Myelitis is acute, but the retroviruses (such as HIV and HTLV) can cause chronic myelitis. Poliomyelitis, or gray matter myelitis, is usually caused by infection of anterior horn of the spinal cord by the enteroviruses (polioviruses, enteroviruses (EV) 70 and 71, echoviruses, coxsackieviruses A and B) and the flaviviruses (West Nile, Japanese encephalitis, tick-borne encephalitis). On the other hand, transverse myelitis or leukomyelitis, or white matter myelitis, are often caused by the herpesviruses and influenza virus. It can be due to direct viral invasion or via immune mediated mechanisms. Bacterial myelitis includes "Mycoplasma Pneumoniae", which is a common agent for respiratory
History of beliefs about the human body is important to understanding histories of coercion and control, sex and gender, and other important but culturally varied aspects of human experience. Another prominent voice in the field at the same time was Caroline Walker Bynum, whose 1988 "Holy Feast and Holy Fast" became a landmark study. Both Bynum and Porter noted that during the 1980s Western history of the body research drew on post-structuralist thought, such as Michel Foucault's ideas of biopolitics and biopower, which emphasised that state power is not abstract, but exercised through and over human bodies. But both expressed a concern that research was focusing too