Gianni Gurnari, Umberto Solimene

Italy

Introduction.

The globalization and the raising of new and more diffused infections from pathogenic bacterias patogeni imposes a greater attention in all the public areas. These areas in fact could represent the cause or the concomitant cause of serious pathologies for persons affected by immune deficiency or generally suffering. A frequent exposure also for limited time (but repeated) as those in a sporting structure or a thermal establishment and medical spas could bring to a worrisome clinical picture in some serious case. In order to limit as far as possible such risk, some measures and techniques of prevention must be adopted. The aim should be a combination of easy usability, guarantee of long lasting results and economic compatibility.

The strategies of prevention in the common environments represent without any doubt a great challenge for our knowledges and for the actual technology.

the current situation.

There are currently two types of strategies adopted to face the coming up problems connected to hospital infections:

1) the contrast through chemical or physical-chemical means, to be introduced in the plants costantly exposed;

2) shock actions aimed to eliminate rapidly the raising of some contamination by bacterias.

The first type consists in the immission in the water-sanitary networks of chlorine or oxidizer composite (characterized by a low impact on the water quality) or in the treatment through exposure to rays UV. A typology of products similar to the treatment of the evaporative cooling towers.

Advantages:

- relative facility of employment;
- generally limited cost;
-
- irrilevant change of the natural qualities of the treated water;
- compatibility with the continuous operating of the structure;
- limited energetic costs.
Disadvantages:

- production of derivate and by-products of the introduced active principles;
- increase of the water aggressiveness with consequent progressive corrosion of the metallic components used inside technological plants;
- discharged by the standards of water potability;
- difficulty in the controls;
- impossibility to guarantee homogeneous sanitary effects on all the points of water network.
The shock actions are generally constituted by rapid increase of the temperatures of the fluids (generally to get superior temperatures to the 75° Cs) or overdose of oxidizers (as the sodium hypochlorite) introduced in the distributive water networks and in the technological plants for a limited time, generally few, up to more than ten hours.

Advantages:

- relative simplicity of employment;
- nearly immediate results;
- relative effectiveness also on the far points.
Disadvantages:

- high energetic costs;
- overcoming of the safety limits and consequent temporary impossibilities of access to the service;
- violent stress of the plants (even if specialistic);
- increase of the corrosive risk;
- ineffectiveness in the short/medium run against biofilm and CFU;
- mechanical problems may occur;
- qualitative problems (unloadings, chemistry of the distributed water) may occur.
Although the strategies of the groups 1) and 2) are broadly diffused and also indicated by the greatest part of the International Guidelines concerning the contrast of the bacteriological contamination, the results of tests made in hospitals, tourism & hospitality, sport and thermal structures are disappointing and they require an heavy employment of aggressive chemistry methods.

Future developments.

In order to contain some relevant limits of the strategies mentioned above and to limit the risk to produce a serious damage, while trying to solve a minor one (plant equipments are very expensive), the theme of the integrated prevention is taken into great consideration.

This strategies includes both the intervention with contrast chemical means (to be selected among those with low aggressiveness) and with mechanicals, like the electromagnetic pulse-power systems that are able to destroy the DNA of the organic substance without possibility of genetic recombination. To increase their effectiveness these contrast actions should be integrated both with the choice of suitable materials (in oder to avoid biofilm creation) and with a careful choice of plants typology (like the simplification of hydraulic networks or the recirculation inlet close to the tap). The critical aspects of the plants can be limited through a specific care of all details. Together with this the revision of the maintenance, the cleaning and the disinfection processes guidelines and the aimed and aware choice of the products and the accessories parts must be considered.

But all this would be insufficient if the standards of control are not increased (with faster and more accurate methods of analytical determination) and with the adoption of extremely wide working plans.

Conclusions.

The possibility of intervention with integrated method compatible with the structures and the materials today available allows to get a discreet and verifiable limitation of the risk. In fact only the total prevention can furnish a suitable answer to the necessity to contain, as much as possible, the possible microbiological contamination in the public areas.

This challenge becomes a real necessity in environments as the thermal ones, in which the resolution of the hygienic problem must not interfere with the characteristics of the therapeutic mean in order to not reduce its efficiency.

Only the collaboration among scientific world, technical, professional and some industrial production can allow the managers of the most different receptive structures to look at the future with a certain optimism. But there’s a long way (technical and technological) to go. In this perspective a lot has to be done about the real experimentation, but also about the sensitization of the users (economically sustainable hygiene cannot exist in the common areas without the collaboration of the customers) and about the training of the various categories of operators.