Sporadic CJD is different from bovine spongiform encephalopathy (mad cow disease) and variant Creutzfeldt–Jakob disease (vCJD). Signs and symptoms
The first symptom of CJD is usually rapidly progressive dementia, leading to memory loss, personality changes, and hallucinations. Myoclonus (jerky movements) typically occurs in 90% of cases, but may be absent at initial onset. Other frequently occurring features include anxiety, depression, paranoia, obsessive-compulsive symptoms, and psychosis. This is accompanied by physical problems such as speech impairment, balance and coordination dysfunction (ataxia), changes in gait, and rigid posture. In most people with CJD, these symptoms are accompanied by involuntary movements. The duration of the disease varies greatly, but sporadic (non-inherited) CJD can be fatal within months or even weeks. Most affected people die six months after initial symptoms appear, often of pneumonia due to impaired coughing reflexes. About 15% of people with CJD survive for two or more years.The symptoms of CJD are caused by the progressive death of the brains nerve cells, which are associated with the build-up of abnormal prion proteins forming in the brain. When brain tissue from a person with CJD is examined under a microscope, many tiny holes can be seen where the nerve cells have died. Parts of the brain may resemble a sponge where the prions were infecting the areas of the brain. Cause
CJD is a type of transmissible spongiform encephalopathy (TSE), which are caused by prions. Prions are misfolded proteins that occur in the neurons of the central nervous system (CNS).
Psittacosis—also known as parrot fever, and ornithosis—is a zoonotic infectious disease in humans caused by a bacterium called Chlamydia psittaci and contracted from infected parrots, such as macaws, cockatiels, and budgerigars, and from pigeons, sparrows, ducks, hens, gulls and many other species of birds. The incidence of infection in canaries and finches is believed to be lower than in psittacine birds. In certain contexts, the word is used when the disease is carried by any species of birds belonging to the family Psittacidae, whereas ornithosis is used when other birds carry the disease. In humans
Signs and symptoms
In humans, after an incubation period of 5–19 days, the symptoms of the disease range from inapparent illness to systemic illness with severe pneumonia. It presents chiefly as an atypical pneumonia. In the first week of psittacosis, the symptoms mimic typhoid fever, prostrating high fevers, joint pains, diarrhea, conjunctivitis, nose bleeds, and low level of white blood cells. Rose spots called Horders spots can appear. Spleen enlargement is common towards the end of the first week. It may become a serious lung infection. Diagnosis can be suspected in case of respiratory infection associated with splenomegaly and/or epistaxis. Headache can be so severe that it suggests meningitis and some nuchal rigidity is not unusual. Towards the end of the first week, stupor or even coma can result in severe cases.The second week is more akin to acute bacteremic pneumococcal pneumonia with continuous high fevers, headaches, cough, and dyspnea.