Psittacosis known serovars. All should be considered to be readily transmissible to humans. "C. psittaci" serovar A is endemic among psittacine birds and has caused sporadic zoonotic disease in humans, other mammals, and tortoises. Serovar B is endemic among pigeons, has been isolated from turkeys, and has also been identified as the cause of abortion in a dairy herd. Serovars C and D are occupational hazards for slaughterhouse workers and for people in contact with birds. Serovar E isolates (known as Cal-10, MP, or MN) have been obtained from a variety of avian hosts worldwide, and although they were associated with
Contagious disease disease. Most epidemics are caused by contagious diseases, with occasional exceptions, such as yellow fever. The spread of non-contagious communicable diseases is changed either very little or not at all by medical isolation of ill persons or medical quarantine for exposed persons. Thus, a "contagious disease" is sometimes defined in practical terms, as a disease for which isolation or quarantine are useful public health responses. Contagious disease A contagious disease is a subset category of transmissible diseases, which are transmitted to other persons, either by physical contact with the person suffering the disease, or by casual contact with their secretions