Wild Poliovirus Type 1 in Oman: A re-emerging threat that requires urgent, targeted and strategic preparedness

An emergency response was triggered by recovery of wild poliovirus type 1 (WPV1) of the South Asia (SOAS) lineage from sewage in southern Israel in April 2013 during routine environmental surveillance. Public health risk assessment necessitated intensification of environmental surveillance in order to facilitate countrywide monitoring of WPV1-SOAS circulation. This involved increasing sampling frequency and broadening the geographical area, for better coverage of the population at risk, as well as modifying sewage testing algorithms to accommodate a newly developed WPV1-SOAS-specific quantitative real-time RT-PCR assay for screening of RNA extracted directly from sewage concentrates, in addition to standard virus isolation. Intensified surveillance in 74 sites across Israel between 1 February and 31 August 2013 documented a sustained high viral load of WPV1-SOAS in sewage samples from six Bedouin settlements and two cities with Jewish and Arab populations in the South district. Lower viral loads and intermittent detection were documented in sampling sites representing 14 mixed communities in three of the five health districts in central and northern Israel. Environmental surveillance plays a fundamental role in routine monitoring of WPV circulation in polio-free countries. The rapid assay specific for the circulating strain facilitated implementation of intensified surveillance and informed the public health response and decision-making.

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Contribution of Contact Sampling in Increasing Sensitivity of Poliovirus Detection During A Polio Outbreak—Somalia, 2013

Open Forum Infectious Diseases ◽

10.1093/ofid/ofw111 ◽

2016 ◽

Vol 3 (2) ◽

Author(s):

Edna Moturi ◽

Abdirahman Mahmud ◽

Raoul Kamadjeu ◽

Chukwuma Mbaeyi ◽

Noha Farag ◽

...

Keyword(s):

Confidence Interval ◽

Acute Flaccid Paralysis ◽

Case Detection ◽

Poliovirus Type ◽

Wild Poliovirus ◽

The Third ◽

Stool Specimens ◽

First Contact ◽

Surveillance Database

Abstract Background. In May 2013, a wild poliovirus type 1 (WPV1) outbreak reported in Somalia provided an opportunity to examine the contribution of testing contacts to WPV detection. Methods. We reviewed acute flaccid paralysis (AFP) case-patients and linked contacts reported in the Somalia Surveillance Database from May 9 to December 31, 2013. We restricted our analysis to AFP case-patients that had ≥3 contacts and calculated the contribution of each contact to case detection. Results. Among 546 AFP cases identified, 328 AFP cases had ≥3 contacts. Among the 328 AFP cases with ≥3 contacts, 93 WPV1 cases were detected: 58 cases (62%; 95% confidence interval [CI], 52%–72%) were detected through testing stool specimens from AFP case-patients; and 35 cases (38%; 95% CI, 28%–48%) were detected through testing stool specimens from contacts, including 19 cases (20%; 95% CI, 14%–30%) from the first contact, 11 cases (12%; 95% CI, 7%–20%) from the second contact, and 5 cases (5%; 95% CI, 2%–12%) from the third contact. Among the 103 AFP cases with ≥4 contacts, 3 (6%; 95% CI, 2%–16%) of 52 WPV1 cases were detected by testing the fourth contact. No additional WPV1 cases were detected by testing >4 contacts. Conclusions. Stool specimens from 3 to 4 contacts of persons with AFP during polio outbreaks are needed to maximize detection of WPV cases.

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