Escherichia coli epidemic spreads. Far from the solution, uncertainty about the causes. The hypothesis of water is not to be excluded. The fundamental role of the ISS

Escherichia coli epidemic spreads. Far from the solution, uncertainty about the causes. The hypothesis of water is not to be excluded. The fundamental role of the ISS

In Germany, the alert on cucumber, tomatoes and salads eaten raw remains, because epidemiological investigations indicate raw vegetables as possible vehicles for the bacterium. It is true that the Spanish cucumber has been acquitted, but the focus on vegetables continues until the cause is identified. The toll is worsening day by day and by now we have reached 17 victims and 2000 people affected, many of whom have manifested the symptoms of Hemolytic Uremic Syndrome (SUE or HUS). 

According to the latest release from the Reuters agency, in the Hamburg Eppendorf hospital alone, 102 patients are currently hospitalized, 30-40% of whom are in intensive care.

The current situation is more serious than at the beginning , because the rejection of the Spanish thesis combined with the blocking of imports was a useless measure, and now the cause of the epidemic must be found. However, if the Spanish vegetables are innocent, the outbreak of the epidemic is in Germany.

This thesis was put forward by a few days ago,  assuming water contamination. The cycle could be this: Escherichia coli O 104 present in the wastewater of a farm, due to a flood caused by thunderstorms or other reasons, contaminates the waters that flow into a surface basin destined to supply the aqueduct. In the cases found up to now it has always been rural water contamination affecting small towns, but nothing can exclude contamination in larger centers caused by even temporary failures to the water treatment plant.

If the bacterium reaches the net it contaminates the vegetables and Escherichia coli thanks to the excellent ability to cling to the outer surface of cucumbers or other vegetables, reproduces and is ingested by people. At this point the first cases of hemorrhagic dysentery (HUS) begin, the first patients die and the story takes on the characteristics of an epidemic.

The thesis may seem daring but the high number of cases suggests a form of extensive, perhaps temporary, contamination that has affected a certain area, and microbiologists in these cases always think of water.

“The hypothesis of water contamination – explains Antonello Paparella, professor of food microbiology at the University of Teramo – cannot be excluded and it would be desirable that the investigations in Germany extend to agricultural areas located near crops. In Ontario in 2000 there were 2,300 cases with 7 deaths, due to contamination of the water supply following a flood (Fratamico and Smith, 2006). Even in the E. coli outbreakO157: H7 of 2006 in the United States, when baby spinach was the food carrier involved, the responsible strain was isolated in river water and in wastewater from cattle farms, near one of the spinach crops (Wendel et al. , 2009). The situation is undoubtedly delicate – continues Paparella – the infectious dose of STEC serotypes is very low, on the order of one cell per gram ”.

Some accuse the German authorities of being superficial , of having accused the Spanish cucumbers too soon, but the question is complex and cannot be resolved with a joke. Chronicle of events helps to understand.

Faced with hundreds of HUS patients detected in 10 days, the Hamburg health authorities are conducting the first research. The analyzes on patients identify Escherichia coli O 104 as an infectious agent, which however is almost unknown.

In the meantime, the health workers interrogate 25 sick people to try to understand the source of the contamination and focus attention on vegetables. The trace turns out to be correct but the specific research methods for Escherichia coli do not exist so that the microbes of Spanish cucumbers are similar to those of the sick and the researchers, perhaps pressured by the increase in the number of deaths and the epidemic, blame the cucumbers . Unfortunately, in the course of other control analyzes carried out by the national authorities in Berlin and by the European Reference Laboratory which is based in Rome at the Higher Institute of Health and is directed by Alfredo Caprioli, it turns out that the microorganism of the sick is not the same. cucumbers and Spain is acquitted.

However, the problem remains and the European Reference Laboratory at the ISS already on 27 May developed an official method specific for Escherichia coli O 104 and since then more in-depth analyzes have begun. All this is not trivial because we are talking about an almost unknown microorganism until a few weeks ago.

Research to identify the causes is ongoing and German laboratories are examining a thousand fruit and vegetable samples, but there is some skepticism on the part of experts about the method undertaken. To trace the cause of an epidemic it is necessary to carry out a very accurate epidemiological analysis of the eating behaviors of the affected patients, it is a sort of police investigation on what the sick did in the days before the illness, to monitor the movements, the habits of life to understand what are the common behaviors and focus attention as much as possible on possible infectious agents.

Pending new developments we can say that the first analyzes carried out in Italy on vegetables taken in detail at the experimental zooprophylactic institutes of Piedmont, Liguria, Valle d’Aosta and that of Lombardy and Emilia-Romagna using the method developed by the Higher Institute of health care have given negative results. One more confirmation to say that the problem is German and must be looked for.
In this situation, the Russian decision to block imports of vegetables from the European Union is at least ridiculous and is certainly not a measure adopted to protect citizens.

You may also like...

Leave a Reply

Your email address will not be published. Required fields are marked *

error: Content is protected by eFoodChef Team Thanks