Outbreak Of Psittacosis Research Articles

Investigation of an unusual cluster of illness among staff at a wildlife rescue centre

Abstract When two previously fit and well staff from a wildlife rescue centre were hospitalised in early September 2018 with severe pneumonia and meningitis symptoms, the Health Protection Team began an investigation. Possible diagnoses included influenza and legionella, although it was not flu season, and initial testing proved negative. There were reports of other staff illness over the preceding weeks. The centre had accepted a wide range species over the Summer, including high numbers of gulls and pigeons, and an outbreak of psittacosis was suspected; the patients responded rapidly to doxycycline. An incident management team was rapidly convened to investigate and determine control measures. A testing algorithm was developed: including for Influenza A&B, Urine legionella & pneumococcal antigen; reference laboratory serology testing and real-time PCR for Chlamydia.psittaci; and pan-corona viruses. Case finding was conducted by telephone interviews and a select-survey of all 55 staff gained 46 responses. A series of site visits examined working practices at the site. Avian and environmental sampling was undertaken. A total of 22 staff met the agreed case definition for psittacosis, five of whom were later confirmed. Clinical features ranged from mild to severe. The onset dates of illness ranged from July to September. There was no evidence of person-to-person transmission. Analysis did not show a clear correlation between PPE use and illness. Clinical, microbiological, environmental, veterinary, and epidemiological evidence indicated zoonotic transmission of psittacosis. Variable compliance with PPE, hygiene when handling birds, and disinfection had likely contributed via aerosolization of dust. This was likely exacerbated by very high bird stocks and unusually warm weather conditions. Comprehensive recommendations were made to reduce the chances of future outbreaks, which are generalisable to other countries. Key messages • This was one of the largest clusters of human psittacosis described in a workplace in England. • Biosecurity in animal rescue centres is crucial to limit the chance of psittacosis and other zoonoses.

Chlamydia psittaci should be a notifiable infectious disease everywhere

Previously in The Lancet Microbe, Zhenjie Zhang and colleagues1 described the outbreak of psittacosis in China that occurred at the end of 2020.1 Psittacosis, arising from infection with the Gram-negative, obligate intracellular bacterium Chlamydia psittaci, is a global and important zoonotic disease, with numerous laboratory-confirmed cases being reported in a growing number of countries, including China, the USA, and Australia.2–4 The clinical presentation of psittacosis frequently overlaps with that of life-threatening viral infections and so psittacosis is often overlooked in diagnostic algorithms and misdiagnosed in clinical practice.

Severe community-acquired pneumonia caused by Chlamydia psittaci genotype E/B strain circulating among geese in Lishui city, Zhejiang province, China

ABSTRACT Between November 2021 and January 2022, four patients of community-acquired pneumonia were admitted to the hospitals in Lishui city, Zhejiang province, China. Their main clinical manifestations were fever and dry cough as well as radiographic infiltrate, but the empiric antimicrobial therapy or traditional Chinese medicine was not effective for their illness. Clinical specimens from the patients as well as environmental and poultry specimens were collected for the determination of the causative pathogen. The ompA gene and seven housekeeping genes of Chlamydia psittaci were successfully amplified from all the patients, and the sequences of each gene were identical to one another, suggesting that they were infected by the same strain of C. psittaci. A novel strain of C. psittaci (LS strain) was isolated from the bronchoalveolar lavage fluid of patient 2 and its whole genome was obtained. Phylogenetic analyses based on the whole-genome sequences showed that the isolate is most closely related to the strain (WS/RT/E30) identified as genotype E/B. In addition, The ompA gene and four housekeeping genes of C. psittaci were also amplified from two of four faeces samples of geese at the home of patient 2, and the sequences from geese were 100% identical to those from the patients. Accordingly, these cases could be attributed to a circulating C. psittaci strain of genotype E/B in the local geese. Therefore, there is an urgent need to strengthen the regional surveillance on C. psittaci among poultry and humans for prevention and control of the outbreak of psittacosis in the city.

Metagenomic next-generation sequencing identified psittacosis among poultry processing workers in Shandong Province, China

Human infection with Chlamydia psittaci is rare but difficult to recognize. We report an outbreak of psittacosis among poultry processing workers in China. We applied metagenomic next-generation sequencing and identified Chlamydia psittaci reads from samples of all seven patients, four of which were subsequently confirmed by PCR. Epidemiological results suggested that the poultry processed in the factory was the possible source of human infection.

Metagenomic next-generation sequencing in the family outbreak of psittacosis: the first reported family outbreak of psittacosis in China under COVID-19

ABSTRACT Chlamydia psittaci infection in humans, also known as psittacosis, is usually believed to be an uncommon disease which mainly presents as community-acquired pneumonia (CAP). It is usually sporadic, but outbreaks of infection may occasionally occur. In outbreaks, diagnosis and investigations were usually hampered by the non-specificity of laboratory testing methods to identify C. psittaci. In this study, we use metagenomic next-generation sequencing (mNGS) in the diagnosis of a family outbreak of psittacosis under COVID-19. Three members of an extended family of 6 persons developed psittacosis with pneumonia and hepatic involvement with common symptoms of fever and weakness. Two newly purchased pet parrots, which had died successively, were probably the primary source of infection. Imagings show lung consolidations and infiltrates, which are difficult to be differentiated from CAP caused by other common pathogens. mNGS rapidly identified the infecting agent as C. psittaci within 48 h. The results of this work suggest that there are not characteristic clinical manifestations and imagings of psittacosis pneumonia which can differentiate from CAP caused by other pathogens. The use of mNGS can improve accuracy and reduce the delay in the diagnosis of psittacosis especially during the outbreak, which can shorten the course of the disease control. Family outbreak under COVID-19 may be related to the familial aggregation due to the epidemic. To our knowledge, this is the first reported family outbreak of psittacosis in China, and the first reported psittacosis outbreak identified by the method of mNGS in the world.

A Psittacosis Outbreak among English Office Workers with Little or No Contact with Birds, August 2015.

Introduction:On 14th August 2015 an office manager informed Public Health England of five employees known to have been diagnosed with pneumonia over the previous three weeks. We investigated to establish whether an outbreak occurred and to identify and control the source of infection.Methods:We undertook case finding for self-reported pneumonia cases at local businesses (July-August 2015). Clinical samples from a hospitalised case were tested for common respiratory pathogens, but returned negative results. Further testing confirmed Chlamydia psittaci infection in this case (serology and PCR). We subsequently undertook C. psittaci testing for all cases, redefining them as confirmed (C. psittaci PCR or high antibody titre via serology) or probable (inconclusive C. psittaci serology). Twenty-eight day exposure histories informed descriptive epidemiological analysis. We conducted an environmental investigation at the office to identify potential sources of exposure.Results:We identified six office workers with pneumonia; four met case definitions (three confirmed, one probable) with symptom onset between 29th July and 4th August 2015. Workplace was the only epidemiological link and only one case reported limited, indirect bird contact. Environmental investigations identified pigeons roosting near the office which were being fed by workers (none cases).Discussion:This was a probable outbreak of psittacosis with no direct bird-to-human contact reported. Cases recovered after receiving appropriate antibiotics. Feeding of pigeons was stopped. A deep clean of office ventilation systems was conducted and workers were advised to avoid bird contact. We hypothesised that indirect environmental exposure to infected pigeons was to the source of this outbreak. This work provides evidence that health professionals should consider psittacosis in the differential diagnosis of cases of severe or atypical respiratory illness even without overt bird contact.

An outbreak of psittacosis at a veterinary school demonstrating a novel source of infection

In November 2014, New South Wales Health was notified of a cluster of respiratory illness in a veterinary school. Active case finding identified another case at a local equine stud. All cases had exposure to the equine fetal membranes of Mare A. This tissue subsequently tested positive for Chlamydia psittaci using quantitative real-time polymerase chain reaction. We conducted a cohort study of the university and stud farm staff to determine risk factors for disease. Nine people were exposed to the fetal membranes of Mare A. Of these, five cases of psittacosis were identified. Two required hospital admission. Contact with birds was not associated with illness (RR=0.5, 95% CI=0.09–2.73). People who had direct contact with the abnormal fetal membranes were more likely to develop disease (RR=11.77, 95% CI=1.02–∞). The emergence of an association between horse exposure and C. psittaci infection has important implications for the prevention and control of psittacosis.Article summary line: Investigation of an outbreak of psittacosis in a rural veterinary school demonstrates novel source of infection for psittacosis through exposure to abnormal equine fetal membranes.

Outbreak of psittacosis in a group of women exposed to Chlamydia psittaci-infected chickens

Eight cases of psittacosis due to Chlamydia psittaci were identified in May 2013 among 15 individuals involved in chicken gutting activities on a mixed poultry farm in France. All cases were women between 42 and 67 years-old. Cases were diagnosed by serology and PCR of respiratory samples. Appropriate treatment was immediately administered to the eight hospitalised individuals after exposure to birds had been discovered. In the chicken flocks, mainly C. gallinacea was detected, a new member of the family Chlamydiaceae, whereas the ducks were found to harbour predominantly C. psittaci, the classical agent of psittacosis. In addition, C. psittaci was found in the same flock as the chickens that the patients had slaughtered. Both human and C. psittaci-positive avian samples carried the same ompA genotype E/B of C. psittaci, which is widespread among French duck flocks. Repeated grassland rotations between duck and chicken flocks on the farm may explain the presence of C. psittaci in the chickens. Inspection by the veterinary service led to temporary closure of the farm. All birds had to be euthanised on site as no slaughterhouses accepted processing them. Farm buildings and grasslands were cleaned and/or disinfected before the introduction of new poultry birds.

A Novel Psittacine Adenovirus Identified During an Outbreak of Avian Chlamydiosis and Human Psittacosis: Zoonosis Associated with Virus-Bacterium Coinfection in Birds

Chlamydophila psittaci is found worldwide, but is particularly common among psittacine birds in tropical and subtropical regions. While investigating a human psittacosis outbreak that was associated with avian chlamydiosis in Hong Kong, we identified a novel adenovirus in epidemiologically linked Mealy Parrots, which was not present in healthy birds unrelated to the outbreak or in other animals. The novel adenovirus (tentatively named Psittacine adenovirus HKU1) was most closely related to Duck adenovirus A in the Atadenovirus genus. Sequencing showed that the Psittacine adenovirus HKU1 genome consists of 31,735 nucleotides. Comparative genome analysis showed that the Psittacine adenovirus HKU1 genome contains 23 open reading frames (ORFs) with sequence similarity to known adenoviral genes, and six additional ORFs at the 3′ end of the genome. Similar to Duck adenovirus A, the novel adenovirus lacks LH1, LH2 and LH3, which distinguishes it from other viruses in the Atadenovirus genus. Notably, fiber-2 protein, which is present in Aviadenovirus but not Atadenovirus, is also present in Psittacine adenovirus HKU1. Psittacine adenovirus HKU1 had pairwise amino acid sequence identities of 50.3–54.0% for the DNA polymerase, 64.6–70.7% for the penton protein, and 66.1–74.0% for the hexon protein with other Atadenovirus. The C. psittaci bacterial load was positively correlated with adenovirus viral load in the lung. Immunostaining for fiber protein expression was positive in lung and liver tissue cells of affected parrots, confirming active viral replication. No other viruses were found. This is the first documentation of an adenovirus-C. psittaci co-infection in an avian species that was associated with a human outbreak of psittacosis. Viral-bacterial co-infection often increases disease severity in both humans and animals. The role of viral-bacterial co-infection in animal-to-human transmission of infectious agents has not received sufficient attention and should be emphasized in the investigation of disease outbreaks in human and animals.

Clinical features of endemic community-acquired psittacosis.

Following a large outbreak of community-acquired psittacosis in 2002 in residents of the Blue Mountains, New South Wales, Australia, we reviewed new cases in this area over a 7-year period from 2003 to 2009. Using the 2010 criteria from the Centers for Disease Control National Notifiable Diseases Surveillance System, 85 patients with possible psittacosis were identified, of which 48 were identified as definite or probable infection. Clinical features of these cases are summarized. In addition to Chlamydia-specific serology, specimens, where available, underwent nucleic acid testing for chlamydial DNA using real-time PCR. Chlamydophila psittaci DNA was detected in samples from 23 patients. Four of 18 specimens were culture positive. This is the first description of endemic psittacosis, and is characterized in this location by community-acquired psittacosis resulting from inadvertent exposure to birds. The disease is likely to be under-diagnosed, and may often be mistaken for gastroenteritis or meningitis given the frequency of non-respiratory symptoms, particularly without a history of contact with birds. Clinical characteristics of endemic and outbreak-associated cases were similar. The nature of exposure, risk factors and reasons for the occurrence of outbreaks of psittacosis require further investigation.

1737Managing a Cluster Outbreak of Psittacosis

1737Managing a Cluster Outbreak of Psittacosis

Chlamydophila psittaci Infections in Humans during an Outbreak of Psittacosis from Poultry in Germany

In 2005, an outbreak of severe respiratory disease in a mixed poultry flock that was infected with Chlamydophila (C.) psittaci led to dissemination of the infection to at least 100 small poultry farms in 11 districts of Central Germany. At the same time, a total of 24 persons in contact with poultry from one of the flocks reported flu-like symptoms to their physician, thus suggesting zoonotic transmission. Within 3 weeks, seven individuals had to be hospitalized, with three of them requiring intensive care. Analysis of ompA sequences from chlamydial isolates and directly from clinical samples revealed the presence of both genotype A and E/B of C. psittaci at the source of the outbreak and in contact flocks. Genotype A was also detected in the three severely ill patients. The findings of the present study demonstrate the high zoonotic potential of avian chlamydiae. To ensure speedy eradication of psittacosis in poultry flocks and effective treatment of infected humans, fast, sensitive and species-specific detection of the causative agent is essential, as well as close collaboration between regional public health services, attending physicians and the diagnostic laboratories involved.

An outbreak of psittacosis in a bird park in Japan

An outbreak of psittacosis related to a bird park occurred in Matsue City, Shimane Prefecture, Japan, during winter 2001. Seventeen cases of psittacosis (12 visitors, three staff, and two student interns) were confirmed. A cohort study was conducted among the park staff and students to determine the risk factors for the development of acute serologically confirmed psittacosis (SCP) infection. Being 'bird staff' had an increased risk of SCP infection (RR 3.96, 95% CI 1.48-10.58). Entering the staff building, where ill birds were maintained without proper isolation, was also associated with an increased risk of SCP infection (RR 3.61, 95% CI 1.03-12.6). Isolation of ill birds and quarantine measures were found to be insufficient. Dehumidifiers and a high-pressure water spray under a closed ventilation environment may have raised the concentration of Chlamydophila psittaci in the hothouses. Bird park staff and visitors should be educated about psittacosis.

An outbreak of psittacosis due to Chlamydophila psittaci genotype A in a veterinary teaching hospital

An outbreak of psittacosis in a veterinary teaching hospital was recognized in December 2004. Outbreak management was instituted to evaluate the extent of the outbreak and to determine the avian source. Real-time PCR, serologic testing and sequencing of the ompA gene of Chlamydophila psittaci were performed. Sputum samples from patients, throat-swab samples from exposed students and staff, and faecal specimens from parrots and pigeons were tested. In this outbreak, 34 % (10/29) of the tested individuals were infected. The clinical features of the infection ranged from none to sepsis with multi-organ failure requiring intensive-care-unit admission. C. psittaci genotype A was identified as the outbreak strain. Parrots, recently exposed to a group of cockatiels coming from outside the teaching facility, which were used in a practical class, appeared to be the source of the outbreak. One of the tested pigeons harboured an unrelated C. psittaci genotype B strain. The microbiological diagnosis by real-time PCR on clinical specimens allowed for rapid outbreak management; subsequent genotyping of the isolates identified the avian source. Recommendations are made to reduce the incidence and extent of future outbreaks.

Probable Psittacosis Outbreak Linked to Wild Birds

In autumn 2002, an outbreak of probable psittacosis occurred among residents of the Blue Mountains district, Australia. We conducted a case-control study to determine independent risk factors for psittacosis by comparing exposures between hospitalized patients and other residents selected randomly from the telephone directory. Of the 59 case-patients with laboratory results supportive of psittacosis, 48 participated in a case-control study with 310 controls. Independent risk factors were residence in the upper Blue Mountains (odds ratio [OR] 15.2, 95% confidence interval [CI] 5.6-41.7), age of 50-64 years (OR 3.9, 95% CI 1.5-10.5), direct contact with wild birds (OR 7.4, 95% CI 2.5-22), and mowing lawns without a grass catcher (OR 3.2, 95% CI 1.3-8.0). Protective equipment is recommended for residents in areas frequented by free-ranging birds if contact with birds and their droppings is likely when performing outdoor activities such as lawn mowing.

Community outbreak of psittacosis in a rural Australian town

Health authorities in Victoria, Australia were notified of three men from a rural town with atypical pneumonia, admitted to hospital over 8 days. Initial serological testing suggested Chlamydia psittaci as the cause. We did a case-control study to find risk factors for psittacosis. We searched for cases of pneumonia or severe flu-like illness through family physicians and the regional hospital. We selected three controls per case from the region's electoral roll. We collected blood for serological tests and administered questionnaires to all cases and controls. We found 16 cases of psittacosis and one died. Most cases were clustered within a small geographical area, with a median age of 58 years (range 23-76), 15 (94%) of whom were male. Keeping, handling, or feeding domestic or wild birds was not associated with illness. Cases spent a median of 17.5 h per week in their garden, compared with a median of 5.2 h for controls (p=0.04) and were more likely to have mowed lawns during the 3 weeks before onset of illness than controls (odds ratio 4.81 [95% CI 1.08-33.37]). We showed that psittacosis outbreaks are not limited to direct contact with birds and pose new challenges for disease control. Modifications may be needed to work outdoors to decrease the risk of psittacosis.

Domiciliary outbreak of psittacosis in dogs: potential for zoonotic infection.

Domiciliary outbreak of psittacosis in dogs: potential for zoonotic infection.

An Epidemic of Avian and Human Psittacosis

Psittacosis may occur in epidemic or sporadic form. We report an outbreak of avian and human psittacosis associated with an aviary in Philadelphia, Pa. The epidemic spread among birds in the aviary and then to men and women who were in contact with the birds. Chlamydia psittaci was cultured from infected birds, and the human patients were evaluated clinically and serologically. After proper treatment of the birds, cleaning of their cages, and institution of appropriate bird-handling techniques, the outbreak among the birds resolved. The human patients were treated, and no subsequent cases have been seen.

An outbreak of psittacosis

An outbreak of chlamydia infection affecting seven people from a small town in Grampian is described. The origin of the outbreak seemed to be a local pet shop. The difficulties of diagnosis and tracing the connections with the pet shop are discussed. The clinical histories of the seven patients are described including those of the two who died.

An outbreak of psittacosis in Minnesota turkey industry workers: implications for modes of transmission and control.

From June through November 1986, an outbreak of psittacosis occurred in turkey industry workers in central Minnesota. A total of 186 suspect cases were identified, and 122 cases (66%) were serologically confirmed. Cases occurred in three turkey processing plants, two rendering plants, one farm, and one "further processing" plant (where meat is removed from previously eviscerated carcasses and consumer products, such as roasts, are made). As in previous outbreaks, workers exposed to the viscera of infected birds were at greatest risk of becoming infected. However, our data showed that 31 (25%) of the confirmed cases occurred in workers at the further processing plant who had contact only with previously eviscerated carcasses. Although the specific source of infection and the mode of transmission in these workers are unclear, the use of gloves and masks by all processing workers during an outbreak might help to limit exposure. Control measures, which focused on identifying and treating ill turkey flocks, were initiated in early September; however, cases continued to occur in turkey industry workers through November. One of the flocks suspected of causing illness appeared healthy and, therefore, was not treated. Chlamydia psittaci infection in this flock was confirmed by culture after the flock had been processed. A rapid test for diagnosing C. psittaci infection in turkey flocks at the time of processing might be useful in preventing exposure of large numbers of workers.