Shiloh
Editor, Senior Moderator
Source: http://www.cidrap.umn.edu/news-perspective/2013/11/news-scan-nov-11-2013
News Scan for Nov 11, 2013
More Syrian polio cases; Poliovirus type 3 missing in action
Filed Under:
Polio
Syrian polio cases rise to 13
Three more wild poliovirus type 1 (WPV-1) infections have been confirmed in Syria, pushing the number of cases to 13, the World Health Organization (WHO) said today.
Further genetic sequencing testing of the WPV-1 strain isolated in the Syrian outbreak suggests that its closest relative is a virus found in an environmental sample in Egypt in December 2012, which itself had been linked to a WPV circulating in Pakistan, according to the WHO. The agency said that the virus detected in Syria is also closely related to environmental samples found in Israel, West Bank, and Gaza Strip since February.
The WHO said risk of further international WPV-1 spread is high, given frequent population movements in the region and the challenge in maintaining vaccination levels that keep the spread of the disease in check.
The report on the new cases comes amid an emergency campaign to vaccinate about 1.6 million kids in the war-torn country against polio and other childhood diseases, as well as a broader effort to reach 20 million kids in Syria and six other Middle East countries over the next 6 months.
Nov 11 WHO outbreak update
Nov 8 CIDRAP News story "Syria's polio outbreak prompts huge Mideast immunization drive"
One of two remaining poliovirus types not seen in a year
It has been a full year since any wild poliovirus type 3 (WPV-3)?one of two remaining polio types?has been detected, suggesting that vaccination efforts may have exterminated the strain, though experts are not ready to say that, according to a Canadian Press report yesterday.
The disappearance of type 3 viruses would mean that only WPV-1 remains to be conquered to achieve the long-sought goal of polio eradication, the story said.
The last WPV-3 detection occurred in Nigeria in November 2012. Pakistan, one of the other two countries in which polio remains endemic, last reported a WPV-3 infection in April 2012, according to the story. Before that, the US Centers for Disease Control and Prevention (CDC) had been reporting a decline in the number of type 3 lineages.
"I think the available information is cause for some cautious optimism," Olen Kew, PhD, a senior CDC virologist and polio expert, told the Canadian Press. "But in particular in Nigeria I think we would look for more evidence before we would . . . uncork the champagne."
Polio surveillance in Nigeria is less than ideal, the story noted. But in Pakistan, testing of sewage in Peshawar has not revealed WPV-3, which is encouraging, said Kew.
The global polio eradication effort started in 1988, the story notes. WPV-2 has not been detected since 1999.
WPV-1, the type that recently turned up in Syria and in Israel's sewage, is the most aggressive polio strain and can easily travel great distances. WPV-3 is less likely to travel, but it is harder to detect, because only 1 in 1,200 infections leads to paralysis, the story said. That fact prompts experts to be very wary of saying the strain has disappeared from Nigeria.
Nov 10 Canadian Press story
News Scan for Nov 11, 2013
More Syrian polio cases; Poliovirus type 3 missing in action
Filed Under:
Polio
Syrian polio cases rise to 13
Three more wild poliovirus type 1 (WPV-1) infections have been confirmed in Syria, pushing the number of cases to 13, the World Health Organization (WHO) said today.
Further genetic sequencing testing of the WPV-1 strain isolated in the Syrian outbreak suggests that its closest relative is a virus found in an environmental sample in Egypt in December 2012, which itself had been linked to a WPV circulating in Pakistan, according to the WHO. The agency said that the virus detected in Syria is also closely related to environmental samples found in Israel, West Bank, and Gaza Strip since February.
The WHO said risk of further international WPV-1 spread is high, given frequent population movements in the region and the challenge in maintaining vaccination levels that keep the spread of the disease in check.
The report on the new cases comes amid an emergency campaign to vaccinate about 1.6 million kids in the war-torn country against polio and other childhood diseases, as well as a broader effort to reach 20 million kids in Syria and six other Middle East countries over the next 6 months.
Nov 11 WHO outbreak update
Nov 8 CIDRAP News story "Syria's polio outbreak prompts huge Mideast immunization drive"
One of two remaining poliovirus types not seen in a year
It has been a full year since any wild poliovirus type 3 (WPV-3)?one of two remaining polio types?has been detected, suggesting that vaccination efforts may have exterminated the strain, though experts are not ready to say that, according to a Canadian Press report yesterday.
The disappearance of type 3 viruses would mean that only WPV-1 remains to be conquered to achieve the long-sought goal of polio eradication, the story said.
The last WPV-3 detection occurred in Nigeria in November 2012. Pakistan, one of the other two countries in which polio remains endemic, last reported a WPV-3 infection in April 2012, according to the story. Before that, the US Centers for Disease Control and Prevention (CDC) had been reporting a decline in the number of type 3 lineages.
"I think the available information is cause for some cautious optimism," Olen Kew, PhD, a senior CDC virologist and polio expert, told the Canadian Press. "But in particular in Nigeria I think we would look for more evidence before we would . . . uncork the champagne."
Polio surveillance in Nigeria is less than ideal, the story noted. But in Pakistan, testing of sewage in Peshawar has not revealed WPV-3, which is encouraging, said Kew.
The global polio eradication effort started in 1988, the story notes. WPV-2 has not been detected since 1999.
WPV-1, the type that recently turned up in Syria and in Israel's sewage, is the most aggressive polio strain and can easily travel great distances. WPV-3 is less likely to travel, but it is harder to detect, because only 1 in 1,200 infections leads to paralysis, the story said. That fact prompts experts to be very wary of saying the strain has disappeared from Nigeria.
Nov 10 Canadian Press story