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Poliovirus circulation in wastewater in Guyana
Following the detection of poliovirus type PVDV 3 derived from the Sabin vaccine strain in wastewater in Guyana, Public Health France is reiterating the importance of vaccination in the fight against poliomyelitis.
Updated October 28, 2024
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What do we know about the situation in Guyana?
As part of a research project coordinated by ANRS-MIE, polioviruses derived from the Sabin vaccine strain type 3 (VDPV 3), with a similar genetic profile, were detected in wastewater samples collected between May and August 2024 in several treatment plants in French Guiana (Cayenne, Saint-Georges and Remire-Montjoly).
Genetic analyses of these samples carried out by the National Reference Centre for Enteroviruses and Parechoviruses (Institut Pasteur Paris) show that the viruses have enough mutations (more than 10), compared to the strain contained in the oral vaccine, to consider it as a strain derived from the Sabin 3 vaccine strain (VDPV 3), and that they are genetically related to each other. These genetic analyses also indicate that these strains should be considered as wild poliovirus strains since they could cause paralysis.
These strains have not been identified in other countries to date. In Guyana, although no cases of poliomyelitis have been reported to date, the detection of these strains from samples from different locations at least two months apart confirms human-to-human transmission, without prejudging its exclusive nature to Guyana, and the classification as circulating poliovirus cPVDV3 according to the World Health Organization.
Public Health France is taking stock of the risks of contracting polio for the population and is strengthening its surveillance system in conjunction with the ARS Guyane and its partners.
Why are polioviruses detected in wastewater?
In cases of poliovirus infection, the virus multiplies in the intestine and is excreted in the stool of an infected person. Virus particles present in the stool then end up in wastewater. Since most poliovirus infections are asymptomatic, wastewater monitoring can detect circulation of the virus even before a case of paralysis occurs.
In France, this surveillance was operational from 1973 to 2018 on 4 wastewater treatment plants in Ile-de-France, but it was stopped at the end of 2018 due to low detection of poliovirus and high vaccination coverage.
This is the first detection of VDPV circulating in a region in France since the 2000s. These detections demonstrate silent circulation of PVDV3 within a Guyanese population with population groups that are insufficiently vaccinated.
What is the origin of these viruses?
Since the oral vaccine is not used in Guyana, these vaccine-derived viruses were imported by one or more people who received the oral vaccine abroad, and transmission from one individual to another may have been facilitated within population groups that were insufficiently vaccinated. It should be noted that the oral polio vaccine (OPV) is still used in some South American countries.
Although the Americas region has been considered free of poliovirus circulation since 1984 by the WHO, this detection has consequences at the international level. Thus, the World Health Organization ( PAHO ) has since reminded all countries in the Americas region of the importance of strengthening surveillance for flaccid paralysis in children but also in adults, and of achieving high vaccination coverage (95% at 3 doses). In addition, the ECDC has endorsed the WHO temporary recommendations for EU/EEA citizens who are residents or long-term visitors (>4 weeks) to Guyana: an additional dose of poliovirus vaccine should be administered between four weeks and 12 months before international travel. Travellers to Guyana should be vaccinated in accordance with their national schedules.
What is the risk for the Guyanese population?
Whatever the geographical origin of these viruses, the currently clinically silent circulation of PVDV3 in the Cayenne metropolitan area and in Saint Georges is associated with a low risk of paralytic forms (8 out of 10,000 people infected for type 3 viruses, variable according to age; low risk than for type 1 viruses for which it is estimated at 1 in 200) of developing poliomyelitis in people who have not been or have not been sufficiently vaccinated, in particular children and infants and immunocompromised people.
The risk of developing severe neurological forms is, however, extremely low for people who are up to date with their vaccinations.
In French Guiana, despite a diversified vaccination offer through several actors (private sector, PMI Centers, Delocalized Prevention and Care Centers, local hospitals or associations), vaccination coverage is lower than that of mainland France, with population groups insufficiently vaccinated, particularly in isolated areas. Insufficient vaccination coverage, combined with precarious living conditions or promiscuity (community living) favoring the mainly fecal-oral transmission of the virus by direct contamination (dirty hands or contaminated objects) or through a dirty environment (wastewater, food) or even direct respiratory transmission, increases the risk of developing poliomyelitis as well as human-to-human transmission of poliovirus.
What recommendations and measures have been put in place by the health authorities?
Faced with the situation, several actions are being implemented by the health authorities in collaboration with health professionals:
...
https://www.santepubliquefrance.fr/...n-de-poliovirus-dans-les-eaux-usees-en-guyane
Poliovirus circulation in wastewater in Guyana
Following the detection of poliovirus type PVDV 3 derived from the Sabin vaccine strain in wastewater in Guyana, Public Health France is reiterating the importance of vaccination in the fight against poliomyelitis.
Updated October 28, 2024
...
What do we know about the situation in Guyana?
As part of a research project coordinated by ANRS-MIE, polioviruses derived from the Sabin vaccine strain type 3 (VDPV 3), with a similar genetic profile, were detected in wastewater samples collected between May and August 2024 in several treatment plants in French Guiana (Cayenne, Saint-Georges and Remire-Montjoly).
Genetic analyses of these samples carried out by the National Reference Centre for Enteroviruses and Parechoviruses (Institut Pasteur Paris) show that the viruses have enough mutations (more than 10), compared to the strain contained in the oral vaccine, to consider it as a strain derived from the Sabin 3 vaccine strain (VDPV 3), and that they are genetically related to each other. These genetic analyses also indicate that these strains should be considered as wild poliovirus strains since they could cause paralysis.
These strains have not been identified in other countries to date. In Guyana, although no cases of poliomyelitis have been reported to date, the detection of these strains from samples from different locations at least two months apart confirms human-to-human transmission, without prejudging its exclusive nature to Guyana, and the classification as circulating poliovirus cPVDV3 according to the World Health Organization.
Public Health France is taking stock of the risks of contracting polio for the population and is strengthening its surveillance system in conjunction with the ARS Guyane and its partners.
Why are polioviruses detected in wastewater?
In cases of poliovirus infection, the virus multiplies in the intestine and is excreted in the stool of an infected person. Virus particles present in the stool then end up in wastewater. Since most poliovirus infections are asymptomatic, wastewater monitoring can detect circulation of the virus even before a case of paralysis occurs.
In France, this surveillance was operational from 1973 to 2018 on 4 wastewater treatment plants in Ile-de-France, but it was stopped at the end of 2018 due to low detection of poliovirus and high vaccination coverage.
This is the first detection of VDPV circulating in a region in France since the 2000s. These detections demonstrate silent circulation of PVDV3 within a Guyanese population with population groups that are insufficiently vaccinated.
What is the origin of these viruses?
Since the oral vaccine is not used in Guyana, these vaccine-derived viruses were imported by one or more people who received the oral vaccine abroad, and transmission from one individual to another may have been facilitated within population groups that were insufficiently vaccinated. It should be noted that the oral polio vaccine (OPV) is still used in some South American countries.
Although the Americas region has been considered free of poliovirus circulation since 1984 by the WHO, this detection has consequences at the international level. Thus, the World Health Organization ( PAHO ) has since reminded all countries in the Americas region of the importance of strengthening surveillance for flaccid paralysis in children but also in adults, and of achieving high vaccination coverage (95% at 3 doses). In addition, the ECDC has endorsed the WHO temporary recommendations for EU/EEA citizens who are residents or long-term visitors (>4 weeks) to Guyana: an additional dose of poliovirus vaccine should be administered between four weeks and 12 months before international travel. Travellers to Guyana should be vaccinated in accordance with their national schedules.
What is the risk for the Guyanese population?
Whatever the geographical origin of these viruses, the currently clinically silent circulation of PVDV3 in the Cayenne metropolitan area and in Saint Georges is associated with a low risk of paralytic forms (8 out of 10,000 people infected for type 3 viruses, variable according to age; low risk than for type 1 viruses for which it is estimated at 1 in 200) of developing poliomyelitis in people who have not been or have not been sufficiently vaccinated, in particular children and infants and immunocompromised people.
The risk of developing severe neurological forms is, however, extremely low for people who are up to date with their vaccinations.
In French Guiana, despite a diversified vaccination offer through several actors (private sector, PMI Centers, Delocalized Prevention and Care Centers, local hospitals or associations), vaccination coverage is lower than that of mainland France, with population groups insufficiently vaccinated, particularly in isolated areas. Insufficient vaccination coverage, combined with precarious living conditions or promiscuity (community living) favoring the mainly fecal-oral transmission of the virus by direct contamination (dirty hands or contaminated objects) or through a dirty environment (wastewater, food) or even direct respiratory transmission, increases the risk of developing poliomyelitis as well as human-to-human transmission of poliovirus.
What recommendations and measures have been put in place by the health authorities?
Faced with the situation, several actions are being implemented by the health authorities in collaboration with health professionals:
- Launch of a vaccination catch-up campaign :
- In schools by the ARS to vaccinate children and adolescents who are not vaccinated or who are not up to date with their vaccinations for all compulsory vaccinations in schools in Cayenne, Rémire-Montjoly, Matoury and St-Georges de l'Oyapock.
- Outside of schools, in particular to vaccinate infants and children not admitted to communities and who are not up to date with their vaccinations, always in the geographical area concerned by this detection.
- All healthcare professionals in Guyana authorized to vaccinate are also invited to check the vaccination status of their patients throughout the territory, particularly children and immunocompromised people, and to catch up on vaccinations if necessary.
- Raising awareness among healthcare professionals of the risk of polio cases occurring with a reminder of the conduct to adopt in the event of any suspicion of polio, in particular the taking of samples suitable for genome research by PCR and/or culture (2 stools taken 24 hours apart) by the CNR of enteroviruses and parechoviruses and for the search for differential diagnoses (nasopharyngeal sample, blood) by the CNR or any other medical biology laboratory.
- Establishment of a one-year environmental monitoring program on wastewater : the Pasteur Institute of Guyana, which is already responsible for the physicochemical monitoring of wastewater, will also look for the polio virus during this period in collaboration with the CNR of enteroviruses of the Pasteur Institute in Paris, also a WHO collaborative center. This study, planned for one year, should make it possible to define the extent and evolution of the circulation of the poliovirus in wastewater, and to draw conclusions in terms of health management. It will make it possible to verify whether the measures put in place make it possible to stop the circulation of these strains of poliovirus in Guyana, and to decide on any other possible actions to be implemented.
...
https://www.santepubliquefrance.fr/...n-de-poliovirus-dans-les-eaux-usees-en-guyane