental sampling (ENV) sites and processed for poliovirus isolation through 2-phase separation method. Poliovirus isolates were identified as Sabin-like or wild type through real-time polymerase chain reaction (PCR). Wild-type strains were subjected to VP1 gene sequencing and phylogenetic analysis performed using MEGA 5.0. RESULTS: During 2011-2013, a total of 668 samples were collected from 4 provinces that resulted in 40% of samples positive for wild poliovirus type-1 (WPV-1). None of the samples were positive for WPV-3. The areas with high frequency of WPV-1 detection were Karachi-Gadap (69%), Peshawar (82%), and Rawalpindi (65%), whereas the samples from Quetta and Sukkur remained negative for WPV during 2013. Phylogenetic analysis revealed 3 major clusters with multiple poliovirus lineages circulating across different country areas as well as in bordering areas of Afghanistan. CONCLUSIONS: Environmental surveillance in Pakistan has been proven to be a powerful tool to detect WPV circulation in the absence of poliomyelitis cases in many communities. Our findings emphasize the need to continue and expand such surveillance activities to other high-risk areas in the country.
BACKGROUND: The environmental surveillance has proven to be a useful tool to identify poliovirus circulation in different countries and was started in Pakistan during July 2009 to support the acute flaccid paralysis (AFP) surveillance system. METHODS: Sewage samples were collected from 27 environmental sampling (ENV) sites and processed for poliovirus isolation through 2-phase separation method. Poliovirus isolates were identified as Sabin-like or wild type through real-time polymerase chain reaction (PCR). Wild-type strains were subjected to VP1 gene sequencing and phylogenetic analysis performed using MEGA 5.0. RESULTS: During 2011-2013, a total of 668 samples were collected from 4 provinces that resulted in 40% of samples positive for wild poliovirus type-1 (WPV-1). None of the samples were positive for WPV-3. The areas with high frequency of WPV-1 detection were Karachi-Gadap (69%), Peshawar (82%), and Rawalpindi (65%), whereas the samples from Quetta and Sukkur remained negative for WPV during 2013. Phylogenetic analysis revealed 3 major clusters with multiple poliovirus lineages circulating across different country areas as well as in bordering areas of Afghanistan. CONCLUSIONS: Environmental surveillance in Pakistan has been proven to be a powerful tool to detect WPV circulation in the absence of poliomyelitis cases in many communities. Our findings emphasize the need to continue and expand such surveillance activities to other high-risk areas in the country.
Authors: Andrés Lizasoain; Fernanda M Burlandy; Matías Victoria; Luis F López Tort; Edson E da Silva; Rodney Colina Journal: Food Environ Virol Date: 2018-06-16 Impact factor: 2.778
Authors: Tori L Cowger; Cara C Burns; Salmaan Sharif; Howard E Gary; Jane Iber; Elizabeth Henderson; Farzana Malik; Syed Sohail Zahoor Zaidi; Shahzad Shaukat; Lubna Rehman; Mark A Pallansch; Walter A Orenstein Journal: PLoS One Date: 2017-07-25 Impact factor: 3.240
Authors: Kathleen M O'Reilly; Robert Verity; Elias Durry; Humayun Asghar; Salmaan Sharif; Sohail Z Zaidi; M Zubair M Wadood; Ousmane M Diop; Hiro Okayasu; Rana M Safdar; Nicholas C Grassly Journal: BMC Infect Dis Date: 2018-04-13 Impact factor: 3.090
Authors: Laina D Mercer; Rana M Safdar; Jamal Ahmed; Abdirahman Mahamud; M Muzaffar Khan; Sue Gerber; Aiden O'Leary; Mike Ryan; Frank Salet; Steve J Kroiss; Hil Lyons; Alexander Upfill-Brown; Guillaume Chabot-Couture Journal: BMC Med Date: 2017-10-11 Impact factor: 8.775
Authors: Steve J Kroiss; Maiwand Ahmadzai; Jamal Ahmed; Muhammad Masroor Alam; Guillaume Chabot-Couture; Michael Famulare; Abdirahman Mahamud; Kevin A McCarthy; Laina D Mercer; Salman Muhammad; Rana M Safdar; Salmaan Sharif; Shahzad Shaukat; Hemant Shukla; Hil Lyons Journal: PLoS One Date: 2018-12-28 Impact factor: 3.240