Epidemiological update: Polio virus in sewage and human faecal samples in Israel, August 2013Archived
In May 2013, Israel announced the detection of wild poliovirus type 1 (WPV1) in the south of the country (1). As reported until mid-August, during the routine monitoring of sewage samples the virus had been found in 67 sewage samples from 24 sampling sites since February 2013.
In May 2013, Israel announced the detection of wild poliovirus type 1 (WPV1) in the south of the country (1). As reported until mid-August, during the routine monitoring of sewage samples the virus had been found in 67 sewage samples from 24 sampling sites since February 2013. A faecal survey conducted among individuals in the southern part of the country confirmed WPV1 transmission among asymptomatic carriers; 26 were children appropriately immunised for their age group with inactivated polio vaccine (IPV); one was a young infant aged two months and one an elderly person in their 70s. No symptomatic polio cases have been identified to date.
On 4 August 2013, in response to the detection of WPV1 in sewage and clinical samples, Israel started a poliovirus supplementary vaccination campaign in southern parts of the country with a bivalent oral polio vaccine (OPV), targeting all children below nine years of age (and aged above 2 months)(2). On 9 August 2013, the Ministry of Health decided to expand the vaccination campaign to the entire country starting on 18 August (3). OPV, which is known to be effective at producing mucosal immunity, has not been used since 2005 in Israel. The current immunisation schedule in Israel consists of five doses of inactivated poliovirus vaccine (IPV). Childhood immunisation coverage against polio in Israel, with four doses of IPV, is very high (90%–95%). During the campaign, IPV is also being offered to all incompletely vaccinated adults and those without documentation.
In addition to the vaccination campaign, the Israeli Ministry of Health is continuing environmental sampling; is enhancing routine acute flaccid paralysis surveillance by targeting all age groups and is screening aseptic meningitis cases for poliovirus.
The World Health Organization (WHO) “estimates the risk of further international spread of wild poliovirus type 1 (WPV1) from Israel [is] to remain moderate to high” due to the “increasing geographic extent of circulation over a prolonged period of time”(4).
Polio was eliminated in the WHO European Region and the Region was certified polio-free in 2002. However, in 2010 an outbreak of polio due to WPV1 was detected in Tajikistan (5) with 711 cases of acute flaccid paralysis (AFP), and 458 laboratory-confirmed cases (6). That number was higher than the number of confirmed polio cases in the rest of the world in 2010. This served as a reminder to European countries that high vaccination coverage, monitoring of protective immunity and maintaining surveillance are important to maintain the polio-free situation. Poliovirus vaccination is included in the routine schedule of all EU/EEA countries and reaching high vaccination coverage is extremely important for the control of polio in the EU/EEA. Furthermore, the detection of polio from routine sampling by the Israeli Ministry of Health demonstrates the importance of robust surveillance in identifying and controlling the spread of polio in Europe.
The Global Polio Eradication Initiative began in 1988 and the number of cases decreased from an estimated 350 000 in 125 polio-endemic countries in 1988 to 181 between 1 January and 13 August 2013. Of the cases in 2013, 71 were in three endemic countries (Nigeria, Pakistan and Afghanistan) and 110 were related to an outbreak in the Horn of Africa, with 10 cases confirmed in Kenya and 100 Somalia (7). WHO’s International Travel and Health recommends (4) that all travellers to and from polio affected areas need to be fully vaccinated against polio.