Venezuela: 2018 Polio - three suspected cases in Delta Amacuro State - vaccine virus confirmed, VAPP suspected

[Shiloh]

Source: https://www.thetimes.co.uk/edition/w...ears-vm9vbm38x

Venezuela suffers its first outbreak of polio in 30 years
Stephen Gibbs, Caracas
June 9 2018, 12:01am, The Times
A crisis in the healthcare system means that some people have not been vaccinated since 2016

Polio is suspected to have broken out in Venezuela, 24 years after the Americas were declared free of the disease.

The Venezuelan Society of Public Health, a non-governmental doctors? association, said that three suspected cases were detected among an indigenous population in the remote northeastern state of Delta Amacuro, where the Orinoco River delta is located...

[alert]

Published Date: 2018-06-09 17:20:58
Subject: PRO/EDR> Poliomyelitis update (19): Venezuela, vaccine virus found, VAPP susp
Archive Number: 20180609.5848416
POLIOMYELITIS UPDATE (19): VENEZUELA, VACCINE VIRUS FOUND, VACCINE-ASSOCIATED PARALYTIC POLIO SUSPECTED
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In this update:
[1] PAHO Epidemiological update
[2] Comment

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[1] PAHO Epidemiological update
Date: Fri 8 Jun 2018
Source: Pan American Health Organization (PAHO) Epidemiological Update Poliomyelitis [edited] [link to PDF]

https://www.paho.org/hq/index.php?option=com_topics&view=article&id=257&Itemid=40900&lang=en

Detection of Sabin type 3 vaccine poliovirus in a case of acute flaccid paralysis
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Situation summary
On [7 Jun 2018], the World Health Organization (WHO) International Health Regulations (IHR) Regional Contact Point received an unofficial report on the detection of Sabin type 3 vaccine poliovirus in a sample of a Venezuelan patient with acute flaccid paralysis (AFP). The same day [7 Jun 2018], a request for verification was sent to the Venezuela IHR National Focal Point (NFP).

On [8 Jun 2018], PAHO/WHO received updated information. The case is child aged 2 years and 10 months, with no history of vaccination, resident of an under-immunized indigenous community in Delta Amacuro, Venezuela; with paralysis onset on [29 Apr 2018]. As of [31 May 2018], the flaccid paralysis persisted in a lower limb. A Sabin type 3 vaccine poliovirus was isolated and typified by the national reference laboratory, the National Institute of Hygiene "Rafael Rangel" (INHRR), in the sample of this patient obtained on [30 Apr 2018]. The sample will be sent to a regional reference laboratory for confirmatory testing. Other children from the same community were vaccinated in April 2018 with oral bivalent polio vaccine.

The ongoing field investigation identified an 8 year old girl, resident of the same community with a vaccine history of at least 1 dose of tOPV, who presented flaccidity in a lower limb. No additional AFP cases have been identified to date through active search for AFP cases carried out in the community.

Advice to national authorities
PAHO/WHO reiterates to member states the importance of reaching and maintaining polio vaccination coverage of more than 95 per cent in each district or municipality, maintaining high quality of epidemiological surveillance, and updating the national poliovirus outbreak response plans.

References
1. PAHO/WHO. Final report of the 3rd Ad-Hoc Meeting of the TAG. Ad-hoc Virtual Meeting, 19 March 2018. Available at: https://bit.ly/2Jt8lrH
2. PAHO/WHO. Polio Weekly Bulletin, 2018. Available at: https://bit.ly/2JmhVR2

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[2] Comment
Date: Thu 7 Jun 2018
From: T Jacob John,


The polio could be VAPP following infection with Sabin 3 in OPV. This is to supplement your comment that it could be WPV3 or cVDPV-3.

Sabin 3 is the commonest cause of VAPP in OPV-given children. It is usually sporadic, since PV-3 is a very inefficient spreader. Hope we will have a clear picture very soon.

--
T Jacob John
Retired Prof and Head of Department of Clinical Virology
Christian Medical College, Vellore
India


[The above information provides more detailed technical description on the reported case of acute flaccid paralysis in Venezuela. From the information provided it appears as though this child's illness would be classified as a case of VAPP -- vaccine-associated paralytic poliomyelitis -- in a contact of a recently vaccinated individual. VAPPs can occur in recipients of the OPV (oral poliovirus vaccine) or in close contacts of recently vaccinated individuals. The incidence of VAPP cited by WHO is approximately 1 per 2.7 million doses. Cases of VAPP are distinctly different from those associated with cVDPV where the virus has undergone significant changes in neurovirulence and have not been reported to cause outbreaks.

When I was involved with polio surveillance as an Epidemic Intelligence Service [EIS] officer at the Centers for Disease Control and Prevention (many moons ago), in the era when the USA was using OPV as the primary vaccine for polio prevention, the overwhelming majority of polio cases confirmed in the USA were cases of VAPP in both recipients as well as contacts (usually parents of recently vaccinated children). As always, Professor T Jacob John was right on target with his excellent reminder comment in response to my original post. Unfortunately in my haste to post on the media report, I got as far as the VDPV discussion but neglected to mention the possibility of this being a VAPP, which Prof T Jacob John rightfully reminded me and to whom I am very grateful.

The disconcerting information in the above report (and in the media report we posted on 7 Jun 2018) is the mention of a possible 2nd case of AFP in this community. The other disconcerting information from the original media report was the noticeable absence of mention of a vaccination campaign in the affected community preceding the onset of illness, but rather a comment that there had been no vaccination in the community since 2016. An apparent manipulation of the facts.

We await further information on confirmatory testing by the reference laboratory as well as additional information on this 2nd AFP case.

[Shiloh]

Source: https://www.cnn.com/2018/06/15/healt...-bn/index.html

Polio has not returned to Venezuela, WHO says
By Debra Goldschmidt, CNN
Updated 3:42 PM ET, Fri June 15, 2018

CNN)A child in Venezuela who was reported to have a common symptom of polio does not have the viral disease, World Health Organization said Friday.

When the child, who is almost 3 years old, near the Orinoco delta in Delta Amacuro state showed symptoms of acute flaccid paralysis on April 29, it was of great concern. Acute flaccid paralysis is a sudden onset of weakness or loss of the ability to move any part of the body in a child younger than 15. More than 100,000 cases are identified and investigated every year as part of polio surveillance, according to WHO.

There has not been a case of polio in Venezuela in 29 years, but this area, one of the nation's poorest, is known to have low vaccination rates.

Stool samples were obtained from the child, and the Sabin type 3 poliovirus was isolated for testing. In a statement, WHO noted that finding the virus in a stool sample is not unexpected among people who have been vaccinated.

"Final laboratory analysis received today has confirmed that the AFP symptoms are not associated with wild or vaccine-derived poliovirus," the statement said.
Acute flaccid paralysis can be caused by "a number of conditions or infections," including polio. Doctors are still trying to determine the cause of this child's paralysis...

[Pathfinder]

Laboratory tests rule out the presence of wild and vaccine-derived poliovirus in the case of acute flaccid paralysis in Venezuela


Washington, DC, June 15, 2018 (PAHO/WHO) -Tests carried out by the specialized global laboratory for genetic sequencing have ruled out the presence of both wild poliovirus and vaccine-derived poliovirus (VDPV). The latter- VDPV- is a Sabin virus with genetic mutations that give it the ability to produce the disease. There is no risk of spread to the community or outbreaks of polio from this case.

An epidemiological update from the Pan American Health Organization (PAHO) published today reported that a 34-month-old boy had an onset of symptoms of acute flaccid paralysis (AFP) on April 29,2018. This child lives in a community with low vaccination coverage in the Orinoco Delta of Delta Amacuro State. A Sabin type 3 polio virus had been initially isolated from the child's stool samples.

The global reference laboratory confirmed the presence of a Sabin type 3 virus. Isolation of Sabin type 3 poliovirus is possible in children and communities immunized with oral bivalent polio vaccine, which contains attenuated (weakened) type 1 and type 3 Sabin strains.

A number of different causes and diseases can lead to AFP, poliovirus being just one of them. In rare cases, the vaccine virus could be associated with paralysis. As part of global polio surveillance efforts, more than 100,000 cases of AFP are detected and investigated worldwide each year.

The child is being further evaluated clinically to determine alternative causes of paralysis. The final classification of the case of acute flaccid paralysis [to define whether or not it is associated with the vaccine] will be based on clinical and virological criteria assessed at 60 days after the onset of paralysis.

PAHO calls on countries to maintain strong surveillance together with high polio vaccination coverage in all communities, in order to minimize the risk and consequences of any eventual reintroduction or reappearance of poliovirus. PAHO and the partners of the Global Polio Eradication Initiative (GPEI) will continue to support local and national public health authorities in these efforts.

Links
— Epidemiological Update on Detection of Sabin type 3 vaccine poliovirus in a case of Acute Flaccid Paralysis

Last Updated on Friday, 15 June 2018 16:08


https://www.paho.org/hq/index.php?op...d=1926&lang=en