ABSTRACT
Other diseases result from external factors, such as cancers or infectious diseases caused by viruses or bacteria. Infectious diseases generally kill their host before any telltale signature of the disease can be seen in tissues. Major infectious diseases that do result in tissue pathology include tuberculosis, leprosy, treponemal diseases (e.g., syphilis), polio, and malaria. Degenerative disorders include deossification and erosive arthritis (e.g., rheumatoid arthritis and gout). Other common diseases include dental pathologies and parasitic infections. Finally, a number of congenital abnormalities (cf. birth defects) and syndromes, such as spina bifida, scoliosis, dwarfism, Down syndrome, and Marfan syndrome, may also be present.
