When the first signs of spring appear, humans are not the only ones eager to greet the great outdoors - biting bugs and insects are also clamouring for a taste of spring. Flies and mosquitoes make up the fourth largest group of insects, comprising over sixty thousand species. So, your chances of meeting one when you're out and about in the spring and summer months are very high indeed.

Usually insect bites are just a mere annoyance and can be avoided with a good repellent and proper precautions, but sometimes bites and stings can be a health risk. When insects bite they first inject saliva, which helps them to feed on our blood. If we are allergic to this saliva, the skin around the bite becomes red, inflamed and painful. Some people are highly sensitive to certain insect bites or can have a severe allergic reaction. The effects of a bee sting, for example can mimic those of a heart attack, and this anaphylactic shock can be life threatening, requiring immediate medical attention.

Even people who experience less severe reactions to insect bites can develop secondary infections, which are usually the result of scratching and then breaking the itching area of skin, which may then become contaminated by bacteria. Impetigo is a common bacterial skin infection among children that is highly contagious and can quickly spread through a family or a classroom. In extreme cases, the infection can invade a deeper layer of skin and develop into eczema. Keeping the bite cool and using after-bite creams, or antihistamine tablets if the irritation is intense, can help to reduce the itching and scratching.

Around the world, 500,000,000 people suffer each year from serious diseases caused by insect bites. More than 2,500,000 die annually in the tropics from malaria transmitted by mosquitoes and annually there are around 2000 cases of malaria in the UK (caught abroad) with a few fatalities. Mosquitoes can also cause yellow fever and dengue or 'break-bone' fever. Sleeping sickness is caused by the tse-tse fly, and river blindness by the black fly. Sandfly bites can result in large unhealing sores caused by Leishmaniasis. Even common house flies and horse flies can transmit serious diseases, such as anthrax, tuberculosis, tetanus, typhoid, dysentery and cholera.