Is sarcoidosis a rickettsiosis? An archival study

Bilateral retinal vasculitis due to presumed sarcoidosis with rickettsial retinitis

OBJECTIVE

To describe a case of bilateral retinal vasculitis due to presumed sarcoidosis and rickettsial retinitis complicated with neovascularization with tear biomarker analysis.

METHODS

A retrospective case report.

RESULTS

A 16-year-old male presented with bilateral retinal vasculitis and retinitis in both eyes with inferotemporal quadrant neovascularization in the right eye. Multimodal imaging revealed the presence of active inflammation in both eyes. Weil Felix test was positive with raised ACE levels. This patient was treated with local and systemic steroids, doxycycline, and laser photocoagulation followed by oral methotrexate therapy which resulted in clinical resolution with recovery of visual acuity. Tear biomarker analysis showed raised sICAM-1 and MMP-9 levels in both eyes which significantly reduced following treatment.

CONCLUSION

Ocular sarcoidosis with rickettsial infection is a rare association. Tear biomarkers correlated well with clinical and imaging manifestations. High index of suspicion and aggressive anti-inflammatory therapy can help control inflammation and restore good vision.

Regional, seasonal, biennial and landscape-associated distribution of Anaplasma phagocytophilum and Rickettsia spp. infections in Ixodes ticks in northern Germany and implications for risk assessment at larger spatial scales

Tick-associated Rickettsiales are important pathogens with relevance for public and animal health; therefore, knowledge regarding their distribution is essential for risk assessment and disease prevention. To investigate the prevalence of Anaplasma phagocytophilum and Rickettsia spp. in northern Germany, Ixodes ticks were flagged monthly from April to October in 2018 and 2019 at three collection sites each in the regions of Bremen, Emsland, Hanover, Kassel and Uelzen. A total of 3150 ticks (1052 females, 1048 males and 1050 nymphs) were individually examined for rickettsial infections using probe-based quantitative real-time PCR. Overall prevalence of A. phagocytophilum was 6.4 % (202/3150; 6.7 % [71/1052] in females, 7.5 % [79/1048] in males and 5.0 % [52/1050] in nymphs). For Rickettsia spp., the overall prevalence was 29.6 % (931/3150; 33.4 % [351/1052] in females, 28.3 % [297/1048] in males and 27.0 % [283/1050] in nymphs). Rickettsia species identification by real-time pyrosequencing on a subset of 409 positive samples was successful in 407 cases (99.5 %). Rickettsia helvetica was the predominant species with a detection rate of 99.8 % (406/407). Additionally, Rickettsia monacensis was detected in one tick (0.2 %). Generalized linear mixed models showed significant regional as well as monthly differences regarding the prevalence of both pathogens. In addition, the prevalence of both pathogens was significantly higher in 2018 (A. phagocytophilum: 8.0 % [126/1575], Rickettsia spp.: 35.4 % [558/1575]) than in 2019 (A. phagocytophilum: 4.8 % [76/1575], Rickettsia spp.: 23.9 % [373/1575]). In contrast, no effect of landscape type on pathogen prevalence was found. As Rickettsia spp.-detection was based on the single-copy gene gltA, it was possible to calculate the individual pathogen load per tick, which was significantly higher in female ticks than in nymphs (mean values: 8.19 × 10⁴ vs. 9.58 × 10³). Regional, seasonal and biennial prevalence differences of tick-transmitted Rickettsiales show the necessity to investigate ticks from multiple locations, over several months and in more than one year to reliably assess the infection risk on a larger geographical scale.

Molecular Evidence of Rickettsia spp., Anaplasma phagocytophilum, and "Candidatus Neoehrlichia mikurensis" in Ticks from Natural and Urban Habitats in Eastern Romania

Ixodid ticks are competent vectors for multiple pathogens, several of which cause infections in human. The medical importance of tick-borne pathogens is well known, yet unanswered questions remain regarding the occurrence of pathogens such as Rickettsia spp., Anaplasma phagocytophilum, and "Candidatus Neoehrlichia mikurensis" in questing ticks in Romania. Our objectives were to identify three emerging tick-borne zoonotic pathogens in eastern Romania, to assess their prevalence, establish co-infection rates, and to compare infection levels of selected pathogens in questing ticks collected from one suburban area in the city of Iaşi and one forested area located in the Danube Delta Biosphere Reserve. We collected 490 questing nymphs or adult ticks (467 Ixodes ricinus, 4 Dermacentor reticulatus, and 19 Haemaphysalis punctata). We individually analyzed ticks for the presence of Rickettsia spp., A. phagocytophilum, and "C. N. mikurensis." Rickettsia spp. was detected in 9.4% of ticks from both sampling areas. Rickettsia spp. included R. helvetica (n = 17 I. ricinus ticks), R. monacensis (n = 28 I. ricinus ticks), and R. raoultii (n = 1 D. reticulatus). "C. N. mikurensis" had an infection rate of 4.9% while A. phagocytophilum was detected only in the forested area with a global prevalence of 1.2%. The overall prevalence of ticks infected with at least one pathogen was 15.5%, and 5.3% of infected ticks were tested positives for dual pathogen association. Our study documents the presence of pathogens in questing ticks in the urban recreational areas of Iaşi and forested areas located in the Danube Delta Biosphere Reserve. Worth mentioning, is the presence of "C. N. mikurensis" in ticks from eastern Romania, an agent just recently described in Romania, and the existence of co-infections in ticks at a similar prevalence to other European countries.

Is there any association between Sarcoidosis and infectious agents?: a systematic review and meta-analysis

Background

During the last few years, investigators have debated the role that infectious agents may have in sarcoidosis pathogenesis. With the emergence of new molecular biology techniques, several studies have been conducted; therefore, we performed a meta-analysis in order to better explain this possible association.

Methods

This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement from the Cochrane collaboration guidelines. Four different databases (Medline, Scopus, Web of Science, and Cochrane Collaboration) were searched for all original articles published from 1980 to 2015. The present meta-analysis included case–control studies that reported the presence of microorganisms in samples of patients with sarcoidosis using culture methods or molecular biology techniques. We used a random effects or a fixed-effect model to calculate the odds ratio (OR) and 95% confidence intervals (CI). Sensitivity and subgroup analyses were performed in order to explore the heterogeneity among studies.

Results

Fifty-eight studies qualified for the purpose of this analysis. The present meta-analysis, the first, to our knowledge, in evaluation of all infectious agents proposed to be associated with sarcoidosis and involving more than 6000 patients in several countries, suggests an etiological link between Propionibacterium acnes and sarcoidosis, with an OR of 18.80 (95% CI 12.62, 28.01). We also found a significant association between sarcoidosis and mycobacteria, with an OR of 6.8 (95% CI 3.73, 12.39). Borrelia (OR 4.82; 95% CI 0.98, 23.81), HHV-8 (OR 1.47; 95% CI 0.02, 110.06) as well as Rickettsia helvetica, Chlamydia pneumoniae, Epstein-barr virus and Retrovirus, although suggested by previous investigations, were not associated with sarcoidosis.

Conclusion

This meta-analysis suggests that some infectious agents can be associated with sarcoidosis. What seems clear is that more than one infectious agent might be implicated in the pathogenesis of sarcoidosis; probably the patient’s geographical location might dictate which microorganisms are more involved. Future investigations and more clinical trials are need to bring these evidences to a more global level.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0332-z) contains supplementary material, which is available to authorized users.

Ixodes ricinus and Its Transmitted Pathogens in Urban and Peri-Urban Areas in Europe: New Hazards and Relevance for Public Health

Tick-borne diseases represent major public and animal health issues worldwide. Ixodes ricinus, primarily associated with deciduous and mixed forests, is the principal vector of causative agents of viral, bacterial, and protozoan zoonotic diseases in Europe. Recently, abundant tick populations have been observed in European urban green areas, which are of public health relevance due to the exposure of humans and domesticated animals to potentially infected ticks. In urban habitats, small and medium-sized mammals, birds, companion animals (dogs and cats), and larger mammals (roe deer and wild boar) play a role in maintenance of tick populations and as reservoirs of tick-borne pathogens. Presence of ticks infected with tick-borne encephalitis virus and high prevalence of ticks infected with Borrelia burgdorferi s.l., causing Lyme borreliosis, have been reported from urbanized areas in Europe. Emerging pathogens, including bacteria of the order Rickettsiales (Anaplasma phagocytophilum, "Candidatus Neoehrlichia mikurensis," Rickettsia helvetica, and R. monacensis), Borrelia miyamotoi, and protozoans (Babesia divergens, B. venatorum, and B. microti) have also been detected in urban tick populations. Understanding the ecology of ticks and their associations with hosts in a European urbanized environment is crucial to quantify parameters necessary for risk pre-assessment and identification of public health strategies for control and prevention of tick-borne diseases.

Ixodes ricinus and Its Transmitted Pathogens in Urban and Peri-Urban Areas in Europe: New Hazards and Relevance for Public Health

Tick-borne diseases represent major public and animal health issues worldwide. Ixodes ricinus, primarily associated with deciduous and mixed forests, is the principal vector of causative agents of viral, bacterial, and protozoan zoonotic diseases in Europe. Recently, abundant tick populations have been observed in European urban green areas, which are of public health relevance due to the exposure of humans and domesticated animals to potentially infected ticks. In urban habitats, small and medium-sized mammals, birds, companion animals (dogs and cats), and larger mammals (roe deer and wild boar) play a role in maintenance of tick populations and as reservoirs of tick-borne pathogens. Presence of ticks infected with tick-borne encephalitis virus and high prevalence of ticks infected with Borrelia burgdorferi s.l., causing Lyme borreliosis, have been reported from urbanized areas in Europe. Emerging pathogens, including bacteria of the order Rickettsiales (Anaplasma phagocytophilum, "Candidatus Neoehrlichia mikurensis," Rickettsia helvetica, and R. monacensis), Borrelia miyamotoi, and protozoans (Babesia divergens, B. venatorum, and B. microti) have also been detected in urban tick populations. Understanding the ecology of ticks and their associations with hosts in a European urbanized environment is crucial to quantify parameters necessary for risk pre-assessment and identification of public health strategies for control and prevention of tick-borne diseases.

Update on tick-borne rickettsioses around the world: a geographic approach

Tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus Rickettsia. These zoonoses are among the oldest known vector-borne diseases. However, in the past 25 years, the scope and importance of the recognized tick-associated rickettsial pathogens have increased dramatically, making this complex of diseases an ideal paradigm for the understanding of emerging and reemerging infections. Several species of tick-borne rickettsiae that were considered nonpathogenic for decades are now associated with human infections, and novel Rickettsia species of undetermined pathogenicity continue to be detected in or isolated from ticks around the world. This remarkable expansion of information has been driven largely by the use of molecular techniques that have facilitated the identification of novel and previously recognized rickettsiae in ticks. New approaches, such as swabbing of eschars to obtain material to be tested by PCR, have emerged in recent years and have played a role in describing emerging tick-borne rickettsioses. Here, we present the current knowledge on tick-borne rickettsiae and rickettsioses using a geographic approach toward the epidemiology of these diseases.

Tick-borne rickettsioses in Europe

Rickettsioses are caused by obligate intracellular bacteria within the genus Rickettsia, mainly transmitted by arthropods. Until recently, Mediterranean spotted fever (MSF) caused by Rickettsia conorii was considered the only tick-borne rickettsiosis in Europe. However, 'new' TBR have been described in Europe during last years. For instance, other subspecies such as R. conorii caspia and R. conorii israelensis have been involved in MSF. Dermacentor-borne necrosis erythema and lymphadenopathy/tick-borne lymphadenopathy (DEBONEL/TIBOLA) cases caused by Rickettsia slovaca, Rickettsia raoultii, and Rickettsia rioja been described in several countries where Dermacentor marginatus ticks (the mainly implicated vector) are present. Rickettsia helvetica has also been involved as a human pathogen in cases of fever with and without rash and in patients with meningitis and carditis. Other TBR such as lymphangitis-associated rickettsioses (LAR), caused by Rickettsia sibirica mongolitimonae, have been diagnosed in different European countries (France, Spain, Portugal and Greece). Rickettsia massiliae is considered an etiological agent of MSF-like illness in the Mediterranean basin. Furthermore, Rickettsia monacensis that is distributed all along Europe has been isolated from patients with MSF-like illness in Spain. Although Rickettsia aeschlimannii has been associated with MSF-like in Africa and is distributed in the Mediterranean area, no autochthonous human cases have been reported for Europe. Other Rickettsia species detected in ticks and unrelated to human disease (Candidatus Rickettsia kotlanii, Candidatus Rickettsia barbariae, Candidatus Rickettsia vini) could be potentially involved in the next years. Climate changes, among other factors, may contribute to the emergence of other rickettsioses or change their distribution. Lastly, African tick-bite fever (ATBF), caused by Rickettsia africae, is frequently diagnosed in Europe in patients returning from endemic areas.

Use of DNA sequences for Rickettsia identification in Ixodes ricinus ticks: the first detection of Rickettsia monacensis in Poland

The cosmopolitan tick Ixodes ricinus inhabiting Europe, including Poland, is a vector for many pathogens, such as various Rickettsia species, which spread to new territories. They are present mainly in the Mediterranean countries, but have also been found in Central Europe at increasing frequency. In the present study, the gltA gene, encoding citrate synthase, and an internal transcribed spacer (ITS) were employed to detect the DNA and identify the species of tick-borne pathogens of the Rickettsia genus. The presence of bacterial DNA was detected in 9.5% of the examined I. ricinus individuals. Based on the nucleotide sequences of the analysed genomic fragments, most pathogens were identified as Rickettsia helvetica, while Rickettsia monacensis was revealed in one case. We have described for the first time, to our knowledge, the occurrence of this species in Poland. Both markers employed in the experiments were successful in species identification of R. helvetica. The newly described species R. monacensis may be identified by the protein-coding gene, but the ITS nucleotide sequences proved insufficient.