Although they look very much like the kind of insect that would transmit disease, like mosquitoes, there are no records anywhere of disease transmission caused by bed bugs - even from sick host to healthy host.
A study carried out by scientists at the Department of Medicine, University of Mississippi Medical Center, Jackson, USA, that reviewed the available evidence on bed bugs found that while they are highly resistant to various ways of getting rid of them, they seem to be more of a nuisance than a serious health problem, but the possibility that they could one day serve as a vehicle for disease has not been well researched.
Scientists say there may be as many as 40 pathogens that could potentially live inside a bed bug or around its mouth area. However, tests have concluded that bed bugs are highly unlikely to carry disease from host to host.
Researchers have concluded that they are much less hazardous to human health than fleas, or other common insects. Nevertheless, these are well formulated opinions, rather than the results of conclusive studies. Some say hepatitis B or Chagas disease could not be discarded as possibilities if the setting were right.
As mentioned before, the biggest risk for humans comes from secondary bacterial infection, which in this case would be as a result of scratching the skin. Scratching, if it breaks the skin, allows bacteria to penetrate - but the bacteria would not have been from the bed bug.
Although they are not known to carry diseases, bed bugs can affect the quality of life of a person who has been bitten, causing distress, discomfort, embarrassment and unsettled sleep.
What happens when I get bitten?
When you are bitten a raised red bump of flat welt (also called a papule or a wheal) will appear, often accompanied by very intense itching. The anesthetic contained in the bed bugs saliva causes an allergic reaction which results in the red bumps. They look very similar to mosquito bites, but last a lot longer. Signs and symptoms of bug bites will only affect the surface of the skin.
Bites can sometimes take up to nine days to become visible. Unlike flea bites, bed bug bites do not usually have a red dot in the center.
Bed bugs, like fleas, tend to bite in rows. There are likely to be two or three bites all in a row. This is probably because the bed bug is disturbed while feeding, and then comes back about half an inch further down for its next bite; or perhaps it had been trying to find a good vein, and needed several attempts.
About 50% of people who are bitten show no symptoms at all and do not know it happened. This makes it more difficult to prevent or identify potential infestations. Some individuals, however, may become ill and nauseous. It is possible get skin infections and scars from scratching the bites.
When people know they have an infestation of bed bugs in their house they tend to become alarmed. Research, however, indicates that bed bugs do not transmit disease, even though they do bite and take blood. Infections will occur as a result of scratching, and not from a pathogen passed on from the bug.
Very rarely, some people may have an anaphylactic reaction to bed bug bites. It is possible to have an asthmatic reaction when they shed skin as they grow and die; but cases are very rare.