It is generally regarded that illnesses following Mosquito bites are rare, there is of course risks to be aware of, and taking preventative measures in the first place will help to keep your health in tact. Diseases are contractible of course, by the very nature of how the Mosquito operates. The female Mosquito bites in order to feed, and, as with anything going into your bloodstream, risks of infection are there. Normally, in healthy adults, the immune system should be able to fight off the initial infection, because the saliva from the Mosquito stimulates an immune response which is seen in the swelling.
Mosquitoes do carry fatal diseases, more details of which can be found on medical-dictionary.thefreedictionary.com. It is important though to understand that different mosquitoes can carry different diseases. Therefore, wherever you are in the world, the risk of catching a more fatal disease from a mosquito bite will change, depending on the native mosquito. Yellow Fever, for example is longer seen across Europe and North America, but its prevalent in Africa. There is no treatment for the Yellow Fever disease, only the symptoms can be treated, symptoms which are very similar to those of Malaria. Can you die from Mosquitoes biting you? Yes, of course it is possible, but the odds are long, and there are many things you can do to keep them that way. Protecting yourself from Mosquito bites in the first place is the main course of prevention.
Along with Yellow Fever, the other most common fatal disease that is carried by Mosquitoes is Malaria. Unlike Yellow Fever though, Malaria is completely treatable through drugs. While there are nearly 1 million deaths from Malaria recorded each year, see cdc.gov for more information, the chance of contracting this to a fatal degree are minimal in the western world. Because of the accessibility of modern treatments, the disease can be counteracted. It is important to see a doctor as soon as possible, if after being bitten by a mosquito, you develop symptoms such as headaches, malaise and muscle weakness, stiff neck and other flu like symptoms. With Yellow Fever there will likely be vomiting and jaundice of the skin.
HIV is not transmittable by Mosquitoes because the disease cannot live within them. Once thought a very high risk of transmissions, further research has since discovered that is not possible. Because of the different fatal disease that Mosquitoes do carry, the chances that you can die from Mosquitoes are still slim. It is important to remember that there are repellents available to keep them at bay in order to protect yourself. If you do not get bitten by these highly receptive insects, then you are not going to be put at risk. Longer clothing and not going out between dusk and dawn in the summer will help to minimise risk.
Across the world, in certain zones your risks will be higher. There is Encephalitis to be concerned about, and the Western Nile strain has found its way to the eastern coast of the United States, where substantial growth has been detected. Dengue Fever is another dangers viral disease, with native roots in Asia. Dengue Fever presents a lot of different symptoms, many of the them flu like and this poses a major threat, primarily to children.
Can you die from Mosquitoes having bitten you? Yes. Are you likely too? No. If you are armed with right information, if you take steps to repel the insects so that you are not at risk of being bitten in the first place, if you take note after being bitten to go to the doctor as soon as you start developing symptoms after being bitten, if you do all that then the likelihood is that you will remain in good health and not be at risk from anything fatal. The diseases are out there, the Mosquitoes are out there. Be informed and be as mosquito-proof as you can.