Re: India: 2012 Polio cases-(VDPV) type 2 case in West Bengal
Re: India: 2012 Polio cases-(VDPV) type 2 case in West Bengal
Apparently, the two infants mentioned in the above articles are not the same case (might the first case have come back completely negative, and the second one positive for VDPV?):
http://www.promedmail.org/
Published Date: 2012-03-19 10:52:13
Subject: PRO/EDR> Poliomyelitis - worldwide (04): India, VDPV2, RFI
Archive Number: 20120319.1074212
POLIOMYELITIS - WORLDWIDE (04): INDIA, VACCINE DERIVED POLIOVIRUS TYPE 2, REQUEST FOR INFORMATION
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[1]Date: Mon 19 Mar 2012
Source: The Times of India (TOI), Times News Network (TNN) [edited]
http://timesofindia.indiatimes.com/...o-reported-in-Bengal/articleshow/12321814.cms
Vaccine derived poliovirus/oral polio vaccine
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India has reported its 1st case of vaccine derived poliovirus (VDPV) infection of 2012. A 5-month-old child from the Murshidabad district of West Bengal has got infected with the virus after taking the oral polio vaccine.
This, however, does not threaten India's recently awarded polio free status because, though detecting VDPV is part of the surveillance system, it does not get added when putting together a country's polio numbers.
Only infections caused by wild poliovirus [WPV] strains like P1 and P3 get counted. "The infected child is from Lalbagh block of Murshidabad district. Detailed follow-up investigations are being carried out. Preliminary reports indicate that the child was admitted to a hospital recently and has been ill for prolonged periods indicating the possibility of immunodeficiency," a ministry official told TOI.
Oral polio vaccines (OPV) contain a weakened version of poliovirus, activating an immune response in the body. A vaccinated person transmits the weakened virus to others, who also develop antibodies to polio, ultimately stopping transmission of poliovirus in a community. According to experts, in very rare instances, the virus in the vaccine can mutate into a form that can paralyze -- this is what is known as a VDPV.
In 2011, India reported 7 cases of VDPVs -- one of them in a child with congenital immune deficiency in Dhamtari district in Chhattisgarh and the others in areas with low routine immunization coverage like Udaipur (Rajasthan), Ghaziabad and Badaun (Uttar Pradesh), Barnala (Punjab), Vidisha (Madhya Pradesh), and Jajpur (Orissa).
"None of the VDPVs detected in India during the past 2 years have shown evidence of circulation. None of the VDPV strains detected in India during 2010 and 2011 are genetically linked to each other. In response to the VDPV cases, state and district authorities have conducted catch up routine vaccination and localized polio vaccination campaigns," India's National Polio Surveillance Programme said.
Health ministry officials say importation of wild poliovirus remains the greatest threat to children in India.
Experts say OPV is a very safe and effective vaccine that has protected millions of children from paralysis. It was the bivalent polio vaccine that brought down India's polio cases to zero. This is why last month [February 2012], India was removed from the list of polio endemic countries after completing a full year without reporting a single case of wild poliovirus infection.
According to WHO, from 2000 to 2010, more than 10 billion doses of OPV were administered to over 2.5 billion children. As a result, more than 3.5 million polio cases were prevented. During that time, 18 outbreaks of circulating VDPVs occurred in 16 countries, resulting in 510 VDPV cases.
"The small risk of VDPVs pales in significance to the tremendous public health benefits associated with OPV. Every year, hundreds of thousands of cases due to wild poliovirus are prevented. Well over 8 million cases have been averted since large scale administration of OPV began 20 years ago," WHO said.
Circulating VDPVs in the past have been rapidly stopped with 2-3 rounds of high-quality immunization campaigns. The solution is the same for all polio outbreaks: immunize every child several times with the oral vaccine to stop polio transmission, regardless of the origin of the virus.
India's achievement in stopping wild poliovirus transmission is being considered one of the greatest achievements in public health in the 21st century. India's last case of wild polio infection was reported on [13 Jan 2011], also from West Bengal.
Prime Minister Dr Manohan Singh said the real credit for this major achievement goes to the 23 lakh [2.3 million] volunteers who repeatedly vaccinated children "even in the most remote areas, often in very bad weather conditions."
India recorded 741 cases of polio in 2009 -- nearly half the number of global cases. But in a remarkable turn of events, India reported just one case of the crippling disease in 2011 and went on to record zero cases in over 12 months since then.
[Byline: Kounteya Sinha]
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[2]
Date: Sat 17 Mar 2012
Source: Deccan Herald News Service [edited]
http://www.deccanherald.com/content/235345/paralytic-polio-returns-dent-indias.html
Paralytic polio returns to dent India's pride
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Paralytic polio-derived from oral polio vaccine (OPV) -- used for vaccinating millions of children -- has struck India to cripple a child in West Bengal within a week of the World Health Organisation (WHO) declaring the country free from the wild poliovirus [WPV].
A case of vaccine derived poliovirus (VDPV) type 2 has been confirmed in a 5-month-old child in the Lalbagh block of Murshidabad district, reminding the health policy planner that the battle with polio is yet to be won.
However, there is a basic difference between the polio that struck the Bengal block and the virus that did not raise its ugly head in the country over the last one year. While the WHO recognition comes due to the effort to keep the country free from wild poliovirus, the incident that occurred in West Bengal is a case of vaccine derived polio, which is rare but with the real danger of continuing with the oral polio vaccine for years without improving the overall immunisation scenario.
Even though the country was free from wild poliovirus in 2011, there were 7 cases of VDPV last year [2011] in Chhattisgarh, Rajasthan, Madhya Pradesh, Punjab, Orissa, and Uttar Pradesh. While one child had congenital immune deficiency in Dhamtari district in Chhattisgarh, others lived in areas with low routine immunization coverage, according to the national polio surveillance being run by the Union Health Ministry and the WHO.
The classification, however, means little for the victims as both wild and vaccine-derived polioviruses cause the same crippling paralysis in children.
In VDPV, the virus was derived from OPV due to prolonged intestinal infection and removal of certain beneficial genetic changes, veteran virologist T Jacob John said, adding that VDPV was similar to wild poliovirus as it was neurovirulent and could be transmitted easily.
It happens because OPV is made from live but weakened poliovirus, a few which can come back as disease-causing agents. In India most of the VDPV cases are P-2 variety, which was eliminated from the wild way back in 1999.
"Circulating VDPV is wild-like and if allowed to survive in humans, it will replace the niche vacated by wild viruses. So it is indeed a threat to eradication," John who retired as professor at Christian Medical College in Vellore and advises the Union Health Ministry on polio told Deccan Herald.
The NPSP [National Polio Surveillance Project] claimed that none of the VDPVs detected in India in the last 2 years showed evidence of circulation. None of the VDPV strains detected in India during 2010 and 2011 are genetically linked to each other.
VDPV is [a] risk, long recognised in the OPV campaign. "VDPVs may already be in silent transmission. If so, they will flare up into outbreaks, epidemics, and exportation. So we must stop OPV but we cannot simply stop OPV. Its a Catch 22 situation," John commented.
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Communicated by:
ProMED-mail Rapporteur Mary Marshall
[The newswires above provide information on a case of vaccine-derived-poliovirus associated polio in a 5-month-old child from Murshidabad district in West Bengal. From the newswires, it appears as though this child might have an underlying immunodeficiency disorder that renders the child more susceptible to infections, and especially to infections with polio vaccine viruses. There is mention that the virus isolated is a vaccine derived poliovirus (VDPV) so that presumably this child was infected from a VDPV in the community and not from receiving the vaccine itself.
In a prior ProMED-mail post on 13 Jan 2012, there was mention of another case of acute flaccid paralysis in an 18-month-old child in South 24 Parganas district of West Bengal (see Poliomyelitis - worldwide (03): India susp, Nigeria, RFI 20120313.1068769). An apparently different incident, as the geographic location of residence of this above mentioned VDPV associated case is different (Murshidabad district vs South 24 Parganas district), and the age of the case is different (5 months old vs 18 months old). (For a map of West Bengal State in India showing districts, see
http://www.mapsofindia.com/maps/westbengal/westbengal-district.htm.)
Murshidabad district is in the northern part of West Bengal bordering with Bangladesh, whereas South 24 Parganas district is in the south of the state, on the Bay of Bengal, bordering with Kolkata.
In response to the earlier newswires, the Global Polio Eradication Initiative weekly update of 14 Mar 2012 had the following statement: "Media reports of acute flaccid paralysis case in India: In India, while no cases have been reported since January 2011, eradication activities are continuing strongly to secure the gains achieved. Large-scale immunization activities are being conducted in March [2012], and active surveillance for acute flaccid paralysis (AFP) cases is continuing. As such, reports of AFP cases is not unexpected or unusual -- quite the opposite, in fact, it means disease surveillance is working. Every month, approximately 5000 AFP cases are identified and investigated across the country. Symptoms of AFP are caused by a number of different pathogens, poliovirus being just one of many potential causes. Strong disease surveillance means that at least 2 AFP cases per 100 000 population (aged less than 15 years) are identified, to ascertain the presence or absence of poliovirus circulation in a given environment. The extensive immunization and surveillance activities ongoing in India will need to continue, as long as endemic poliovirus has not been eradicated in the remaining 3 countries. The combination of high population immunity levels and strong disease surveillance is the best way for a country to minimize the risk and consequences of polio re-emergence or re-introduction." (
http://www.polioeradication.org/Dataandmonitoring/Poliothisweek.aspx).
ProMED-mail awaits further information on the type of virus isolated from the AFP case in South 24 Parganas district. - Mod.MPP]
[To add to the tragic irony, wild poliovirus of type 2 has been eradicated from the world. - Mod.LM
A HealthMap/ProMED-mail map can be accessed at:
http://healthmap.org/r/1-kv.]
