Psittacosis

When ornithosis is a reportable animal disease in Germany ( zoonosis ), which is transmitted primarily by birds. This severe, flu-like systemic disease normally runs under the lungs predominantly involving ( bronchopneumonia ) from. If these pathogens can be detected in psittacines ( psittacines ), it is called psittacosis ( psittacosis, parrot fever ). These animal disease is notifiable. The disease is rare in humans, 2010, there was in Germany to 25 cases. The disease ( detection and treatment ) is subject to § 7 IfSG.

• 6.1 Historical forms
• 6.2 symptoms
• 6.3 immunity

Pathogen

The pathogen is the most common gram- negative bacterium Chlamydophila psittaci. The pathogen is an obligate intracellular. The reservoir of this pathogen are animals ( zoonosis ), especially birds (such as parrots, pigeons, seagulls ). The animals themselves show as usual reservoir hosts, usually no or few symptoms.

Transmission

The pathogen is usually taken by droplet infection, ie inhalation through inhalation of infectious fecal dust or aerosol. In this type of transmission is probably the upper respiratory tract of the gateway. A transmission can also occur through contact infection or by contact infection, which almost exclusively people are infected with close contact with infectious animals. At extremely pathogenic ( infectious ) strains may occur to person in rare cases, a transmission from humans.

Therefore, even a disease in occupationally exposed ( the pathogen particularly vulnerable ) people such as bird traders or workers in poultry farms are recognized as an occupational disease.

Pathogenesis

The multiplication of the pathogen is primarily probably in the respiratory epithelium of the upper respiratory tract ( dry cough ), then after bacteremia secondary to so-called reticulo - endothelial system (RES ), mainly in the spleen (splenomegaly ), rarely hepatosplenomegaly (liver and spleen ). The lung is likely to be infected secondarily via the bloodstream. Here it comes to the image of an atypical pneumonia with proliferation of lymphocytes, interstitial edema of the connective tissue between the typical organ cells, rarely with necrosis of the alveolar wall and hemorrhage. The respiratory epithelium of the bronchi remains intact.

Diagnostics

Clinical picture

The diagnosis of psittacosis is usually provided on the basis of the clinical picture in exposed persons. In the blood no leukocytosis (increase in white blood cell count ), but a slight leukopenia is usually determined (reduction of leukocyte count ) of about 4000-6000/mm ³ with a left shift, relative lymphopenia and an elevated ESR.

Serology

The indirect detection of the pathogen is best based on Titerverläufen of Chlamydia -specific antibodies in the serum of patients ( complement fixation, ELISA). An accurate determination of chlamydia species can be accomplished by immunofluorescence against specific initial body. The culture of the pathogen is usually done only in special laboratories because of the infectivity of the pathogen and the difficult culture conditions.

Differential Diagnosis

In the differential diagnosis, other agents come into consideration, which can trigger an atypical pneumonia (eg Legionnaire's disease, Q fever, influenza, Chlamydia pneumoniae pneumonia). Furthermore, typhoid fever, typhus fever and general sepsis are excluded.

Course of the disease

Progressive forms

Depending on the age and immunocompetence ( preparedness of the immune system ) of the patients develop different courses:

• Inapparent
• Flu -like
• Atypical pneumonia with some severe cases
• Typhoid form ( rare)

Symptoms

The disease begins after an incubation period of about six to 20 days with the following symptoms:

• Body aches
• Temporal and frontal headache
• Low back pain
• Fever ( 39 ° C or more)
• Bradycardia (slow heart beat sequence )
• , mucopurulent later after about five days cough, initially dry cough
• Splenomegaly
• Rarely, myocarditis, encephalitis and hepatitis, dyspnoea
• Greenish diarrhea

In the fourth week slower decrease fever and leisurely recreation; complete recovery and normalization of the lung, especially after severe disease after several weeks. After surviving a disease many years lasting immunity is acquired.

Untreated or a fever lasting more than three weeks, however, the disease ( mortality rate 20 to 50 %) runs often fatal especially during an infection with virulent pathogen strains.

Immunity

By cellular immune response, there is a 30 day long immunity, after a re-infection is possible.

Therapy

A disease must be treated by a doctor. Usually an antibiotic treatment with tetracycline ( as tetracycline, doxycycline ) or macrolides (such as clarithromycin, erythromycin) over two to three weeks is performed.