As requested by Israeli health authorities, a team of international
poliomyelitis (polio) experts, coordinated by WHO, completed a five-day
mission to Israel on 26 June 2013. The team assessed the risks and
recommended action following the detection of wild poliovirus type 1
(wPV1) in sewage in the Southern District of the country. No cases of
paralytic polio have been detected.
Following the mission, a supplementary immunization campaign with
oral polio vaccine is planned, even though Israel continues to maintain
high vaccination coverage and polio immunity in the population. The
decision to launch the campaign reflects both the estimated extent of
circulation of the virus and the Israeli authorities’ commitment to
interrupt transmission as rapidly as possible.
The virus was originally isolated from sewage samples collected in
Beersheva in February 2013. Since then it has been isolated in further
samples from different locations, most recently in early June. Genetic
sequencing and epidemiological investigations have established that it
is of the South Asian genotype and not related to the virus currently
affecting the Horn of Africa. WHO experts are working with scientists
from Israel’s national polio laboratory to gain further understanding of
the origins of the virus.
Israel has systematically conducted environmental sampling for many
years, and the poliovirus was detected thanks to this vigilance. Public
health authorities continue to monitor the situation carefully, and
measures have been taken to increase surveillance and reporting for
possible human cases, regardless of age.
The aim of the supplementary immunization campaign is to protect any
children in the country who may have missed routine vaccinations for any
reason. In southern areas, adults are also being assessed and those
thought to be susceptible are being immunized.
Israel’s Minister of Health, Mrs Yael German, and the Director
General of the Ministry of Health, Dr Ronni Gamzu, expressed their
appreciation for the mission at a press conference on Wednesday, 26
June, praising the team’s professionalism and supportiveness.
Dr Dina Pfeifer, Programme Manager for Vaccine-preventable Diseases
and Immunization at WHO/Europe, acknowledged the Israeli public health
authorities’ readiness to cooperate with the WHO-led mission: “We have
reviewed the evidence and the steps that have been taken to date. We are
thankful to the Government of Israel for their openness and we are
fully committed to supporting their efforts.”
Israel and polio
Israel has been free of indigenous wPV transmission for 25 years, the
last cases of paralytic polio having occurred in 1988. At that time the
authorities launched a mass vaccination campaign immunizing the
population aged 0–40 years with oral polio vaccine.
Risk and preparedness
Given the high level of population immunity and the continuing
response to the detection of wPV in the environment, WHO assesses the
risk of the further international spread of this virus strain from
Israel as moderate. The relevant WHO regional offices are working
closely to ensure a coordinated response in the area and neighbouring
Nevertheless, it is vital that all countries, particularly those with
frequent travel and contacts with polio-affected countries, strengthen
surveillance for cases of acute flaccid paralysis, to rapidly detect any
new poliovirus importation and respond.
Countries should also analyse data on routine immunization coverage
to identify any susceptible groups in the population. Such information
can guide catch-up immunization activities and thereby minimize the
consequences of new poliovirus introduction. Priority should be given to
areas where the risk of importation is high and vaccine coverage is
less than 80%.
WHO’s information on international travel and health recommends that
all travellers to and from polio-affected areas be fully vaccinated
against polio. Indigenous transmission of wPV remains endemic in 3
countries: Afghanistan, Nigeria and Pakistan. In addition, The Horn of
Africa is experiencing an outbreak of wPV, with 31 cases confirmed in
Kenya and Somalia.
Original Article: http://www.euro.who.int/en/what-we-do/health-topics/communicable-diseases/poliomyelitis/news/news/2013/07/who-sends-mission-to-israel-following-detection-of-wild-poliovirus-in-sewage