Insects
If a cockroach were to walk across your table at a restaurant, you'd leave. But, if a fly were to land on your lunch you'd probably just shoo it away. Big Mistake! The fly carries as many diseases as a cockroach and should be controlled with the same degree of vigilance.

Flies cannot eat solid food, so to soften it up, they vomit on it. Then they stomp the vomit in to a form of liquid, adding a few germs for good measure. After this they suck it all back up again, dropping some excrement at the same time. And when they've finished eating - its your turn.
Flying insects spread disease
By their nature, flies breed and feed in unsanitary conditions where larvae feed on decaying organic matter. Female flies choose suitable areas of rotting vegetation and decaying animal matter in which to lay their eggs. Adults emerge from pupae in these unsavoury sites and in the process become contaminated with disease-causing agents. Often they move into sensitive areas to look for their own food. These are often areas where our food is prepared, processed or consumed.

The habits of wasps are just as unsavoury as those of flies and can carry disease in much the same way. In addition, wasps are attracted to fruit and pastries and can be caught up in these and eaten. Death through wasp stings in the throat is quite common, and has been shown to account for 50% of all fatalities caused by venomous animals.

Vermin
It is no surprise that rats and mice are carriers of disease. You might be surprised to learn however, that infections are more likely to occur from contact (either direct or indirect exposure) to the urine of infected vermin, rather than from their bites. However, the mechanical injury of a bite by breaking intact skin and the possibility of the presence of urine in the vermin's mouth, particularly if it has just groomed itself, may be important. Therefore, handling live or recently killed vermin is a risk.

Contamination by urine can be to food and drinking water. The organism may gain entry either through cuts and abrasions of the skin, or via eyes, nose, mouth or ears.

In conclusion, the effective control of both the House Mouse and Brown Rat is necessary to reduce the risk of contamination.

The potential for contamination of human food with disease-causing agents has been proven over the years. Such agents are able to survive on the outside body surfaces of the insects, particularly amongst the numerous hairs. They also survive in the gut and in the blood system.

Amongst the most dangerous of these disease-causing organisms which have been found on flying insects are: -

Klebsiella
These bacteria are often the cause of many lower respiratory and urinary tract infections. They have been found on the outside cuticle of the fly and within the gut.
Campylobacter
These bacteria have been found to be the causative agents of many acute gastro-enteritis type complaints.
Streptococci
Often found in skin and gut infections in humans, they too can be carried by flying insects.
Chlamydia
These are parasites that can cause a variety of complaints in humans and there is increasing evidence that flies can transmit them.

There are also many fungi which cause disease such as Candida sp, Mucor sp, Asperguillus sp, etc., and research shows that flies can carry all of them. Food poisoning outbreaks can occur from a minute dose of bacteria. In these cases, the disease has usually been spread by flying insects, a fact which is rarely understood or appreciated. Food hygiene regulations require that food is wholesome and safe and has not been contaminated by flying pests.

Rats and mice as a source of Leptospirosis - Weil's Disease
Mice, particularly the House Mouse, are important carriers of Leptospirosis. Several strains of spirochaete bacterium (the casual organism) are carried by mice, and there is evidence of a growing risk to man. Although rarely fatal, the disease transmitted by mice can be extremely debilitating. The only way to prevent the spread of disease is by effective mouse control.

It has been estimated that between 50 and 70 per cent of rats carry the disease, and these can excrete up to 100 million bacteria per millilitre of urine. Leptospirosis is a potentially fatal disease, with 10 - 15% of infected people succumbing. The only way to prevent the spread of the disease is by effective rat control.