The strange case of polio delta

Stool samples of affected children were sent to the National Institute of Hygiene Rafael Rangel, Caracas national reference, which isolated and typified Sabin type 3 poliovirus in one of the samples , which could be expected in populations immunized with the oral vaccine, which contains the attenuated strains 1 and 3 of the poliovirus. PAHO received an informal report, through the Regional Contact Point for the International Health Regulations on the Detection of Poliovirus mentioned above, and forwarded it to WHO (7 June 2009). 2018). On June 8, WHO published an epidemiologic report with up-to-date information (Ref 2) confirming the presence of poliovirus in the child. In order to confirm the results, the samples were sent to a laboratory. regional reference, unidentified. in report

The unofficial report received by WHO from PAHO was promptly disseminated by the Venezuelan Public Health Society and the National Epidemiology Defense Network through a statement , using the right to inform and alert public opinion. It was also mentioned that the Venezuelan Ministry of Health was aware of the case, had reserved the information and had not notified the findings to the WHO within 24 hours, as established by the International Health Regulations.

The impact of this information on the public was immediate: polio reappears in Venezuela! Underlined, it has been broadcast by international news agencies with the monotony characteristic of its comprehensive information processing, faithfully followed by Venezuelan agencies and media, with little or no further in-depth study on the subject. This columnist also joined the opinion block, in a press article devoted to the regime's responsibility in the current Venezuelan health crisis (Ref3).

The further development.

The overall result of analyzes performed on samples sent to an unidentified regional reference laboratory, for confirmation, was published in a PAHO / WHO report, Washington, 15 June 2018 (Ref 1 ). It was announced that laboratory tests excluded the presence of wild poliovirus and the oral vaccine derivative (abbreviation VDPV) provided to the Delta population, so that there would be no spread or damage. Polio epidemic. With him the initial tumult was disarmed. Venezuela was still free from poliomyelitis

The report also indicated that the reference laboratory would perform genetic sequencing and add something about the genetic mutation of the vaccine virus.

Was the erroneous finding justifiable?

The need to investigate and replicate the reasons why the health authorities involved in coverage and monitoring of the situation at Delta Amacuro came to an erroneous conclusion, including PAHO, is self-evident : it is the strangeness of the case. The confluence of several factors indicates this: a) the detection of PFA, b) the child with no history of vaccination and c) the presence of Sabin PV3 poliovirus in their feces, which apparently guided the health authorities to which seemed obvious and in that sense they decided, faced with the pressure of the delicate health situation that they faced. They were confronted with a typical bioethical location of risk / benefit assessment and the application of the precautionary principle.

If the child had not received the oral vaccine, why was the poliovirus present in his stool? A few weeks before the PFA was detected in the child, the oral vaccine was given in the same community. Polioviruses (wild and incorporated in the oral vaccine) are known to multiply in the gastrointestinal tract, to undergo mutations that tend to restore their original neurovirulence, to replicate (multiply), to excrete and to disperse in the body. population. Probably, the child acquired PV3 poliovirus as a result of this vaccination, by the fecal-oral route, which coincided with the development of PFA.

Genetic sequencing (or rather nucleotide sequencing?) Is a powerful tool Molecular analysis in the hands of experts, who should have received more accurate information in the WHO report, about what was done in the sample (oligonucleotide mapping, PCR amplification – polymerase chain reaction), which allows direct viral RNA detection in clinical samples and serves to differentiate between a similar method or another). It has not been reported where the results and conclusions of nucleotide sequencing could be accessed, so that the Global Polio Eradication Initiative (GPEI) as a group pilot for the global eradication of polio which appears to be the group that funded the analyzes, as in the updated report of the WHO (Ref 1).

This analytical tool clarified and dispelled the problem. But the question of the PFA cause remains unresolved. Would it be too bold to think that it could never be known?

Some basic academic information

The intention of this columnist is to present the reader with a brief additional information to facilitate his understanding of the important topic discussed, which we hope to tolerate

• The poliovirus, the causative agent of poliomyelitis, has a ribonucleic acid genome (RNA) single-stranded and positive sense, of a length corresponding to about 7500 nucleotides, surrounded by a protein capsule (capsid) ; The detection of the composition and the ordering of these nucleotides is called sequencing. It is one of the best characterized viruses, very useful as a model for the study of the biology of RNA viruses
• The poliovirus has 3 serotypes (PV1, PV2 and PV3), all extremely infectious. PV2 was declared extinct in 2015 and is not listed in the current oral vaccine.
• The only known natural host and reservoir of poliovirus is the human species, which would facilitate its control and extinction through vaccination. The remarkable efforts of Salk and Sabin, half a century ago, to produce the two types of known vaccines currently in use were directed there. In endemic areas, poliovirus is detectable in wastewater and in the environment, it remains active for several weeks to spread. In humans, it spreads through the fecal-oral route and through contact with water and food, especially in areas of low resources and poor sanitation.
• The poliovirus multiplies in the intestine, empties into the blood and spinal cord (anterior motor horns) and the brain, which can lead to known paralysis.
• Faecal detection of poliovirus is effective at about 80% if it is practiced in the first two weeks of the initial infection of the disease.
• The oral vaccine is designed with genetic characteristics to provide maximum immune efficiency and minimal virulence in the vaccinated patient. But the poliovirus RNA in the vaccine can undergo mutations (alteration of the nucleotide sequence, estimated at 1% per year), which can restore its wild virulence, so that the people who receive it can transmit it to d & # 39; Others or acquire chronic or acute infections. In other words, it is genetically unstable. This could lead to that in the future, the number of cases of virus circulating in the oral vaccine exceeds the number of cases with the wild virus, which, according to specialists, suggests to suspend the virus. use of the oral vaccine as soon as it is safe. Since 1998, vaccines have been administered in Europe using vaccines injected with the killed virus (Salk), which prevents their transmission. The famous Robert Koch Institute in Germany has stopped recommending the oral vaccine
• However, it should be noted that in the world, cases of poliomyelitis have considerably decreased, from 350 000 in 1988 to only 37 in 2016, having been avoided around 16 million, thanks to vaccination campaigns planned and supervised by WHO, within the framework of the IMEP objectives. Also in Venezuela,

The Ministry and Medical Guild

The Venezuelan Medical Association has been very clear and timely, as mentioned at the beginning of this text, the contents of the report sent to you. WHO has been published by the Society. Venezuelan public health and the network defend national epidemiology. Ministerial silence was censored by hiding information on the reappearance of the poliovirus and ignoring the WHO to which it is linked. This behavior, championed by the then Minister of Health, was consistent with the disinformation strategy of the Venezuelan regime, even

Specialists of this union reported that between 2008 and 2017, about two million children were in danger because they were not in danger. had not been vaccinated in time, which has fractured the health programmatic line and shows the irresponsibility of the scheme.

According to Jaime Torres, board member of the International Society of Infectious Diseases (ISID), the most dissected population of the country with a vaccination coverage of less than 40%. "It is necessary to maintain high levels of vaccination in all countries, before the global eradication of polio," according to Spanish specialists.

It should be noted that low immunization rates are also partly responsible the resurgence of diphtheria and measles in Venezuela Currently, many hospitals lack vaccines.To contain the resurgence of these diseases, the regime must act quickly to immunize the population and improve their general living conditions and health.

Short final examination.

Polioviruses derived from the oral vaccine can circulate in humans for many years, without being detected.This could incite the health authorities and the informed public to believe, wrongly if they have been eradicated, if vaccination campaigns are neglected, these circulating polioviruses may result in reintroduction or recurrence of For this reason, if the oral vaccine continues to be used, poliomyelitis will not be eradicated in Venezuela. The case of Delta Amacuro is an early warning.

References

(1) https://www.paho.org/hq/index.php?option=com_docman&task=doc_view&Itemid=270&gid=45364&lang=fr

(2) http: // www.el-nacional.com/noticias/columnista/los-crimenes-narcotirania-venezolana_244336

(3) https://www.paho.org/hq/index.php?option=com_content & view = article & id = 14445 & Itemid = 1926 & lang = en

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