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Preventive Veterinary Medicine Jul 2021Chamydia species are bacterial pathogens that can infect a wide range of animal hosts including humans. In birds, Chlamydia psittaci is a leading cause of chlamydial... (Meta-Analysis)
Meta-Analysis
Chamydia species are bacterial pathogens that can infect a wide range of animal hosts including humans. In birds, Chlamydia psittaci is a leading cause of chlamydial infections (avian chlamydiosis) and is a zoonotic pathogen causing human psittacosis. The objectives of this study were to estimate the global prevalence of chlamydial infections in birds, to assess heterogeneity of the prevalence for some particular characteristics (continents, bird orders, specimen types, and diagnostic techniques), and to determine the trend of the prevalence over time. The relevant citations on the prevalence of chlamydial infections in birds were retrieved from PubMed, Scopus, and Web of Science. Titles and abstracts of the retrieved citations were screened for possible eligibility. Then, full-texts of eligible articles were assessed for data extraction. A random effects model was used for estimating the global prevalence of chlamydial infections in birds and for all other meta-analyses. Subgroup meta-analysis was used to assess heterogeneity of the prevalence for the characteristics mentioned above. Meta-regression analysis and cumulative meta-analysis were used to determine the trend of the prevalence over time. The quality of each included study was also evaluated. Of 579 citations, 74 studies (a total of 39,225 bird samples from 26 countries, five continents) were included in meta-analysis. Almost all included studies reported birds with C. psittaci infections. The global prevalence of chlamydial infections in birds was 19.5 % (95 % CI, 16.3 %-23.1 %). No significant differences of the prevalence were observed among continents, the prevalence ranged from 16.5 % (95 % CI, 9.8 %-26.5 %) in South America to 21.7 % (95 % CI, 12.1 %-35.9 %) in North America. No significant differences of the prevalence were observed among bird orders, the prevalence ranged from 13.4 % (95 % CI, 7.0 %-23.9 %) in Passeriformes to 32.0 % (95 % CI, 20.6 %-46.1 %) in Galliformes. No significant differences of the prevalence were observed between specimen types; the prevalence was 18.4 % (95 % CI, 15.2 %-22.2 %) for live specimens and 26.3 % (95 % CI, 17.1 %-38.1 %) for carcass specimens. The prevalence was significantly higher in non-PCR techniques (29.5 %, [95 % CI, 22.4 %-37.8 %]) than in PCR techniques (15.3 %, [95 % CI, 12.1 %-19.1 %]). The cumulative evidence showed that the prevalence of chlamydial infections in birds has been relatively stable around 20 % since 2012. This study indicates that the global prevalence of chlamydial infections in birds is quite high and all bird orders are potential sources for human psittacosis.
Topics: Animals; Bird Diseases; Birds; Chlamydophila psittaci; Prevalence; Psittacosis
PubMed: 33984601
DOI: 10.1016/j.prevetmed.2021.105370 -
BMC Infectious Diseases Mar 2020Human psittacosis, caused by Chlamydia (C.) psittaci, is likely underdiagnosed and underreported, since tests for C. psittaci are often not included in routine...
BACKGROUND
Human psittacosis, caused by Chlamydia (C.) psittaci, is likely underdiagnosed and underreported, since tests for C. psittaci are often not included in routine microbiological diagnostics. Source tracing traditionally focuses on psittacine pet birds, but recently other animal species have been gaining more attention as possible sources for human psittacosis. This review aims to provide an overview of all suspected animal sources of human psittacosis cases reported in the international literature. In addition, for each animal species the strength of evidence for zoonotic transmission was estimated.
METHODS
A systematic literature search was conducted using four databases (Pubmed, Embase, Scopus and Proquest). Articles were included when there was mention of at least one human case of psittacosis and a possible animal source. Investigators independently extracted data from the included articles and estimated strength of evidence for zoonotic transmission, based on a self-developed scoring system taking into account number of human cases, epidemiological evidence and laboratory test results in human, animals, and the environment.
RESULTS
Eighty articles were included, which provided information on 136 different situations of possible zoonotic transmission. The maximum score for zoonotic transmission was highest for turkeys, followed by ducks, owls, and the category 'other poultry'. Articles reporting about zoonotic transmission from unspecified birds, psittaciformes and columbiformes provided a relatively low strength of evidence. A genotypical match between human and animal samples was reported twenty-eight times, including transmission from chickens, turkeys, guinea fowl, peafowl, pigeons, ducks, geese, songbirds, parrot-like birds and owls.
CONCLUSIONS
Strong evidence exists for zoonotic transmission from turkeys, chickens and ducks, in addition to the more traditionally reported parrot-like animal sources. Based on our scoring system, the evidence was generally stronger for poultry than for parrot-like birds. Psittaciformes should not be disregarded as an important source of human psittacosis, still clinicians and public health officials should include poultry and birds species other than parrots in medical history and source tracing.
Topics: Animals; Chlamydophila psittaci; Columbidae; Genotype; Humans; Poultry; Poultry Diseases; Psittacosis; Public Health; Public Health Administration; Songbirds; Strigiformes; Zoonoses
PubMed: 32131753
DOI: 10.1186/s12879-020-4918-y -
BMC Infectious Diseases Aug 2018Psittacosis outbreak investigations require rapid identification of cases in order to trace possible sources and perform public health risk assessments. In recent... (Review)
Review
BACKGROUND
Psittacosis outbreak investigations require rapid identification of cases in order to trace possible sources and perform public health risk assessments. In recent outbreaks in the Netherlands, such investigations were hampered by the non-specificity of laboratory testing methods to identify human Chlamydia psittaci infections.
METHOD
A systematic search of PubMed and Scopus databases of literature published between 01 January, 1986 and 03 July, 2017 was done to find best practices of laboratory-testing methods used in psittacosis outbreaks of two or more human cases. Reference lists of included articles were hand searched to identify additional articles.
RESULTS
Thirty-seven eligible articles were identified, describing 44 human psittacosis outbreaks in 12 countries. Laboratory tests performed were PCR (with various targets), serologic tests (complement binding reactions, ELISA's, immunofluorescence tests and immuno-peroxidase tests) and culture, in various combinations. The literature provided no 'gold standard' laboratory testing strategy to identify recent human C. psittaci infections. In most psittacosis outbreaks, for a considerable number of cases (or tested individuals in an exposed cohort), C. psittaci infection could not be confirmed, nor excluded as causative pathogen. None of the testing strategies was found to be suitable for (nearly) full case finding.
CONCLUSION
PCR enables rapid identification of human psittacosis patients and helps source finding by genotyping but has the disadvantage that sensitivity is high only in the acute phase. In outbreak situations, there is often a time delay and therefore, there is a need for new serologic testing methods next to PCR, with good specificity and sensitivity. Moreover, serum is easier to collect than the preferred diagnostic materials for PCR. A serologic test that can reliably confirm infection status without the necessity of convalescent serum sampling would enhance case finding, source tracing, identification of risk factors and assessment of burden of disease in various settings.
Topics: Animals; Birds; Chlamydophila psittaci; Clinical Laboratory Techniques; DNA, Bacterial; Databases, Factual; Disease Outbreaks; Humans; Polymerase Chain Reaction; Psittacosis
PubMed: 30165831
DOI: 10.1186/s12879-018-3317-0 -
Epidemiology and Infection Nov 2017Psittacosis is a zoonotic infectious disease caused by the transmission of the bacterium Chlamydia psittaci from birds to humans. Infections in humans mainly present as... (Meta-Analysis)
Meta-Analysis Review
Psittacosis is a zoonotic infectious disease caused by the transmission of the bacterium Chlamydia psittaci from birds to humans. Infections in humans mainly present as community-acquired pneumonia (CAP). However, most cases of CAP are treated without diagnostic testing, and the importance of C. psittaci infection as a cause of CAP is therefore unclear. In this meta-analysis of published CAP-aetiological studies, we estimate the proportion of CAP caused by C. psittaci infection. The databases MEDLINE and Embase were systematically searched for relevant studies published from 1986 onwards. Only studies that consisted of 100 patients or more were included. In total, 57 studies were selected for the meta-analysis. C. psittaci was the causative pathogen in 1·03% (95% CI 0·79-1·30) of all CAP cases from the included studies combined, with a range between studies from 0 to 6·7%. For burden of disease estimates, it is a reasonable assumption that 1% of incident cases of CAP are caused by psittacosis.
Topics: Chlamydophila psittaci; Community-Acquired Infections; Humans; Pneumonia, Bacterial; Psittacosis
PubMed: 28946931
DOI: 10.1017/S0950268817002060 -
PloS One 2014Around 67 million pets are owned by households in the United Kingdom, and an increasing number of these are exotic animals. Approximately a third of pets are purchased... (Review)
Review
BACKGROUND
Around 67 million pets are owned by households in the United Kingdom, and an increasing number of these are exotic animals. Approximately a third of pets are purchased through retail outlets or direct from breeders. A wide range of infections can be associated with companion animals.
OBJECTIVES
This study uses a systematic literature review to describe the transmission of zoonotic disease in humans associated with a pet shop or other location selling pets (incidents of rabies tracebacks and zoonoses from pet food were excluded).
DATA SOURCES
PubMed and EMBASE.
RESULTS
Fifty seven separate case reports or incidents were described in the 82 papers that were identified by the systematic review. Summary information on each incident is included in this manuscript. The infections include bacterial, viral and fungal diseases and range in severity from mild to life threatening. Infections associated with birds and rodents were the most commonly reported. Over half of the reports describe incidents in the Americas, and three of these were outbreaks involving more than 50 cases. Many of the incidents identified relate to infections in pet shop employees.
LIMITATIONS
This review may have been subject to publication bias, where unusual and unexpected zoonotic infections may be over-represented in peer-reviewed publications. It was also restricted to English-language articles so that pathogens that are more common in non-Western countries, or in more exotic animals not common in Europe and the Americas, may have been under-represented.
CONCLUSIONS/IMPLICATIONS
A wide spectrum of zoonotic infections are acquired from pet shops. Salmonellosis and psittacosis were the most commonly documented diseases, however more unusual infections such as tularemia also appeared in the review. Given their potential to spread zoonotic infection, it is important that pet shops act to minimise the risk as far as possible.
Topics: Animals; Commerce; Humans; Pets; Risk Assessment; Zoonoses
PubMed: 24586679
DOI: 10.1371/journal.pone.0089309