Environmental surveillance for polioviruses in the Global Polio Eradication Initiative.

May combine two claims.

About 60% of Kano population waste goes through the open sewage channel, which made it possible to collect multiple good-quality environmental samples.

“Despite the various methods of waste disposal identified, it was observed that around 60% of population waste is through the open sewage channel, thus making it possible to collect multiple good-quality samples for the purpose of environmental sampling.”

May combine two claims.

Wild poliovirus was found in Lahore without AFP cases, which allowed vaccination efforts to continue against silent transmission in Lahore and prevent spread across the province.

“For example, WPV was found in Lahore in the absence of AFP cases, which allowed the program to continue the inclusion of vaccination efforts to stop silent WPV transmission within Lahore and prevent spread throughout the province.”

May combine two claims.

From 2010 through 2013, wild poliovirus transmission remained endemic in northern Nigerian states, and Kano state was considered an epicenter of polio in Nigeria.

“From 2010 through 2013, WPV transmission has remained endemic in northern Nigerian states, with Kano state in northern Nigeria considered an epicenter of polio in Nigeria [12].”

• cites [12]Not checked yet

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May combine two claims.

A feasibility assessment documented that Kano state had no organized or functioning sewage wastewater disposal or treatment systems, though remnants of five nonfunctional sewage-pumping stations existed.

“During this feasibility assessment, it was documented that there were no organized/functioning sewage wastewater disposal/treatment systems in Kano state; however, there were remnants of 5 nonfunctional sewage-pumping stations.”

May combine two claims.

In Nigeria, although AFP surveillance targets were met in all states, virological data indicated that AFP surveillance alone was not sensitive enough to detect all wild poliovirus transmission chains promptly.

“In Nigeria, although AFP surveillance targets continue to be met in all states, virological data have indicated that AFP surveillance alone has not been sufficiently sensitive to detect all chains of WPV transmission in a timely manner.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

In these countries, environmental surveillance is conducted in large population centers and other strategic sites with the highest poliovirus circulation risk.

“In these countries, ES is undertaken in large population centers and other strategic locations where the risk of poliovirus circulation is highest.”

May combine two claims.

Sites in Sindh and Punjab provinces repeatedly yielded wild poliovirus isolates without matching AFP cases, which supported preventive action in those areas.

“Samples from sites in some areas (eg, Sindh and Punjab provinces) have consistently yielded WPV isolates in the absence of WPV-positive AFP cases from the same area, thereby enabling a focus on preventive action in these areas because of the detected circulation in locations where either no AFP cases have yet occurred or are cases have been underreported.”

May combine two claims.

Wild poliovirus type 1 was found at all but one Karachi sampling site, while wild poliovirus type 3 was last detected in mid-2010.

“WPV type 1 (WPV1) has been found in all except one sampling site of Karachi, while WPV3 was last detected in mid 2010.”

May combine two claims.

In Nigeria, wild poliovirus transmission in 2012 mainly involved type 1, and no type 3 was detected in 2013.

“Transmission of WPV in 2012 in Nigeria has predominantly involved WPV1, and no WPV3 has been detected in 2013.”

May combine two claims.

Environmental surveillance in Pakistan began in Karachi and Lahore in 2009 and expanded to major cities in all four provinces, increasing sampling sites from 17 in 2011 to 23 in 2012.

“In Pakistan, ES started in Karachi (Sindh province) and Lahore (Punjab) during 2009 and was extended to the other major cities in all 4 provinces (Quetta, in Balochistan; Multan, Rawalpindi, and Faisalabad, in Punjab; and Peshawar, in Khyber Pakhtunkhwa), thereby increasing the number of ES sampling sites from 17 in 2011 to 23 in 2012.”

May combine two claims.

After poliovirus stopped being found in human cases, environmental surveillance documented the absence of endemic wild poliovirus transmission and detected imported wild poliovirus.

“After poliovirus ceased to be detected in human cases, ES documented the absence of endemic WPV transmission and detected imported WPV.”

Probably not a substantial claim: may not pass S3 (load-bearing).

In India, sewage sampling helped describe poliovirus circulation epidemiology in places with high vaccination coverage but continuing paralytic polio.

“In India, sampling of sewage helped to characterize the epidemiology of poliovirus circulation, as previously described [2,4].”

• cites [2] sourceNot checked yet

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• cites [4] sourceNot checked yet

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May combine two claims.

The number of Pakistani districts affected by wild poliovirus was similar in 2009 and 2012, with 17 and 19 districts respectively, in northern and southern transmission zones.

“The number of districts affected by WPV has remained largely unchanged from 2009 (17 districts) to 2012 (19 districts), and these districts are located in the northern transmission zone (northwestern Khyber Pakhtunkhwa province and the Federally Administered Tribal Areas, bordering eastern Afghanistan), and in the southern transmission zone (Balochistan, bordering southern Afghanistan).”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Three selected Sokoto sampling sites were in Sokoto North LGA and one in Sokoto South LGA, and both LGAs were known high-risk areas for poliovirus circulation.

“Three of these sites (Kofar Dundaye, Kofar Kware, and Rumbukawa) are located in Sokoto North LGA, and 1 site (Tudun Wada) is in Sokoto South LGA. Both of these LGAs are known high-risk areas for poliovirus circulation.”

May combine two claims.

Wild poliovirus transmission has been documented in Israel, where environmental surveillance has served since 1988 as an early warning system for imported wild poliovirus.

“WPV transmission has been documented in Israel, where the ES system has been used since 1988 as an early warning system to detect imported WPV [5–7].”

• cites [5]Not checked yet

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• cites [6]Not checked yet

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• cites [7]Not checked yet

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May combine two claims.

Environmental surveillance detects poliovirus in sewage and is used to monitor community transmission.

“ES detects poliovirus circulation in environmental sewage and is used to monitor transmission in communities.”

May combine two claims.

In 2012, two type 2 vaccine-derived polioviruses were isolated in Karachi through environmental surveillance and later genetically linked to circulating vaccine-derived poliovirus isolates from AFP cases in Balochistan.

“In addition, in 2012, 2 type 2 VDPVs were isolated in Karachi through ES, which were subsequently genetically linked to circulating VDPV isolates from AFP cases in Balochistan”

May combine two claims.

The Jakara channel is the single major sewage channel passing through Kano city and the sole drainage system for the identified high-risk local government areas.

“There was one major sewage channel, referred to as Jakara, that passes through the city and is the sole drainage system for the identified high-risk LGAs.”

May combine two claims.

Although Nigerian environmental surveillance was not geographically representative, its results matched the serotype distribution in AFP cases, with type 1 detected more often than type 3.

“Although ES in Nigeria is not geographically representative, results are consistent with the serotype distribution in AFP cases, as WPV1 has been more frequently detected than WPV3.”

May combine two claims.

The last detections of wild poliovirus types 1 and 3 in Delhi sewage occurred in August 2010 and July 2010, respectively.

“The last detection of WPV1 and WPV3 strains in sewage samples in Delhi occurred in August 2010 and July 2010, respectively (Figure 4).”

May combine two claims.

From 2008 onward in Mumbai, wild poliovirus isolation frequency gradually declined and then wild poliovirus became completely absent from sewage samples.

“A gradual decline in isolation frequency and, finally, complete absence of WPV in sewage samples was observed from 2008 onward.”

May combine two claims.

In 2013 in Israel and the West Bank, a related wild poliovirus strain was detected and triggered vaccination responses, with no confirmed AFP cases.

“In 2013 in Israel and the West Bank, a related strain of WPV was detected that triggered vaccination responses. Similarly to Egypt, no WPV-confirmed AFP cases were detected [5–7].”

• cites [5]Not checked yet

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• cites [6]Not checked yet

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• cites [7]Not checked yet

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May combine two claims.

Egypt has conducted systematic environmental surveillance for poliovirus since 2000, revealing wild polioviruses in sewage one year after AFP detection ceased in 2004, four independent wild poliovirus importations, and several vaccine-derived polioviruses in various locations.

“Systematic ES for poliovirus circulation has been conducted in Egypt since 2000, during which surveillance has revealed (1) WPVs in sewage, 1 year after cessation of detection in AFP cases in 2004; (2) 4 independent importations of WPV; and (3) several VDPVs, which have been detected in various locations.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Countries at high risk of importation and recent outbreaks include Kenya, Somalia, and countries bordering Nigeria in West and Central Africa.

“For example, some countries at high risk of importation and recent outbreaks include Kenya, Somalia, and those bordering Nigeria in West and Central Africa.”

May combine two claims.

From late 2013 through early 2014, wild poliovirus related to virus circulating in Israel, the West Bank, and Egypt was detected in 36 AFP cases in Syria and then one case in Iraq, prompting outbreak response in the Middle East.

“However, in late 2013 through early 2014, WPV related to the virus circulating in Israel, the West Bank, and Egypt was detected in AFP cases in Syria (36 cases) and subsequently in Iraq (1 case), thereby leading to further outbreak response efforts throughout these and neighboring Middle Eastern countries.”

May combine two claims.

Environmental surveillance findings identified type 2 vaccine-derived polioviruses in Nigeria, indicating population groups with major immunity gaps to type 2 poliovirus who were excreting the virus.

“However, the findings of ES identified type 2 VDPVs, indicating the existence of population groups with profound immunity gaps to type 2 poliovirus who are excreting the virus in the environment.”

May combine two claims.

In Mumbai, the last wild poliovirus type 1 strain was detected in sewage in November 2010, and the last type 3 strain was recovered in December 2009.

“In Mumbai, the last WPV1 strain was detected in sewage samples in November 2010, and the last WPV3 strain was recovered in December 2009 (Figure 4).”

May combine two claims.

No wild poliovirus transmission was detected in environmental surveillance samples from Kolkata and Patna, but vaccine-derived polioviruses were isolated.

“No WPV transmission was detected in ES samples from these 2 sites; however, VDPVs were isolated.”

May combine two claims.

In Egypt in December 2012, wild poliovirus type 1 was isolated from two Cairo environmental sites despite no confirmed AFP cases, and no later samples were positive after enhanced sampling and immunization response.

“In Egypt in December 2012, WPV1 was isolated from 2 environmental sites in Cairo, although no WPV-confirmed AFP cases were detected, and no additional samples collected subsequently were found to be positive following enhanced sampling and immunization response activities.”

May combine two claims.

Vaccine-derived polioviruses are uncommon and emerge through multiple genetic reversions and prolonged transmission of attenuated oral poliovirus vaccine viruses, particularly where vaccine coverage is poor.

“such strains, although rare, arise from multiple genetic reversions and sustained transmission over time of the attenuated polioviruses found in oral poliovirus vaccine (OPV), especially in areas with suboptimal vaccine coverage [8].”

• cites [8]Not checked yet

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Classified as probably not a substantial claim. May combine two claims.

For environmental surveillance to assess poliovirus transmission, programs need adequate sensitivity, frequent sampling, suitable isolation methods, and sampling sites targeted to highest-risk locations.

“To evaluate poliovirus transmission, ES programs must be developed in a manner that is sensitive, with sufficiently frequent sampling, appropriate isolation methods, and specifically targeted sampling sites in locations at highest risk for poliovirus transmission.”

May combine two claims.

Testing stool from AFP patients and isolating poliovirus allows focused case investigation and supports community-level risk investigation.

“The examination of stool samples from patients identified through AFP surveillance and subsequent isolation of poliovirus from the stool permits a focused investigation of polio cases and forms the basis for further investigations of the community-level risk of poliovirus transmission [10].”

• cites [10]Not checked yet

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May combine two claims.

Environmental surveillance is especially informative in dense populations where AFP surveillance is weak, persistent virus circulation is suspected, or repeated virus introduction is thought likely.

“ES provides valuable information, particularly in high-density populations where AFP surveillance is of poor quality, persistent virus circulation is suspected, or frequent virus reintroduction is perceived.”

• Also stated in: § RATIONALE FOR ES · plain

  “ES can provide valuable information, particularly in high-density urban populations where AFP surveillance is absent or of poor quality, persistent virus circulation is suspected, or frequent virus reintroduction is perceived.”

• AssumptionRests on an assumption: Infected people excrete poliovirus in feces for up to several weeks regardless of whether they have symptoms.
• AssumptionRests on an assumption: Many excreted poliovirus particles remain infectious in the environment for varying periods depending on wastewater conditions.
• AssumptionRests on an assumption: Testing composite human fecal samples through environmental surveillance links poliovirus isolates from unknown individuals to the populations served by the sewage or wastewater system.

Classified as probably not a substantial claim. May combine two claims.

Surveillance for vaccine-derived poliovirus emergence and monitoring of vaccine virus circulation cessation are highly important during the eradication endgame.

“Surveillance of VDPV emergence and monitoring of cessation of vaccine virus circulation is of high importance during the eradication endgame.”

May combine two claims. The quote only partly states this claim.

Environmental surveillance indicated that large metropolitan areas face constant risk of wild poliovirus reintroduction from endemic sites in India and may help redistribute viruses because many people travel to these cities.

“ES showed that large metropolitan areas are constantly at risk of reintroduction of WPVs from all poliovirus-endemic sites in the country and may also serve to redistribute the viruses, as large numbers of people from all over the country travel to these cities regularly for various purposes, including employment and tourism.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

Resource needs for sample collection and laboratory isolation may require a balanced investment between environmental surveillance and case-based AFP surveillance.

“Resource requirements for sample collection and laboratory isolation may require a balanced investment in ES versus case-based AFP surveillance.”

May combine two claims.

In conclusion, environmental surveillance has been valuable in polio-endemic countries during current eradication efforts and can potentially provide early detection of new importations or vaccine-derived poliovirus transmission.

“In conclusion, ES has been a valuable tool within polio-endemic countries during current eradication efforts, as well as a method to potentially provide early detection of new importations or VDPV transmission.”

May combine two claims.

Environmental surveillance helped detect poliovirus in the final stages of eradication, with India no longer considered endemic in 2012, and continues to document wild poliovirus absence in sewage alongside the absence of AFP cases.

“In summary, ES helped to detect poliovirus in the final stages of eradication, with poliovirus no longer considered to be endemic in India in 2012, and continues to provide important information documenting the absence of WPVs in sewage, in conjunction with the absence of ongoing WPV cases detected through AFP surveillance.”

May combine two claims.

Finding orphan viruses in environmental surveillance indicates undetected poliovirus transmission and supports the need for better surveillance sensitivity.

“The detection of so-called orphan viruses (defined as polioviruses in which nucleotides at ≥1.5% of positions differ from those of known poliovirus) in ES indicates undetected poliovirus transmission, thus supporting the need to improve surveillance sensitivity.”

May combine two claims.

Environmental surveillance complements AFP surveillance and enables linkages that characterize continued circulation and identify remaining wild poliovirus reservoirs.

“As described here, the ES complements AFP surveillance, allowing linkages to characterize continued circulation and identify remaining WPV reservoirs.”

May combine two claims.

Both environmental surveillance and AFP case-based surveillance have proven useful and informative for guiding the final stage of polio eradication.

“Both ES and AFP case-based surveillance have proven to be useful and informative tools to guide the final stage of polio eradication efforts.”

May combine two claims.

As global eradication approaches, expanding environmental surveillance may increase overall poliovirus detection sensitivity in final wild poliovirus reservoirs and help document eradication.

“As the goal of global eradication approaches, the potential expansion of ES may increase the sensitivity of overall poliovirus detection in the final reservoirs of WPV and help document eradication [6].”

• cites [6]Not checked yet

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May combine two claims.

Although genetic sequencing can help trace poliovirus origins to other circulating viruses with similar sequences, the inability to link environmental samples to infected people may limit elucidation of epidemiological linkages and targeting of vaccination strategies.

“Although genetic sequencing may allow the ability to trace the origin of polioviruses to other circulating polioviruses with similar sequences, the inability to link environmental samples with infected persons may limit the ability to elucidate epidemiological linkages and to appropriately target vaccination strategies.”