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Background: Over 200 different animal species are susceptible to infection by tularemia, highly infectious disease caused by Francisella tularensis. Hares (Lepus sp.) and small rodents, such as common vole (Microtus arvalis), have been acknowledged as the most significant sources of human tularemia infection in most European countries. Our objective was to verify ability of these species in predicting incidence of human tularemia in a Central European country, the Czech Republic. Materials and Methods: We used 17 years of data on densities of European hare (Lepus europaeus) and common vole, and climate variability to test effects of these factors on temporal dynamics of tularemia incidence. The data were obtained from annual reports available from online e-repositories. Results: The analysis showed that 33% of the yearly variation in human tularemia incidence was explained solely by the abundance of European hare in the Czech Republic during 2007–2022. Density of common vole and North Atlantic Oscillation index, a measure of climate variability, did not significantly explain tularemia incidence. While hare population declined severely during 1993–2022, we did not detect any clear accompanied decrease in the prevalence of tularemia in humans and hares. Conclusion: Contrary to expectations, only hares proved capable in predicting yearly dynamics in human tularemia incidence in the Czech Republic. We call for continued monitoring of infection rates in hares and advocate the use of hunter estimates of hare abundance as a cheap and effective means of predicting the risk of tularemia. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii may cause fatal infection in European brown hares (Lepus europaeus). However, the role of this parasite in terms of mortality rate in tularaemia endemic areas, amount of parasites in affected organs and circulating genotypes, is still unknown. In total, 36 hares (killed or found dead) were submitted for pathomorphological examination as a part of the national tularaemia and brucellosis monitoring. Tissue samples (lung, heart, liver, spleen and kidney) were tested by quantitative real‐time PCR targeting 529 bp region of T. gondii. Genotyping was performed by a 15 microsatellite markers method in a single multiplex PCR assay. The same tissues of hares were simultaneously used for the bacteriological cultivation. Toxoplasma gondii was detected by qPCR in the tissues of two hares. Spleen and lungs of one infected hare have been found harbouring up to ~7 millions of T. gondii parasites per gram of tissue. Both positive samples were characterized as T. gondii type II, one archetypal clonal type II and the other one a type II variant (W35 = 244). Bacteria Francisella tularensis was proved in pooled samples of three hares but without coinfection with T. gondii; all hares were negative for Brucella suis. Toxoplasma gondii has significant impact on mortality of European brown hares in tularaemia endemic areas and parasite load within the animal tissues may present high risk of human infection. [ABSTRACT FROM AUTHOR]

We retrospectively assessed the utility of a flow cytometry-based test quantifying the percentage of CD3+ T cells with the CD4-/CD8- phenotype for predicting tularemia diagnoses in 64 probable and confirmed tularemia patients treated during 2003-2015 and 342 controls with tularemia-like illnesses treated during 2012-2015 in the Czech Republic. The median percentage of CD3+/CD4-/CD8- T cells in peripheral blood was higher in tularemia patients (19%, 95% CI 17%-22%) than in controls (3%, 95% CI 2%-3%). When we used 8% as the cutoff, this test's sensitivity was 0.953 and specificity 0.895 for distinguishing cases from controls. The CD3+/CD4-/CD8- T cells increased a median of 7 days before tularemia serologic test results became positive. This test supports early presumptive diagnosis of tularemia for clinically suspected cases 7-14 days before diagnosis can be confirmed by serologic testing in regions with low prevalences of tularemia-like illnesses. [ABSTRACT FROM AUTHOR]

We retrospectively assessed the utility of a flow cytometry-based test quantifying the percentage of CD3+ T cells with the CD4-/CD8- phenotype for predicting tularemia diagnoses in 64 probable and confirmed tularemia patients treated during 2003-2015 and 342 controls with tularemia-like illnesses treated during 2012-2015 in the Czech Republic. The median percentage of CD3+/CD4-/CD8- T cells in peripheral blood was higher in tularemia patients (19%, 95% CI 17%-22%) than in controls (3%, 95% CI 2%-3%). When we used 8% as the cutoff, this test's sensitivity was 0.953 and specificity 0.895 for distinguishing cases from controls. The CD3+/CD4-/CD8- T cells increased a median of 7 days before tularemia serologic test results became positive. This test supports early presumptive diagnosis of tularemia for clinically suspected cases 7-14 days before diagnosis can be confirmed by serologic testing in regions with low prevalences of tularemia-like illnesses. [ABSTRACT FROM AUTHOR]

Francisella tularensis is a zoonotic, gram‐negative bacterium that causes tularemia in humans. Depending on its subspecies and the route of transmission, mild to lethal courses have been reported. F. tularensis subsp. holarctica is the only subspecies found in Europe and affects a plenitude of vertebrates including lagomorphs and rodents. Population outbreaks of certain rodent species are likely to be involved in the transmission of this pathogen. This molecular survey aims to evaluate the presence of F. tularensis in small mammals from three Central European countries. Using a real‐time polymerase chain reaction, F. tularensis DNA was detected in common voles (Microtus arvalis) from Switzerland and in field voles (Microtus agrestis) and a bank vole (Myodes glareolus) from Germany, but not in any other small mammal species. All common voles from the Czech Republic were negative for F. tularensis DNA. The prevalence in the three vole species varied between 1.3% and 3.0%. In conclusion, Francisella tularensis DNA was detected in three vole species in two of three countries investigated. The observed low prevalence raises questions on the role of voles for the transmission of Francisella tularensis in Central Europe. [ABSTRACT FROM AUTHOR]

Oropharyngeal tularemia was identified as the cause of a die-off in captured wild prairie dogs at a commercial exotic animal facility in Texas. From this point source, Francisella tularensis-infected prairie dogs were traced to animals distributed to the Czech Republic and to a Texas pet shop. F. tularensis culture isolates were recovered tissue specimens from 63 prairie dogs, including one each from the secondary distribution sites. Molecular and biochemical subtyping indicated that all isolates were F. tularensis subsp. holarctica (Type B). Microagglutination assays detected antibodies against F. tularensis, with titers as great as 1:4,096 in some live animals. All seropositive animals remained culture positive, suggesting that prairie dogs may act as chronic carriers of F. tularensis. These findings demonstrate the need for additional studies of tularemia in prairie dogs, given the seriousness of the resulting disease, the fact that prairie dogs are sold commercially as pets, and the risk for pet-to-human transmission. [ABSTRACT FROM AUTHOR]

Wild small mammals are the most common reservoirs of pathogenic microorganisms that can cause zoonotic diseases. The aim of the study was to detect antibodies related to Borrelia burgdorferi sensu lato, Coxiella burnetii, and Francisella tularensis in wild small mammals from the Czech Republic. In total, sera or heart rinses of 211 wild small mammals (168 Apodemus flavicollis, 28 Myodes glareolus, 9 A. sylvaticus, and 6 Sorex araneus) were examined by modified enzyme-linked immunosorbent assay. Antibodies related to B.burgdorferi s.l., C. burnetii, and F. tularensis were detected in 15%, 19%, and 20% of animals, respectively. The prevalence of B. burgdorferi and F. tularensis statistically differed in localities and F. tularensis also differed in sex. Antibodies against 2–3 pathogens were found in 17% of animals with a higher prevalence in M. glareolus. This study brings new data about the prevalence of the above-mentioned pathogens. [ABSTRACT FROM AUTHOR]

Currently, Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry (MALDI-TOF MS) is being evaluated for its efficacy as a fast bacterial typing tool due to its great speed compared to other molecular methods. In this study, we evaluated MALDI-TOF as a tool for quick identification and typing of Francisella tularensis. This study encompassed 86 strains from two different geographical origins (Spain and the Czech Republic), which were previously characterised by Pulsed-Field Gel Electrophoresis (PFGE) and Multiple-Locus Variable Number Tandem Repeat Analysis (MLVA). The direct colony method was used for microbial identification. High-quality spectra of the 86 strains were obtained and their main spectra profiles (MSPs) were created for epidemiological typing using MALDI-TOF. Based on the MSPs, principal components were generated and a dendrogram was constructed. An in-house MALDI-TOF library entry was created for each group of PFGE and MLVA strains based on their high-quality spectra. Two dendrograms were obtained using these entries and the unique peaks in each entry were searched. All strains were correctly identified to the species level. No clear divisions were found in the 86-strain dendrogram; however, Spanish and Czech strains appeared separately in dendrograms created using MLVA and PFGE entries. Entries from our in-house MALDI-TOF library revealed 2–4 biomarker peaks for the detection of the five PFGE groups and 1–12 biomarker peaks for the detection of the seven MLVA groups. Finally, two and one specific biomarkers were found in the Czech and Spanish strains, respectively. MALDI-TOF can be used to accurately identify F. tularensis strains in less than 15 min. Moreover, data on geographical origin and PFGE and MLVA groups could be obtained in less than one hour after colony growing. • Mass Spectrometry correctly identifies Francisella tularensis strains in less than 15 min, even if protein extraction is not performed. • A reliable clustering could not be achieved by the dendrogram obtained of all strains. • Dendrograms generated from the entries of our in-house library could be useful for the determination of the geographical origin of F. tularensis strains. [ABSTRACT FROM AUTHOR]

We retrospectively assessed the utility of a flow cytometry-based test quantifying the percentage of CD3+ T cells with the CD4-/CD8- phenotype for predicting tularemia diagnoses in 64 probable and confirmed tularemia patients treated during 2003-2015 and 342 controls with tularemia-like illnesses treated during 2012-2015 in the Czech Republic. The median percentage of CD3+/CD4-/CD8- T cells in peripheral blood was higher in tularemia patients (19%, 95% CI 17%-22%) than in controls (3%, 95% CI 2%-3%). When we used 8% as the cutoff, this test's sensitivity was 0.953 and specificity 0.895 for distinguishing cases from controls. The CD3+/CD4-/CD8- T cells increased a median of 7 days before tularemia serologic test results became positive. This test supports early presumptive diagnosis of tularemia for clinically suspected cases 7-14 days before diagnosis can be confirmed by serologic testing in regions with low prevalences of tularemia-like illnesses.

Tularemia, otherwise known as “rabbit fever”, is a zoonotic disease caused by a gram-negative intracellular bacterium - Francisella tularensis. The species is considered as a potential bioterrorism agent due to its high infectivity, the fact of being relatively easy to culture, the absence of human vaccine, and the potential for spreading through aerosol. In the Czech Republic, infection is usually caused by a tick bite, less frequently by a mosquito bite, direct contact with infected animals, or ingestion of contaminated water. The aim of this review is to provide a comprehensive view of tularemia, its diagnosis, clinical symptoms and treatment, along with the military perspective on a potential risk of F. tularensis to be misused as a biological weapon.