coronavirus
  • Tuesday 10 March 2020 à 16h50
  • Khadija KHETTOU

Coronavirus: Analysis protocol at the Pasteur Institute as if you were there - Interview -

Morocco recorded this Tuesday, March 10, its third Coronavirus case in Marrakech, with 66 cases excluded following a negative laboratory result and a confirmed death on the same day of the second person infected with the virus. Globally, Covid-19 continues to spread and claim victims on its way, but cases of recovery are also observed.

But how is the protocol for analyzing the samples sent to the two national laboratories designated as part of the national response plan against epidemics, set up by the Moroccan government, namely the laboratory of the National Institute of Hygiene in Rabat and the Pasteur Institute in Casablanca.

To get the details of this procedure, which is as complicated as it is meticulous, Hespress Fr spoke to Professor Abderrahmane Maaroufi, General Director of the Pasteur Institute in Casablanca, who explained to us the course of the procedure from the patient's arrival at the hospital to the announcement of the final result.

Hespress En: What exactly is expected of the Pasteur Institute?

Dr. Maaroufi : The Pasteur Institute has been designated as a reference laboratory in the same way as the Rabat laboratory as part of the national response plan against the coronavirus. There are two reference laboratories that are designated at this stage to take care of the diagnostic confirmation aspects at the infection laboratory.

What is the detailed protocol that you follow in the analysis of the samples that you receive for suspected cases of Covid-19?

Firstly, I must specify that since the start of this plan we have been working 24/24. First step, we receive the sample. How is this direct debit reception going? As soon as there is a suspicious case and who presents symptoms that could be due to the Coronavirus, he contacts the monitoring cell at the level of the city or province where he is located.

And the primary job of this monitoring cell is to ensure that these signs that the patient presents correspond to the criteria for defining a suspected case. That is to say, he makes sure that he really meets the criteria to say that maybe it is a case of Coronavirus.

So once these criteria are verified and satisfied and the patient has been identified as a suspect case, they will immediately place him in an isolation room at the level of a provincial hospital that has been set up and set up as part of this plan.

Step two, they will take the samples. So it's either a nasopharyngeal or an oropharyngeal swab. And the third step, they will contact the pasteur laboratory to announce that there is a sample that was going to be sent in the minutes or hours that follow. It depends on the distance.

So then, they send us this sample by ambulance transport in accordance with the standards for transporting biological samples, and once the sample arrives at our house, we receive it and then the team starts analyzing it.

What is the method you use to analyze the sample?

This method is called PCM. In general, and very schematically, it is a method that seeks to identify, to verify if there is any genetic material of the virus in said sample. So we're trying to identify if a piece of this genetic material is circulating in the sample. And we know that living beings, whether viruses, bacteria, human beings or others, the main identity is the main element that makes it possible to identify the characteristics, it is the genetic material.

So as soon as this method detects the genetic material of the Corona virus, it almost certainly means that it is an infection that is confirmed. It is a reference method, one of the best methods that virology and the field of microbial medicine have been able to develop.

And this method is available at the Institut Pasteur. We have the technical and reactive equipment as well as the team to be able to do it. And we also have the human competence and the human expertise to be able to interpret the results.

These qualities and these capacities which exist at the level of the pasteur Institute as well as the laboratory of the National Institute of Hygiene in Rabat make it possible to produce results which are safe.

I would like to clarify that when, for example, the result turns out to be positive, to be 100% sure, we repeat the analysis with another technician and another expert independent of the first. This is called an interanalyzer validation to once again make sure, and not to make a mistake because it is very serious.

Announcing a positive result when it is negative is not a good thing. So to avoid the risk of errors, when the result is positive, we repeat it a second time.

If the result is indeed positive and confirmed, at that moment the results are announced as soon as possible. Generally, the analysis lasts between 4 to 5 hours on average.

At first, we communicate the results by telephone, as quickly as possible, then we send the analysis report card. So once the team that sent the sample from the hospital receives the analysis results, if it is negative, the team reassures the patient and prescribes treatment for the symptoms he has.

If the result is positive, at that moment, we trigger all the management measures, in particular the detection of contacts, as well as all the protocol that exists in our country as part of the national monitoring and response plan against the Coronavirus.

For the positive patient, he is taken care of and put in a warm isolation room. It depends on the health problems he has and that we are starting to treat. We're taking care of him until he recovers. And to make sure that he has healed, we do two analyzes, usually at the end, when there are no more signs. We do the first analysis to make sure that it is negative and we repeat a second one to make sure. Once the second analysis result is negative, it is declared that the patient is cured.

How many people make up the Institut Pasteur team?

We have created pairs of two experts. They are analysts who guard 24 hours on 24 hours. Each time a pair. It is absolutely necessary that there are two people working on the analysis so that they supervise each other and check.

And in case of a positive result, the second expert must repeat the analysis. We work in pairs. We usually have 4 pairs of two people, that's at least 8 people who are dedicated for this mission and who work 24/24.

Is it that for the current national situation, with 2 confirmed cases, one death and 66 suspected cases, the Pasteur Institute and the National Institute of Hygiene in Rabat, are sufficient for the moment to meet the national demand for analyzes?

Sincerely, so far we have had 66 suspected cases declared at the national level. And two laboratories were able to really largely satisfy the demand. The situation in Morocco is currently under control. We had 3 cases, not like the countries that have a fairly large spread of the virus.

For now, I think we need to have confidence in our surveillance and response system against epidemics. Moreover, this is not the first time that we have experienced this kind of crisis. In 2015, there was Mers-Cov which was even more serious than Covid-19, because it killed up to 30%

There was also the Ebola epidemic, which lasted at least two years, 2015 and 2016. And also the H1N1 crisis. And during all these crises, our surveillance and response system against epidemics has demonstrated its performance and its capacity. So there is no reason not to believe it today.

We must have confidence in the capacity of our system. All means are being implemented, everything that had to be done has been done and things are currently under control.