There are four main routes for transmission, these are: 

1. physical contact, which can spread directly or indirectly: 
   • direct transmission may occur from contact with non-intact skin or mucous membranes 
   • indirect transmission may occur from contact with infected surfaces or objects (fomite transmission) 
     
     Examples of infections that spread via physical contact include: 
     • ophthalmic infections, such as bacterial and adenoviral conjunctivitis  
     • skin infections, for example staphylococcus, herpes simplex or fungi  
     • enteric infections, for example viral gastroenteritis 
2. airborne particles, including respiratory infections, for example tuberculosis: 
   • airborne particles include respiratory droplets (>5-10 microns in diameter) and aerosols (<5 microns in diameter)  
   • you are at a higher special risk of the transmission of  infection from airborne particles because of your close proximity to the patient’s nose and mouth when undertaking eye care procedures  for an extended period of time 
   • potentially infectious respiratory droplets and aerosols are generated when an individual sneezes, coughs or talks. Particles over five microns in diameter do not normally travel more than one metre, but smaller particles can travel longer distances and remain airborne for longer 
3. contact with blood and other bodily fluids: 
   • Bodily fluids also include secretions and excretions (excluding sweat) 
   • There is extremely low risk of transmitting blood borne viruses, such as human immunodeficiency virus (HIV) and hepatitis B and C, in optometric practice 
   • tears can contain infectious agents (including these viruses, and others that are much more contagious, such as adenovirus) which may be transmitted to you or to other patients, if your hands are not properly decontaminated after the clinical examination 
   • all surfaces soiled with spillages of blood and/or body fluids should be decontaminated immediately using a product that contains a detergent and disinfectant. Do not use mops for this. Use disposable paper towels and dispose of them as clinical waste.¹⁸⁶ 
4. use of sharps: the main risk of transmission is associated with invasive procedures in which injury, for example needlestick, could result in blood from the infected individual entering open tissues of another person. If you suffer an injury from a sharp which may be contaminated, you should: 
   • gently encourage the wound to bleed, if possible whilst holding it under running water 
   • wash the wound using running water and plenty of soap 
   • dry the wound and cover it with a waterproof plaster or dressing 
   • seek urgent medical advice 
   • report the injury to your employer.^{187, 188} 

You should not suck the wound or scrub it while you are washing it.