Psittacosis
 | This article needs to beupdated.(July 2014) |
| Psittacosis | |
|---|---|
 | |
| Direct fluorescent antibodystain of a mouse brain impression smear showingC. psittaci | |
| Specialty | Infectious medicine Pulmonology |
Psittacosis—also known asparrot fever,andornithosis—is azoonoticinfectious diseasein humans caused by abacteriumcalledChlamydia psittaciand contracted from infectedparrots,such asmacaws,cockatiels,andbudgerigars,and frompigeons,sparrows,ducks,hens,gullsand many other species of birds. The incidence of infection in canaries and finches is believed to be lower than inpsittacinebirds.
In certain contexts, the word is used when the disease is carried by any species of birds belonging to the familyPsittacidae,whereasornithosisis used when other birds carry the disease.[1]
In humans
[edit]Signs and symptoms
[edit]In humans, after an incubation period of 5–19 days, the disease course ranges from asymptomatic to systemic illness with severepneumonia.It presents chiefly as an atypical pneumonia. In the first week of psittacosis, the symptoms mimictyphoid fever,causing highfevers,joint pain,diarrhea,conjunctivitis,nose bleeds,andlow level of white blood cells.[2]Rose spotscalledHorder's spotssometimes appear during this stage.[3][4]These are pink, blanching maculopapular eruptions resembling the rose spots oftyphoid fever.[5]Spleen enlargementis common towards the end of the first week, after which psittacosis may develop into a serious lung infection. Diagnosis is indicated where respiratory infection occurs simultaneously with splenomegaly and/or epistaxis.Headachecan be so severe that it suggestsmeningitisand somenuchal rigidityis not unusual. Towards the end of the first week, stupor or evencomacan result in severe cases.[citation needed]
The second week is more akin to acute bacteremicpneumococcalpneumonia with continuous high fevers, headaches, cough, anddyspnea.X-raysat that stage show patchy infiltrates or a diffuse whiteout of lung fields.[citation needed]
Complications in the form ofendocarditis,liver inflammation,inflammation of the heart's muscle,joint inflammation,keratoconjunctivitis(occasionallyextranodal marginal zone lymphomaof the lacrimal gland/orbit)[citation needed],and neurologic complications (brain inflammation) may occasionally occur. Severe pneumonia requiring intensive-care support may also occur. Fatal cases have been reported (less than 1% of cases).[citation needed]
Transmission route
[edit]TheChlamydia psittacibacterium that causes psittacosis can be transmitted by mouth-to-beak contact, or through the airborne inhalation of feather dust, dried faeces, or the respiratory secretions of infected birds.[6]Person-to-person transmission is possible, but rare.[6]
Diagnosis
[edit]Blood analysis usually shows a normal white cell count, but markedleukocytosisis occasionally apparent.Liverenzymes are abnormal in half of the patients, with mild elevation ofaspartate transaminase.The erythrocyte sedimentation rate and C-reactive protein can be markedly elevated. Differential diagnosis must be made with typhus, typhoid, and atypical pneumonia byMycoplasma,Legionella,orQ fever.Exposure history is paramount to diagnosis. Diagnosis involvesmicrobiological culturesfrom respiratory secretions of patients orserologicallywith a fourfold or greater increase inantibodytiters againstC. psittaciin blood samples combined with the probable course of the disease. Typical inclusions called "Leventhal-Cole-Lillie bodies"[7]can be seen within macrophages in BAL (bronchoalveolar lavage) fluid. Culture ofC. psittaciis hazardous and should only be carried out in biosafety laboratories.[citation needed]
Treatment
[edit]The infection is treated withantibiotics;tetracyclinesandchloramphenicolare the choice for treating patients.[8]Most people respond to oral therapydoxycycline,tetracyclinehydrochloride, or chloramphenicol palmitate. For initial treatment of severely ill patients, doxycycline hyclate may be administeredintravenously.Remission of symptoms is usually evident within 48–72 hours. However, relapse can occur, and treatment must continue for at least 10–14 days after fever subsides.[citation needed]
Epidemiology
[edit]Psittacosis was first reported in Europe in 1879.[9]
In 1929, a highly publicizedoutbreak of psittacosishit the United States. Although not the first report of psittacosis in the United States, it was the largest up to that time. It led to greater controls on the import of pet parrots.[9]The aftermath of the outbreak and how it was handled led to the establishment of theNational Institutes of Health.[10]
From 2002 through 2009, 66 human cases of psittacosis were reported to the Centers for Disease Control and Prevention,[citation needed]and most resulted from exposure to infected pet birds, usually cockatiels,parakeets,and macaws. Many more cases may occur that are not correctly diagnosed or reported. Bird owners, pet shop employees, zookeepers, and veterinarians are at risk of the infection. Some outbreaks of psittacosis in poultry-processing plants have been reported.
In birds
[edit]
In birds,Chlamydia psittaciinfection is referred to as avian chlamydiosis. Infected birds shed the bacteria through feces and nasal discharges, which can remain infectious for several months. Many strains remain quiescent in birds until activated under stress. Birds are excellent, highly mobile vectors for the distribution of chlamydial infection because they feed on, and have access to, the detritus of infected animals of all sorts.
Signs
[edit]C. psittaciin birds is often systemic and infections can be inapparent, severe, acute, or chronic with intermittent shedding. Signs in birds include "inflamed eyes, difficulty in breathing, watery droppings, and green urates."[11]
Diagnosis
[edit]Initial diagnosis may be by symptoms, but is usually confirmed by anantigenandantibodytest. Apolymerase chain reaction-based test is also available. Although any of these tests can confirm psittacosis, false negatives are possible, so a combination of clinical and laboratory tests is recommended before giving the bird a clean bill of health.[11]
Epidemiology
[edit]Infection is usually by the droppings of another infected bird, though it can also be transmitted by feathers and eggs,[12]and is typically either inhaled or ingested.[11]
C. psittacistrains in birds infect mucosal epithelial cells and macrophages of the respiratory tract. Septicaemia eventually develops and the bacteria become localized in epithelial cells and macrophages of most organs, conjunctiva, and gastrointestinal tract. It can also be passed in the eggs. Stress commonly triggers onset of severe symptoms, resulting in rapid deterioration and death.C. psittacistrains are similar in virulence, grow readily in cell culture, have 16S-rRNA genes that differ by <0.8%, and belong to eight knownserovars.All should be considered to be readily transmissible to humans.[citation needed]
C. psittaciserovar 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 the 1920s–1930s outbreak in humans, a specific reservoir for serovar E has not been identified. The M56 and WC serovars were isolated during outbreaks in mammals.
Treatment
[edit]Treatment is usually with antibiotics, such as doxycycline or tetracycline, and can be administered through drops in the water or injections.[12]Many strains ofC. psittaciare susceptible tobacteriophages.[citation needed]
Use as a biological weapon
[edit]Psittacosis was one of more than a dozen agents that the United States researched as potentialbiological weaponsbefore the nation suspended itsbiological weapons program.[13]
Notable casualties
[edit]In 1930, during the1929–1930 psittacosis pandemic,Lena Rose Pepperdine died of parrot fever. She was the first wife ofGeorge Pepperdine,the founder ofPepperdine University.[14]
References
[edit]- The initial content for this article was adapted from sources available athttps://www.cdc.gov.
- ^"ornithosis"atDorland's Medical Dictionary[dead link]
- ^Dugdale, David."Psittacosis".MediLine Plus.Retrieved9 September2012.
- ^"Horder's spots".GPnotebook.
- ^Dembek, Zygmunt F.; Mothershead, Jerry L.; Owens, Akeisha N.; Chekol, Tesema; Wu, Aiguo (September 15, 2023)."Psittacosis: An Underappreciated and Often Undiagnosed Disease".Pathogens.12(9): 1165.doi:10.3390/pathogens12091165.PMC10536718.PMID37764973.
- ^"Chlamydia Psittaci (Chlamydophila)".Infectious Disease Advisor.January 20, 2019.
- ^abAustralian Guidelines for the Prevention and Control of Infection in Healthcare(PDF).National Health and Medical Research Council.May 2019. p. 274.ISBN978-1-86496-028-0.Archived fromthe original(PDF)on 14 May 2020.Retrieved23 January2020.
- ^Saif, Y. M. (2003).Diseases of poultry.Ames, Iowa: Iowa State Press. p. 863.ISBN0-8138-0423-X.
- ^Gregory DW, Schaffner W (1997). "Psittacosis".Semin Respir Infect.12(1): 7–11.PMID9097370.
- ^abPotter ME, Kaufmann AK, Plikaytis BD (February 1983)."Psittacosis in the United States, 1979".MMWR Morb. Mortal. Wkly. Rep.32(1): 27SS–31SS.PMID6621602.
- ^"In 1929, Parrot Fever Gripped The Country".National Public Radio All Things Considered.May 31, 2009.
- ^abc"Winged Wisdom Pet Bird Magazine - Zoonotic (Bird-Human) Diseases: Psittacosis, Salmonellosis".Archived fromthe originalon 2007-11-01.Retrieved2007-12-29.
- ^ab"PSITTACOSIS DISEASE - Pet Birds, Pet Parrots, Exotic Birds".Archived fromthe originalon 2007-11-29.Retrieved2007-12-29.
- ^"Chemical and Biological Weapons: Possession and Programs Past and Present",James Martin Center for Nonproliferation Studies,Middlebury College,April 9, 2002, accessed November 14, 2008.
- ^Baird, W. David (2016).Quest for Distinction: Pepperdine University in the 20th Century.Malibu: Pepperdine University Press. pp. 9–10.ISBN978-0-9977004-0-4.
