JP2790596B2 - Hospital infection prevention methods - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing bacterial infection in a hospital, and more particularly to a method for preventing hospital infection using a material having a photocatalytic function in a place where a large number of unspecified ones use in a hospital. .

[0002]

BACKGROUND OF THE INVENTION Recently, MRS caused by abuse of antibiotics
It has been confirmed that antibiotic-resistant bacteria such as A (methicillin-resistant Staphylococcus aureus) are infected in hospitals, which is a major social problem. That is, the in-hospital infection of antibiotic-resistant bacteria, which began at a higher-level medical institution that accommodates severely ill medical patients, has spread widely, posing a major threat to patients and hospital staff. As a countermeasure, it is possible to suppress the increase of resistant bacteria by appropriate use of antibiotics and to prevent the spread of resistant bacteria due to frequent disinfection and sterilization.

[0003] As a method for preventing the spread of resistant bacteria, there are methods of isolating and infecting persons infected with the resistant bacteria, disinfecting and disinfecting the skin and clothes of the infected persons and those who come into contact with the infected persons, and disinfecting and disinfecting used medical equipment. There is no other way than to enforce sterilization, and each hospital has prepared a manual to prevent nosocomial infection. However, even if a person infected with a resistant bacterium is confirmed, isolation in a private room may be difficult, and secondary infection may occur by contact before the infection is confirmed. Preventive measures were eagerly needed.

[0004] Even in hospitals, measures have been taken to prevent infections in areas requiring a high degree of safety, such as isolation wards and operating rooms, but in particular, waiting rooms, corridors, washrooms, etc. where unspecified numbers of people enter and leave. Few measures have been taken in common areas, and even if implemented, frequent disinfection and
In addition to the enormous burden of the sterilization operation, new problems such as the problem of the safety of disinfectants and disinfectants and the problem of the treatment of used chemicals have arisen, and effective and highly safe countermeasures have been desired.

Heretofore, there have been known deodorants and fungicides which do not use chemicals, which utilize the photocatalytic function of a semiconductor. That is, it is known that semiconductors such as titanium oxide exhibit a photocatalytic function by light of a specific wavelength, and have a deodorizing and antifungal function by a strong oxidizing action. No. 13, No. 5, p. 211 (1985) describes that a titanium oxide fine particle fixed membrane is useful as a sterilization reactor. A method for purifying waste using a semiconductor or the like carrying a metal or a metal oxide is described. In the above method, a substance having a photocatalytic function is formed into fine particles and then dispersed in a target waste liquid to perform a purification treatment.
However, the utilization of the photocatalytic function is an experimental stage or is a temporary one, and has not yet reached a practically effective utilization.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly safe, effective bactericidal effect, no need for frequent maintenance, and a widespread use of effective in-hospital bacteria such as antibiotic-resistant bacteria. It is to provide a method for preventing infection.

[0007]

Means for Solving the Problems Claim 1 according to the present application
The described invention is a method for preventing in-hospital infection, wherein the member in the hospital is made of a metal material, an inorganic material, an organic material,
Exposure to light including an ultraviolet wavelength of less than 400 nm , and a material having a photocatalytic function is applied to the member surface, the material having a photocatalytic function is titanium oxide,
Iron oxide, tungsten oxide, zinc oxide, titanium titanate
Metal oxide semiconductor selected from the group consisting of
It is characterized by at least one kind . This metal oxide semiconductor
Body is platinum, gold, palladium, silver, copper, nickel, Kovar
, Rhodium, niobium, tin, ruthenium oxide, niobium oxide
Metal or metal oxide selected from the group consisting of
It is preferably modified.

According to a third aspect of the present invention, the member is one or more solid members selected from a metal material, an inorganic material, and an organic material, and the surface of the member is
Characterized in that it is coated with a thin film made of a material having photocatalytic functions.

[0009] The invention of claim 4, wherein according to the present application, applying said member is a flexible member consisting of one or two or more organic material, a material powder having photocatalytic function on the member surface It is characterized by doing.

[0010]

According to the method for preventing hospital-acquired infection of the present invention, the above-mentioned substance exhibiting a photocatalytic function exposed to light having an ultraviolet wavelength of less than 400 nm is applied to a member in a hospital.
Due to the photocatalytic reaction, an excellent bactericidal effect is exhibited against bacteria adhered to the member surface. In addition, substances that exhibit a photocatalytic function exhibit a germicidal effect semi-permanently without any special maintenance as long as they are exposed to light including ultraviolet wavelengths less than 400 nm , and undesired environmental pollution and waste generation. Since there is no outbreak, safe and effective prevention of nosocomial infection can be performed.

[0011]

The present invention will be described in more detail below.

[0012] In the method for preventing hospital-acquired infection according to the present invention, the members in the hospital to which the substance having a photocatalytic function is applied include:
Floors, walls, window frames, railings, handles, etc., especially in places where unspecified large numbers of people come into contact, such as hospital rooms, corridors, waiting rooms, and washrooms
Faucets, sleeper frames, curtains, carpets and the like. In other words, even in hospitals, infection control measures in places requiring high levels of safety, such as isolation wards, intensive care units, and operating rooms, are completely implemented, but general hospital rooms where unspecified numbers of people enter and exit, This is because infection control measures in corridors, waiting rooms, washrooms, etc. were insufficient.

Among the above members, floors, walls, window frames, handrails,
Handles, faucets, sleeper frames, etc., metallic materials, inorganic materials,
In the case of a solid member made of an organic material, it is preferable to coat the surface of the member with a thin film made of a substance having a photocatalytic function. Examples of the metal material include metal frames used for walls, doors, floor materials, etc., window frames, stairs, handrails of lavatories, etc., door handles, water taps and chairs, and metal frames such as beds. Examples of inorganic materials include tiles, boards such as plaster, wall materials by spraying or painting, glass and wash basins, ceramic materials such as toilet bowls, and organic materials include resin flooring materials, wall materials, and the like. Resin frames such as door handles, taps, chairs, and beds. In these solid members, a thin film made of a material exhibiting a photocatalytic function such as titanium oxide is coated.
If the film thickness is about 1 μm, the film itself is transparent,
It can be applied to each member without impairing the design. When applied to a member that does not require transparency, the thickness may be arbitrarily set to 1 μm or more to improve the film strength.

Examples of the substance exhibiting a photocatalytic function used in the method for preventing hospital-acquired infection of the present invention include metal oxide semiconductors such as titanium oxide. Specifically, 2-9
No. 850, and titanium oxide, iron oxide, tungsten oxide, zinc oxide, strontium titanate, etc. are widely known. The semiconductor used in the method for preventing hospital-acquired infection of the present invention may be any of these, but titanium oxide is particularly preferred from the viewpoint of bactericidal effect and easy availability.

Metals or other metal oxides which modify the above-mentioned metal oxides to improve the catalytic function, such as titanium oxide, are also preferably used to further promote the photocatalytic reaction. For example, platinum, gold, palladium It is preferable to use a metal selected from the group consisting of silver, copper, nickel, cobalt, rhodium, niobium, tin, ruthenium oxide, and nickel oxide in combination.
Gold, palladium and silver are more preferable, and palladium is more preferable in view of easiness of processing and price. The amount of modification is desirably in the range of 0.01 to 20% by weight based on the metal oxide in the present invention.

The metal oxide may be prepared, for example, by evaporating a metal at a high temperature, electrolytic oxidation, chemical vapor deposition, vacuum vapor deposition, coprecipitation, metal halide, etc .; Sum and hydrolysis, hydrolysis of metal alkoxides,
It can be adjusted by a sol-gel method or the like. Moreover, you may use a commercial item. The metal or other metal oxide may be modified by a conventionally used method such as an impregnation method, a precipitation method, an ion exchange method, a photoelectric deposition method, or a kneading method.

As a method for coating a thin film on a solid member, the above-mentioned metal oxide is applied to a part or all of the surface of a member having a flat, curved or complicated shape, for example, by spray coating, dip coating, spin coating, or the like. Method, a method of fixing by at least one or more methods such as a sputtering method, a method of preparing a metal oxide thin film in advance and bonding it to a member surface, a metal used for a metal oxide exhibiting a photocatalytic function, and the modifying function And a method of bonding a material thin film obtained by subjecting a metal alloy having the above to a thin film and performing an oxidation treatment to a member surface.

In the method for preventing hospital-acquired infection according to the present invention, the member in the hospital to which the substance having a photocatalytic function is applied is made of an organic material such as a mat portion of a bed, a resin cushion portion of a chair, a curtain, a carpet, and a fiber wall material. In the case of a flexible member made of, it is preferable to apply a material having a photocatalytic function to the surface of the member in the form of powder. Here, the flexible member includes all members such as resin thin plates, and members easily deformed by stress, such as textiles and synthetic leather. Examples of the application method include a method in which a material having a photocatalytic function such as a modified metal oxide is powdered, and the powder is sprayed on a flexible member together with an adhesive. As a material such as a door mat made of butadiene rubber or the like, a method of spraying powder directly on the surface and the like can be mentioned.

In the present invention, the member needs to be exposed to light, and the light energy has a wavelength corresponding to exciting the photocatalyst and contributes to the photocatalytic reaction. Light energy containing a large amount of ultraviolet wavelengths of 400 nm or less is preferable. Examples of the light energy source include natural light sources of sunlight, light emitted from mercury lamps, light emitted from fluorescent lamps, light generated from filament lamps of halogen lamps, short arc xenon light, and artificial light sources such as laser beams. Further, an artificial light source may be used at the same time as an auxiliary light source for sunlight.

The above-mentioned light irradiating method is a method of directly irradiating a material exhibiting a photocatalytic function applied to a member, if necessary, or, in the case of a transparent member such as glass, irradiating a thin film through the transparent member or sunlight. A method of irradiating a thin film in a multifaceted manner using artificial light together can be used.
No special light irradiation is required, and a sufficient effect can be obtained with light from a fluorescent lamp or the like in a hospital. However, since the disinfecting effect is not exerted in the shaded area where the light of the illumination does not reach, it is preferable to use another light irradiation means to express the disinfecting effect on the entire area where the person comes into contact, if desired. In addition, it is preferable to apply light having a wavelength that promotes the photocatalytic action with sufficient intensity to a member that requires a high sterilizing effect.

As a specific method of applying the material having a photocatalytic function according to the present invention to members in a hospital, there is a method in which a material is directly applied to the solid member by a spray coating method or the like and baked to form a thin film. Alternatively, a tile, a metal tile, or the like having a photocatalytic material thin film formed on the surface may be used. For the flexible member, besides spraying and adhering the powder, a method in which the powder is mixed with a polymer material constituting a fiber or a resin and then molded may be used. In this case, it should be noted that the effect of preventing infection cannot be obtained unless the molding is performed under the condition that the powder is directly exposed on the surface.

(Example 1) Evaluation of bactericidal property Titanium oxide sol was applied on a tile of 150 cm ² by spin coating, and then baked at 700 ° C. to form a thin film, and a titanium oxide thin film was coated on the tile. I got The test piece was cut into 20 cm ² .

FIG. 1 shows an apparatus for evaluating bactericidal properties. The oxidation
Tile specimen surface coated with titanium thin film 10
2 × 10 ^FourOf MRSA in physiological saline
After applying Lusus suspension (bacterial solution) 12 and drying, 30
cm fluorescent lamp 15 W from the top at a distance of 15 cm
Light for 30 minutes, and then on the entire surface of the tile
The cell suspension 12 with a cotton swab
Transfer to a citrate medium and incubate the medium at 37 ° C for 24 hours.
Nourishment, and the number of viable MRSA bacteria was counted.
10^FourMet. Thereby, light irradiation for 30 minutes
It is clear that about 80% of MRSA has died
Was.

When the amount of irradiation of ultraviolet light under these conditions was measured, it was 4.91 μW / cm ² ,
Dose to ² of the test specimens was 98.2μW / 20cm ^2. The number of dead MRSA determined from the number of viable bacteria was 1.6 × 10 ⁴ . The number of killed MRSA was divided by the amount of irradiation of ultraviolet rays and the irradiation time (minutes), and the obtained value was defined as the bactericidal effect. As a result of this evaluation, the bactericidal effect was 5.4.
(Cells / min · μW).

The same evaluation was performed by replacing the white fluorescent lamp with a BL (black light) lamp. The results are shown in FIG. FIG. 2 is a graph showing the relationship between the light irradiation time and the survival rate of MRSA. As is evident from the results, the specimen coated with the titanium oxide thin film on the tile was a white fluorescent lamp,
Irradiation with any of the BL lamps shows a high bactericidal effect on MRSA.

A similar test was performed for Escherichia coli. The results are shown in FIG. FIG. 3 is a graph showing the relationship between the light irradiation time and the survival rate of Escherichia coli. Irradiation time of about 15 minutes for both fluorescent and BL lamps
% Or more of E. coli has been killed.
In addition, it was revealed that E. coli exhibited a high bactericidal effect.

Example 2 Evaluation of Hospital Infection Prevention Method Light irradiation conditions in hospitals, operating tables, general hospital rooms, outpatient waiting rooms and corridors, outpatient consulting rooms, general office work, and service areas in hospitals were measured. The bactericidal effect in the area when the titanium oxide thin film coated tile was applied, and the time required to kill 50 cells / cm ² of bacteria were calculated according to the results of Example 1 and are shown in Table 1. No special addition was made to the light irradiation, and only illumination in each normal area was performed.

[0028]

[Table 1]

In general, it is known that the number of living bacteria in a hospital is less than 50 cells / cm ² ,
In any area, only about 1
It was estimated that this number of bacteria was killed in about 30 minutes.

It is known that the titanium oxide used in this embodiment can produce various colors depending on its thickness. If the titanium oxide film thickness is 1 μm or less as described above,
Being transparent, it can be used in areas that require transparency, such as window glasses and mirrors, and by controlling the film thickness,
Since various colors can be obtained, it is also preferable in terms of design.

In this embodiment, a titanium oxide thin film is used as a material having a photocatalytic function. However, other metal oxide thin films may be used. Further, in order to improve the photocatalytic function, titanium oxide or the like is used. The metal oxide may be modified with a metal such as platinum or palladium to form a thin film. In addition, an alloy of a metal constituting a metal oxide having a photocatalytic function such as titanium and a modified metal such as platinum or palladium is formed and thinned, and the surface is oxidized by performing an oxidation treatment such as anodization. An alloy of titanium and a modified metal, or a thin film having an alloy of titanium and a modified metal inside, may be prepared and used by adhering to an application site.

[0032]

INDUSTRIAL APPLICABILITY The method for preventing hospital-acquired infection of the present invention is highly safe, has an excellent bactericidal effect against antibiotic-resistant bacteria and the like, requires no frequent maintenance, and can be widely used.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for evaluating sterilization.

FIG. 2 is a graph showing the relationship between the light irradiation time and the survival rate of MRSA.

FIG. 3 is a graph showing the relationship between the light irradiation time and the survival rate of Escherichia coli.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Titanium oxide thin film 12 Cell suspension 14 Fluorescent lamp (15W)

──────────────────────────────────────────────────続 き Continuing from the front page (73) Patent holder 592116165 Kazuhito Hashimoto 2073 Iijima-cho, Sakae-ku, Yokohama-shi, Kanagawa 2nd, New City Hongodai D Bldg. 213 (72) Inventor Takatoshi Ogawa 2-5 Minamisuna, Koto-ku, Tokyo No. 14 Takenaka Corporation Technical Research Institute (72) Inventor Toshio Saito 2-5-4 Minamisuna, Koto-ku, Tokyo Tokyo 14 Co., Ltd. Inside Technical Research Center (72) Inventor Kenichi Unno 2-chome Minamisuna, Koto-ku, Tokyo No. 5-14 Takenaka Corporation Technical Research Institute (72) Inventor Kan Hasegawa 2-5-14 Minamisuna, Koto-ku, Tokyo Inside Technical Research Center Takenaka Corporation (72) Inventor Yasuhiko Yoshioka Minamisuna, Koto-ku, Tokyo 2-5-14, Takenaka Corporation Technical Research Institute (72) Inventor Nobuo Tsubouchi 2-5-1-14 Minamisuna, Koto-ku, Tokyo (72) Inventor Seiichi Hosiri 4-1-1-13 Honcho, Chuo-ku, Osaka-shi, Osaka In-house Takenaka Corporation, Osaka Main Store (72) Inventor Toru Katayama, Honcho, Chuo-ku, Osaka-shi, Osaka 4-1-1-13 Takenaka Corporation Osaka Main Branch (72) Inventor Toshiya Watanabe 2-8-1 Kimura Chigasaki-shi, Kanagawa Prefecture Totoki Equipment Co., Ltd. Basic Research Laboratory (72) Inventor Sadao Murasawa Shiga 2-3-1, Nishi-Shibukawa, Kusatsu-shi Ishihara Sangyo Co., Ltd. Functional Materials Research Center (72) Inventor Akira Fujishima 710-5 Nakamaruko Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture (72) Inventor Kazuhito Hashimoto Yokohama, Kanagawa Prefecture 2000 Kosugaya-cho, Sakae-ku, City 10 Minami-Kosugaya House No.2 Building 506 (56) References JP-A-5-253544 (JP, A) JP-A-6-315614 (JP, A) JP-A-6-210170 (JP, A A) JP-A-6-278241 (JP, A) JP-A-63-73336 (JP, U) JP-A-4-8637 (JP U) (58) investigated the field (Int.Cl. ^6, DB name) E04C 2/04 B01J 21/06 B01J 35/02 E04C 2/08 E04C 2/20 E04F 13/00 E04F 15/00

Claims (4)

(57) [Claims] 1. A member in a hospital is made of a metal material, an inorganic material, or an organic material, and has an ultraviolet wavelength of less than 400 nm.
And a material having a photocatalytic function applied to the surface of the member, having the photocatalytic function.
Materials are titanium oxide, iron oxide, tungsten oxide, acid
Selected from the group consisting of zinc oxide and strontium titanate
A method for preventing hospital-acquired infections , which comprises at least one metal oxide semiconductor . 2. The member in a hospital is made of a metal material, an inorganic material, or an organic material, and has an ultraviolet wavelength of less than 400 nm.
And a material having a photocatalytic function applied to the surface of the member, having the photocatalytic function.
Materials are titanium oxide, iron oxide, tungsten oxide, acid
Selected from the group consisting of zinc oxide and strontium titanate
One or more of the metal oxide semiconductors used is platinum, gold, palladium,
Silver, copper, nickel, cobalt, rhodium, niobium,
Select from the group consisting of tin, ruthenium oxide and nickel oxide
A method for preventing nosocomial infection, which is a material modified with a selected metal or metal oxide . Wherein said member is a metallic material, an inorganic material, a one or two or more solid members selected from organic materials, are coated with a thin film is the member surface made of a material having photocatalytic functions 3. The method according to claim 1, wherein
2. The method for preventing hospital-acquired infection according to the above. Wherein said member is a flexible member consisting of one or two or more organic material, applying a powder of a material having a light touch <br/> medium function the member surface The method for preventing hospital-acquired infection according to claim 1 or 2, wherein: