Mosquito
Mosquito-borne diseases are currently most prevalent in East Africa, Latin America,  Southeast Asia, and India; however, emergence of vector-borne diseases in Europe have recently been observed. A weighted risk analysis demonstrated associations to climate for 49% of infectious diseases in Europe including all transmission routes. One statistical model predicts by 2030, the climate of southern Great Britain will be climatically-suitable for malaria transmission "Plasmodium vivax" malaria for 2 months of the year. By 2080 it is predicted that the same will be true for southern Scotland.
Mosquito-malaria theory
The notion that malaria was due to miasma was negated by the discovery of malarial parasite. A German physician Johann Heinrich Meckel was the first to observed in 1847 the protozoan parasites as black pigment granules from the blood and spleen of a patient who died of malaria. But he did not understand the parasitic nature and significance of those granules in connection with malaria. In 1849 a German pathologist Rudolf Virchow realised that it could be those granules that were responsible for the disease. In 1879 an Italian biologist Ettore Afanasiev further argued that the granules were definitely the causative agents.
A major discovery was made by a French Army physician Charles Louis Alphonse Laveran working in Algeria, North Africa. At the hospital in Bône (now Annaba), he noticed spherical bodies from a patient’s blood film, free or adherent to red blood cells. On 6 November 1880 he observed from one patient's blood the actual living parasite, describing it as "a pigmented spherical body, filiform elements which move with great vivacity, displacing the neighboring red blood cells." He also observed the process of maturation of the parasite (which is now called exflagellation of microgametocytes). He meticulously examined 200 patients, and noted the cellular bodies in all 148 cases of malaria but never in those without malaria. He also found that after treatment with quinine, the parasites disappeared from blood. These findings clearly indicated that the parasite was the cause of malaria, and establishing the germ theory (nature) of malaria. He named the parasite "Oscillaria malariae" (later renamed "Plasmodium malariae") and reported his discovery to the French Academy of Medicine in Paris on 23 November and 28 December. For his discovery he was awarded the Nobel Prize for Physiology or Medicine in 1907.