HARTMANN in South Africa
Risk Prevention > Tips for treatment and care > Exogenous causes of contaminations

Exogenous causes of contaminations

Skin, mouth and hands of the operating theater staff are a frequent source of microorganisms which can trigger nosocomial infections.


Pathogenic germs are also transmitted through the air.

Transmission of germs is possible not only through a direct contact but also through the air. The significance of this mode of transmission is disputed. However a relatively low germ count in the ambient air can undoubtedly lead to wound infections.


The right operating theater clothing minimizes the risk of nosocomial infections.

Sterile surgical gowns which offer protection from microbial infection of the wound area through the operating theater staff minimize the risk of infection. Surgical gowns should be abrasion-resistant and prevent permeation of moisture effectively.

Textile garments give off fibers, threads and dust which can also be full of viable pathogenic microorganisms. In this manner pathogens initially reach the clothing from the body surface and then the air of the operating theater with the textile particles coming off the clothing through movements.


Oral and pharyngeal cavity

A mask prevents the transmission of germs through the mouth and nose.

A person exhales droplets loaded with bacteria out of the nose while breathing intensely and out of the mouth while talking. The more talking, coughing or sneezing goes on, the more microorganisms, particularly nosocomial infective pathogens, are scattered.

A mask used in the operating theater must cover the mouth and nose completely. It should consist of a multilayer material but not impede respiration and communication. It is also important that the mask has a high filter capacity and does not rub any skin particles off the face.

Head and hair

Hair is also contaminated with germs and must be covered during operations.

Exfoliated epithelial skin cells can peel off exposed sections of skin in the facial area; dandruff or hair which is contaminated with germs falls off insufficiently covered areas. Hair is always contaminated with scalp germs. Hair in the area of the forehead also has high germ counts.

Suitable head gear for surgical procedures must be designed to completely cover both the hair and forehead; persons with beards must also ensure that the beard is covered.

Skin and hands

Disinfectants reduce germs on hands only temporarily.

The skin’s own germs reproduce in the upper skin layers. Hand washing cannot prevent the release of this resident flora; also disinfectants reduce the germs only temporarily.
Surgical disinfection of hands is not a substitute for wearing sterile surgical gloves. To prevent contamination of the exterior of the gloves by the disinfected but not completely germ-free hands, the rules of hygiene and asepsis must be observed when putting on and changing surgical gloves.
During longer surgical procedures the accumulation of microorganisms in the glove caused by the secretion of hand sweat is unavoidable. Therefore the hands should be re-disinfected regularly and new gloves should be put on. Also if the glove is damaged, germs can enter the operating field and the surgeon’s self-protection is at risk. Of course it is necessary to change the glove and disinfect the hands in this case as well.