The list of pathologies linked to the ingestion of food that can in some way have effects on human health is long, very long. The harmful action for the organism can be linked to various mechanisms. When the same microorganism that is ingested with food is responsible for the symptoms, we speak of food poisoning. If, on the other hand, the microorganism introduced into the body with food releases toxins that generate the symptoms, we are in the field of food poisoning.
And we must not forget that a food, even if it is not contaminated, can become a vehicle for microorganisms with which it has come into contact, even if they have not reproduced inside it. This happens for example in the case of contamination of food or water with the feces of sick people or carriers of the infection. This is the case, for example, of the hepatitis A virus.
Finally, it may also happen that the food comes from infected animals and therefore transmits to man the disease that harbored in the animals themselves. This occurs in so-called zoonoses such as brucellosis or tularemia or following an infestation with trichinella spiralis. In this case we are dealing with a parasite: the foods at greatest risk are raw or undercooked pork, wild boar or horse meat, as well as fresh sausages and other products.
How does trichinosis come about
This pathology is now considered very rare. But it may still be present, as news reports show. Everything comes from trichinella larvaewhich can be found and develop in the muscles of animals, pigs but not only, after they have come into contact with the meat of animals that harbored the parasite.
At that point, if a person consumes meat that has trichinella cysts inside them, or real containers of larvae, the latter can mature, reproduce and move towards the muscles through the blood, then they develop. And it is precisely in the muscles that strong inflammations can occur, that the larvae that progressively tend to aggregate forming cysts. Normally there are muscles that are more frequently “chosen” by the trichinella for the formation of cysts: these are those of the eye, the tongue and those surrounding the chest.
How trichinella infestation manifests itself
Obviously, not all pictures of trichinella infestation give rise to the same clinical manifestations. Think that there are people in whom there are practically no symptoms, while others can experience very serious ailments after ingesting meat that lead to the development of trichinella cysts.
In general, in any case, it takes at least 1-2 weeks before the real symptoms begin, although sometimes there may be slight feverish increases and weakness with diarrhea and abdominal pain which after two days of eating contaminated food . Since the larvae tend to concentrate in some muscles, it is precisely in these locations that the symptoms can most easily manifest. Then, if the eyes are affected, eyelid swelling may occur. If there is a localization of the muscles of the mouth and neck, discomfort such as dysphagia, or difficulty swallowing, as well as speaking, and/or coughing can occur. In some cases, then there may be diarrhea and even skin symptoms such as an itch that is linked to incomprehensible redness.
How to recognize trichinella infestation
If you think that the stool test allows you to diagnose trichinosis, you are misled. Unlike what happens for many foodborne infections, in fact, the search for the parasite in the faeces is not useful. Instead, they can be done blood tests which help to arrive at the diagnosis: this is the case, for example, of the antibodies that are produced following the infection (they are detectable after a few weeks from the beginning of the picture) or also of the search for particular white blood cells, called eosinophils. The rate of these tends to rise in the event of illness, even if it is obviously not a particularly specific index. The doctor can therefore suspect the infection only on the basis of the symptoms and therefore refine his hypotheses on the basis of these parameters. Muscle biopsy to locate the cysts is done only rarely.
How to prevent and treat trichinella infection
On the prevention front, in order not to run risks it is fundamentally necessary bring the meat to full cooking exceeding 60 degrees. Thus the larvae can be destroyed. And they are also killed by freezing the meat for an adequate time.
In terms of therapies, there are specific drugs that can act on trichinella: it is about pesticides such as albendazole and mebendazole. Obviously, in the acute phases, painkillers and cortisone drugs are needed to counteract inflammation.
Bibliographic sources
TrichinellaISS (Higher Institute of Health)
TrichinellaMinistry of Health