A<unk>  is one that can be spread by contamination by<unk> .  The most common examples are HIV, hepatitis B, hepatitis C and viral haemorrhagic fevers.<unk> s that are not usually transmitted directly by<unk>  contact, but rather by insect or other vector, are more usefully classified as vector-borne<unk> , even though the causative agent can be found in<unk> . Vector-borne<unk> s include West Nile virus and malaria.
Many<unk> s can also be transmitted by other means.
Since it is difficult to determine what pathogens any given<unk>  contains, and some<unk> s are lethal, standard medical practice regards all<unk>  (and any body fluid) as potentially infective.<unk>  and Body Fluid precautions are a type of infection control practice that seeks to minimize this sort of<unk>  transmission.<unk>  for<unk>  transfusion is screened for many<unk> s.
Needle exchanges are an attempt to reduce the spread of<unk> s in intravenous drug users.
Blood-borne disease
Foodborne Illness
Opportunistic infection
Waterborne diseases
Foodborne illness
Nosocomial infection
Tick-borne disease
Bacterial disease