Spotted fever rickettsioses in southern and eastern Europe

Tick-Borne Bacterial Diseases in Europe: Threats to public health

BACKGROUND

Tick-borne diseases, caused by bacterial pathogens, pose a growing threat to public health in Europe. This paper provides an overview of the historical context of the discovery of the most impactful pathogens transmitted by ticks, including Borrelia burgdorferi sensu lato, Rickettsia spp., Anaplasma spp., Francisella spp., Ehrlichia spp., and Neoehrlichia mikurensis. Understanding the historical context of their discovery provides insight into the evolution of our understanding of these pathogens.

METHODS AND RESULTS

Systematic investigation of the prevalence and transmission dynamics of these bacterial pathogens is provided, highlighting the intricate relationships among ticks, host organisms, and the environment. Epidemiology is explored, providing an in-depth analysis of clinical features associated with infections. Diagnostic methodologies undergo critical examination, with a spotlight on technological advancements that enhance detection capabilities. Additionally, the paper discusses available treatment options, addressing existing therapeutic strategies and considering future aspects.

CONCLUSIONS

By integrating various pieces of information on these bacterial species, the paper aims to provide a comprehensive resource for researchers and healthcare professionals addressing the impact of bacterial tick-borne diseases in Europe. This review underscores the importance of understanding the complex details influencing bacterial prevalence and transmission dynamics to better combat these emerging public health threats.

Serological and molecular epidemiological investigation of Mediterranean spotted fever in Yunnan Province, China

OBJECTIVES

Given the limited research and its potential hazards, the study aimed to determine the prevalence of Mediterranean spotted fever (MSF) caused by Rickettsia conorii (R. conorii), a tick-borne disease, in Yunnan Province, China.

METHODS

Through stratified sampling across five distinct regions in Yunnan, 5358 blood samples were obtained from the general healthy population. Enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IFA), and Polymerase chain reaction (PCR) were employed for analysis.

RESULTS

IFA identified 27 (0.50%) subjects with immunoglobulin G (IgG) positivity; none were positive for immunoglobulin M (IgM) via ELISA. PCR detected one individual with R. conorii outer membrane protein A (ompA). Significant seroprevalence variation was observed, particularly in Southern Yunnan (P = 0.032), with R. conorii subsp. conorii confirmed in the PCR-positive sample.

CONCLUSIONS

This research reveals a correlation between MSF prevalence, geography, and climate in Yunnan. The paucity of prior studies underscores MSF's potential diagnostic challenges in the region. Comprehensive understanding of the pathogen's distribution is pivotal for intervention. Given the study's scope and Yunnan's unique setting, additional research is advocated.

Ehrlichia canis and Rickettsia conorii Infections in Shelter Dogs: Seropositivity and Implications for Public Health

A cross-sectional study was conducted to gain insight into the epidemiology of canine ehrlichiosis and rickettsiosis in northern Portugal. Specific IgG antibodies to Ehrlichia canis were analysed using a commercial enzyme-linked immunosorbent assay (ELISA), and antibodies to Rickettsia conorii were analysed using a commercial indirect immunofluorescence antibody test (IFAT). A total of 113 dogs from two different shelters were sampled, and seroprevalence values of 0.9% (95% confidence (CI): 0.2-4.8%) for E. canis and 9.7 (95% CI: 5.5-16.6%) for R. conorii were found. Multiple logistic regression investigated risk factors for seropositivity. The odds ratios (ORs) of R. conorii seropositivity were higher for female dogs (OR = 6.429; 95% CI: 1.201-34.407). Dogs seropositive for co-infection (E. canis + R. conorii) were more frequently observed among females (OR = 7.606; CI 95%: 1.478-39.132) and in Shelter 2 (OR = 18.229; 95% CI: 2.190-151.756). These findings show that shelter dogs in northern Portugal are exposed to E. canis and R. conorii, which can affect both canines and humans. It is imperative to adopt a One Health approach to educate the public about the hazards of canine zoonoses and develop legislation and procedures to control their spread and preserve public health.

First report of spotted fever group Rickettsia aeschlimannii in Hyalomma turanicum, Haemaphysalis bispinosa, and Haemaphysalis montgomeryi infesting domestic animals: updates on the epidemiology of tick-borne Rickettsia aeschlimannii

Tick-borne Rickettsia spp. have long been known as causative agents for zoonotic diseases. We have previously characterized Rickettsia spp. in different ticks infesting a broad range of hosts in Pakistan; however, knowledge regarding Rickettsia aeschlimannii in Haemaphysalis and Hyalomma ticks is missing. This study aimed to obtain a better understanding about R. aeschlimannii in Pakistan and update the knowledge about its worldwide epidemiology. Among 369 examined domestic animals, 247 (66%) were infested by 872 ticks. Collected ticks were morphologically delineated into three genera, namely, Rhipicephalus, Hyalomma, and Haemaphysalis. Adult females were the most prevalent (number ₌ 376, 43.1%), followed by nymphs (303, 34.74%) and males (193, 22.13%). Overall, genomic DNA samples of 223 tick were isolated and screened for Rickettsia spp. by the amplification of rickettsial gltA, ompA, and ompB partial genes using conventional PCR. Rickettsial DNA was detected in 8 of 223 (3.58%) ticks including nymphs (5 of 122, 4.0%) and adult females (3 of 86, 3.48%). The rickettsial gltA, ompA, and ompB sequences were detected in Hyalomma turanicum (2 nymphs and 1 adult female), Haemaphysalis bispinosa (1 nymph and 1 adult female), and Haemaphysalis montgomeryi (2 nymphs and 1 adult female). These rickettsial sequences showed 99.71-100% identity with R. aeschlimannii and phylogenetically clustered with the same species. None of the tested Rhipicephalus microplus, Hyalomma isaaci, Hyalomma scupense, Rhipicephalus turanicus, Hyalomma anatolicum, Rhipicephalus haemaphysaloides, Rhipicephalus sanguineus, Haemaphysalis cornupunctata, and Haemaphysalis sulcata ticks were found positive for rickettsial DNA. Comprehensive surveillance studies should be adopted to update the knowledge regarding tick-borne zoonotic Rickettsia species, evaluate their risks to humans and livestock, and investigate the unexamined cases of illness after tick bite among livestock holders in the country.

Boutonneuse Fever in Southeastern Romania

Boutonneuse fever (BF) is an eruptive disease and is classified as a spotted fever, which is endemic in the Mediterranean basin (i.e., Marseille fever or Mediterranean spotted fever) and the Black Sea, caused by Rickettsia conorii, with dog ticks being a vector (i.e., Rhipicephalus sanguineus). In Romania, although the first reported outbreak of BF occurred during the summer of 1931 in Constanta, the disease was discovered in 1910. Although the disease has occurred most frequently in the two counties of the Dobruja region (Constanta and Tulcea), a region of the Balkan Peninsula, during the last few years, other counties in southeastern Romania have started to report BF cases. In a period of 9 years, 533 cases were registered in Constanta county, while in a period of 11 years, 339 cases were registered in Bucharest county. In this review, we describe the bacterial tick-borne disease caused by R. conorii in southeastern Romania, focusing on its history and epidemiology, pathophysiology, clinical aspects, diagnosis, treatment and preventive measures in the context of climate changes. Although R. conorii is the principal etiologic agent of BF in southeastern Romania, we should take into consideration that other Rickettsia spp. could be present and involved in disease transmission.

Tick-Borne Diseases of Humans and Animals in West Africa

Ticks are a significant group of arthropod vectors that transmit a large variety of pathogens responsible for human and animal diseases worldwide. Ticks are the second biggest transmitters of vector-borne diseases, behind mosquitoes. However, in West Africa, there is often only limited knowledge of tick-borne diseases. With the scarcity of appropriate diagnostic services, the prevalence of tick-borne diseases is generally underestimated in humans. In this review, we provide an update on tick-borne pathogens reported in people, animals and ticks in West Africa by microscopic, immunological and molecular methods. A systematic search was conducted in PubMed and Google Scholar. The selection criteria included all studies conducted in West Africa reporting the presence of Rickettsia, Borrelia, Anaplasma, Ehrlichia, Bartonella, Coxiella burnetii, Theileria, Babesia, Hepatozoon and Crimean-Congo haemorrhagic fever viruses in humans, animals or ticks. Our intention is to raise awareness of tick-borne diseases amongst human and animal health workers in West Africa, and also physicians working with tourists who have travelled to the region.

History and Current Status of Mediterranean Spotted Fever (MSF) in the Crimean Peninsula and Neighboring Regions along the Black Sea Coast

Mediterranean spotted fever (MSF) is a tick-borne rickettsiosis caused by Rickettsia conorii subspecies conorii and transmitted to humans by Rhipicephalus sanguineus ticks. The disease was first discovered in Tunisia in 1910 and was subsequently reported from other Mediterranean countries. The first cases of MSF in the former Soviet Union were detected in 1936 on the Crimean Peninsula. This review summarizes the historic information and main features of MSF in that region and contemporary surveillance and control efforts for this rickettsiosis. Current data pertinent to the epidemiology of the disease, circulation of the ticks and distribution of animal hosts are discussed and compared for each of the countries in the Black Sea basin where MSF occurs.

The Biological and Ecological Features of Northbound Migratory Birds, Ticks, and Tick-Borne Microorganisms in the African-Western Palearctic

Identifying the species that act as hosts, vectors, and vehicles of vector-borne pathogens is vital for revealing the transmission cycles, dispersal mechanisms, and establishment of vector-borne pathogens in nature. Ticks are common vectors for pathogens causing human and animal diseases, and they transmit a greater variety of pathogenic agents than any other arthropod vector group. Ticks depend on the movements by their vertebrate hosts for their dispersal, and tick species with long feeding periods are more likely to be transported over long distances. Wild birds are commonly parasitized by ticks, and their migration patterns enable the long-distance range expansion of ticks. The African-Palearctic migration system is one of the world's largest migrations systems. African-Western Palearctic birds create natural links between the African, European, and Asian continents when they migrate biannually between breeding grounds in the Palearctic and wintering grounds in Africa and thereby connect different biomes. Climate is an important geographical determinant of ticks, and with global warming, the distribution range and abundance of ticks in the Western Palearctic may increase. The introduction of exotic ticks and their microorganisms into the Western Palearctic via avian vehicles might therefore pose a greater risk for the public and animal health in the future.

Co-Occurrence of Francisella, Spotted Fever Group Rickettsia, and Midichloria in Avian-Associated Hyalomma rufipes

The migratory behavior of wild birds contributes to the geographical spread of ticks and their microorganisms. In this study, we aimed to investigate the dispersal and co-occurrence of Francisella and spotted fever group Rickettsia (SFGR) in ticks infesting birds migrating northward in the African-Western Palaearctic region (AWPR). Birds were trapped with mist nests across the Mediterranean basin during the 2014 and 2015 spring migration. In total, 575 ticks were collected from 244 birds. We screened the ticks for the species Francisella tularensis, the genus Francisella, and SFGR by microfluidic real-time PCR. Confirmatory analyses and metagenomic sequencing were performed on tick samples that putatively tested positive for F. tularensis during initial screenings. Hyalomma rufipes was the most common tick species and had a high prevalence of Francisella, including co-occurrence of Francisella and SFGR. Metagenomic analysis of total DNA extracted from two H. rufipes confirmed the presence of Francisella, Rickettsia, and Midichloria. Average nucleotide identity and phylogenetic inference indicated the highest identity of the metagenome-assembled genomes to a Francisella-like endosymbiont (FLE), Rickettsia aeschlimannii, and Midichloria mitochondrii. The results of this study suggest that (i) FLE- and SFGR-containing ticks are dispersed by northbound migratory birds in the AWPR, (ii) H. rufipes likely is not involved in transmission of F. tularensis in the AWPR, and (iii) a dual endosymbiosis of FLEs and Midichloria may support some of the nutritional requirements of H. rufipes.

Spotted Fever Group Rickettsia spp. Diversity in Ticks and the First Report of Rickettsia hoogstraalii in Romania

Simple Summary

Ticks are important parasites that feed on the blood of various host species, representing the most important arthropods transmitting diseases in Europe. Continuous changes in both tick distribution and abundance are related to multiple factors, including climate change. These changes have strong implications for both animal and human health; therefore, continuous surveillance of tickborne diseases is required for an appropriate evaluation of the potential risks faced by animals and humans in a given area. The spotted fever group Rickettsia comprises a large number of zoonotic agents with an increasing importance recognized in the last 30 years. The aim of this study was to evaluate these bacteria in ticks in Romania. Five Rickettsia species were identified in different tick species, with new pathogen–tick associations reported. Rickettsia hoogstraalii, one member of this group, was detected for the first time in Romania and in Rhipicephalus rossicus ticks. This species was first described in 2006 in Croatia, and its pathogenicity is not well known. In addition, the detection of R. raoultii and R. monacensis in unfed larvae of Haemaphysalis punctata reinforce the hypothesis of transmission of Rickettsia from female ticks to larvae; therefore the bite of larvae could pose a health risk.

Abstract

Tickborne bacterial pathogens have been described worldwide as risk factors for both animal and human health. Spotted fevers caused by Rickettsiae may cause non-specific symptoms, which make clinical diagnosis difficult. The aim of the current study was to evaluate and review the diversity of SFG Rickettsiae in ticks collected in 41 counties in Romania. A total of 2028 questing and engorged ticks collected in Romania belonging to five species were tested by PCR amplification of Rickettsia spp. gltA and 17-D gene fragments: Ixodes ricinus (n = 1128), Dermacentor marginatus (n = 507), D. reticulatus (n = 165), Rhipicephalus rossicus (n = 128) and Haemaphysalis punctata (n = 100). Five Rickettsia species were identified following DNA sequence analysis: R. helvetica, R. monacensis, R. slovaca, R. raoultii, and R. hoogstraalii. The most common species detected was R. monacensis. Moreover, R. hoogstraalii was detected for the first time in Romania and in R. rossicus ticks. The detection of R. raoultii and R. monacensis in questing larvae of Hae. punctata suggests the possible transovarial transmission of these Rickettsia species in ticks. The detection of R. hoogstraalii for the first time in Romania increases the reported SFG Rickettsia diversity in the country.

Rickettsia massiliae circulation in sheep and attached Rhipicephalus sanguineus in Central Portugal

Rickettsiosis is considered an emerging/re-emerging vector-borne disease that causes significant public health threats. Ticks are reservoirs and vectors of Rickettsia having a significant role in the transmission of rickettsiae. In Portugal, little is known about tick-borne Rickettsia species in sheep. Therefore, this study aimed to investigate rickettsiae infection in ticks and their sheep host from 27 farms in four districts of central Portugal, to clarify the role of the sheep host in the circulation of this zoonotic agent. Between March and May 2021, EDTA blood samples (n = 100) of healthy grazing sheep and their ticks (n = 100, one tick per animal) were collected during a herd health program in central Portugal. Obtained ticks were identified as Rhipicephalus sanguineus sensu lato by PCR targeting a partial sequence of 16S rRNA gene followed by sequence analysis. Rhipicephalus sanguineus s.l. and host sheep blood were tested for the presence of Rickettsia spp. by PCR targeting a partial sequence of ompB and ompA genes. From a total of 100 paired R. sanguineus s.l. and host sheep, Rickettsia massiliae was detected in 62 ticks and 35 grazing sheep blood samples, collected in central Portugal, 2021. All 35 positive sheep had attached positive R. sanguineus s.l., with matching nucleotidic sequences. These findings suggest that sheep may develop rickettsiemia and are likely capable of transmitting and amplifying the infection to uninfected ticks maintaining rickettsiae in circulation in the domestic cycle.

High Prevalence of Tick-Borne Zoonotic Rickettsia slovaca in Ticks from Wild Boars, Northeastern Italy

Simple Summary

Tick-borne rickettsioses are emerging diseases that have become widespread in many European countries, particularly in those facing the Mediterranean basin. Although Rickettsia conorii was traditionally thought to be the most threatening species, in recent decades, thanks to the improvements in biomolecular tools, other zoonotic species have been identified, such as Rickettsia slovaca, the etiological agent of scalp eschar and neck lymphadenopathy after tick bite (SENLAT), as well as other neglected species. These pathogens are present in Italy, but few data are available. This research aimed to improve the epidemiological knowledge of rickettsial infections in tick and wild boar populations in the Euganean Hills Regional Park, an enclosed area in northeastern Italy. Both tick and wild boar blood samples were tested using biomolecular methods to detect and identify Rickettsia species. Only ticks tested positive, and Rickettsia slovaca was the most frequently detected species, showing a high prevalence, followed by Rickettsia monacensis and Rickettsia helvetica. These data highlight a non-negligible presence of these pathogens in northern Italy and outline that rickettsial infections deserve further investigation.

Abstract

Tick-borne rickettsiae are emerging pathogens that are becoming widespread in Europe. Rickettsiae are endemic in Italy, but epidemiological data are currently scarce. This study aimed to improve our knowledge about rickettsial infections in tick and wild boar populations. Blood and ticks were collected from 102 wild boars in 2010 and 2018. Ticks were also collected from the vegetation in the area. All of the samples were examined using real-time PCR targeting the gltA gene to detect Rickettsia DNA. Positivity was confirmed by PCR amplifying the gltA and/or ompB genes. A total of 254 ticks and 89 blood samples were analyzed. Zoonotic rickettsiae were detected in the ticks but not in the blood samples. Rickettsia slovaca (R. slovaca) was the most prevalent in ticks and was found in 23.7% of Dermacentor marginatus (D. marginatus) and in 3.4% of Ixodes ricinus (I. ricinus). Other zoonotic species were identified, such as Rickettsia monacensis, which was detected in 12% of I. ricinus ticks, and Rickettsia helvetica which was found in 3.4% of questing I. ricinus ticks and in 1.1% of D. marginatus collected from wild boars. This study highlights a high prevalence of zoonotic rickettsiae, particularly that of R. slovaca, in northeastern Italy. As rickettsioses are underreported and underdiagnosed in human medicine, both clinicians and researchers should pay more attention to this topic.

Prevalence of causative agents of transmissive tick-borned ricketsious in the Crimean peninsula

The paper presents the results of a study of the prevalence of Ixodid ticks - potential carriers of tick-borne rickettsiosis pathogens. Ectoparasites were collected in various natural and climatic zones of the Crimean Peninsula within the year 2016-2018. As a result of screening with the help of real-time PCR analysis (PCR-RT), a genetic marker (a section of the gltA gene) of the rickettsia group of tick-borne spotted fever was detected in ticks. The most common DNA marker of rickettsia was found in ticks in the eastern regions of the steppe zone - 50,6 %, in the north-western part of the steppe zone this value was 12,0 %. The least amount of rickettsia target DNA was detected in ticks collected in the mountain forest and south bank zones - 4,5 %. As a result of sequencing of positive DNA samples from fragments of the gltA, ompA, ompB, and sca4 genes, the species composition of rickettsias was established. The DNA of 8 species of rickettsia was identified: Circulation of three R. conorii, R. massiliae, R. sibirica subsp. mongolotimonae, R. slovaca, R. aeschlimannii, R. monacensis, R. helvetica, R. raoultii. R. massiliae, R. slovaca, and R. helvetica were established in the Crimean Peninsula for the first time. The peculiarities of the geographical distribution of the identified rickettsia species were determined, which was due to the spread of mites-carriers of pathogens. The revealed diversity of rickettsia species and their vectors, due to the isolation of the areas of the main feeding animals and the established routes of migratory birds, suggests the circulation of other rickettsia species on the territory of the Crimean Peninsula. The obtained results suggest that the diseases of tick-borne rickettsiosis in the Crimean Peninsula can be caused not only by R. conorii, as previously thought, but also by other types of rickettsii.

Molecular Detection of Zoonotic and Non-Zoonotic Pathogens from Wild Boars and Their Ticks in the Corsican Wetlands

Corsica is the main French island in the Mediterranean Sea and has high levels of human and animal population movement. Among the local animal species, the wild boar is highly prevalent in the Corsican landscape and in the island’s traditions. Wild boars are the most commonly hunted animals on this island, and can be responsible for the transmission and circulation of pathogens and their vectors. In this study, wild boar samples and ticks were collected in 17 municipalities near wetlands on the Corsican coast. A total of 158 hunted wild boars were sampled (523 samples). Of these samples, 113 were ticks: 96.4% were Dermacentor marginatus, and the remainder were Hyalomma marginatum, Hyalomma scupense and Rhipicephalus sanguineus s.l. Of the wild boar samples, only three blood samples were found to be positive for Babesia spp. Of the tick samples, 90 were found to be positive for tick-borne pathogens (rickettsial species). These results confirm the importance of the wild boar as a host for ticks carrying diseases such as rickettsiosis near wetlands and recreational sites. Our findings also show that the wild boar is a potential carrier of babesiosis in Corsica, a pathogen detected for the first time in wild boars on the island.

Potential Role of Avian Populations in the Epidemiology of Rickettsia spp. and Babesia spp

Birds often are carriers of hard and/or soft ticks harboring pathogens of humans and veterinary concern. Migratory avian species, which cover long distance by their flight, may deeply influence the ticks’ distribution worldwide; in particular, they can introduce in a given geographic area new tick species and related tick-borne pathogens. Studies about the detection of tick-borne agents in birds are not numerous, whereas more attention has been turned to the presence of these microorganisms in ticks carried by birds. The present review focused on the role of avian populations in the epidemiology of rickettsioses and babesioses, which represent two severe problems for the health of humans and other mammals.

Microorganisms associated with the North African hedgehog Atelerix algirus and its parasitizing arthropods in Algeria

Hedgehogs are small mammals. They are potential reservoirs of various zoonotic agents. This study was conducted in Bouira, a north-central region of Algeria. A total of 21 Atelerix algirus corpses were picked up on roadsides and gardens. Hedgehog kidneys, spleens and ectoparasites were collected. Twelve hedgehogs were infested with ectoparasites, including Archaeopsylla erinacei, Rhipicephalus sanguineus s.l. and Haemaphysalis erinacei. Hedgehog organs and randomly selected arthropods were screened for microorganisms using molecular methods. Coxiella burnetii was detected in kidneys, spleens, A. erinacei, Hae. erinacei and Rh. sanguineus s.l. Leptospira interrogans was detected in kidneys. Rickettsia felis and Rickettsia massiliae were detected respectively in A. erinacei and in Rh. sanguineus s.l. DNA of an uncultivated Rickettsia spp. was found in Hae. erinacei. Wolbachia spp. DNA was detected in fleas. The DNA of potential new Bartonella and Ehrlichia species were found respectively in fleas and ticks. This study highlights the presence of DNA from a broad range of microorganisms in hedgehogs and their ectoparasites that may be responsible for zoonoses in Algeria.

Spotted fever diagnosis: Experience from a South Indian center

Spotted fever (SF) is an important treatable cause of acute febrile illness (AFI) with rash and has reemerged in India. A prospective AFI with rash study was undertaken at a South Indian hospital to correlate specific clinical findings with laboratory confirmation of spotted fever. During the study period (December 2017 to May 2019), 175 patients with fever and rash were suspected to have spotted fever. Molecular assays for scrub typhus and spotted fever (47 kDa and ompA qPCR) and serology (IgM ELISA) was performed on the 96 individuals recruited. Laboratory confirmed SF cases (ompA qPCR positive) were 21, whereas laboratory supported SF cases (ompA negative but sero-positive by SF IgM ELISA) were 27. Among the 48 spotted fever (SF) cases, 70% of had maculopapular rash, 12.5% had macular rash, purpuric/petechial rash (severe rash) was seen in 8 patients (16.7%). Presence of rash on the palms and soles was associated with a relative risk (RR) of 4.36 (95% CI: 2.67-7.10; p < 0.001). Our study suggests that ompA qPCR though useful for confirming the diagnosis of spotted fever is not always positive. A positive SF IgM ELISA in febrile individuals with palmo-plantar rash supports the diagnosis of spotted fever especially when other causes of febrile rash have been excluded. Multi-centric prospective studies employing the serological reference standard, IFA (immunofluorescence assay) in addition to the assays used in this study are needed to validate these findings.

Preliminary Evidence of Rickettsia slovaca and Rickettsia conorii Infection in the Sera of Sheep, Dogs and Deer from an Area of Northern Spain

Limited information is available on the presence of rickettsial infection in animal reservoirs in Spain. Antibodies against Rickettsia slovaca and Rickettsia conorii were therefore sought in the sera of farm, domestic and wild animals (n = 223 samples) in an area of northern Spain. Indirect immunofluorescence assays showed: (A) 17/120 and 16/120 (14.2% and 13.3%) of serum samples from sheep (farm animals) reacted with R. slovaca and R. conorii antigens, respectively; (B) 10/73 and 10/73 (13.7% and 13.7%) of samples from dogs (domestic animals) did the same; (C) as did 22/30 and 20/30 (73.3% and 66.6%) of samples from deer (wild animals) (overall titre range: 1/40 to 1/1280). The prevalence of both types of infection was significantly greater in the wild animals than either the farm or domestic animals. The largest titres were recorded for R. slovaca in all three groups.

Serological Survey on the Occurrence of Rickettsia spp., Neospora caninum, Bartonella henselae and Toxoplasma gondii in Cats from Tuscany (Central Italy)

Simple Summary

Domestic and stray cats are frequently infected by pathogens, some of which are zoonotic. The occurrence of microorganisms such as Bartonella henselae and Toxoplasma gondii, even though they are well known, could be underestimated because they are not regularly investigated in cats. Other pathogens, such as Neospora caninum and Rickettsia spp., have not been largely studied in feline populations and data about their spreading in Italian cats are very scanty. Monitoring of domestic and stray cats for these pathogens is important to evaluate the health status of the animals, but also, regarding B. henselae, Rickettsia spp. and T. gondii, from a One Health perspective.

Abstract

Asymptomatic cats often harbor pathogens, some of which have not been largely investigated in feline populations. The aim of this study was to evaluate the occurrence of antibodies against Rickettsia conorii, Rickettsia felis, Rickettsia typhi, Neospora caninum, Bartonella henselae and Toxoplasma gondii in cats from Tuscany. Ninety-five blood serum samples, previously collected, were analyzed by indirect immunofluorescence assay. Fifty-six (58.94%) cats had antibodies to at least one investigated pathogen: 28 (29.47%) cats were positive for B. henselae, 17 (17.89%) for R. felis, 14 (14.73%) for R. conorii, 14 (14.73%) for T. gondii, 2 (2.1%) for N. caninum. No cats were positive for R. typhi. Positive reactions to two or more pathogens were detected in 18 (18.94%) cats. The occurrence of antibodies against these microorganisms suggests that cats, even though asymptomatic, may be infected by pathogens, often zoonotic, and thus may be a source of infections for other animals and humans.

Renal Involvement in Mediterranean Spotted Fever: Clinical and Histopathological Data

OBJECTIVE

Mediterranean spotted fever (MSF) is a tick-borne rickettsial infection endemic to the Mediterranean coastline countries. As a result of growing tourism, imported cases have been registered in many nonendemic countries and regions. We present clinical laboratory parameters and histopathological data on renal impairment in patients with MSF. The study meets our goal of identifying kidney involvement and detecting renal damage in people with MSF.

SUBJECTS AND METHODS

Three hundred fifty patients with MSF with a diagnosis confirmed by immunofluorescence analysis were tested for serum urea, creatinine, and albumin. Fifty-five patients with malignant form of MSF were divided into 2 groups: 19 fatalities and 36 survivors. The percentage of patients with acute renal failure (ARF) was compared in both groups.

RESULTS

Subjects with elevated urea and creatinine levels increased from 5.21 to 3.47% in mild to 48.78 and 29.26% in severe MSF, respectively. Loss of serum albumin also increased from mild to severe MSF. Renal impairment comprised 60% of the cohort of 55 patients with malignant MSF: 89.4% in the group of deaths and almost twice less in the survivors. ARF developed in 84.2% of fatal cases and was >2 times less in survivors. Postmortem light microscopy of renal samples of 9 fatal cases revealed perivascular mononuclear inflammatory infiltrates, vasculitis with fibrinoid necrosis, acute tubular necrosis, interstitial edema, hemorrhage, and thrombosis.

CONCLUSION

Renal pathology associated with MSF rickettsial infection consists of systemic small vessel vasculitis and vascular injury, leading to ARF in the most severe cases.

Towards New Horizons: Climate Trends in Europe Increase the Environmental Suitability for Permanent Populations of Hyalomma marginatum (Ixodidae)

Ticks and tick-borne pathogens are changing their current distribution, presumably due to the impact of the climate trends. On a large scale, these trends are changing the environmental suitability of Hyalomma marginatum, the main vector of several pathogens affecting human health. We generated annual models of environmental suitability for the tick in the period 1970-2018, using harmonic regression-derived data of the daily maximum and minimum temperature, soil moisture and water vapor deficit. The results demonstrate an expansion of the suitable area in Mediterranean countries, southeast central Europe and south of the Balkans. Also, the models allowed us to interpret the impact of the ecological variables on these changes. We deduced that (i) maximum temperature was significant for all of the biogeographical categories, (ii) soil humidity has an influence in the Mediterranean climate areas, and (iii) the minimum temperature and deficit water vapor did not influence the environmental suitability of the species. The conclusions clearly show that climate change could create new areas in Europe with suitable climates for H. marginatum, while keeping its "historical" distribution in the Mediterranean. Therefore, it is necessary to further explore possible risk areas for H. marginatum and its associated pathogens.

Follow-up of a Rickettsia felis encephalitis: Some new insights into clinical and imaging features

Rickettsia felis (R. felis) infection is a cause of unspecified encephalitis. However, the incidence has been underestimated due to the intracellular features of the pathogen and insufficient understanding of its clinical picture. This study reported a case of R. felis infection in a 26-year-old female who only manifested with certain neurological symptoms. With a lack of specific systemic inflammatory symptoms, the diagnosis was initially misdiagnosed as a brain glioma. However, a brain tissue biopsy showed prominent perivascular inflammatory infiltrations, which indicated inflammatory disease. Spinal fluid metagenomic next-generation sequencing (mNGS) was taken after ruling out other common infectious and autoimmune diseases. The results suggested R. felis infection, which was also supported by Weil-Felix reaction in the serum. After the diagnosis was corrected as R. felis encephalitis, the patient was successfully treated with doxycycline and had a good prognosis at the 1-year follow-up.

Molecular-based Survey of Rickettsia spp. and Coxiella burnetii in Mosquitoes (Diptera: Culicidae) from Fars Province, Southern Iran, during 2017-18

Objectives:

Since there have not been any studies on the roles of the Iranian mosquitoes in the transmission of Rickettsia spp. and Coxiella burneti, the present study investigates the roles of mosquitoes in the transmission of the pathogens using the PCR techniques for the first time in Iran.

Methods:

The present study was conducted in Fars province during the activity seasons of mosquitoes in 2017-18. The primer design was done to investigate the probability of mosquito’s contamination with Rickettsia spp. and Coxiella burnetii. The conventional PCR was used after the extraction of DNA from mosquitoes to study the contamination.

Results:

A total of 1103 adult mosquitoes were collected and identified. Among them, 3 genera and 11 species were identified, including Anopheles (25.74%), Culex (51.84%) and Culiseta (22.39%) genera. All tested mosquitoes were negative in terms of contamination to Rickettsia spp. and Coxiella burnetii.

Conclusion:

Based on the results, mosquitoes are not considered as vectors of Rickettsia spp. and Coxiella burnetii in this part of the country currently. Further studies on a larger scale are needed to examine the exact role of mosquitoes (as a possible vector with high abundance and mobility) in the transmission of these pathogens in tropical areas of Iran.

Molecular detection of pathogens in ticks and fleas collected from companion dogs and cats in East and Southeast Asia

Background

Ticks and fleas are considered amongst the most important arthropod vectors of medical and veterinary concern due to their ability to transmit pathogens to a range of animal species including dogs, cats and humans. By sharing a common environment with humans, companion animal-associated parasitic arthropods may potentially transmit zoonotic vector-borne pathogens (VBPs). This study aimed to molecularly detect pathogens from ticks and fleas from companion dogs and cats in East and Southeast Asia.

Methods

A total of 392 ticks and 248 fleas were collected from 401 infested animals (i.e. 271 dogs and 130 cats) from China, Taiwan, Indonesia, Malaysia, Singapore, Thailand, the Philippines and Vietnam, and molecularly screened for the presence of pathogens. Ticks were tested for Rickettsia spp., Anaplasma spp., Ehrlichia spp., Babesia spp. and Hepatozoon spp. while fleas were screened for the presence of Rickettsia spp. and Bartonella spp.

Result

Of the 392 ticks tested, 37 (9.4%) scored positive for at least one pathogen with Hepatozoon canis being the most prevalent (5.4%), followed by Ehrlichia canis (1.8%), Babesia vogeli (1%), Anaplasma platys (0.8%) and Rickettsia spp. (1%) [including Rickettsia sp. (0.5%), Rickettsia asembonensis (0.3%) and Rickettsia felis (0.3%)]. Out of 248 fleas tested, 106 (42.7%) were harboring at least one pathogen with R. felis being the most common (19.4%), followed by Bartonella spp. (16.5%), Rickettsia asembonensis (10.9%) and “Candidatus Rickettsia senegalensis” (0.4%). Furthermore, 35 Rhipicephalus sanguineus ticks were subjected to phylogenetic analysis, of which 34 ticks belonged to the tropical and only one belonged to the temperate lineage (Rh. sanguineus (sensu stricto)).

Conclusion

Our data reveals the circulation of different VBPs in ticks and fleas of dogs and cats from Asia, including zoonotic agents, which may represent a potential risk to animal and human health.

Survival of Rickettsia conorii in artificially contaminated whole and leukoreduced canine blood units during the storage period

Background

The ability of tick-borne agents to survive in stored blood bags is a key factor for their transmissibility by blood transfusion. The aim of this study was to evaluate the survival and potential infectivity of Rickettsia conorii (RC) in artificially contaminated canine whole blood (WB) and in leukoreduced whole blood (LR-WB) during the storage period.

Methods

RC was cultured on L929 cells. We used a one-week 25-cm² flask with 70–80% of L929 infected cells to prepare the bacterial inoculum by pelleting cells and suspending the pellet in the donors’ serum. We infected five 100 ml WB units with RC within 2 h from the collection and maintained it at room temperature for 4 h prior to refrigeration. We filtered 50 ml of each WB bag to obtain leukoreduced WB (LR-WB) at day 1 post-infection (dpi). We checked WB and LR-WB bags at 1, 4, 7, 14, 21, 28, 35 dpi for RC presence and viability through real-time PCR (rPCR) for DNA and mRNA, respectively, and by isolation. Identification of isolates was confirmed by indirect immunofluorescence and rPCRs.

Results

RC survived for the entire storage period in both whole and leukoreduced blood. All bags contained viable bacteria until 7 dpi; RC viability generally decreased over time, particularly in LR-WB bags where the isolation time was longer than in WB. Viable bacteria were still isolated at 35 dpi in 3 WB and 3 LR-WB.

Conclusions

Leukoreduction reduced but did not eliminate RC in infected units. The survival and infectivity of RC in canine blood during the storage period may represent a threat for recipients.

An overview of rickettsiae in Southeast Asia: Vector-animal-human interface

Rickettsioses are emerging, and re-emerging diseases caused by obligate intracellular arthropod-borne bacteria that infect humans and animals worldwide. Various rickettsiae such as Orientia, Rickettsia, Anaplasma and Ehrlichia have been circulated in companion, domesticated and wild animals through bites of infected ticks, fleas, lice or mites. This review summarizes the infections of rickettsiae, including the newly discovered regional species Rickettsia thailandii, Candidatus Rickettsia sepangensis, Candidatus Rickettsia johorensis, Candidatus Rickettsia laoensis, Candidatus Rickettsia mahosotii, Candidatus Rickettsia khammouanensis, Candidatus Anaplasma pangolinii, and other novel genotypes in vectors, humans and animals in Southeast Asia. Issues on some unidentified rickettsiae that elicit immune responses and production of antibodies that are cross-reactive with the antigens used are discussed. Knowledge gaps which required attention are also identified in this review.

The molecular detection of Anaplasma phagocytophilum and Rickettsia spp. in cat and dog fleas collected from companion animals

Companion animals can be infested by various species of parasitic insects. Cat flea Ctenocephalides felis (C. felis felis) (Bouché, 1835) and dog flea Ctenocephalides canis (Curtis, 1826) belong to multihost external parasites of mammals, which most frequently occur on domestic cats Felis catus Linnaeus and dogs Canis familiaris Linnaeus. The main aim of this study was to investigate the presence of pathogens, such as Anaplasma phagocytophilum (syn. Ehrlichia phagocytophila) and Rickettsia spp., in adult C. felis and C. canis fleas. Flea sampling has been realised from January 2013 to April 2017 in veterinary clinics, animal shelters and pet grooming salons. Fleas were collected from domestic cats and dogs, directly from the pet skin or hair. Then, the DNA was isolated from a single flea by using the alkaline hydrolysis and samples were screened for the presence of pathogens using PCR method. Anaplasma phagocytophilum has occurred in 29% of examined C. felis and 16% of C. canis individuals. In turn, the prevalence of Rickettsia spp. in cat fleas population was only 3%, and the dog fleas 7%. The present study showed the presence of pathogenic agents in cat and dog fleas, which indicates the potential role of these insects in circulation of A. phagocytophilum and Rickettsia spp. in the natural habitat. Furthermore, exposition to these flea species, whose hosts are domestic cats and dogs, can pose a potential risk of infection for humans.

Thymol: Effects on reproductive biology and Gene's organ morphology in Rhipicephalus sanguineus sensu lato engorged females (Acari: Ixodidae)

Thymol is a monoterpene with proven acaricidal activity on different tick species and life stages. The objective of this work was to evaluate the effect of thymol on the reproductive biology of engorged females of Rhipicephalus sanguineus sensu lato and the morphological changes caused in the cells of the tubular and accessory glands of Gené's organ. The females were exposed to thymol by immersion. Seven groups were established: group I (distilled water), group II (30% ethanol), group III (thymol 1.25 mg/mL), group IV (thymol 2.5 mg/mL), group V (thymol 5.0 mg/mL), group VI (thymol 10.0 mg/mL), and group VII (thymol 20.0 mg/mL), with 20 replicates for each treatment. The ticks were kept in a BOD incubator at 27 ± 1 °C and RH > 80 ± 10%. Ten females from each group were evaluated daily until death, and the remaining ten were kept in the incubator under the same conditions for five days and then dissected for the removal of Gené's organ to note possible damage to cell morphology by scanning electron microscopy (SEM) and hematoxylin-eosin (HE) techniques. Thymol demonstrated 63% and 98% efficacy in groups VI (10.0 mg/mL) and VII (20.0 mg/mL), respectively. In these groups, the cells of the tubular and accessory glands of Gené's organ showed signs of damage: irregular eosin staining, rupture and deformation of the cellular limit, presence of fragmented nuclei, changes in cytoplasmic homogeneity and areas with deformation (folds) in the basal region.

Rickettsial infections of the central nervous system

As a result of migrations and globalization, people may face a possible increase in the incidence of central nervous system rickettsial infections (CNS R). These diseases, caused by Rickettsia species and transmitted to humans by arthropod bites, are putatively lethal. However, the diagnosis of CNS R is challenging and often delayed due to their nonspecific clinical presentation and the strict intracellular nature of rickettsiae. Furthermore, transfer of rickettsiae to the brain parenchyma is not yet understood. The aim of this review is to analyze and summarize the features and correlated findings of CNS R in order to focus attention on these intriguing but frequently neglected illnesses. We also incorporated data on CNS infections caused by Rickettsia-related microorganisms.

Serological Evidence of Anaplasma phagocytophilum and Spotted Fever Group Rickettsia spp. Exposure in Horses from Central Italy

Anaplasma phagocytophilum and Rickettsia spp. are tick-borne bacteria of veterinary and human concern. In view of the One-Health concept, the present study wanted to evaluate the spreading of these pathogens in horses living in central Italy. In particular, the aim of the investigation was to verify the exposure to A. phagocytophilum in order to update the prevalence of this pathogen in the equine population from this area, and to spotted fever group (SFG) Rickettsia spp. to evaluate a possible role of horses in the epidemiology of rickettsiosis. Indirect immunofluorescent assay was carried out to detect antibodies against A. phagocytophilum and SFG (spotted fever group) Rickettsia spp. in blood serum samples collected from 479 grazing horses living in central Italy during the period from 2013 to 2018. One hundred and nine (22.75%) horses were positive for A. phagocytophilum, 72 (15.03%) for SFG Rickettsia spp., and 19 (3.96%) for both antigens. The obtained results confirm the occurrence of A. phagocytophilum in equine populations, and also suggest the involvement of horses in the epidemiology of SFG rickettsiosis. In both cases, in view of the zoonotic aspect of these pathogens and the frequent contact between horses and humans, the monitoring of equine populations could be useful for indication about the spreading of the tick-borne pathogens in a certain geographic area.

Exploring the bacteriome in anthropophilic ticks: To investigate the vectors for diagnosis

OBJECTIVE

The aim of this study was to characterize the bacterial microbiome of hard ticks with affinity to bite humans in La Rioja (North of Spain).

METHODS

A total of 88 adult ticks (22 Rhipicephalus sanguineus sensu lato, 27 Haemaphysalis punctata, 30 Dermacentor marginatus and 9 Ixodes ricinus) and 120 I. ricinus nymphs (CRETAV collection, La Rioja, Spain), representing the main anthropophilic species in our environment, were subjected to a metagenomic analysis of the V3-V4 region of the 16S rRNA gene using an Illumina MiSeq platform. Data obtained with Greengenes database were refined with BLAST. Four groups of samples were defined, according to the four tick species.

RESULTS

Proteobacteria was the predominant phylum observed in all groups. Gammaproteobacteria was the most abundant class, followed by Alphaproteobacteria for R. sanguineus, H. punctata and D. marginatus but the relative abundance of reads for these classes was reversed for I. ricinus. This tick species showed more than 46% reads corresponding to 'not assigned' OTUs (Greengenes), and >97% of them corresponded to 'Candidatus Midichloriaceae' using BLAST. Within Rickettsiales, 'Candidatus Midichloria', Rickettsia, Ehrlichia, 'Candidatus Neoehrlichia' and Wolbachia were detected. I. ricinus was the most alpha-diverse species. Regarding beta-diversity, I. ricinus and H. punctata samples grouped according to their tick species but microbial communities of some R. sanguineus and D. marginatus specimens clustered together.

CONCLUSIONS

The metagenomics approach seems useful to discover the spectrum of tick-related bacteria. More studies are needed to identify and differentiate bacterial species, and to improve the knowledge of tick-borne diseases in Spain.

Mediterranean spotted fever rickettsiosis in Italy, 2001-2015: Spatio-temporal distribution based on hospitalization records

The Mediterranean spotted fever (MSF) rickettsiosis is the predominant rickettsial disease among the spotted fever group (SFG) rickettsiae in the Mediterranean countries and North Africa. Its causative agent is Rickettsia conorii, although, SFG rickettsiosis - cases due to Rickettsia monacensis, Rickettsia massiliae and Rickettsia aeschlimannii were also described. A retrospective study based on hospital discharge records with a diagnosis of SFG rickettsiosis was carried out to describe the spatial pattern, the trend of the disease, and the epidemiological characteristics of persons hospitalized in the period 2001-2015. Standardized hospitalization ratios were calculated at municipal level using the European population. Smoothed maps were produced using a localised smoothing Poisson model. The mean annual standardized hospitalization rate was 1.36/100,000 person years (95%CI: 1.34; 1.39). Rates showed strong summer seasonality and tended to decrease over time. During the study period, 28.89% of municipalities had smoothed standardized hospitalization ratios greater than 1 and 14.01% above 20. Higher standardized hospitalization ratios were found in areas along the Tyrrhenian coast, especially in the south of Calabria and in the islands of Sardinia and Sicily, where the disease is of public health relevance.

Tick-borne zoonoses in the Order Rickettsiales and Legionellales in Iran: A systematic review

BACKGROUND

Tick-borne zoonoses in the Order Rickettsiales and Legionellales cause infections that often manifest as undifferentiated fevers that are not easy to distinguish from other causes of acute febrile illnesses clinically. This is partly attributed to difficulty in laboratory confirmation since convalescent sera, specific diagnostic reagents, and the required expertise may not be readily available. As a result, a number of tick-borne zoonoses are underappreciated resulting in unnecessary morbidity, mortality and huge economic loses. In Iran, a significant proportion of human infectious diseases are tick-borne, with anecdotal evidence suggesting that tick-borne zoonoses are widespread but underreported in the country. Epidemiological review is therefore necessary to aid in the effective control and prevention of tick-borne zonooses in Iran. The aim of this review is to provide an in-depth and comprehensive overview of anaplasmosis, ehrlichiosis, spotted fever group rickettsioses and coxiellosis in Iran.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, all relevant publications on tick-borne zoonoses in the Order Rickettsiales and Legionellales in Iran were searched using a number of search terms. The search was confined to authentic resources from repositories of popular data bases among them PubMed, Web of Science, Google Scholar, Science Direct, SpringerLink and SCOPUS. The search items included peer reviewed journals, books and book chapters published between 1996 and 2017.

RESULTS

A total of 1 205 scientific publications and reports were sourced, of which 63 met the search criteria and were reviewed. Of the 63 articles reviewed, 36 (57.1%) reported on coxiellosis, 15 (23.8%) on anaplasmosis, 11 (17.5%) on ehrlichiosis and 1(1.6%) on spotted fever group rickettsiae in a large scale study involving four countries, among them Iran. The existence of tick-borne pathogens in the Order Rickettsiales and Legionellales was confirmed by molecular, serological and microscopic techniques conducted on samples obtained from sheep, cattle, goats, camels, poultry, animal products (milk and eggs), dogs, ticks and even human subjects in different parts of the country; pointing to a countrywide distribution.

DISCUSSION

Based on the review, coxiellosis, anaplasmosis, ehrlichiosis, and SFG rickettsiae can be categorized as emerging tick-borne zoonotic diseases in Iran given the presence of their causiative agents (C. burnetii, A. phagocytophilum, A. marginale, A. bovis, A. ovis, A. central, E. canis, E. ewingii, E. chaffeensis and R. conorii) collectively reported in a variety of domestic animals, animal products, arthropods and human beings drawn from 22 provinces in Iran.

CONCLUSION

Given the asymptomatic nature of some of these zoonoses, there is a high likelihood of silent transmission to humans in many parts of the country, which should be considered a public health concern. Presently, information on the transmission intensity of tick-borne zoonoses caused by pathogens in the Order Rickettsiales and Legionellales to humans and its public health impact in Iran is scanty.

The importance of wildlife in the ecology and epidemiology of the TBE virus in Sweden: incidence of human TBE correlates with abundance of deer and hares

Background

Tick-borne encephalitis (TBE) is one tick-transmitted disease where the human incidence has increased in some European regions during the last two decades. We aim to find the most important factors causing the increasing incidence of human TBE in Sweden. Based on a review of published data we presume that certain temperature-related variables and the population densities of transmission hosts, i.e. small mammals, and of primary tick maintenance hosts, i.e. cervids and lagomorphs, of the TBE virus vector Ixodes ricinus, are among the potentially most important factors affecting the TBE incidence. Therefore, we compare hunting data of the major tick maintenance hosts and two of their important predators, and four climatic variables with the annual numbers of human cases of neuroinvasive TBE. Data for six Swedish regions where human TBE incidence is high or has recently increased are examined by a time-series analysis. Results from the six regions are combined using a meta-analytical method.

Results

With a one-year time lag, the roe deer (Capreolus capreolus), red deer (Cervus elaphus), mountain hare (Lepus timidus) and European hare (Lepus europaeus) showed positive covariance; the Eurasian elk (moose, Alces alces) and fallow deer (Dama dama) negative covariance; whereas the wild boar (Sus scrofa), lynx (Lynx lynx), red fox (Vulpes vulpes) and the four climate parameters showed no significant covariance with TBE incidence. All game species combined showed positive covariance.

Conclusions

The epidemiology of TBE varies with time and geography and depends on numerous factors, i.a. climate, virus genotypes, and densities of vectors, tick maintenance hosts and transmission hosts. This study suggests that the increased availability of deer to I. ricinus over large areas of potential tick habitats in southern Sweden increased the density and range of I. ricinus and created new TBEV foci, which resulted in increased incidence of human TBE. New foci may be established by TBE virus-infected birds, or by birds or migrating mammals infested with TBEV-infected ticks. Generally, persistence of TBE virus foci appears to require presence of transmission-competent small mammals, especially mice (Apodemus spp.) or bank voles (Myodes glareolus).

Electronic supplementary material

The online version of this article (10.1186/s13071-018-3057-4) contains supplementary material, which is available to authorized users.

Effect of Climate and Land Use on the Spatio-Temporal Variability of Tick-Borne Bacteria in Europe

The incidence of tick-borne diseases caused by Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Rickettsia spp. has been rising in Europe in recent decades. Early pre-assessment of acarological hazard still represents a complex challenge. The aim of this study was to model Ixodes ricinus questing nymph density and its infection rate with B. burgdorferi s.l., A. phagocytophilum and Rickettsia spp. in five European countries (Italy, Germany, Czech Republic, Slovakia, Hungary) in various land cover types differing in use and anthropisation (agricultural, urban and natural) with climatic and environmental factors (Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), Land Surface Temperature (LST) and precipitation). We show that the relative abundance of questing nymphs was significantly associated with climatic conditions, such as higher values of NDVI recorded in the sampling period, while no differences were observed among land use categories. However, the density of infected nymphs (DIN) also depended on the pathogen considered and land use. These results contribute to a better understanding of the variation in acarological hazard for Ixodes ricinus transmitted pathogens in Central Europe and provide the basis for more focused ecological studies aimed at assessing the effect of land use in different sites on tick–host pathogens interaction.

Clinically-diagnosed Mediterranean Spotted Fever in Malta

BACKGROUND

Mediterranean Spotted Fever (MSF) is a tick-borne zoonosis caused by Rickettsia conorii which is endemic in Malta, an island in the South Mediterranean that is a popular tourist destination. Diagnosis is frequently based on clinical manifestations as laboratory results are often limited to a retrospective diagnosis. We describe the clinical presentation, diagnosis and treatment of children <16 years who presented with MSF from 2011 to 2016.

METHOD

The demographics, clinical findings, laboratory results, management and outcome of all children hospitalised with suspected MSF based on the presence of fever and an eschar, were retrieved from their case notes.

RESULTS

Over the five-year study period six children, aged between 17 months and 15 years, were diagnosed with MSF. All children had contact with ticks and the majority presented in summer. Laboratory results were non-specific and included elevated inflammatory markers, lymphocytosis/lymphopenia and hyponatraemia. Serological and molecular techniques were used for diagnosis. Response to clarithromycin or doxycycline was immediate.

CONCLUSION

MSF should be included in the differential diagnosis of fever, rash and an eschar in children who travel to Malta. Despite advances in molecular diagnostics, clinical diagnosis remains important in the management of children with suspected MSF.

Detection of Rickettsia massiliae/Bar29 and Rickettsia conorii in red foxes (Vulpes vulpes) and their Rhipicephalus sanguineus complex ticks

To determine the prevalence of exposure to Rickettsia massiliae/Bar29 and Rickettsia conorii in wild red foxes, we collected blood samples and ticks from 135 foxes shot in different game reserve areas in Catalonia. To detect SFG rickettsia in Rhipicephalus sanguineus complex ticks collected from the foxes, we used real-time polymerase chain reaction (PCR) to screen for ompA gene and a tick-borne bacteria flow chip technique based on multiplex PCR. Serum samples were positive for antibodies against spotted fever group (SFG) rickettsiae in 68 (50.3%). Molecular techniques identified R. massiliae in 107 ticks, R. aeschlimannii in 3 ticks, and R. slovaca in one tick; no R. conorii was identified in any of the ticks analyzed. We conclude that red foxes can carry ticks with SFG rickettsia.

My patient is thrombocytopenic! Is (s)he? Why? And what shall I do?

Solving the riddle of a thrombocytopenic patient is a difficult and fascinating task. The spectrum of possible aetiologies is wide, ranging from an in vitro artefact to severe treatment-resistant thrombocytopenic bleeding conditions, or even life-threatening prothrombotic states. Moreover, thrombocytopenia by itself does not protect from thrombosis and sometimes a patient with a low platelet count requires concomitant antithrombotic treatment as well. In order to identify and treat the cause and the effects of the thrombocytopenia, you have to put together several pieces of information, solving a unique jig-jaw puzzle.

The present work is not a textbook article about thrombocytopenia, rather a collection of differential diagnostic thoughts, treatment concepts, and some basic knowledge, that you can retrieve when facing your next thrombocytopenic patient. Enjoy reading it, but most importantly enjoy taking care of patients with a low platelet count. I bet the present work will assist you in this challenging and rewarding clinical task.

Potential exposure of humans to Rickettsia felis in Greece

Rickettsia felis is a flea-transmitted pathogen however, in Greece, much work has been done on another flea-borne pathogen, R. typhi; human cases have been described and high-risk areas have been characterized. Nevertheless, little is known about human infections caused by R. felis in the country since human cases are not routinely tested for antibodies against this pathogen. During the past seven years, we have set up a protocol at the National Reference Centre in order to improve the testing of tick-borne diseases in Greece. Based on this protocol, R. conorii, R. typhi R. slovaca, R. felis, and R. mongolotimonae have been added into the routine analysis; during these last years, eight (8) cases of potential exposure to R. felis were identified by serology. On an environmental investigation carried out at the residences of the patients, the pathogen was detected in C. felis only. The demonstration of R. felis potential presence highlights the need for better testing and surveillance of the pathogen.

Spotted fever group rickettsiae associated with ixodid ticks in wild environment in Southern Italy

Ixodidae ticks are vectors and reservoirs of several species of rickettsiae, and tick-borne rickettsioses are reported worldwide. This study was aimed to verify the distribution of spotted fever group rickettsiae associated with ticks in a wild environment, the National Park of Gargano, where there is proximity between wild and domestic animals, and which is within an endemic area for rickettsiosis. Ticks were collected from animals or vegetation, morphologically identified and tested by a PCR targeting the 17kDa gene, and by a loop-mediated isothermal amplification (LAMP) targeting ompB gene. Out of 34 tested tick pools, 2 from Dermacentor marginatus, 1 from Ixodes ricinus, and 1 from Rhipicephalus turanicus resulted positive. Nucleotide sequences of amplicons showed high similarity with sequences from Rickettsia slovaca, Rickettsia raoultii, Rickettsia helvetica, and Rickettsia felis. The overall calculated infection rate was 26.19 per 1,000, while it rose up to 107.77 when only D. marginatus was considered. The results highlight the association among Ri. slovaca, Ri. raoultii, D. marginatus and wild boars from which infected ticks were collected. Finally, the study shows the low efficacy of the previously described LAMP method for the detection of Rickettsia spp., when compared to PCR, making urgent the development of most effective LAMP protocols.

Detection of tick-borne bacteria and babesia with zoonotic potential in Argas (Carios) vespertilionis (Latreille, 1802) ticks from British bats

Ticks host a wide range of zoonotic pathogens and are a significant source of diseases that affect humans and livestock. However, little is known about the pathogens associated with bat ticks. We have collected ectoparasites from bat carcasses over a seven year period. Nucleic acids (DNA and RNA) were extracted from 296 ticks removed from bats and the species designation was confirmed in all ticks as Argas (Carios) vespertilionis. A subset of these samples (n = 120) were tested for the presence of zoonotic pathogens by molecular methods. Babesia species, Rickettsia spp., within the spotted fever group (SFG), and Ehrlichia spp. were detected in ticks removed from 26 bats submitted from 14 counties across England. The prevalence of Rickettsia spp. was found to be highest in Pipistrellus pipistrellus from southern England. This study suggests that the tick species that host B. venatorum may include the genus Argas in addition to the genus Ixodes. As A. vespertilionis has been reported to feed on humans, detection of B. venatorum and SFG Rickettsia spp. could present a risk of disease transmission in England. No evidence for the presence of flaviviruses or Issyk-Kul virus (nairovirus) was found in these tick samples.

Anaplasma, Ehrlichia and Rickettsia species infections in cats: European guidelines from the ABCD on prevention and management

Overview:

Anaplasma species, Ehrlichia species and Rickettsia species are vector-borne pathogens infecting a wide variety of mammals, but causing disease in very few of them.

Infection in cats:

Anaplasma phagocytophilum is the most important feline pathogen among these rickettsial organisms, and coinfections are possible. Little information is available on the pathogenesis of these agents in cats. Clinical signs are usually reported soon after tick infestation. They are mostly non-specific, consisting of fever, anorexia and lethargy. Joint pain may occur.

Infection in humans:

Some rickettsial species ( A phagocytophilum, Ehrlichia chaffeensis, Ehrlichia ewingii, Rickettsia conorii, Rickettsia rickettsii, Rickettsia felis, Rickettsia typhi and Candidatus Neoehrlichia mikurensis) are of zoonotic concern. Direct contact with cat saliva should be avoided because of potential contamination by R felis. Infected cats are ‘sentinels’ of the presence of rickettsial pathogens in ticks and fleas in a given geographical area, and they signal a risk for people exposed to vectors.

Israeli Spotted Fever in Sicily. Description of two cases and minireview

Mediterranean spotted fever (MSF) is endemic in Italy, where Rickettsia conorii subsp. conorii was thought to be the only pathogenic rickettsia and Rhipicephalus sanguineus the vector and main reservoir. R. conorii subsp. israelensis, which belongs to the R. conorii complex, is the agent of Israeli spotted fever (ISF); apart from Israel, it has also been found in Italy (Sicily and Sardinia) and in different regions of Portugal. We describe here two severe cases of ISF which occurred in otherwise healthy Italian adults. Their characteristics are analyzed and discussed in the light of other 91 cases found through a systematic review of international literature.

Mediterranean spotted fever in Spain, 1997-2014: Epidemiological situation based on hospitalization records

Introduction

Mediterranean spotted fever (MSF) is a zoonotic disease caused by Rickettsia conorii. In Spain, deficiencies in the official reporting result in misreporting of this disease. This study aims to describe the clinical and temporal-spatial characteristics of MSF hospitalizations between 1997 and 2014.

Materials and methods

We performed a retrospective descriptive study using the Hospitalization Minimum Data Set (CMBD). All CMBD’s hospital discharges with ICD-9 CM code 082.1 were analyzed. Hospitalization rates were calculated and clinical characteristics were described. Spatial distribution of cases and their temporal behavior were also assessed.

Results

A total of 4,735 hospitalizations with MSF diagnosis were recorded during the study period, out of which 62.2% were male, mean age of 48. Diabetes mellitus, alcohol dependence syndrome, and chronic liver disease occurred in 10.8%, 2.4% and 2.8% hospitalizations, respectively. The median annual hospitalization rate showed a decreasing trend from a maximum of 12.9 in 1997 to a minimum rate of 3.1 in 2014. Most admissions occurred during the summer, showing a significant annual seasonal behavior. Important regional differences were found.

Discussion

Although MSF hospitalization rates have decreased considerably, it remains a public health problem due to its severity and economic impact. Therefore, it would be desirable to improve its oversight and surveillance.

The enzootic life-cycle of Borrelia burgdorferi (sensu lato) and tick-borne rickettsiae: an epidemiological study on wild-living small mammals and their ticks from Saxony, Germany

BACKGROUND

Borrelia burgdorferi (sensu lato) and rickettsiae of the spotted fever group are zoonotic tick-borne pathogens. While small mammals are confirmed reservoirs for certain Borrelia spp., little is known about the reservoirs for tick-borne rickettsiae. Between 2012 and 2014, ticks were collected from the vegetation and small mammals which were trapped in Saxony, Germany. DNA extracted from ticks and the small mammals' skin was analyzed for the presence of Rickettsia spp. and B. burgdorferi (s.l.) by qPCR targeting the gltA and p41 genes, respectively. Partial sequencing of the rickettsial ompB gene and an MLST of B. burgdorferi (s.l.) were conducted for species determination.

RESULTS

In total, 673 small mammals belonging to eight species (Apodemus agrarius, n = 7; A. flavicollis, n = 214; Microtus arvalis, n = 8; Microtus agrestis, n = 1; Mustela nivalis, n = 2; Myodes glareolus, n = 435; Sorex araneus, n = 5; and Talpa europaea, n = 1) were collected and examined. In total, 916 questing ticks belonging to three species (Ixodes ricinus, n = 741; Dermacentor reticulatus, n = 174; and I. trianguliceps, n = 1) were collected. Of these, 474 ticks were further investigated. The prevalence for Rickettsia spp. and B. burgdorferi (s.l.) in the investigated small mammals was 25.3 and 31.2%, respectively. The chance of encountering Rickettsia spp. in M. glareolus was seven times higher for specimens infested with D. reticulatus than for those which were free of D. reticulatus (OR: 7.0; 95% CI: 3.3-14.7; P < 0.001). In total, 11.4% of questing I. ricinus and 70.5% of D. reticulatus were positive for Rickettsia spp. DNA of B. burgdorferi (s.l.) was detected only in I. ricinus (5.5%). Sequence analysis revealed 9 R. helvetica, 5 R. raoultii, and 1 R. felis obtained from 15 small mammal samples.

CONCLUSION

Small mammals may serve as reservoirs for Rickettsia spp. and B. burgdorferi (s.l.). While the prevalence for Rickettsia spp. in M. glareolus is most likely depending on the abundance of attached D. reticulatus, the prevalence for B. burgdorferi (s.l.) in small mammals is independent of tick abundance. Dermacentor reticulatus may be the main vector of certain Rickettsia spp. but not for Borrelia spp.

Kampinos National Park: a risk area for spotted fever group rickettsioses, central Poland?

Ixodid ticks are important vectors of a variety of bacterial and protozoan pathogens which cause infections in humans. In this study, altogether 1041 questing Ixodes ricinus (n = 305) and Dermacentor reticulatus ticks (n = 736), sympatrically occurring in Kampinos National Park (KPN), central-east Poland, were analyzed by PCR for Rickettsia species. Overall, the pathogen prevalence in ticks was 27.5 % for I. ricinus and 42.8 % for D. reticulatus. Sequencing analysis showed that the first tick species was exclusively infected with R. helvetica, whereas the latter was infected with R. raoultii. These organism may pose a threat for populations exposed to ticks. Preliminary results of a serosurvey of 74 KPN employees, inhabitants and visitors from the same area showed a 31.1 % total seroprevalence against SFG rickettsiae compared to 13.3 % seropositive blood donors of the control group. Risk factors significantly associated with IgG seropositivity were: occupational exposure to ticks (p = 0.002), frequency of tick bites (p = 0.02) and male gender (p = 0.005). Seropositive and seronegative individuals occupationally exposed to ticks did not differ significantly with respect to age and years of employment.

Randomized Trial of Clarithromycin for Mediterranean Spotted Fever

The classic antibiotic treatment for Mediterranean spotted fever (MSF) is based on tetracyclines or chloramphenicol, but chloramphenicol's bone marrow toxicity makes tetracyclines the treatment of choice. However, it is convenient to have alternatives available for patients who are allergic to tetracyclines, pregnant women, and children <8 years old. We conducted a randomized clinical trial to compare clarithromycin with doxycycline or josamycin in the treatment of MSF. Forty patients were evaluated (23 male; mean age, 39.87 years); 13 patients were aged <14 years. Seventeen patients received clarithromycin, and 23 received doxycycline or josamycin. The interval between the onset of symptoms and the start of treatment was 4.04 ± 1.70 days in the clarithromycin group versus 4.11 ± 1.60 days in the doxycycline/josamycin group (P = not significant [NS]). Time to the disappearance of fever after treatment was 2.67 ± 1.55 days in the clarithromycin group versus 2.22 ± 1.35 days in the doxycycline/josamycin (P = NS). The symptoms had disappeared at 4.70 ± 2.25 days in the clarithromycin group versus at 4.75 ± 3.08 days in the doxycycline/josamycin (P = NS). There were no adverse reactions to treatment or relapses in either group. In conclusion, clarithromycin is a good alternative to doxycycline or josamycin in the treatment of MSF.

A case of uveitis due to Rickettsia conorii infection in Southeastern France

We describe a case of skin rash and bilateral uveitis secondary to Rickettsia conorii infection. A 60-year-old female patient, living in the rural hinterland of Cannes, was referred to our hospital in mid-August 2012 for skin rash, fever, and arthromyalgia. Blood tests showed increased inflammatory markers, hepatic cytolysis and anicteric cholestasis. Ophthalmic examination revealed bilateral papillitis and focal chorio-retinitis. Fluoroscopic angiography demonstrated early hypofluorescence, with a few arteriolar occlusions, and subsequent hyperfluorescence and focal vasculitis. R. conorii antibodies were identified by immunofluorescence antibody test. Investigation of other infective agents and the immunological panel were negative. A 2-week course of doxycycline 200 mg/day was prescribed, and fever rapidly subsided, the skin rash resolved and vision improved. Ophthalmic examination a month and a half later showed almost all retinal lesions had disappeared and inflammation markers had returned to normal.

Wild Red Foxes (Vulpes vulpes) as Sentinels of Parasitic Diseases in the Province of Soria, Northern Spain

Four hundred red foxes (Vulpes vulpes) were examined for ecto- (arthropods) and endoparasites (Leishmania spp., Trichinella spp., and intestinal parasites). Different species of flea (total prevalence, 40.50%), tick (16.25%), mite (7.25%), and fly (1.50%) were identified. The most prevalent flea was Pulex irritans (found on 29% of the foxes); the most prevalent tick, mite, and fly were Ixodes canisuga (on 5%), Sarcoptes scabiei (on 5.25%), and Hippobosca equina (on 1%), respectively. The endoparasites identified included Leishmania spp. (found in 12% of the foxes), Trichinella spp. (in 15.5%, with T. britovi the most prevalent species in 15.25%), Cestoda (in 72.75%, with Mesocestoides spp. the most prevalent in 69.50%), and intestinal ascarids (in 73.25%, with Ancylostoma caninum the most prevalent in 12.50%). No animal was free of parasites. The present results suggest that foxes can act as sentinels of diseases transmitted by ecto- and endoparasites.