What causes the diseases yellow fever encephalitis and measles in humans?

Yellow fever is caused by the yellow fever virus, which is transmitted to humans through the bites of infected mosquitoes, primarily Aedes aegypti. Encephalitis can be caused by various viruses, including arboviruses and herpes simplex virus, often transmitted through mosquito bites or direct contact. Measles is caused by the measles virus, a highly contagious virus that spreads through respiratory droplets when an infected person coughs or sneezes. Vaccination is key in preventing measles and reducing the risk of severe outcomes from these diseases.