Disease the time between infection and the appearance of symptoms. The latency period is the time between infection and the ability of the disease to spread to another person, which may precede, follow, or be simultaneous with the appearance of symptoms. Some viruses also exhibit a dormant phase, called viral latency, in which the virus hides in the body in an inactive state. For example, varicella zoster virus causes chickenpox in the acute phase; after recovery from chickenpox, the virus may remain dormant in nerve cells for many years, and later cause herpes zoster (shingles). Diseases may be classified by cause,
National Centre for Disease Control centers in India, which started surveillance of HIV infection in the country. On 30 July 2009, it was named as National Centre for Disease Control. NCDc has eight divisions under it namely Doctors from NCDC had been previously summoned to investigate potential outbreaks of diseases including suspected cases of Pneumonic plague in Punjab in 2002, SARS outbreaks in 2004, meningitis outbreak in Delhi in 2005, and avian influenza in 2006. The NCDC in collaboration with the Centers for Disease Control and Prevention has set up the Global Disease Detection Regional Center in New Delhi, India. This will lead to long-term