Psittacosis

Biologically hazardous agents at work and efforts to protect workers' health: a review of recent reports

Because information on biological agents in the workplace is lacking, biological hazard analyses at the workplace to securely recognize the harmful factors with biological basis are desperately needed. This review concentrates on literatures published after 2010 that attempted to detect biological hazards to humans, especially workers, and the efforts to protect them against these factors. It is important to improve the current understanding of the health hazards caused by biological factors at the workplace. In addition, this review briefly describes these factors and provides some examples of their adverse health effects. It also reviews risk assessments, protection with personal protective equipment, prevention with training of workers, regulations, as well as vaccinations.

Detecção e classificação molecular de Chlamydophila psittaci em amostras fecais de aves assintomáticas

Chlamydophila psittaci é uma bactéria que causa doença respiratória ou sistêmica em aves e em seres humanos. Em vista do risco de transmissão para humanos, o objetivo deste estudo foi detectar a presença de Chlamydophila spp. em amostras de fezes ou suabes cloacais de aves assintomáticas. Foram colhidas 403 amostras fecais ou suabes cloacais, provenientes de aves domésticas, selvagens ou exóticas. As amostras foram submetidas à PCR em tempo real para C. psittaci, para amplificação de fragmento parcial do gene da subunidade 16S do rRNA, utilizando o SsoFastTM EvaGreen® Supermix (Bio-Rad) e análise da curva de dissociação. Para determinação do genótipo de C. psittaci, foi usada a hemi-nested PCR visando à amplificação de fragmento parcial do gene OMP-A, realizada nas amostras positivas pela PCR em tempo real, seguida de sequenciamento dos fragmentos amplificados. A PCR em tempo real revelou positividade em 17 (4,21%) amostras. A hemi-nested foi positiva em 2 amostras positivas pela PCR em tempo real. O genótipo A de C. psittaci foi identificado pelo sequenciamento de uma amostra amplificada pela hemi-nested PCR. Os resultados deste experimento demonstram que a PCR em tempo real, visando à amplificação de fragmento parcial da subunidade 16S do rRNA, seguida da análise da curva de dissociação, pode ser utilizada para detecção de DNA de Chlamydophila sp. em amostras fecais de aves assintomáticas. A classificação da espécie de Chlamydophila e do genótipo de C. psittaci deve ser realizada por meio de PCR tendo como alvo o gene ompA e sequenciamento dos fragmentos amplificados.

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.

Bakterielle Infektionen: Atypische Bakterien

Chlamydophila (früher Chlamydia) pneumoniae ist im Kindesalter ein seltener Erreger respiratorischer Infektionen, vor allem der Pneumonie, wenn die PCR als direkte Nachweismethode herangezogen wird. Die höhere Nachweisrate von Antikörpern gegen C. pneumoniae deutet auf eine hohe Rate asymptomatischer oder unspezifischer Infektionen durch C. pneumoniae hin.

Der Mensch ist weltweit das einzige Erregerreservoir. Kranke, seltener auch asymptomatische Ausscheider (Wochen bis 1 Jahr) sind die Ansteckungsquelle. Die Übertragung erfolgt als „Tröpfcheninfektion“ mit respiratorischen Sekreten. Eine epidemische Krankheitshäufung ist beschrieben. In feuchtem Milieu können Chlamydien bis zu 30 h auf unbelebtem Material überleben.

Im Erwachsenenalter haben 50–75 % der Bevölkerung Antikörper gegen C. pneumoniae. Die höchsten Titer werden in der Altersklasse der 5- bis 14-Jährigen gefunden – ein Indiz für das Hauptmanifestationsalter der Primärinfektion. Seroprävalenzdaten aus Deutschland decken sich mit den Angaben aus der internationalen Literatur (5 % der unter 10-Jährigen, 64 % der unter 18-Jährigen besitzen Antikörper gegen C. pneumoniae). Ambulant erworbene Pneumonien werden im Kindesalter möglicherweise in bis zu 18 % der Fälle (serologische Diagnose) durch C. pneumoniae verursacht. Untersuchungen mittels PCR hingegen weisen C. pneumoniae nur in sporadischen Fällen nach. Koinfektionen mit Mykoplasmen, aber auch Pneumokokken und Adenoviren sind keine Seltenheit.

The value of signs and symptoms in differentiating between bacterial, viral and mixed aetiology in patients with community-acquired pneumonia

Current diagnostics for community-acquired pneumonia (CAP) include testing for a wide range of pathogens, which is costly and not always informative. We compared clinical and laboratory parameters of patients with CAP caused by different groups of pathogens to evaluate the potential for targeted diagnostics and directed treatment. In a prospective study, conducted between April 2008 and April 2009, adult patients with CAP were tested for the presence of a broad range of possible respiratory pathogens using bacterial cultures, PCR, urinary antigen testing and serology. Of 408 patients with CAP, pathogens were detected in 263 patients (64.5%). Streptococcus pneumoniae and influenza A virus were the most frequently identified bacterial and viral pathogens, respectively. Age had a significant effect on the prediction of aetiology (P = 0.054), with an increase in the relative contribution of viruses with advancing age. Multivariate analyses further showed that the presence of cough increased the likelihood of detecting a viral pathogen [odds ratio (OR) 5.536, 95% confidence interval (CI) 2.130-14.390], the presence of immunodeficiency decreased the likelihood of detecting a bacterial pathogen (OR 0.595, 95 % CI 0.246-1.437) and an increase in pneumonia severity index score increased the likelihood of detecting a pathogen in general. Although several variables were independently associated with the detection of a pathogen group, substantial overlap meant there were no reliable clinical predictors to distinguish aetiologies. Therefore, testing for common respiratory pathogens is still necessary to optimize treatment.

A path forward for the chlamydial virulence factor CPAF

CPAF is a conserved and secreted protease from obligate intracellular bacteria of the order Chlamydiales. Recently, it was demonstrated that most of its host targets are an artifact of inaccurate methods. This review aims to summarize key features of CPAF and propose new approaches for evaluating its role in chlamydial pathogenesis.

Family outbreak of psittacosis with an exhumation-based diagnosis: following in the footsteps of Dr. House

Diagnosis and treatment of the uncommon zoonotic infection psittacosis may be delayed or missed if a history of bird exposure is not obtained. Pulmonary infiltrates that persist or are refractory to usual therapy can be a clue to this diagnosis. An outbreak or cluster of cases may occur if there is a common source of the bacterium. If possible, examination of household members, both human and avian, might be helpful in making this diagnosis.

Chlamydophila psittaci eradication with doxycycline as first-line targeted therapy for ocular adnexae lymphoma: final results of an international phase II trial

PURPOSE

The pathogenic association between Chlamydophila psittaci (Cp) and ocular adnexal marginal zone lymphoma (OAMZL) and the efficacy of doxycycline monotherapy have been investigated in retrospective series with variations in stage, management, and follow-up duration. To our knowledge, this is the first international phase II trial aimed at clarifying Cp prevalence and activity of first-line doxycycline in a homogeneous series of consecutive patients with newly diagnosed stage I OAMZL.

PATIENTS AND METHODS

Forty-seven patients were registered. Tumor tissue, conjunctival swabs, and peripheral blood from 44 patients were assessed for seven Chlamydiaceae infections by three polymerase chain reaction protocols. Thirty-four patients with measurable or parametrable disease were treated with doxycycline and assessed for chlamydial eradication and lymphoma response (primary end point).

RESULTS

Cp DNA was detected in biopsies of 39 patients (89%); no other Chlamydiaceae were detected. Twenty-nine patients had Cp DNA in baseline swabs and/or blood samples and were evaluable for chlamydial eradication, which was achieved in 14 patients (48%). Lymphoma regression was complete in six patients and partial in 16 (overall response rate, 65%; 95% CI, 49% to 81%); 11 had stable disease, and one had progressive disease. At a median follow-up of 37 months (range, 15 to 62 months), 20 patients remained relapse free (5-year progression-free survival [PFS] ± standard deviation, 55% ± 9%). Cp eradication was associated with improved response rate (86% v 47%; P = .02) and 5-year PFS (68% v 47%; P = .11).

CONCLUSION

Upfront doxycycline is a rational and active treatment for patients with stage I Cp-positive OAMZL. Lymphoma regression is consequent to Cp eradication, which can easily be monitored on conjunctival and blood samples. Prospective trials aimed at identifying more effective administration schedules for doxycycline are warranted.

Zoonotic diseases of common pet birds: psittacine, passerine, and columbiform species

Zoonotic transmission of disease from pet birds is uncommon, but there are some recognized dangers. Most notably, Chlamydophila psittaci can be transmitted from pet birds to humans. Allergic responses to pet birds, including pneumonitis and contact dermatitis, have also been documented. Bite wounds from pet birds are rarely reported but can cause trauma and develop infection. The other diseases discussed here are considered potential zoonotic diseases of pet birds because of either isolated reports of suspected but unconfirmed transmission to humans or from reports of wild conspecifics being reported to have the disease.

Risk assessment and management of Chlamydia psittaci in poultry processing plants

Chlamydia psittaci causes respiratory disease in poultry and can be transmitted to humans. Historical outbreaks of psittacosis in poultry workers indicated the need for higher awareness and an efficient risk assessment and management. This group reviewed relevant previous research, practical guidelines, and European directives. Subsequently, basic suggestions were made on how to assess and manage the risk of psittacosis in poultry processing plants based on a classical four-step approach. Collective and personal protective measures as well as the role of occupational medicine are described. Despite the finding that exposure is found in every branch, abattoir workstations seem to be associated with the highest prevalence of psittacosis. Complete eradication is difficult to achieve. Ventilation, cleaning, hand hygiene, and personal protective equipment are the most important protective measures to limit and control exposure to C. psittaci. Adequate information, communication, and health surveillance belong to the responsibilities of the occupational physician. Future challenges lay in the rigorous reporting of infections in both poultry and poultry workers and in the development of an avian and human vaccine.

Doxycycline vs. macrolides in combination therapy for treatment of community-acquired pneumonia

We assessed the comparative efficacy of empirical therapy with beta-lactam plus macrolide vs. beta-lactam plus doxycycline for the treatment of community-acquired pneumonia (CAP) among patients in the Australian Community-Acquired Pneumonia Study. Both regimens demonstrated similar outcomes against CAP due to either 'atypical' (Chlamydophila, Legionella or Mycoplasma spp.) or typical bacterial pathogens.