The incubation period for psittacosis is 1 to 4 weeks. The majority of infections cause symptoms in 5 to 14 days.

Symptoms

• Community-acquired pneumonia: influenza resembling symptoms, non-productive cough, dyspnea, soreness of the throat, nosebleed, pleuritic chest pain (rare), signs of systemic illness, fever, lethargy. It may follow a gradual, subtly evolving course or arise rapidly with acute sepsis and respiratory failure.
• Gastrointestinal symptoms: nausea, vomiting, abdominal cramps, diarrhoic phenomena and jaundice. These symptoms are not particularly common.
• Neurological symptoms (commonly observed): severe headache, photophobia, or extreme weakness.
• Dermatological symptoms: facial rash (Horder's spots), resembling the manifestations of the spots observed in typhoid fever.

Signs

Psittacosis often causes cardiac involvement, including bradycardia, pericarditis, endocarditis or myocarditis. Signs of pneumonic consolidation may arise, although a chest examination does not produce any characteristic results. Chest x-ray can also unveil the degree of pulmonary involvement. A less common feature observable by a physical examination is splenomegaly, which, if accompanied by  pneumonia, makes the diagnosis of psittacosis more likely. Dermatological signs include Horder's spots, erythema nodosum, or erythema multiforme.

• Splenomegaly

  Later there may be coughing, difficulty in breathing, abdominal distress, and often splenomegaly. Prostration may occur. Infiltrates may appear in the chest x-ray. Special laboratory tests are necessary for accurate diagnosis. [medical-dictionary.thefreedictionary.com]

  A less common feature observable by a physical examination is splenomegaly, which, if accompanied by pneumonia, makes the diagnosis of psittacosis more likely. Dermatological signs include Horder's spots, erythema nodosum, or erythema multiforme. [symptoma.com]

  Presentations: Follows 5-15 day incubation period Subclinical, asymptomatic infection (common) Flu-like illness Mono-like illness (fever, Pharyngitis, hepatosplenomegaly) Typhoid-like illness (fever, Bradycardia, Splenomegaly ) Atypical Pneumonia (fever [fpnotebook.com]

  A confirmedt case is defined as a clinical specimen positive for C. psittacit or clinical illness characterized by any combination of fever, chills, lower or upper respiratory disease, myalgia, headache, photophobia, and splenomegaly, plus a fourfold [cdc.gov]

  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. [en.wikipedia.org]

• Fever

  (inanition) (of unknown origin) (persistent) (with chills) (with rigor) R50.9 ICD-10-CM Diagnosis Code R50.9 Fever, unspecified 2016 2017 2018 2019 Billable/Specific Code Applicable To Fever NOS Fever of unknown origin [FUO] Fever with chills Fever with [icd10data.com]

  Presentations: Follows 5-15 day incubation period Subclinical, asymptomatic infection (common) Flu-like illness Mono-like illness (fever, Pharyngitis, hepatosplenomegaly) Typhoid-like illness (fever, Bradycardia, Splenomegaly ) Atypical Pneumonia (fever [fpnotebook.com]

  Patients usually provisionally diagnosed as having typhoid fever or pneumonia are regularly admitted to the Rietfontein Fever Hospital suffering from psittacosis. [ncbi.nlm.nih.gov]

• Veterinarian

  Here we describe an epidemiological investigation conducted by physicians and veterinarians after a reported case of psittacosis. [ncbi.nlm.nih.gov]

  The only way to know for sure what’s going on with your bird is to take it to an avian veterinarian for a thorough examination including bloodwork. There are multiple types of diagnostic tests available to veterinarians. [petcha.com]

  If you think your bird has any of these symptoms, take it to a veterinarian right away. Some birds can seem healthy while carrying the disease, so it's important to have all new birds examined and tested by a veterinarian. [in.gov]

• Chills

  Two weeks later the bird died, and a week after that the patient became ill with cough, fever, headache, and chills. [cdc.gov]

  Chlamydia, chlamydial A74.9 ICD-10-CM Diagnosis Code A74.9 Chlamydial infection, unspecified 2016 2017 2018 2019 Billable/Specific Code Applicable To Chlamydiosis NOS psittaci A70 (infection) Fever (inanition) (of unknown origin) (persistent) (with chills [icd10data.com]

  The main symptoms are intense headache, chills and fever and an irritating non-productive cough. Later most patients develop signs of pneumonitis most clearly seen on radiographic examination. [ncbi.nlm.nih.gov]

• Pain

  We report the case of a psittacosis patient with severe abdominal pain who subsequently developed acute respiratory failure. The main symptoms of psittacosis are considered to be upper respiratory inflammation and influenza-like symptoms. [ncbi.nlm.nih.gov]

  Comfort Cool Tennis Elbow Braces - Elbow Wraps, Sleeves & Bands Finger - Thumb Supports Foot and Ankle Braces - Supports Foot Pain & Injury Hernia Aids and Support Hip Surgery and Injury Knee Braces & Support Orthopedic Back Cushions Orthopedic Pillows [activeforever.com]

  Breathing (respiratory) abnormalities may develop including a dry, nonproductive cough, difficulty breathing (dyspnea), a sore throat, and, in rare cases, chest pain. [rarediseases.org]

  Generalized Fever Chills Joint aches Muscle pain Malaise Headaches (mild) Respiratory Dry cough (initially) Blood-tinged sputum (later) Shortness of breath Bloody nose (epistaxis) Sore throat Abnormal breathing sounds Chest pain when breathing (uncommon [healthhype.com]

• Fatigue

  If you've been exposed to birds, whether they're wild or domestic, and you develop a lingering case of the flu (symptoms include: fever and chills, nausea and vomiting, muscle and joint pain, diarrhea, fatigue, cough, and fatigue), you need to see a doctor [wideopenpets.com]

  Symptoms may include: Blood-tinged sputum Dry cough Fatigue Fever and chills Headache Joint aches Muscle aches (most often in the head and neck) Shortness of breath Diarrhea Swelling in the back of the throat (pharyngitis) Swelling of the liver Confusion [nlm.nih.gov]

  About 1 to 3 weeks after being infected, a person develops a fever, chills, fatigue, and loss of appetite. A cough develops, which is initially dry but later brings up greenish sputum (thick or discolored mucus). [merckmanuals.com]

  […] parrots, pigeons and poultry birds (the bacteria causes avian chlamydiosis in these birds), but other birds can also transmit the disease This condition primarily targets the lungs and damages them, leading to the symptoms of dry cough, fever, chills, fatigue [dovemed.com]

• Cough

  A cough develops, which is initially dry but later brings up greenish sputum (thick or discolored mucus). Fever persists for 2 to 3 weeks and then slowly subsides. [merckmanuals.com]

  There is fever, headache, sore throat, cough, muscle pain, lethargy and depression. [medical-dictionary.thefreedictionary.com]

  The main symptoms are intense headache, chills and fever and an irritating non-productive cough. Later most patients develop signs of pneumonitis most clearly seen on radiographic examination. [ncbi.nlm.nih.gov]

• Dry Cough

  Symptoms may include: Blood-tinged sputum Dry cough Fatigue Fever and chills Headache Joint aches Muscle aches (most often in the head and neck) Shortness of breath Diarrhea Swelling in the back of the throat (pharyngitis) Swelling of the liver Confusion [nlm.nih.gov]

  Psittacosis was a well-defined illness that was characterized by an abrupt onset of fever, rigors, sweats, and prominent headache, and a mild dry cough which appeared late frequently. However, respiratory symptoms were absent in 18% of patients. [ncbi.nlm.nih.gov]

  cough, fever, chills, fatigue, and shortness of breath. [dovemed.com]

  Symptoms include fever, chills, headache, muscle aches, weakness, and a dry cough. Some people may experience difficulty breathing. If left untreated, pneumonia and other serious complications can develop. [bphc.org]

  This may include aerosolized (suspended in the air) feces, feather dust, and droplets from sneezing or coughing birds. Psittacosis symptoms include fever, headache, body aches, and a dry cough. Pneumonia may also occur. [encyclopedia.com]

• Pharyngitis

  On the suspicion of psittacosis, pharyngeal swabs from the couple were taken and sent to the Belgian reference laboratory for psittacosis. [ncbi.nlm.nih.gov]

  Signs: Atypical Pneumonia Fever Pharyngeal erythema Pulmonary rales Hepatomegaly Horder's Spots Similar to Typhoid Fever related Rose Spot s Pink, blaching maculopapular rash VIII. Complications: Complications are rare XI. [fpnotebook.com]

  Symptoms may include: Blood-tinged sputum Dry cough Fatigue Fever and chills Headache Joint aches Muscle aches (most often in the head and neck) Shortness of breath Diarrhea Swelling in the back of the throat (pharyngitis) Swelling of the liver Confusion [nlm.nih.gov]

• Dyspnea

  The chlamydia cause respiratory infection manifested with fever, malaise, cough, dyspnea, sore throat, photophobia and headaches. [icd10data.com]

  The second week is more akin to acute bacteremic pneumococcal pneumonia with continuous high fevers, headaches, cough, and dyspnea. X-rays show patchy infiltrates or a diffuse whiteout of lung fields. [en.wikipedia.org]

  Symptoms Community-acquired pneumonia: influenza resembling symptoms, non-productive cough, dyspnea, soreness of the throat, nosebleed, pleuritic chest pain (rare), signs of systemic illness, fever, lethargy. [symptoma.com]

  Breathing (respiratory) abnormalities may develop including a dry, nonproductive cough, difficulty breathing (dyspnea), a sore throat, and, in rare cases, chest pain. [rarediseases.org]

• Tachypnea

  A persistent dry, hacking cough, fine crepitant rales, and tachypnea are typical. Morphological features: Lungs: Psittacosis begins as an inflammatory process in the lung and progresses to consolidation, primarily lobular but occasionally lobar. [histopathology-india.net]

• Diarrhea

  […] psit·ta·co·sis | \ ˌsi-tə-ˈkō-səs \ Definition of psittacosis : an infectious disease of birds caused by a bacterium ( Chlamydia psittaci synonym Chlamydophila psittaci ), marked by diarrhea and wasting, and transmissible to humans in whom it occurs as [merriam-webster.com]

  Symptoms are generally those of the flu - fever, diarrhea, chills, congunctivitis, and sore throat. A number of tests are available to diagnose the disease in the live bird. [birdsnways.com]

  In pet birds, common symptoms include anorexia, weight loss, diarrhea, yellowish droppings, sinusitis, respiratory distress, nervous signs, and conjunctivitis. [state.nj.us]

• Vomiting

  Symptoms in humans include fever, chills, cough, fatigue, muscle and chest, pain, loss of appetite, nausea, vomiting and diarrhoea. Other symptoms include headaches, sweating and abnormal intolerance to light. [bbc.com]

  Symptoms of Psittacosis may be often associated with the flu (flu-like) and include: fever and chills nausea and vomiting muscle and joint pain diarrhoea weakness fatigue cough, typically dry abrupt onset of headache Thankfully, the disease is uncommon [farmerhealth.org.au]

  If you've been exposed to birds, whether they're wild or domestic, and you develop a lingering case of the flu (symptoms include: fever and chills, nausea and vomiting, muscle and joint pain, diarrhea, fatigue, cough, and fatigue), you need to see a doctor [wideopenpets.com]

  Signs and Symptoms The symptoms of psittacosis may include fever, headache, rash, loss of appetite, vomiting, neck and back pain, muscle aches, chills, fatigue, upper and lower respiratory symptoms and cough. [health.hawaii.gov]

  Vomiting, bloody diarrhea, fever and dehydration may occur. Recovery may occur in 2 - 4 days. Salmonella can be transmitted from person to person. Humans carrying salmonella can infect their pet birds. [birdsnways.com]

• Nausea

  Symptoms in humans include fever, chills, cough, fatigue, muscle and chest, pain, loss of appetite, nausea, vomiting and diarrhoea. Other symptoms include headaches, sweating and abnormal intolerance to light. [bbc.com]

  Symptoms of Psittacosis may be often associated with the flu (flu-like) and include: fever and chills nausea and vomiting muscle and joint pain diarrhoea weakness fatigue cough, typically dry abrupt onset of headache Thankfully, the disease is uncommon [farmerhealth.org.au]

  If you've been exposed to birds, whether they're wild or domestic, and you develop a lingering case of the flu (symptoms include: fever and chills, nausea and vomiting, muscle and joint pain, diarrhea, fatigue, cough, and fatigue), you need to see a doctor [wideopenpets.com]

  These include: fever, chills, cough, weakness or fatigue, muscle and chest pain, loss of appetite, nausea, vomiting, diarrhea, headache, sweating, abnormal intolerance to light. [skedaddlewildlife.com]

  It includes the following: Dry cough, sore throat Shortness of breath, fatigue Chest pain Fever and chills Headache, joint aches, and muscle aches Nausea and vomiting Pneumonia Abdominal pain Jaundice Photophobia (increased sensitivity to light) How is [dovemed.com]

• Abdominal Pain

  We report the case of a psittacosis patient with severe abdominal pain who subsequently developed acute respiratory failure. The main symptoms of psittacosis are considered to be upper respiratory inflammation and influenza-like symptoms. [ncbi.nlm.nih.gov]

  It includes the following: Dry cough, sore throat Shortness of breath, fatigue Chest pain Fever and chills Headache, joint aches, and muscle aches Nausea and vomiting Pneumonia Abdominal pain Jaundice Photophobia (increased sensitivity to light) How is [dovemed.com]

• Hepatomegaly

  Signs: Atypical Pneumonia Fever Pharyngeal erythema Pulmonary rales Hepatomegaly Horder's Spots Similar to Typhoid Fever related Rose Spot s Pink, blaching maculopapular rash VIII. Complications: Complications are rare XI. [fpnotebook.com]

  A thorough physical exam should also be conducted in order to establish the existence of typical findings: fever, pharyngeal erythema, diffuse rales, hepatomegaly, splenomegaly and potentially, tachycardia, are all compatible with a respiratory psittacosis [symptoma.com]

  Frequent nosebleeds (epistaxis) and abnormal enlargement of the liver and spleen (hepatomegaly) are also common findings. [rarediseases.org]

  In pigeons, common lesions include hepatomegaly, airsacculitis, enteritis, and conjunctivitis with swollen and encrusted eyelids. The spleen may rupture. In cage birds, the liver may be enlarged and yellow with focal necrosis. [state.nj.us]

• Hepatosplenomegaly

  Presentations: Follows 5-15 day incubation period Subclinical, asymptomatic infection (common) Flu-like illness Mono-like illness (fever, Pharyngitis, hepatosplenomegaly) Typhoid-like illness (fever, Bradycardia, Splenomegaly ) Atypical Pneumonia (fever [fpnotebook.com]

  Pharyngitis, malaise, anorexia and painful myalgias and arthralgias are common, as is hepatosplenomegaly. A persistent dry, hacking cough, fine crepitant rales, and tachypnea are typical. [histopathology-india.net]

  Particularly helpful clinical clues are hepatosplenomegaly, hemoptysis, epistaxis, rash, and relative bradycardia. [antimicrobe.org]

• Chest Pain

  Symptoms in humans include fever, chills, cough, fatigue, muscle and chest, pain, loss of appetite, nausea, vomiting and diarrhoea. Other symptoms include headaches, sweating and abnormal intolerance to light. [bbc.com]

  Signs and symptoms Symptoms are very varied, but commonly include: fever cough, usually without much phlegm headache rash muscle aches chest pain shortness of breath sore throat swollen lymph glands. [sahealth.sa.gov.au]

  Other symptoms may be a dry cough, chest pain and breathlessness, and in severe cases pneumonia may develop. In birds, symptoms may include diarrhoea, weakness, runny eyes or nose, ruffled feathers, or the bird not eating. [dhhs.tas.gov.au]

  People with psittacosis often develop: fever chills headache weakness muscle aches a dry cough chest pain breathless In severe cases, pneumonia develops. [health.nsw.gov.au]

• Cyanosis

  […] chills, moderate to high fever, slow pulse, severe headache, myalgias, anorexia, N&V, arthralgia and mental clouding; pneumonic Sx are uncommon, with production of minimal mucoid sputum mixed with hemorrhage, and if severe, accompanied by hypoxia and cyanosis [medical-dictionary.thefreedictionary.com]

• Tachycardia

  A thorough physical exam should also be conducted in order to establish the existence of typical findings: fever, pharyngeal erythema, diffuse rales, hepatomegaly, splenomegaly and potentially, tachycardia, are all compatible with a respiratory psittacosis [symptoma.com]

• Myalgia

  Patients typically present with 1 week of fevers, headache, myalgias, and a nonproductive cough. Although pneumonia is the most common manifestation, all organ systems can be involved. [ncbi.nlm.nih.gov]

  Other signs and symptoms reported by more than 25% of the patients included headache, chills, weakness and fatigue, and myalgia. One patient with a fourfold titer rise to chlamydial group antigens died. [cdc.gov]

  Laboratory suggestive evidence Detection of IgM or single high IgG antibody titre 2 to C. psittaci by MIF OR A single high C. psittaci CF antibody titre. 2 Clinical evidence Pneumonia OR AT LEAST TWO of the following: fever, headache, myalgia, rigors, [health.gov.au]

  Affected individuals may develop fever, chills, muscle pain (myalgia), headaches, and a general feeling of poor health (malaise). Pneumonia commonly occurs and, in some cases, can be severe. [rarediseases.org]

  Symptoms: Atypical Pneumonia Fever (>50% of cases) Non-productive cough (>50% of cases) Headache (>30% of cases) Myalgias and chills VII. [fpnotebook.com]

• Arthralgia

  Pharyngitis, malaise, anorexia and painful myalgias and arthralgias are common, as is hepatosplenomegaly. A persistent dry, hacking cough, fine crepitant rales, and tachypnea are typical. [histopathology-india.net]

  […] birds–parrots, parakeets, cockatoos, which may be sick or carriers of C psittaci Clinical Most Pts are asymptomatic; symptomatic cases have a 1-2 wk incubation, followed by chills, moderate to high fever, slow pulse, severe headache, myalgias, anorexia, N&V, arthralgia [medical-dictionary.thefreedictionary.com]

• Photophobia

  The chlamydia cause respiratory infection manifested with fever, malaise, cough, dyspnea, sore throat, photophobia and headaches. [icd10data.com]

  A confirmedt case is defined as a clinical specimen positive for C. psittacit or clinical illness characterized by any combination of fever, chills, lower or upper respiratory disease, myalgia, headache, photophobia, and splenomegaly, plus a fourfold [cdc.gov]

  It includes the following: Dry cough, sore throat Shortness of breath, fatigue Chest pain Fever and chills Headache, joint aches, and muscle aches Nausea and vomiting Pneumonia Abdominal pain Jaundice Photophobia (increased sensitivity to light) How is [dovemed.com]

  Identification of psittacosis Clinical features The clinical presentation can be variable, but the onset of psittacosis is usually abrupt, with fever, prominent headache, photophobia, myalgia, and upper or lower respiratory tract symptoms. [www2.health.vic.gov.au]

• Epistaxis

  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. [en.wikipedia.org]

  Generalized Fever Chills Joint aches Muscle pain Malaise Headaches (mild) Respiratory Dry cough (initially) Blood-tinged sputum (later) Shortness of breath Bloody nose (epistaxis) Sore throat Abnormal breathing sounds Chest pain when breathing (uncommon [healthhype.com]

  Frequent nosebleeds (epistaxis) and abnormal enlargement of the liver and spleen (hepatomegaly) are also common findings. [rarediseases.org]

• Headache

  Psittacosis is a systemic disease that causes fever, headache and pneumonia. Although potentially serious, it is rarely fatal unless respiratory or renal failure occurs. [ncbi.nlm.nih.gov]

  There is fever, headache, sore throat, cough, muscle pain, lethargy and depression. [medical-dictionary.thefreedictionary.com]

  Two weeks later the bird died, and a week after that the patient became ill with cough, fever, headache, and chills. [cdc.gov]

• Lethargy

  They are usually similar to influenza, with lethargy, as well as fevers (mine up to 40oC, 104oF), chest pains (which I only had when coughing), headaches, dry cough and nausea. [birdsnways.com]

  In birds, symptoms include discharge from the eyes, swollen eyes, respiratory distress, lethargy, lack of appetite, and watery green droppings. [wideopenpets.com]

  Psittacosis in Birds Symptoms Include:  Lethargy  Decreased appetite  Ruffled feathers  Ocular or nasal discharge  Diarrhea and/or green to yellow-green droppings The typical incubation period for birds ranges from 3 days to several weeks. [slideshare.net]

  There is fever, headache, sore throat, cough, muscle pain, lethargy and depression. [medical-dictionary.thefreedictionary.com]

  Illness in birds is known as avian chlamydiosis; symptoms range from mild to severe and may include anorexia, lethargy, oculonasal discharge and diarrhoea. Healthy birds may be carriers. Cats, dogs, goats and sheep may be infected but this is rare. [www2.health.vic.gov.au]

• Confusion

  He was febrile but not confused, and he responded rapidly to treatment with erythromycin. [ncbi.nlm.nih.gov]

  Symptoms may include: Blood-tinged sputum Dry cough Fatigue Fever and chills Headache Joint aches Muscle aches (most often in the head and neck) Shortness of breath Diarrhea Swelling in the back of the throat (pharyngitis) Swelling of the liver Confusion [nlm.nih.gov]

  The two diseases should not be confused. [cockatoo-info.com]

• Excitement

  Enter a word (“newspaper”), a word combination (“exciting trip”) or a phrase (“with all good wishes”) into the search box. [en.pons.com]

A detailed medical history is vital for the direction of diagnostic tests towards a possible C. psittaci infection. Should the symptoms resemble those of psittacosis, a physician has to inquire about possible contact to birds, such as canaries and parrots, or other mammals. In many occasions, pets or domesticated birds and animals that are infected with the bacterium can simultaneously transmit it to the whole family; therefore, a family history of symptoms similar to the patients' should also raise suspicion of a potential psittacosis case.

A thorough physical exam should also be conducted in order to establish the existence of typical findings: fever, pharyngeal erythema, diffuse rales, hepatomegaly, splenomegaly and potentially, tachycardia [1], are all compatible with a respiratory psittacosis. More specifically, an erythema of the sclera is usually the one and only finding in cases of psittacosis strictly confined to the eye [11].

Blood tests are also useful in detecting markers of mild inflammation and serological markers. The white blood cell count will most likely be found normal or augmented with a left shift and sometimes eosinophilia is present. Liver enzymes are normal or slightly elevated. As far as serology is concerned, microimmunofluorescence (MIF) antibody is used to detect a C. psittaci infection. Cultured pleural fluid, sputum or blood may also produce a positive result, but the procedure should not be attempted by professionals without much clinical experience, since there is a significant danger of creating aerosolized particles and contaminating the laboratory grounds. Regarding imaging techniques, a chest x-ray may unveil the presence of cellular exudate in the pulmonary alveoli, a typical finding of pneumonia [1].

Sputum tested by means of a polymerase chain reaction (PCR) is a relatively new test for detecting a C. psittaci infection. Its use is currently limited and has primarily been applied to unveil the presence of C. psittaci in tissue harvested from animals [12].

• Pulmonary Infiltrate

  Each of the patients had pulmonary infiltrates, prominent headache, abdominal complaints, and serologic evidence for infection with Chlamydia psittaci. [ncbi.nlm.nih.gov]

• Complement Fixing Antibody

  In the subsequent investigation of this problem, human psittacosis was defined as a fourfold rise in complement-fixing antibody titer to > or = 32 or a single titer of > or = 32 in a patient with fever and/or respiratory symptoms. [ncbi.nlm.nih.gov]

First-line treatment of psittacosis includes tetracycline or doxycycline for 2-3 weeks to prevent the potential relapse [6]. In cases where the aforementioned treatment is not indicated, erythromycin may alternatively be administered. ICU or high-dependency treatment may be a necessity for patients with severe coexisting pathologies.

Patients with a C. psittaci infection greatly benefit from a therapeutic scheme including antibiotic agents. Symptoms usually subside within 24 hours, even though symptomatology can re-emerge in cases of persistent infection [1].

Patients with severe symptomatology are in risk of succumbing to potentially fatal complications, such as pulmonary and cardiac incidents [1], should proper IV drugs not be administered promptly. Antibiotic resistance has been reported by non-scientific data and concerns azithromycin [10].
Mortality can amount up to 20% in patients who do not receive any treatment [1].

Psittacosis is a result of an infection with chlamydia psittaci and is a disease known to the medical community for over a century [3]. People can contract the bacterium from direct contact with poultry, birds, mammals, or their secretions, excrement and tissue. Therefore, individuals whose profession involves close contact to potentially infected animals do run a higher risk of contracting C. psittaci [4]. Bacterial transmission from one person to another is a rare observation [5] [6].

Psittacosis' frequency has followed declining pattern, as far as the industrialized world is concerned, although it can be observed in any part of the world. Data indicates that from 1988 to 2003, the Center for Disease Control and Prevention (CDC) recorded 935 reports of psittacosis; the average incidence of the disease was 62 cases per year [7]. However, in the time period 2005 to 2009, only 66 additional cases reached the CDC, and so, averagely 16 human cases per year were recorded [8]. It is, however, believed, that in reality, the number of psittacosis-affected patients was larger and remained undiagnosed because the condition responds well to antibiotics administered empirically for cases of pneumonia.

Mortality rate used to amount to a staggering 15-20% in the past, due to lack of appropriate treatment. With the advent of antibiotics, the numbers have decreased to 1%. Psittacosis can affect people of all ages, ethnicities and genders. A slight increase of the number of people who contract C. psittaci in the industrialized world may be explained by the importation of exotic birds to these countries.

Psittacosis can affect all people irrespective of age, but is usually observed amongst people in their middle decades.

C. psittaci has a specific two-phased developmental cycle, featuring the contagious elementary body form (EB) and the reticulate body form (RB). While in the EB form, the bacterium latches on to the host cell and is endophagocytosed. It is then surrounded by an inclusion body, which assists the bacterium in its survival, as the lysosomes are unable to penetrate the structure. The EB then transforms into a replicating RB and produces the so-called intermediate bodies, where chromatin subsequently follows a condensation process, transforming into an EB. Cell lysis or exocytosis are the procedures responsible for EB's release from its host; the cell sustains no damage itself and the newly-produced EBs can further infect other cells in the vicinity, something which is expected to happen 36-48 hours after contagion [1]. 

C. psittaci can be cultured in various substrates, but protective measures and caution are advised, for fear of producing aerosolized particles. Aerosolized particles and contact with excrement, nasal secretions, or tissue are the ways a human can get infected. 7 known C. psittaci genotypes have been identified, all of which can be contracted by humans [9]. The length of its maturation cycle and its endurance are the factors that probably result in chronic infection, which cannot be eradicated with the usual antimicrobial medication. There are also bacterial types that are deemed more lethal. For a treatment scheme to be successful, a longer period of antibiotic administration is necessary; even in these cases, some patients may still have sustained difficult-to-eradicate infection.

One of the first measures one can take to prevent psittacosis is making sure that pet birds will not contract it themselves. Measures include: cleaning birdcages daily, taking good care of pet birds to prevent an infection, proper food and enough space, so they are not always close to one another in the cage. If there are more cages with birds, keeping the cages at a distance will prevent excrement and other biological substances from being transferred from one cage to another.

Any new bird expected to join the cage should be kept at separate surroundings and monitored for at least 30 days, before it can be placed together with other birds.

Psittacosis is an infectious disease caused by Chlamydia psittaci, an obligate, intracellular, gram-negative bacterium [1]. The primary hosts of C. psittaci are birds and mammals, with humans being only accidental hosts [1]. Humans can get infected irrespective of age; contracting the bacterium results in conjunctivitis and community-acquired pneumonia [1] [2]. Psittacosis also goes by the names parrot fever and ornithosis, and is sometimes reserved for the disease when it is carried by birds of the Psittacidae family; ornithosis is used when other birds are the disease carriers.

Psittacosis is a contagious disease caused by Chlamydophila psittaci. It is a type of organism (bacterium), which infects birds and mammals and can infect humans who come into contact with their excrement and secretions. People who run a higher risk for contracting C. psittaci are those who have direct contact to animals: veterinarians, bird owners, pet shop employees. The birds that are most frequently infected are parrots, parakeets, and budgerigars, although other birds and animals can also be affected by the disease and transmit it to humans. Typical symptoms include fever, chills, head and muscle aches, blood in one's sputum and malaise.

In order to diagnose the disease, a physician will carry out a detailed physical examination and will also ask for a detailed medical history. Other laboratory tests on sputum and blood, a chest CT scan or x-ray can also contribute to the successful diagnosis of a psittacosis infection. Patients are treated with antibiotics upon the diagnosis and are expected to have a full recovery, if they have no other diseases.

In order to prevent the disease, avoid exposure to birds that you suspect to be ill, such as imported parrots or unknown birds. Take good care of other conditions you might be affected by, so that your immune system is as strong as possible against all types of infection.

1. Schlossberg D. Chlamydophila (chlamydia) psittaci (psittacosis). In: Mandell GL, Bennett JE, Dolin R, eds. Principles and practice of infectious diseases, 6th ed. Philadelphia, PA: Churchill Livingston; 2005:2256-2258.
2. Dean D, Kandel RP, Adhikari HK, et al. Multiple Chlamydiaceae species in trachoma: implications for disease pathogenesis and control. PLoS Med. 2008;5:e14.
3. Harris RL, Williams TW Jr. "Contribution to the question of pneumotyphus": a discussion of the original article by J. Ritter in 1880. Rev Infect Dis. 1985;7:119-122.
4. Gaede W, Reckling KF, Dresenkamp B, et al. Chlamydia psittaci infections in humans during an outbreak of psittacosis from poultry in Germany. Zoonoses Public Health. 2008;55:184-188.
5. Harkinezhad T, Geens T, Vanrompay D. Chlamydia psittaci infections in birds: a review with emphasis on zoonotic consequences. Vet Microbiol. 2009;135:68-77.
6. Ito I, Ishida T, Mishima M, et al. Familial cases of psittacosis: possible person-to-person transmission. Intern Med. 2002;41:580-583.
7. Smith KA, Bradley KK, Stobierski MG, et al. Compendium of measures to control Chlamydophila psittaci (formerly Chlamydia psittaci) infection among humans (psittacosis) and pet birds, 2005. J Am Vet Med Assoc. 2005 Feb 15. 226(4):532-9.
8. Smith KA, Campbell CT, Murphy J, et al. Compendium of measures to control Chlamydophila psittaci infection among humans (psittacosis) and pet birds (avian chlamydiosis), 2010. J Exotic Pet Med. 2011 Jan. 20 (1):32-45.
9. Vanrompay D, Harkinezhad T, van de Walle M, et al. Chlamydia psittaci transmission from pet birds to humans. Emerg Infect Dis. 2007;13:1108-1110.
10. Binet R, Maurelli AT. Frequency of development and associated physiological cost of azithromycin resistance in Chlamydia psittaci 6BC and C. trachomatis L2. Antimicrob Agents Chemother. 2007;51:4267-4275.
11. Dean D. Pathogenesis of chlamydial ocular infections. In: Tasman W, Jaeger EA, eds. Duane's foundations of clinical ophthalmology. Philadelphia, PA. Lippincott Williams & Wilkins, 2010.
12. Sprague LD, Schubert E, Hotzel H, et al. The detection of Chlamydophila psittaci genotype C infection in dogs. Vet J. 2009;181:274-279.