Prevalence of Anaplasma phagocytophilum and Coxiella burnetii in Ixodes ricinus ticks in Switzerland: an underestimated epidemiologic risk

Pilloux, Ludovic; Baumgärtner, A.; Jaton, Katia; Lienhard, Reto; Ackermann-Gäumann, Rahel; Beuret, Christian; Greub, Gilbert

doi:10.1016/j.nmni.2018.08.017

Cited by 25 publications

(21 citation statements)

References 25 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The largest sampling size of 62,889 ticks, exclusively I. ricinus, was collected in a study in Switzerland. No C. burnetiipositive tick was detected by using ompA as the target gene in this study (78). Also, 16S ribosomal RNA (rRNA) sequencing was used for the detection of Coxiella spp.…”

Section: Detection Methodsmentioning

confidence: 81%

The Prevalence of Coxiella burnetii in Hard Ticks in Europe and Their Role in Q Fever Transmission Revisited—A Systematic Review

et al. 2021

View full text Add to dashboard Cite

The zoonosis Q fever is caused by the obligate intracellular bacterium Coxiella burnetii. Besides the main transmission route via inhalation of contaminated aerosols, ticks are discussed as vectors since the first isolation of the pathogen from a Dermacentor andersonii tick. The rare detection of C. burnetii in ticks and the difficult differentiation of C. burnetii from Coxiella-like endosymbionts (CLEs) are questioning the relevance of ticks in the epidemiology of Q fever. In this review, literature databases were systematically searched for recent prevalence studies concerning C. burnetii in ticks in Europe and experimental studies evaluating the vector competence of tick species. A total of 72 prevalence studies were included and evaluated regarding DNA detection methods and collection methods, country, and tested tick species. Specimens of more than 25 different tick species were collected in 23 European countries. Overall, an average prevalence of 4.8% was determined. However, in half of the studies, no Coxiella-DNA was detected. In Southern European countries, a significantly higher prevalence was observed, possibly related to the abundance of different tick species here, namely Hyalomma spp. and Rhipicephalus spp. In comparison, a similar proportion of studies used ticks sampled by flagging and dragging or tick collection from animals, under 30% of the total tick samples derived from the latter. There was no significant difference in the various target genes used for the molecular test. In most of the studies, no distinction was made between C. burnetii and CLEs. The application of specific detection methods and the confirmation of positive results are crucial to determine the role of ticks in Q fever transmission. Only two studies were available, which assessed the vector competence of ticks for C. burnetii in the last 20 years, demonstrating the need for further research.

show abstract

Section: Detection Methodsmentioning

confidence: 81%

The Prevalence of Coxiella burnetii in Hard Ticks in Europe and Their Role in Q Fever Transmission Revisited—A Systematic Review

et al. 2021

View full text Add to dashboard Cite

show abstract

“…However, evidence is growing that for many vector-borne pathogens, the prevalence in vectors is very low and transmission is inefficient. For example, tick-borne encephalitis virus prevalence was 0.5–2% in Ixodes ricinus in endemic areas [86] and 1.7% of the same species of tick were infected with Anaplasma phagocytophilum in Switzerland [87]. Even if transmission is infrequent in nature, this may be sufficient to maintain and spread the pathogen in the population.…”

Section: Resultsmentioning

confidence: 99%

Scrub typhus ecology: a systematic review of Orientia in vectors and hosts

et al. 2019

View full text Add to dashboard Cite

Scrub typhus, caused by Orientia tsutsugamushi, is an important and neglected vector-borne zoonotic disease with an expanding known distribution. The ecology of the disease is complex and poorly understood, impairing discussion of public health interventions. To highlight what we know and the themes of our ignorance, we conducted a systematic review of all studies investigating the pathogen in vectors and non-human hosts. A total of 276 articles in 7 languages were included, with 793 study sites across 30 countries. There was no time restriction for article inclusion, with the oldest published in 1924. Seventy-six potential vector species and 234 vertebrate host species were tested, accounting for over one million trombiculid mites (‘chiggers’) and 83,000 vertebrates. The proportion of O. tsutsugamushi positivity was recorded for different categories of laboratory test and host species. Vector and host collection sites were geocoded and mapped. Ecological data associated with these sites were summarised. A further 145 articles encompassing general themes of scrub typhus ecology were reviewed. These topics range from the life-cycle to transmission, habitats, seasonality and human risks. Important gaps in our understanding are highlighted together with possible tools to begin to unravel these. Many of the data reported are highly variable and inconsistent and minimum data reporting standards are proposed. With more recent reports of human Orientia sp. infection in the Middle East and South America and enormous advances in research technology over recent decades, this comprehensive review provides a detailed summary of work investigating this pathogen in vectors and non-human hosts and updates current understanding of the complex ecology of scrub typhus. A better understanding of scrub typhus ecology has important relevance to ongoing research into improving diagnostics, developing vaccines and identifying useful public health interventions to reduce the burden of the disease.

show abstract

“…With the introduction of PCR methods, several studies investigating the prevalence of tick-borne pathogens in Europe showed C. burnetii DNA in over 10% of the examined arthropods [20,21]. Contrary, in other studies, no C. burnetii-specific DNA was detected in ticks [22][23][24]. In addition, tick feces samples were found to contain C. burnetii or DNA of this agent [17,25].…”

Section: Introductionmentioning

confidence: 99%

Uptake and fecal excretion of Coxiella burnetii by Ixodes ricinus and Dermacentor marginatus ticks

et al. 2020

View full text Add to dashboard Cite

Background: The bacterium Coxiella burnetii is the etiological agent of Q fever and is mainly transmitted via inhalation of infectious aerosols. DNA of C. burnetii is frequently detected in ticks, but the role of ticks as vectors in the epidemiology of this agent is still controversial. In this study, Ixodes ricinus and Dermacentor marginatus adults as well as I. ricinus nymphs were fed on blood spiked with C. burnetii in order to study the fate of the bacterium within putative tick vectors. Methods: Blood-feeding experiments were performed in vitro in silicone-membrane based feeding units. The uptake, fecal excretion and transstadial transmission of C. burnetii was examined by quantitative real-time PCR as well as cultivation of feces and crushed tick filtrates in L-929 mouse fibroblast cells and cell-free culture medium. Results: Ticks successfully fed in the feeding system with engorgement rates ranging from 29% (D. marginatus) to 64% (I. ricinus adults). Coxiella burnetii DNA was detected in the feces of both tick species during and after feeding on blood containing 10 5 or 10 6 genomic equivalents per ml blood (GE/ml), but not when fed on blood containing only 10 4 GE/ml. Isolation and cultivation demonstrated the infectivity of C. burnetii in shed feces. In 25% of the I. ricinus nymphs feeding on inoculated blood, a transstadial transmission to the adult stage was detected. Females that molted from nymphs fed on inoculated blood excreted C. burnetii of up to 10 6 genomic equivalents per mg of feces. Conclusions: These findings show that transstadial transmission of C. burnetii occurs in I. ricinus and confirm that I. ricinus is a potential vector for Q fever. Transmission from both tick species might occur by inhalation of feces containing high amounts of viable C. burnetii rather than via tick bites.

show abstract

Prevalence of Anaplasma phagocytophilum and Coxiella burnetii in Ixodes ricinus ticks in Switzerland: an underestimated epidemiologic risk

Cited by 25 publications

References 25 publications

The Prevalence of Coxiella burnetii in Hard Ticks in Europe and Their Role in Q Fever Transmission Revisited—A Systematic Review

The Prevalence of Coxiella burnetii in Hard Ticks in Europe and Their Role in Q Fever Transmission Revisited—A Systematic Review

Scrub typhus ecology: a systematic review of Orientia in vectors and hosts

Uptake and fecal excretion of Coxiella burnetii by Ixodes ricinus and Dermacentor marginatus ticks

Contact Info

Product

Resources

About