Legionella is a Gram - ubiquitous bacterium that is widespread in nature. It is found associated with the presence of water, especially if it is stagnant. It has been isolated from the natural water of rivers and lakes, even in low concentrations. The optimal development conditions have a temperature range that goes from 25-42 ° C. Therefore, ventilation systems such as air conditioners, boilers, dehumidifiers, shower heads, whirlpools, saunas, cooling towers are the ideal niche. From here, the potentially contaminated water can be sprayed into the environment in the form of aerosols and reach the lung alveoli by inhalation. Legionella pneumophila serogroup 1 is the species that causes the most frequent infections that can occur with Pontiac Fever, with flu-like symptoms, or Legionnaires' Disease. The latter is a more or less severe infectious pneumonia, difficult to diagnose because it does not have clinical and radiological specificities. Among the serious complications of Legionellosis there can be: lung abscess, empyema, renal failure. The minimum infectious dose for humans based on the number of colony forming units (CFU) present in contaminated water samples is not known. For the most vulnerable categories such as the elderly, smokers, alcoholics, immunocompromised, terminally ill, dialysis patients, people suffering from degenerative diseases such as diabetes, hypertension, chronic obstructive bronchopathy, or infectious diseases, exposure to charges below 100 CFU / L carries a greater risk of contagion. Antibiotic treatment can be carried out by administering Fluoroquinolone, in the most severe patients, Erythromycin, Azithromycin or Doxycycline in patients with mild pneumonia. Considering the health, economic and image implications that may derive from these episodes, the most pragmatic approach is to implement all those measures necessary for the prevention of the disease. On January 13, 2005, an agreement was published in the Official Gazette called “Guidelines containing indications on Legionellosis for managers of tourist-accommodation and spa facilities”. It was developed in order to offer the managers of tourist-accommodation and spa structures the elements of judgment for the assessment of the Legionellosis risk in said structures. It is a set of technical-practical suggestions and resulting on scientific evidence most suitable for minimizing the risk of exposure. The Legionella risk protocol is divided into three sequential and correlated phases: Assessment (investigation that identifies in the structure the conditions that link the actual or potential presence of Legionella and the possibility of contracting the infection), Management (interventions and procedures that remove or contain the critical points that emerged during the assessment phase) and Risk communication (actions that inform and sensitize those affected by the potential risk in order to correctly apply the prevention and control measures of the disease). The main actions to be carried out in order to prevent the risk of exposure are the annual sampling of water in tourist-accommodation and hospital facilities, drafting a risk assessment document, establishing corrective procedures if there were any non-conformities, adequately training the staff employee and raise awareness of the risks.
La Legionella è un batterio Gram– ubiquitario e ampiamente diffuso in natura. Lo si trova associato alla presenza di acqua, specialmente se stagnante. Esso è stato isolato dall’acqua naturale di fiumi e di laghi, anche in basse concentrazioni. Le condizioni di sviluppo ottimali hanno un range di temperatura che va da 25-42°C. Perciò i sistemi di areazione come condizionatori, caldaie, deumidificatori, soffioni delle docce, vasche idromassaggio, saune, torri di raffreddamento sono la nicchia ideale. Da qui, l’acqua potenzialmente contaminata può essere nebulizzata nell’ambiente sottoforma di aerosol e raggiungere gli alveoli polmonari per inalazione. Legionella pneumophila sierogruppo 1 è la specie che causa le infezioni più frequenti che si possono manifestare con Febbre di Pontiac, con sintomatologia simil influenzale, o Malattia dei Legionari. Quest’ultima è una polmonite infettiva più o meno grave, di difficile diagnosi perché che non presenta specificità cliniche e radiologiche. Tra le complicanze gravi della Legionellosi vi possono essere: ascesso polmonare, empiema, insufficienza renale. Non è nota la dose minima infettante per l’uomo sulla base del numero di unità formanti colonie (CFU) presenti nei campioni di acqua contaminata. Per le categorie più vulnerabili quali anziani, fumatori, alcolisti, immunocompromessi, malati terminali, dializzati, persone affette da patologie degenerative come diabete, ipertensione, broncopatia cronico-ostruttiva, o da patologie infettive, l’esposizione a cariche inferiori a 100 CFU/L comporta un rischio maggiore di contagio. Il trattamento antibiotico può essere effettuato somministrando Fluorochinolone, nei pazienti più gravi, Eritromicina, Azitromicina o Doxiciclina cei pazienti con polmonite lieve. Considerando le implicazioni sanitarie, economiche e di immagine che possono derivare da questi episodi, l’approccio più pragmatico è quello di mettere in atto tutte quelle misure necessarie alla prevenzione della malattia. Il 13 gennaio 2005 è stato pubblicato in Gazzetta Ufficiale un accordo denominato “Linee guida recanti indicazioni sulla Legionellosi per i gestori di strutture turistico-recettive e termali”. È stato elaborato al fine di offrire ai direttori di strutture turistico-recettive e termali gli elementi di giudizio per la valutazione del rischio Legionellosi in dette strutture. È un insieme di suggerimenti tecnico-pratici e comportamenti basati su evidenze scientifiche più aggiornate per ridurre al minimo il rischio di esposizione. Il protocollo del rischio Legionellosi si divide in tre fasi sequenziali e correlate: Valutazione (indagine che individua nella struttura le condizioni che collegano la presenza effettiva o potenziale di Legionella e la possibilità di contrarre l’infezione), Gestione (interventi e procedure che rimuovono o contengono i punti critici emersi durante la fase di valutazione) e Comunicazione del rischio (azioni che informano e sensibilizzano i soggetti interessati dal potenziale rischio al fine di applicare correttamente le misure di prevenzione e controllo della malattia). Le azioni principali da realizzare al fine di prevenire il rischio di esposizione sono il campionamento annuo delle acque nelle strutture turistico-recettive e ospedaliere, redigere un documento di valutazione del rischio, stabilire le procedure correttive qualora vi fossero delle non conformità, formare adeguatamente il personale addetto e sensibilizzare la popolazione sui rischi.
Il rischio di esposizione da Legionella spp.: igiene, sicurezza e prevenzione nei luoghi di lavoro
ZANOTTO, SILVIA
2021/2022
Abstract
Legionella is a Gram - ubiquitous bacterium that is widespread in nature. It is found associated with the presence of water, especially if it is stagnant. It has been isolated from the natural water of rivers and lakes, even in low concentrations. The optimal development conditions have a temperature range that goes from 25-42 ° C. Therefore, ventilation systems such as air conditioners, boilers, dehumidifiers, shower heads, whirlpools, saunas, cooling towers are the ideal niche. From here, the potentially contaminated water can be sprayed into the environment in the form of aerosols and reach the lung alveoli by inhalation. Legionella pneumophila serogroup 1 is the species that causes the most frequent infections that can occur with Pontiac Fever, with flu-like symptoms, or Legionnaires' Disease. The latter is a more or less severe infectious pneumonia, difficult to diagnose because it does not have clinical and radiological specificities. Among the serious complications of Legionellosis there can be: lung abscess, empyema, renal failure. The minimum infectious dose for humans based on the number of colony forming units (CFU) present in contaminated water samples is not known. For the most vulnerable categories such as the elderly, smokers, alcoholics, immunocompromised, terminally ill, dialysis patients, people suffering from degenerative diseases such as diabetes, hypertension, chronic obstructive bronchopathy, or infectious diseases, exposure to charges below 100 CFU / L carries a greater risk of contagion. Antibiotic treatment can be carried out by administering Fluoroquinolone, in the most severe patients, Erythromycin, Azithromycin or Doxycycline in patients with mild pneumonia. Considering the health, economic and image implications that may derive from these episodes, the most pragmatic approach is to implement all those measures necessary for the prevention of the disease. On January 13, 2005, an agreement was published in the Official Gazette called “Guidelines containing indications on Legionellosis for managers of tourist-accommodation and spa facilities”. It was developed in order to offer the managers of tourist-accommodation and spa structures the elements of judgment for the assessment of the Legionellosis risk in said structures. It is a set of technical-practical suggestions and resulting on scientific evidence most suitable for minimizing the risk of exposure. The Legionella risk protocol is divided into three sequential and correlated phases: Assessment (investigation that identifies in the structure the conditions that link the actual or potential presence of Legionella and the possibility of contracting the infection), Management (interventions and procedures that remove or contain the critical points that emerged during the assessment phase) and Risk communication (actions that inform and sensitize those affected by the potential risk in order to correctly apply the prevention and control measures of the disease). The main actions to be carried out in order to prevent the risk of exposure are the annual sampling of water in tourist-accommodation and hospital facilities, drafting a risk assessment document, establishing corrective procedures if there were any non-conformities, adequately training the staff employee and raise awareness of the risks.File | Dimensione | Formato | |
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https://hdl.handle.net/20.500.12608/32095