Serological survey of Bartonella spp., Borrelia burgdorferi, Brucella spp., Coxiella burnetii, Francisella tularensis, Leptospira spp., Echinococcus, Hanta-, TBE- and XMR-virus infection in employees of two forestry enterprises in North Rhine-Westphalia, Germany, 2011-2013

Molecular detection and phylogenetic analysis of Borrelia Spp. In blood samples of cats and dogs by the nested-PCR method in West Azerbaijan Province, Iran

The objective of this study was to investigate the presence and genetic attributes of Borrelia spp. in cats and dogs from the West Azerbaijan Province, located in the northwest of Iran. A total of 250 blood samples from cats and 300 blood samples from dogs were collected, and information regarding their age, sex, breed, ownership status, sampling time and region was recorded. The identification of positive samples was accomplished through nested-PCR and sequencing, with subsequent analysis of the gene sequences conducted using BioEdit software. The gene sequences for Borrelia spp. in this study showed 100% similarity to reference sequences in the GenBank® database. Phylogenetic trees were built using MEGA11. The outcomes indicated that among 250 blood samples from cats, 48 (19.2%) tested positive for Borrelia spp. gene, with a CI from 14.8 to 24.53% for cats. Similarly, out of 300 blood samples from dogs, 45 (15%) tested positive for the Borrelia spp. gene, with a CI from 11.4 to 19.48% for dogs.

Seroepidemiology of Human Tularemia-Systematic Review and Meta-analysis of Seroprevalence Studies

Background

Seroepidemiologic studies of human tularemia have been conducted throughout the northern hemisphere. The purposes of this study were (1) to provide an overview of Francisella tularensis seroprevalence data, and (2) to generate an estimate of the proportion of study participants whose infection remained subclinical.

Methods

We conducted a systematic review of F tularensis seroprevalence studies according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We searched PubMed, Embase, and Web of Science covering the period from 1951 to 2023.

Results

The weighted pooled seroprevalence among 44 486 participants recruited in 52 studies was 3.7% (95% confidence interval [CI], 2.7-5.1). Reported seroprevalences ranged between 0.2% and 31.3%. Occupational activities associated with an increased likelihood of exposure (risk ratio, 3.51 [95% CI, 3.2-3.86]) and studies from North America versus Europe and Asia (4.53 [4.15-4.94]) were associated with significantly increased seropositive rates. Twenty-eight data sets (47%) reported clinical information on a total of 965 seropositive participants. The weighted pooled estimate for subclinical seropositivity was 84.4% (95% CI, 72.9%-991.7%). Studies from F tularensis type A areas (risk ratio, 0.37 [95% CI, .27-.51) and studies from sites where pulmonary tularemia prevailed (0.38 [.28-.51]) reported lower subclinical seropositivity rates than studies from type B areas and from areas of predominance of (ulcero)glandular or oropharyngeal tularemia, respectively.

Conclusions

Throughout the northern hemisphere, only a small proportion of study participants showed serologic evidence of exposure to F tularensis. Eight of 10 seropositive participants had no historical evidence of past clinical tularemia.

Risk factors for Leptospira seropositivity in rural Northern Germany, 2019

We investigated seroprevalence and factors associated with Leptospira spp. infections in humans in rural Northern Germany. Sera of 450 participants were tested for leptospira-reactive IgG antibodies by two enzyme-linked immunosorbent assays (ELISA). A narrow (specific) and a broad (sensitive) case definition were applied and results compared in the analysis. Personal data were collected via questionnaire and associations with the serostatus were investigated by multivariable logistic regression. The seroprevalence estimates were 1.6% (95%-confidence interval (CI) = 0.63-3.2) under the narrow and 4.2% (95%-CI = 2.6-6.5%) under the broad case definition. Few (14%) participants knew about the pathogen. No seropositive participant recalled a prior leptospirosis diagnosis. Spending more than two hours a week in the forest was significantly associated with anti-leptospira IgG in both models (broad case definition: adjusted odds ratio (aOR) = 2.8, 95%-CI = 1.2-9.1; narrow case definition: aOR = 11.1, 95%-CI = 1.3-97.1). Regular cleaning of storage rooms was negatively associated in the broad (aOR = 0.17, 95%-CI = 0.03-0.98) and touching a dead rodent in the past 10 years in the narrow case definition model (aOR = 0.23, 95%-CI = 0.05-1.04). Our findings support risk factors identified in previous investigations. To counter the low awareness for the pathogen, we recommend that health authorities communicate risks and preventive measures to the public by using target-group specific channels.

Cluster of human Puumala orthohantavirus infections due to indoor exposure?-An interdisciplinary outbreak investigation

Puumala orthohantavirus (PUUV) is the most important hantavirus species in Europe, causing the majority of human hantavirus disease cases. In central and western Europe, the occurrence of human infections is mainly driven by bank vole population dynamics influenced by beech mast. In Germany, hantavirus epidemic years are observed in 2- to 5-year intervals. Many of the human infections are recorded in summer and early autumn, coinciding with peaks in bank vole populations. Here, we describe a molecular epidemiological investigation in a small company with eight employees of whom five contracted hantavirus infections in late 2017. Standardized interviews with employees were conducted to assess the circumstances under which the disease cluster occurred, how the employees were exposed and which counteractive measures were taken. Initially, two employees were admitted to hospital and serologically diagnosed with hantavirus infection. Subsequently, further investigations were conducted. By means of a self-administered questionnaire, three additional symptomatic cases could be identified. The hospital patients' sera were investigated and revealed in one patient a partial PUUV L segment sequence, which was identical to PUUV sequences from several bank voles collected in close proximity to company buildings. This investigation highlights the importance of a One Health approach that combines efforts from human and veterinary medicine, ecology and public health to reveal the origin of hantavirus disease clusters.

Seroprevalence of vector-borne pathogens in outdoor workers from southern Italy and associated occupational risk factors

Background

Vector-borne diseases (VBDs) represent an emerging global threat to public health due to the geographical expansion of arthropod vectors. The study aims to assess the seroprevalence of selected vector-borne pathogens (VBPs) in different groups of outdoor workers and the occupational risk factors for exposure to arthropod bites.

Methods

A cross-sectional study was conducted on 170 workers recruited in two different regions of southern Italy, including farmers, forestry workers, veterinarians, geologists/agronomists and administrative employees, and tested for IgG antibodies against Bartonella henselae, Borrelia spp. Coxiella burnetii and Rickettsia conorii, using a chemiluminescent immunoassay (CLIA). The relationship among job characteristics, tick exposure and the prevalence of seropositive subjects for each pathogen was investigated by applying categorical principal component analysis (CATPCA).

Results

A high seroprevalence for C. burnetii (30.0%) and R. conorii (15.3%) was reported, mainly in farmers (67.7% and 54.8%, respectively) and forestry workers (29.0% and 16.1%, respectively), while a low prevalence was observed for B. henselae and Borrelia spp. (8.8% and 4.1%, respectively). The regression equation by CATPCA was significant for C. burnetii and R. conorii (P < 0.001), showing a positive association with job, tick bite exposure, working area and contact with animals.

Conclusions

These findings highlight the need of activating an appropriate occupational health response for minimizing the risk of arthropod vector exposure in workplaces, considering specific preventive measures in particular in high-risk job categories.

Graphical Abstract

Emerging rodent-associated Bartonella: a threat for human health?

Background

Species of the genus Bartonella are facultative intracellular alphaproteobacteria with zoonotic potential. Bartonella infections in humans range from mild with unspecific symptoms to life threatening, and can be transmitted via arthropod vectors or through direct contact with infected hosts, although the latter mode of transmission is rare. Among the small mammals that harbour Bartonella spp., rodents are the most speciose group and harbour the highest diversity of these parasites. Human–rodent interactions are not unlikely as many rodent species live in proximity to humans. However, a surprisingly low number of clinical cases of bartonellosis related to rodent-associated Bartonella spp. have thus far been recorded in humans.

Methods

The main purpose of this review is to determine explanatory factors for this unexpected finding, by taking a closer look at published clinical cases of bartonellosis connected with rodent-associated Bartonella species, some of which have been newly described in recent years. Thus, another focus of this review are these recently proposed species.

Conclusions

Worldwide, only 24 cases of bartonellosis caused by rodent-associated bartonellae have been reported in humans. Possible reasons for this low number of cases in comparison to the high prevalences of Bartonella in small mammal species are (i) a lack of awareness amongst physicians of Bartonella infections in humans in general, and especially those caused by rodent-associated bartonellae; and (ii) a frequent lack of the sophisticated equipment required for the confirmation of Bartonella infections in laboratories that undertake routine diagnostic testing. As regards recently described Bartonella spp., there are presently 14 rodent-associated Candidatus taxa. In contrast to species which have been taxonomically classified, there is no official process for the review of proposed Candidatus species and their names before they are published. This had led to the use of malformed names that are not based on the International Code of Nomenclature of Prokaryotes. Researchers are thus encouraged to propose Candidatus names to the International Committee on Systematics of Prokaryotes for approval before publishing them, and only to propose new species of Bartonella when the relevant datasets allow them to be clearly differentiated from known species and subspecies.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05162-5.

Occupational Lyme Disease: A Systematic Review and Meta-Analysis

Lyme disease (LD) can have significant consequences for the health of workers. The frequency of infection can be estimated by using prevalence and incidence data on antibodies against Borrelia Burgdoferi (BB). A systematic search of studies published in English between 2002 and 2021 and a meta-analysis were conducted in PubMed/Medline, Web of Science, Scopus, and Google Scholar databases. Out of a total of 1125 studies retrieved, 35 articles were included in the systematic review. Overall, in these studies, outdoor workers showed a 20.5% BB seroprevalence rate. Meta-analysis, performed on 15 studies (3932 subjects), revealed a significantly increased risk in outdoor activities (OR 1.93 95%CI 1.15–3.23), with medium-level heterogeneity (I² = 69.2%), and non-significant publication bias. The estimated OR in forestry and agricultural workers was 2.36 (CI95% 1.28; 4.34) in comparison with the controls, while a non-significant increase in risk (OR = 1.05, CI95% 0.28; 3.88) was found in the remaining categories of workers (veterinarians, animal breeders, soldiers). The estimated pooled risk was significantly higher in the studies published until 2010 (OR 3.03 95%CI 1.39–6.61), while in more recent studies the odds became non-significant (OR 1.08 95% CI 0.63–1.85). The promotion of awareness campaigns targeting outdoor workers in endemic areas, and the implementation of local programs aimed at controlling range expansion of vectors, are key strategies for protecting workers.

Occupational Hantavirus Infections in Agricultural and Forestry Workers: A Systematic Review and Metanalysis

Hantaviruses are zoonotic pathogens that can cause serious human disorders, including hemorrhagic fever with renal syndrome and hantavirus cardiopulmonary syndrome. As the main risk factor for human infections is the interaction with rodents, occupational groups such as farmers and forestry workers are reportedly at high risk, but no summary evidence has been collected to date. Therefore, we searched two different databases (PubMed and EMBASE), focusing on studies reporting the prevalence of hantaviruses in farmers and forestry workers. Data were extracted using a standardized assessment form, and results of such analyses were systematically reported, summarized and compared. We identified a total of 42 articles, including a total of 28 estimates on farmers, and 22 on forestry workers, with a total workforce of 15,043 cases (821 positive cases, 5.5%). A pooled seroprevalence of 3.7% (95% confidence interval [95% CI] 2.2–6.2) was identified in farmers, compared to 3.8% (95% CI 2.6–5.7) in forestry workers. Compared to the reference population, an increased occurrence was reported for both occupational groups (odds ratio [OR] 1.875, 95% CI 1.438–2.445 and OR 2.892, 95% CI 2.079–4.023 for farmers and forestry workers, respectively). In summary, our analyses stress the actual occurrence of hantaviruses in selected occupational groups. Improved understanding of appropriate preventive measures, as well as further studies on hantavirus infection rates in reservoir host species (rodents, shrews, and bats) and virus transmission to humans, is needed to prevent future outbreaks.

Hantaviruses in Agricultural and Forestry Workers: Knowledge, Attitudes and Practices in Italian Physicians

Hantaviruses are viral pathogens usually endemic in rodent populations. Human exposure follows inhalation of dusts contaminated with rodent excreta, and most individuals have been infected in occupational settings heavily contaminated with rodent droppings, such as agricultural and forestry. To date, knowledge, attitudes and practices of medical professionals, especially occupational physicians (OP), regarding hantavirus disease in at-risk workers have been scarcely investigated. We investigated these topics through a structured questionnaire administered through an online survey of 223 medical professionals (42.2% of them working as OP). Adequate general knowledge of hantavirus disease was found in 48.9% of respondents, with OP exhibiting a better understanding of clinical features of human hantavirus infections. OP aware of the endemic status of hantavirus in North-Eastern Italy exhibited higher risk perception for agricultural workers (odds ratio 21,193, 95% confidence interval 3.666-122.505). On the contrary, a better knowledge of hantaviruses was association with acknowledging an increased risk of hantavirus infection in forestry workers (odds ratio 5.880, 95% confidence interval 1.620-21.343). Hantavirus in Italy represent an often-overlooked biological risk in occupational settings. The lack of preventive immunization, the inappropriate risk perception and the unsatisfying awareness of hantavirus issues collectively stress the importance of appropriate information campaigns among health care providers.

Exposure to tick-borne encephalitis virus among nature management workers in the Netherlands

Tick-borne encephalitis virus (TBEV) has only recently been detected in the Netherlands. With still few autochthonous tick-borne encephalitis (TBE) patients, human exposure to TBEV is expected to be very low among the general population. We aimed to assess the exposure to TBEV among persons with an occupationally high risk of tick bites in the Netherlands. In our cross-sectional serological survey, employees and volunteers of nature management organizations provided a single blood sample and completed an online questionnaire in 2017. The sera were screened in the anti-TBEV IgG Enzyme-Linked Immunosorbent Assay (ELISA), after which a TBEV-specific virus neutralization test (VNT) was applied to confirm positive ELISA outcomes. Ten sera tested positive for IgG antibodies in the TBEV ELISA, among 556 participants who did not report vaccination against TBEV. Through confirmation in VNT, TBEV-specific IgG antibodies were detected among 0.5% (3/556, 95%CI 0.1%-1.6%). During the five years prior to the questionnaire, 87% reported tick bites. Half of the participants considered that most of their tick bites (75% to 100%) had been acquired while being at work. A very low seroprevalence of TBEV exposure was observed among these nature management workers, even though they report a six times higher exposure to tick bites, compared to our general population. Nonetheless, the emergence of TBEV in the Netherlands reaffirms the need for education and preventative measures against tick bites and tick-borne diseases.

Dynamics of Borrelia burgdorferi-Specific Antibodies: Seroconversion and Seroreversion between Two Population-Based, Cross-Sectional Surveys among Adults in Germany

Lyme borreliosis (LB) caused by Borrelia burgdorferi spp. is the most common human tick-borne disease in Europe. Although seroprevalence studies are conducted in several countries, rates of seroconversion and seroreversion are lacking, and they are essential to determine the risk of infection. Seropositivity was determined using a two-step approach-first, a serological screening assay, and in the event of a positive or equivocal result, a confirmatory immunoblot assay. Seroconversion and seroreversion rates were assessed from blood samples taken from participants included in two nation-wide population-based surveys. Moreover, the impact of antigen reactivity on seroreversion rates was assessed. The seroprevalence of antibodies reacting against B. burgdorferi spp. in the German population was 8.5% (95% CI 7.5-9.6) in 1997-99 and 9.3% (95% CI 8.3-10.4) in 2008-2011. Seroprevalence increased with age, up to 20% among 70-79 year-olds. The age-standardized seroprevalence remained the same. The yearly seroconversion rate was 0.45% (95% CI: 0.37-0.54), and the yearly seroreversion rate was 1.47% (95% CI: 1.24-2.17). Lower levels of antibodies were associated with seroreversion. Participants with a strong response against antigen p83 had the lowest odds on seroreversion. Given the yearly seroreversion rate of 1.47% and a seroprevalence up to 20% in the oldest age groups, at least 20% of the German population becomes infected with B. burgdorferi in their lifetime. The slight increase in seroprevalence between the two serosurveys was caused by an aging population.

Seroepidemiology, Spatial Distribution, and Risk Factors of Francisella tularensis in Jordan

There is a paucity of data on Francisella tularensis in the Middle East and North Africa. This is the first countrywide study to determine the seroprevalence, spatial distribution, and risk factors for F. tularensis in Jordan. A total of 828 Jordanians were serologically tested for F. tularensis by ELISA. These individuals filled out a self-administered questionnaire to collect demographic and risk factor information. Bivariate and multivariate logistic regressions were performed to determine which variables are associated with seropositivity. The overall seroprevalence of F. tularensis was 7.7% (95% CI: 6.10-9.75). The bivariate analyses showed that age, region of residence, small ruminant ownership, and practicing horticulture were significantly associated with seropositivity, and these variables were controlled for in the multivariate analysis. The multivariate analysis showed an increased odds of seropositivity among individuals living in northern desert, middle, and northern highland areas, compared with individuals living in the drier southern area, as 7.27 (95% CI: 2.49-21.19), 3.79 (95% CI: 1.53-9.39), and 3.52 (95% CI: 1.45-388.55), respectively. Individuals owning a small ruminant had 1.86 (95% CI: 1.02-3.40) greater odds for seropositivity than individuals who do not own a small ruminant. Individuals practicing horticulture had 2.10 (95% CI: 1.20-3.66) greater odds for seropositivity than individuals who do not practice horticulture. This is the first study to address the seroprevalence of F. tularensis in Jordan and the Middle East. Further research is needed to identify clinical cases of tularemia in Jordan and to determine the circulating F. tularensis subspecies.

Epidemiological serosurvey of vector-borne and zoonotic pathogens among homeless people living in shelters in Marseille: cross-sectional one-day surveys (2005-2015)

Homeless people are often exposed to unhygienic environments as well as to animals carrying arthropods which both transmit zoonotic infections and human louse-borne pathogens. We attempted to determine the prevalence of antibodies against several vector-borne and zoonotic pathogens among homeless adults living in Marseille. During the 2005-2015 period, we collected sera samples from 821 homeless adults living in shelters. Antibodies against Bartonella quintana, Bartonella henselae, Borrelia recurrentis, Coxiella burnetii, Francisella tularensis (with a cut-off of 1:100), Rickettsia akari, Rickettsia conorii, Rickettsia felis, Rickettsia prowazekii, and Rickettsia typhi (with a cut-off of 1:64) were searched by microimmunofluorescence (MIF). MIF-positive serum samples were confirmed by cross-adsorption to characterise cross-reacting antigens and immunoblotting. Positive sera by Western blot were further tested using qPCR. We evidenced a prevalence of 4.9% seroreactivity to at least one pathogen including phase II C. burnetii (2.1%), B. quintana (1.7%), R. conorii (0.4%), R. prowazekii (0.4%), R. typhi (0.1%), B. recurrentis (0.1%), and F. tularensis (0.1%). No DNA from any pathogens was detected. A comparison with studies conducted prior to the 2000-2003 period showed a decrease in the overall seroprevalence of several vector-borne and zoonotic infections.

Borrelia prevalence and species distribution in ticks removed from humans in Germany, 2013-2017

Lyme borreliosis caused by spirochaetes of the Borrelia burgdorferi sensu lato (s.l.) complex is the most common tick-borne disease in Europe. In addition, the relapsing-fever spirochaete Borrelia miyamotoi, which has been associated with febrile illness and meningoencephalitis in immunocompromised persons, is present in Europe. This study investigated Borrelia prevalence and species distribution in ticks removed from humans and sent as diagnostic material to the Institute for Parasitology, University of Veterinary Medicine Hannover, in 2013-2017. A probe-based real-time PCR was carried out and Borrelia-positive samples were subjected to species determination by reverse line blot (RLB), including a B. miyamotoi-specific probe. The overall Borrelia-infection rate as determined by real-time PCR was 20.02 % (510/2547, 95 % CI: 18.48-21.63 %), with annual prevalences ranging from 17.17 % (90/524, 95 % CI: 14.04-20.68 %) in 2014 to 24.12 % (96/398, 95 % CI: 19.99-28.63 %) in 2015. In total, 271/475 (57.1 %) positive samples available for RLB were successfully differentiated. Borrelia afzelii was detected in 30.53 % of cases (145/475, 95 % CI: 26.41-34.89), followed by B. garinii/B. bavariensis (13.26 % [63/475], 95 % CI: 10.34-16.65). Borrelia valaisiana occurred in 5.89 % (28/475, 95 % CI: 3.95-8.41), B. spielmanii in 4.63 % (22/475, 95 % CI: 2.93-6.93), B. burgdorferi sensu stricto (s.s.)/B. carolinensis in 2.32 % (11/475, 95 % CI: 1.16-4.11), B. lusitaniae in 0.63 % (3/475, 95 % CI: 0.13-1.83) and B. bisettiae in 0.42 % (2/475, 95 % CI: 0.05-1.51) of positive ticks. Borrelia kurtenbachii was not detected, while B. miyamotoi was identified in 7.37 % (35/475, 95 % CI: 5.19-10.10) of real-time PCR-positive samples. Sanger sequencing of B. garinii/B. bavariensis-positive ticks revealed that the majority were B. garinii-infections (50/52 successfully amplified samples), while only 2 ticks were infected with B. bavariensis. Furthermore, 6/12 B. burgdorferi s.s./B. carolinensis-positive samples could be differentiated; all of them were identified as B. burgdorferi sensu stricto. Thirty-nine ticks (8.21 %, 95 % CI: 5.90-11.05) were coinfected with two different species. Comparison of the species distribution between ticks removed from humans in 2015 and questing ticks collected in the same year and the same area revealed a significantly higher B. afzelii-prevalence in diagnostic tick samples than in questing ticks, confirming previous observations. The obtained data indicate that Borrelia prevalence fluctuated in the same range as observed in a previous study, analysing the period from 2006 to 2012. Detection of B. miyamotoi in 7.37 % of Borrelia-positive samples points to the fact that clinicians should be aware of this pathogen as a differential diagnosis in cases of febrile illness.

[Leptospirosis in Germany: current knowledge on pathogen species, reservoir hosts, and disease in humans and animals]

Leptospirosis is a zoonotic disease with a wide spectrum of clinical symptoms in humans and animals, ranging from subclinical infections to severe signs of multiorgan dysfunction. In Germany, laboratory confirmation of acute human infection is notifiable based on the Protection Against Infection Act. Disease or occurrence of the pathogen in pigs and sheep must be reported according to the regulation on reportable animal diseases. Transmission occurs via direct and indirect contact with the urine of infected animals, with rodents acting as the main reservoir. With an average annual incidence of 0.1 notified cases per 100,000 inhabitants, leptospirosis is a rare disease in Germany.This review article presents the current knowledge on leptospirosis in Germany in the framework of the project "Improving public health through a better understanding of the epidemiology of rodent-transmitted diseases" (RoBoPub) funded by the Ministry of Education and Research. In a One-Health approach, information about clinical manifestation, available prevalence data in humans and animals, knowledge of pathogen distribution, host association, mode of transmission, and survival in the environment is summarized. Preliminary findings on the influence of fluctuations in rodent populations on the occurrence of leptospirosis are also discussed. The aim of the article is to increase the awareness of this currently neglected disease in Germany.In future, higher temperatures and more frequent heavy rainfalls, which could occur due to climate change, should be taken into account.

Knowledge, habits and attitudes towards TBE and other tick-borne diseases in German forestry trainees

Tick-borne encephalitis (TBE) is an occupational hazard for forestry workers. We measured knowledge levels, misbeliefs, and vaccination rates in forestry trainees in order to tailor specific measures aimed at reducing occupational TBE incidence. A paper-based survey was performed at a central training site for forestry workers in the state of Baden-Wuerttemberg. The questionnaire contained items regarding vaccination status against tick-borne encephalitis virus (TBEV), self-reported tick-borne diseases, knowledge of and attitudes towards tick-borne disease, and practices in the context of ticks and tick bites. All trainees in the period June-December 2018 were surveyed. Statistical analyses were conducted using Mann-Whitney-Rank sum test and one-way ANOVA tests. Two-hundred-twenty-five trainees participated in the survey. Almost all (>99%) were aware of living in a TBE high-risk area. Eighty-three percent of respondents were vaccinated in line with current recommendations. Seventeen percent had no effective vaccination status. Twenty-seven percent believed that ticks can transmit only TBEV and Borrelia spp. Sixty-two percent knew that TBEV infections can be fatal. Only 8% of respondents use tick repellents and only 17% wear long sleeves and pants. Trainees who graduated from a six and (eight or) nine secondary school (Realschule and Abitur respectively) had more knowledge on ticks and tick-borne disease compared to graduates from a five year school (Hauptschule) (p = 0.002 and p = 0,037 respectively). Overall, the TBE vaccination rate is not high enough in this high-risk occupational group. We identified gaps in knowledge and practices that could have an impact on TBE incidence in this group if addressed. Further epidemiological research is needed on knowledge, attitudes, and practices in different high-risk populations.

The seroprevalence of Bartonella spp. in the blood of patients with musculoskeletal complaints and blood donors, Poland: a pilot study

BACKGROUND

Bartonella spp. can cause a variety of diseases, such as lymphadenopathies, cat scratch disease, and trench fever, but can also give rise to many non-specific symptoms. No data exists regarding the prevalence of Bartonella spp. in patients with musculoskeletal complaints, nor among blood donors in Poland.

METHODS

The presence of anti-Bartonella IgM and IgG in the serum of blood donors (n = 65) (Lodz, Poland) and in the patients of the Department of Rheumatology Clinic (n = 40) suffering from musculoskeletal symptoms was tested by immunofluorescence. Blood samples were cultured on enriched media. Epidemiological questionnaires were used to identify key potential risk factors, such as sex, age, contact with companion animals, and bites from insects or animals.

RESULTS

Altogether, 27 of the 105 tested subjects were seropositive for Bartonella henselae IgG (23%) and three for Bartonella quintana IgG (2.85%); IgMs against B. henselae were found in three individuals (2.85%), and IgMs against B. quintana were found in one (1.54%). No statistically significant difference was found between the prevalence of B. henselae in the blood of donors or patients and the presence of unexplained musculoskeletal complaints (23% vs 30%). Individuals who had kept or been scratched by cats were not more likely to be B. henselae seropositive (p > 0.01). Tick bites were more commonly reported in patients, but insignificantly (p > 0.01).

CONCLUSION

This is the first report of a high seroprevalence of anti-Bartonella IgG in patients with musculoskeletal symptoms and in blood donors in Poland. The obtained results indicate that such seroprevalence may have a possible significance in the development of musculoskeletal symptoms, although it should be confirmed on a larger group of patients. Asymptomatic bacteremia might occur and pose a threat to recipients of blood from infected donors. Hence, there is a need for more detailed research, including molecular biology methods, to clarify the potential risk of Bartonella spp. being spread to immunocompromised individuals.

KEY POINTS

• This is the first study presenting high seroprevalence of Bartonella spp. in Poland. • IgG and IgM antibodies against B. quintana were found in blood samples of blood donors.

Development of a Specific and Sensitive Enzyme-Linked Immunosorbent Assay as an In Vitro Diagnostic Tool for Detection of Bartonella henselae Antibodies in Human Serum

Bartonella henselae causes cat scratch disease and several other clinical entities. Infections with B. henselae are frequently occurring; however, the infection is only rarely diagnosed, mainly due to a lack of knowledge in the medical community. Microscopic immunofluorescence assays (IFA) are widely used for the serodiagnosis of B. henselae infections but are laborious and time-consuming, and interpretation is subjective. An easy and reliable method for the serological diagnosis of B. henselae infections is needed to overcome the shortcomings of the current IFA. Here, we report the development of an ELISA detecting human anti-B. henselae antibodies from serum samples. By separating the water-insoluble fraction of B. henselae Houston-1 via ion-exchange chromatography, 16 subfractions were generated and tested for immunoreactivity via line blotting. One particular fraction (fraction 24) was selected and spotted on ELISA plates using an industrial production platform. By use of well-characterized human sera from the strictly quality-controlled serum library of the German National Consiliary Laboratory for Bartonella infections, the sensitivity of this ELISA was 100% for PCR-proven infections and 76% for clinically suspected infections at a specificity of 93%. This ELISA is therefore a reliable high-throughput method allowing the serodiagnosis of B. henselae infections.

Seroprevalence of Borrelia burgdorferi in Belgian forestry workers and associated risk factors

Background

As forest is the preferred environment for ticks, forestry workers are exposed to tick bites and tick-borne diseases. We assessed the seroprevalence of anti-Borrelia burgdorferi (Bb) antibodies and investigated, using an integrated landscape approach, the individual and environmental factors associated with the seroprevalence of Bb in Belgian forestry workers, a high-risk group in Belgium.

Methods

A group of 310 Belgian forest workers was examined to assess the seroprevalence of anti-Borrelia IgG antibodies. Using principal component analysis and binary logistic regression, the joint effects of individual characteristics and environmental characteristics were examined.

Results

Sixty-seven of the 310 workers were seropositive for Lyme disease (LD), leading to a seroprevalence of 21.6%. The seroprevalence was higher among forest workers visiting forests more frequently (P = 0.003) or who reported over 100 tick bites (P-value < 0.001). The intensity of tick bites and the use of protection measures against tick bites have a positive impact on LD seroprevalence while the quantity of shadow from trees at ground level had a negative one.

Conclusions

This study showed that forest workers are a population at risk for LD and, by extension, at risk for various tick-borne diseases. In addition to the role of the environment, our results also showed the importance of considering exposure when predicting the risk of infection by Bb.

Leptospira Genomospecies and Sequence Type Prevalence in Small Mammal Populations in Germany

Leptospirosis is a worldwide emerging infectious disease caused by zoonotic bacteria of the genus Leptospira. Numerous mammals, including domestic and companion animals, can be infected by Leptospira spp., but rodents and other small mammals are considered the main reservoir. The annual number of recorded human leptospirosis cases in Germany (2001-2016) was 25-166. Field fever outbreaks in strawberry pickers, due to infection with Leptospira kirschneri serovar Grippotyphosa, were reported in 2007 and 2014. To identify the most commonly occurring Leptospira genomospecies, sequence types (STs), and their small mammal host specificity, a monitoring study was performed during 2010-2014 in four federal states of Germany. Initial screening of kidney tissues of 3,950 animals by PCR targeting the lipl32 gene revealed 435 rodents of 6 species and 89 shrews of three species positive for leptospiral DNA. PCR-based analyses resulted in the identification of the genomospecies L. kirschneri (62.7%), Leptospira interrogans (28.3%), and Leptospira borgpetersenii (9.0%), which are represented by four, one, and two STs, respectively. The average Leptospira prevalence was highest (∼30%) in common voles (Microtus arvalis) and field voles (Microtus agrestis). Both species were exclusively infected with L. kirschneri. In contrast, in bank voles (Myodes glareolus) and yellow-necked mice (Apodemus flavicollis), DNA of all three genomospecies was detected, and in common shrews (Sorex araneus) DNA of L. kirschneri and L. borgpetersenii was identified. The association between individual infection status and demographic factors varied between species; infection status was always positively correlated to body weight. In conclusion, the study confirmed a broad geographical distribution of Leptospira in small mammals and suggested an important public health relevance of common and field voles as reservoirs of L. kirschneri. Furthermore, the investigations identified seasonal, habitat-related, as well as individual influences on Leptospira prevalence in small mammals that might impact public health.

XMRV and Public Health: The Retroviral Genome Is Not a Suitable Template for Diagnostic PCR, and Its Association with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Appears Unreliable

A few years ago, a highly significant association between the xenotropic murine leukemia virus-related virus (XMRV) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a complex debilitating disease of poorly understood etiology and no definite treatment, was reported in Science, raising concern for public welfare. Successively, the failure to reproduce these findings, and the suspect that the diagnostic PCR was vitiated by laboratory contaminations, led to the retraction of the paper. Notwithstanding, XMRV continued to be the subject of researches and public debates. Occasional positivity in humans was also detected recently, even if the data always appeared elusive and non-reproducible. In this study, we discuss the current status of this controversial association and propose that a major role in the unreliability of the results was played by the XMRV genomic composition in itself. In this regard, we present bioinformatic analyses that show: (i) aspecific, spurious annealings of the available primers in multiple homologous sites of the human genome; (ii) strict homologies between whole XMRV genome and interspersed repetitive elements widespread in mammalian genomes. To further detail this scenario, we screen several human and mammalian samples by using both published and newly designed primers. The experimental data confirm that available primers are far from being selective and specific. In conclusion, the occurrence of highly conserved, repeated DNA sequences in the XMRV genome deeply undermines the reliability of diagnostic PCRs by leading to artifactual and spurious amplifications. Together with all the other evidences, this makes the association between the XMRV retrovirus and CFS totally unreliable.

High seroprevalence for indigenous spotted fever group rickettsiae in forestry workers from the federal state of Brandenburg, Eastern Germany

In the last decade six Rickettsia species, including Rickettsia slovaca have been characterized in Germany. All of these species could be linked to distinct clinical syndromes in humans. However, due to lack of seroepidemiological data an estimation of the prevalence and the public health impact of rickettsial infections in Germany is difficult. The aim of the present study was to determine the seroprevalence of spotted fever group (SFG) rickettsiae in a population with an elevated exposure risk to ticks. For that purpose, 559 sera of forestry workers in the federal state of Brandenburg, Eastern Germany, were screened for SFG-rickettsiae reactive IgG antibodies. Positive sera were subsequently titrated by microimmunofluorescence assay against R. helvetica, R. raoultii, R. felis, "R. monacensis" and R. slovaca. The total average IgG seroprevalence rate against SFG rickettsiae of 27.5% was found to be represented by 9.7% R. helvetica, 5% R. raoultii, 2.7% R. felis, 0.5% "R. monacensis" and 0.5% R. slovaca. The remaining 9.1% positive test results were of non-differentiable origin. IgG seroprevalences ranged from 11% to 55% in the different forestry districts. Older and male participants had a significantly higher probability for seropositivity and higher anti-rickettsia antibody titer level. In addition, the number of recent as well as the recalled lifetime tick bites was significantly associated with seropositivity and higher titers against SFG rickettsiae. In conclusion, we found an unexpected high total seroprevalence against SFG rickettsiae in forestry workers and serological evidence confirming the occurrence of R. raoultii, R. felis, "R. monacensis" and R. helvetica in the federal State of Brandenburg.

Detection of Leptospira DNA in urine and presence of specific antibodies in outdoor cats in Germany

Objectives Clinical manifestation of infection with Leptospira species in cats is rare. Nevertheless, cats can develop specific antibodies against the spirochetes after infection. In Canada, Taiwan and the USA it was recently demonstrated that naturally infected cats can also shed DNA from pathogenic Leptospira species in their urine, but the zoonotic potential of infected cats is still unclear. The objective of this study was to demonstrate if outdoor cats in Germany shed DNA from pathogenic Leptospira species in their urine. As a second aim, antibody prevalence was determined. Methods Two hundred and fifteen outdoor cats were prospectively recruited. Urine samples were tested by real-time PCR targeting the lipL32 gene of pathogenic Leptospira species. Antibody titres against eight serovars (Australis, Autumnalis, Bratislava, Canicola, Copenhageni, Grippotyphosa, Pomona, Saxkoebing) belonging to seven serogroups (Australis, Autumnalis, Canicola, Grippotyphosa, Icterohaemorrhagiae, Pomona, Sejroe) were determined by microscopic agglutination test. Results Urine samples from 7/215 cats (3.3%; 95% confidence interval [CI] 0.9-5.7) were PCR-positive. Specific antibodies were detected in 35/195 cats (17.9%; 95% CI: 12.5-23.3) with titres ranging from 1:100 to 1:6400. Australis, Bratislava and Grippotyphosa were the most common serovars. Conclusions and relevance Outdoor cats in Germany can shed DNA from pathogenic Leptospira species. Therefore, outdoor cats should be considered as a possible source of infection for dogs or humans. Further studies are needed to determine the role of Leptospira species as a cause of disease in cats.

Seroprevalence of seven pathogens transmitted by the Ixodes ricinus tick in forestry workers in France

In order to assess the level of occupational exposure to the main pathogens transmitted by the Ixodes ricinus tick, a seroprevalence study was performed on serum samples collected in 2003 from 2975 forestry workers of northeastern France. The global seroprevalence estimated for the seven pathogens studied was 14.1% (419/2975) for Borrelia burgdorferi sl, 5.7% (164/2908) for Francisella tularensis, 2.3% (68/2941) for tick-borne encephalitis virus, 1.7% (50/2908) for Anaplasma phagocytophilum and 1.7% (48/2908) for Bartonella henselae. The seroprevalences of Babesia divergens and Babesia microti studied in a subgroup of participants seropositive for at least one of these latter pathogens were 0.1% (1/810) and 2.5% (20/810), respectively. Borrelia burgdorferi sl seroprevalence was significantly higher in Alsace and Lorraine and F. tularensis seroprevalence was significantly higher in Champagne-Ardenne and Franche-Comté. The results of this survey also suggest low rates of transmission of Bartonella henselae and F. tularensis by ticks and a different west/east distribution of Babesia species in France. The frequency and potential severity of these diseases justify continued promotion of methods of prevention of I. ricinus bites.

Bartonella spp. - a chance to establish One Health concepts in veterinary and human medicine

Infectious diseases remain a remarkable health threat for humans and animals. In the past, the epidemiology, etiology and pathology of infectious agents affecting humans and animals have mostly been investigated in separate studies. However, it is evident, that combined approaches are needed to understand geographical distribution, transmission and infection biology of “zoonotic agents”. The genus Bartonella represents a congenial example of the synergistic benefits that can arise from such combined approaches: Bartonella spp. infect a broad variety of animals, are linked with a constantly increasing number of human diseases and are transmitted via arthropod vectors. As a result, the genus Bartonella is predestined to play a pivotal role in establishing a One Health concept combining veterinary and human medicine.