Psittacosis (also known as parrot fever or ornithosis) is a bacterial infection of humans caused by the organism newly renamed Chlamydophila psittaci. It is a gram-negative small, coccoid, obligatory intracellular, RNA- and DNA-containing parasite. The bacterium has a 2- stage developmental life cycle which involves alternation between elementary bodies (the infectious form), and reticulate bodies (the vegetative, non-infectious, metabolically active form). The bacteria infect a wide range of birds and mammals such as ruminants in which it is the cause of intestinal, respiratory, udder, placental and joint infections. Avian chlamydiosis is often asymptomatic. In humans, the disease manifests itself as a broad range of symptoms, ranging from asymptomatic infections to mild influenza-like illness to a fulminating illness with involvement of several extrapulmonary sites.
There are 3 types of epidemiological exposure that lead to clinical psittacosis. The first is the occupational exposure of veterinarians and poultry—processing staff to infective material. The second type of exposure by which humans may contract psittacosis is by direct contact with domestic or wild birds through feeding and handling or by cage cleaning. Environmental activities represent the third type of exposure. Other epidemiological features of importance include the age of the affected patients, clinical symptoms, the attack rate and the type of birds involved in these outbreaks. Overall, this subject is of high priority for public health.
SIGNS - Flulike symptoms are most common and include fever, headache, respiratory signs and weakness. In humans the disease can be misdiagnosed. If flulike symptoms persist, be sure to alert your physician to the fact there are pet birds in the home.
TREATMENT OF BIRDS - Treatment of birds should begin immediately. The antibiotic tetracycline is an approved drug for the treatment of this disease. Very sick birds also need general supportive care. Isolate all sick birds, thoroughly clean and disinfect the cage and its surroundings, keep circulation of feathers and dust to minimum.
Fortunately, the spread of psittacosis to humans is uncommon, despite the high frequency of disease in pet birds, and most human cases are mild. However, immunosuppressed individuals such as elderly, AIDS patients, cancer patients, are at the highest risk.