Goitre in iodine in the soil. For example, in the English Midlands, the condition was known as Derbyshire Neck. In the United States, goitre was found in the Great Lakes, Midwest, and Intermountain regions. The condition now is practically absent in affluent nations, where table salt is supplemented with iodine. However, it is still prevalent in India, China, Central Asia, and Central Africa. Goitre had been prevalent in the alpine countries for a long time. Switzerland reduced the condition by introducing iodised salt in 1922. The Bavarian tracht in the Miesbach and Salzburg regions, which appeared in the 19th century, includes
Complement deficiency Complement deficiency Complement deficiency is an immunodeficiency of absent or suboptimal functioning of one of the complement system proteins. Because there are redundancies in the immune system, many complement disorders are never diagnosed, some studies estimated that less than 10% are identified. "Hypocomplementemia" may be used more generally to refer to decreased complement levels while "secondary complement disorder" means decreased complement levels that are not directly due to a genetic cause but secondary to another medical condition. The following symptoms (signs) are consistent with complement deficiency in general: Vaccinations for encapsulated organisms (e.g., "Neisseria meningitidis" and "Streptococcus pneumoniae") is crucial