Rapid tests and imaging techniques to identify bacterial infections (and the right antibiotic) – time.news

2023-06-01 12:48:13

Of Adriana Bazzi

Simit’s Italian infectious disease specialists gathered in Palermo to discuss possible strategies against difficult infections, especially those contracted in hospital by fragile patients

There are two aces that infectious disease specialists have up their sleeves and which they can play against “difficult” infections, those that are mainly contracted in hospitals, rehabilitation facilities or residences for the elderly. Which are not controllable with the vast majority of available antibiotics. And which represent an important cause of mortality in the industrialized world, especially for frail people, especially the elderly.

Two strategies

One of the two cards to play hides the opportunities offered by quick tests (the Anglo-Saxons call it “fast microbiology”) which allow the type of infection to be diagnosed within a few hours. Practically a bedside diagnosis. And to implement the most appropriate therapy. The other card is called “imaging” of infectious diseases and borrows all those diagnostic techniques, based precisely on the images taken from tests such as Pet-Tc (a technique that not only allows you to “see” the fabrics, but also to evaluate their functionality) or the scintigraphy (which analyzes tissues thanks to a radioactive tracer) which have amply demonstrated their usefulness in many other fields of medicine.

A silent pandemic

But let’s go in order and take a step back, hearing the opinion of the experts who presented their reports in Mondello (Palermo) on the occasion of a national meeting organized by Simit, the Italian Society of Infectious and Tropical Diseases. Speaking of “difficult” infections, explains the President of Simit Claudio Mastroianni, who is full professor of Infectious Diseases at the La Sapienza University of Rome: “We are facing a silent pandemic, that of infections from multiresistant germs against which most of the available anti-infectives do not work. It’s about iinfections that affect those who are hospitalized: elderly or frail patients, i.e. with diseases that compromise the immune system, such as tumors for example, or people who have undergone organ transplants and are undergoing immunosuppressive treatments. They are called healthcare-associated infections. They are mainly responsible for pneumonia (the leading cause of death from infection in hospitalized patients), but also for sepsis, kidney infections or surgical wounds). Against these germs we had blunt weapons until some time ago, but now the search for new molecules it got back on track and in the last four or five years new antibiotics have arrived in the clinic that are effective above all against bacteria».

Old data

L’Italia would be among first countries in Europe for the number of cases of hospital infections, but it is not easy to find updated epidemiological data because there is no surveillance system and those available are old. In any case, as Mastroianni recalled, the problem exists and having new drugs available helps, but it’s not enough. It is necessary to implement the so-called “stewardship”, i.e. protocols for the management of infectious diseases, within hospitals, which allow them to be prevented (starting from the washing of the hands of healthcare workers: a habit that is struggling to pass, as well as among the public ), to monitor the germs that emerge from time to time in that particular department or in that particular hospital (it is called epidemiological surveillance), and to better manage the administration of antibiotic therapies in individual patients. This is where “fast microbiology” comes in.

Fast microbiology

«It is possible to identify a bacterium (but also other microorganisms responsible for infection, such as fungi) practically at the patient’s bed – comments Marco Falcone, secretary of Simit and next President – They are tests that are performed on secretions (for example bronchial ones, ed ,) or in blood or urine. They give the results, in fact, in 2 or 3 hours» «Not only – adds Mastroianni – but they also identify the resistance genes of the microorganism. Which means that they give indications about the most suitable antibiotic for that casethanks to genetics. A big step forward compared to the old antibiogram which evaluated the sensitivity of germs to antibiotics in much longer times. And which (in the meantime) forced him to blindly administer a so-called “broad-spectrum antibiotic” to the patient, waiting for the results. With waste of drugs. And with a business card for germs that could thus reorganize themselves and develop resistance to antibiotics.

Personalized therapy

«Now even in infectious diseases we have arrived at the so-called “personalized therapy” – comments Chiara Iaria, president of the Simit Congress and Director of Infectious Diseases at the Civico Benfratelli (Arnas) in Palermo – With advantages for patients who are treated immediately and in the best possible way. We literally save some of these lives. But also with savings in health care costs, those spent on inadequate treatments. The important thing is to have resources and implement the infectious disease network, as the lesson of Covid has taught us ». Sure, we’ve had news of how Artificial Intelligence can find a new antibiotic in no time at all against one of the nastiest germs responsible for hospital infections, theAcinetobacter baumannii , but in the meantime we have to think about what’s here and now. And here’s another opportunity that already exists and allows you to manage certain other difficult infections: let’s talk about the other card to play: that of imaging.

“Imaging” of infectious diseases

There are some special infections. For example, those affecting so-called prosthetic devices, such as heart valves or other prostheses, such as those of the hip. «In some of these cases, the so-called biofilm is formed on the prosthesis where the bacteria grow – recalls Mastroianni – Le imaging techniques can flush out these infections and to direct the therapies even if, in these cases, the drugs find it difficult to reach the site of infection”. Last chance for imaging: solving the problem of so-called «fevers of unknown origin«: a rebus for clinicians. Assuming that these fevers have an infectious origin, it is a question of finding the cause and leaving. Here’s the help of imaging again. «With scintigraphy – explains Mastroianni – lymphocytes are marked and their path in the body can be followed. Lymphocytes are white blood cells that concentrate at sites of infection. In this way we can understand where the fever can originate”. Because fever, in any case, is often the first symptom of an infection.

June 1, 2023 (change June 1, 2023 | 12:47)

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