Re: Myanmar: Mass vaccination to target polio return
http://www.promedmail.org/pls/apex/..._BACK_PAGE,F2400_P1001_PUB_MAIL_ID:1000,87265
Archive Number 20110225.0626
Published Date 25-FEB-2011
Subject PRO/EDR> Poliomyelitis, vaccine virus associated - Myanmar: RFI
POLIOMYELITIS, VACCINE VIRUS ASSOCIATED - MYANMAR: REQUEST FOR
INFORMATION
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A ProMED-mail post
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International Society for Infectious Diseases
<http://www.isid.org>
Date: 23 Feb 2011
Source: Reuters, Africa [edited]
<http://af.reuters.com/article/nigeriaNews/idAFLDE71M0MI20110223>
Polio afflicts child in Myanmar, vaccinations planned
-----------------------------------------------------
Myanmar is stepping up its polio vaccinations after the crippling
virus emerged for the 1st time in more than 3 years, infecting an
infant, the World Health Organisation said on Wednesday [23 Feb
2011].
A 7-month-old girl caught a rare strain of polio that can spread when
some people in a community are immunised with oral polio vaccine (OPV)
and others are not, WHO spokesman Oliver Rosenbauer said. She had not
been vaccinated against the disease.
"On very rare occasions, when replicating in the human gut, OPV
strains genetically change and may spread in communities that are not
fully vaccinated, especially in areas where there is poor hygiene,
poor sanitation or overcrowding," he said.
Polio is transmitted in human excrement. Communities that lack clean
water, toilets and sewer systems are particularly vulnerable to
infections when not enough people are immunised against the virus.
There are no other known cases of paralysis from the strain in
Myanmar, which was found in December [2010], according to the WHO.
More than 10 000 children have been immunised in response to the
discovery and more vaccinations are planned.
"It seems to have occurred in an area with population immunity gaps,
so the key is to rapidly raise immunity levels," Rosenbauer said.
Polio attacks the nervous system and can cause irreversible paralysis
within hours, with young children most vulnerable.
There has been a 99 percent drop in the number of infections
worldwide since 1988, when the WHO, Rotary International, UNICEF and
the U.S. Centers for Disease Control and Prevention launched an
effort to eradicate the virus as was done for smallpox.
Polio is now endemic in only 4 countries -- India, Pakistan, Nigeria
and Afghanistan -- compared to 125 when the eradication drive began.
At the time, polio caused paralysis in nearly 1000 children every
day.
Myanmar was declared polio-free in 2000 but had a brief outbreak in
2007 when the virus was imported from elsewhere.
[Byline: Laura MacInnis, Editing: Elizabeth Fullerton]
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[While information on the above case of polio in Myanmar 1st appeared
in the newswires approximately one week ago, as of the 22 Feb 2011
update of the polio eradication website, this case does not appear on
the table containing information on circulating Vaccine Derived
PolioVirus (cVDPV)
(<http://www.polioeradication.org/Dataandmonitoring/Poliothisweek/Circulatingvaccinederivedpoliovirus.aspx>).
Recognizing that reports on vaccine associated problems provide fuel
for the anti-vaccine movement and recognizing that ProMED-mail posts
are widely monitored, this moderator was hesitant to post information
on an as yet not officially confirmed case of polio associated with a
vaccine virus. With the comment from the WHO official in the above
article, this serves as collateral confirmation that a vaccine virus
has been identified in this case. Other newswires on this incident
last mentioned there were 2 additional suspected cases, but according
to the above newswire, they have not been confirmed (as yet) as due to
poliovirus infection (see
<http://www.irinnews.org/Report.aspx?ReportID=91948>).
It is important to mention that surveillance activities as part of
the polio eradication effort focus on the identification of cases of
acute flaccid paralysis (AFP) in individuals less than 15 years of
age. All such cases are to have laboratory specimens obtained for
poliovirus isolation. The internationally accepted indicator is for a
non-endemic country to have a non-polio AFP rate of greater than or
equal to 1 per 100 000 population under age 15 years
(<
http://www.polioeradication.org/Dataandmonitoring/Surveillance.aspx).
According to available data reported to WHO, Myanmar's non-polio AFP
rate has been great than or equal to 1 per 100 000 population annually
since 2000 (in 2010 3.3 per 100 000 population representing 411 AFP
cases investigated and in 2011 through 24 Feb 2011 the rate is 1.8 per
100 000 population -- representing 35 AFP cases investigated). (to
prepare a table with surveillance indicators by country or region, see
<http://apps.who.int/immunization_monitoring/en/diseases/poliomyelitis/case_count.cfm>).
In the above newswire, there is mention that the poliovirus
responsible for paralytic disease in the 7 month old is a vaccine
virus. There isn't mention of other information such as poliovirus
type (VDVP1, VDPV2 or VDPV3) or possible known exposure to a recently
vaccinated individual. (A direct contact of a recently vaccinated
individual is also referred to as a VAPP - Vaccine Associated
Paralytic Poliomyelitis case), different from a case with a cVDPV
where there has been community wide dissemination of the virus (see
references below for further discussions on VAPP and cVDPV) usually in
communities where OPV coverages have been suboptimal over a period of
time.
More information on the genetic studies of the vaccine virus
identified as well as further epidemiologic studies would be greatly
appreciated.
For the interactive HealthMap/ProMED map of Myanmar, see
<http://healthmap.org/r/01PS>.
Suggested references on VAPP and cVDPV
1: Kew OM, Wright PF, Agol VI, Delpeyroux F, Shimizu H, Nathanson N,
Pallansch MA. Circulating vaccine-derived polioviruses: current state
of knowledge. Bull World Health Organ. 2004 Jan;82(1):16-23. Epub 2004
Feb 26. (full article available at:
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2585883/?tool=pubmed>.)
2: Minor P. Vaccine-derived poliovirus (VDPV): Impact on
poliomyelitis eradication. Vaccine. 2009 May 5;27(20):2649-52. Epub
2009 Mar 3. (abstract available at:
<http://www.ncbi.nlm.nih.gov/pubmed/19428874>)
3: Wringe A, Fine PE, Sutter RW, Kew OM. Estimating the extent of
vaccine-derived poliovirus infection. PLoS One. 2008;3(10):e3433.
Epub 2008 Oct 29. (full article available for download at:
<http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0003433>)
4: Centers for Disease Control and Prevention (CDC). Imported
vaccine-associated paralytic poliomyelitis--United States, 2005. MMWR
Morb Mortal Wkly Rep. 2006 Feb 3;55(4):97-9. (full article available
at:
<http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5504a2.htm>)
5: Kew OM, Sutter RW, de Gourville EM, Dowdle WR, Pallansch MA.
Vaccine-derived polioviruses and the endgame strategy for global
polio eradication. Annu Rev Microbiol. 2005;59:587-635. (abstract
available at: <http://www.ncbi.nlm.nih.gov/pubmed/16153180>)
6: John TJ. A developing country perspective on vaccine-associated
paralytic poliomyelitis. Bull World Health Organ. 2004
Jan;82(1):53-7; discussion 57-8. Epub 2004 Feb 26. (full article
available at:
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2585882/?tool=pubmed>)
7: Dowdle WR, De Gourville E, Kew OM, Pallansch MA, Wood DJ. Polio
eradication: the OPV paradox. Rev Med Virol. 2003
Sep-Oct;13(5):277-91. (abstract available at
<http://www.ncbi.nlm.nih.gov/pubmed/12931339>).
