The yellow fever virus is found in tropical and subtropical areas of Africa and South America. The virus is spread to people by the bite of an infected mosquito. Yellow fever is a very rare cause of illness in U.S. travelers. Illness ranges from a fever with aches and...
Whipworm, hookworm, and Ascaris are known as soil-transmitted helminths (parasitic worms). Together, they account for a major burden of disease worldwide. Whipworms live in the large intestine and whipworm eggs are passed in the feces of infected persons. If the...
West Nile virus (WNV) is the leading cause of mosquito-borne disease in the continental United States. It is most commonly spread to people by the bite of an infected mosquito. Cases of WNV occur during mosquito season, which starts in the summer and continues through...
Von Willebrand disease (VWD) is a blood disorder in which the blood does not clot properly. Blood contains many proteins that help the body stop bleeding. One of these proteins is called von Willebrand factor (VWF). People with VWD either have a low level of VWF in...
What is Vision Impairment? Vision loss means that a person’s eyesight is not corrected to a “normal” level. Vision loss can vary greatly among children and can be caused by many things. What causes loss of vision? Vision loss can be caused by damage to the eye itself,...
Viral meningitis is the most common type of meningitis, an inflammation of the lining of the brain and spinal cord. It is often less severe than bacterial meningitis, and most people get better on their own (without treatment). However, anyone with symptoms of...