Pathogens transmitted by Ixodes ricinus.

Ixodes ricinus is the most important tick vector in central and western Europe and one of the most researched parasites. However, in the published literature on the tick and the pathogens it transmits, conjecture about specific transmission cycles and the clinical significance of certain microbes is not always clearly separated from confirmed facts. This article aims to present up-to-date, evidence-based information about the well-researched human pathogens tick-borne encephalitis virus, louping-ill virus, Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato and several Babesia species, with a focus on their development in the tick, transmission dynamics and the competent reservoir hosts that support their circulation in the environment. Borrelia miyamotoi, Neoehrlichia mikurensis, Rickettsia helvetica and Rickettsia monacensis, which are much less common causes of disease but may affect immunocompromised patients, are also briefly discussed. Finally, the possible role of I. ricinus in the transmission of Coxiella burnetii, Francisella tularensis, Bartonella spp. and Spiroplasma ixodetis is reviewed.

The Specificity of Epizootic and Epidemiological Processes in Natural Foci of Hemorrhagic Fever with Renal Syndrome and Tick-Borne Encephalitis in Russia, as the Basis for the Prospects of Creating a Combined Vaccine for the Prevention of These Infections.

Hemorrhagic fever with renal syndrome (HFRS) and tick-borne encephalitis (TBE) are the most common viral diseases in Russia. HFRS is caused by six different types of hantaviruses: Hantaan, Amur, Seoul, Puumala, Kurkino, and Sochi, which are transmitted to humans through small mammals of the Muridae and Cricetidae families. TBE is caused by viruses belonging to five different phylogenetic subtypes. The similarities in the ecology of HFRS and TBE pathogens is presented here. Hantavirus-infected small mammals can transmit the virus to uninfected animals, and ticks can also transmit hantavirus to other ticks and mammals. Hantavirus transmission from ticks to humans is possible only hypothetically based on indirect data. Over the past 23 years, 164,582 cases of HFRS (4.9 per 105 people) and 71,579 cases of TBE (2.5 per 105 people) were registered in Russia. The mortality rate was 0.4% (668 cases) in HFRS and 1.6% deaths (1136 cases) in TBE. There were 4030 HFRS (2.5%) and 9414 TBE (13%) cases in children under 14 years old. HFRS and TBE cases were registered in 42 out of 85 Russian regions; in 18-only HFRS, in 13-only TBE, and 12 had no reported cases. The prospects of applying a combined vaccine for HFRS and TBE prevention are shown in this paper.

First report of Leishmania tropica in domestic and wild animal hosts in hyperendemic areas of human cutaneous leishmaniasis in western Yemen: a neglected tropical disease needing One Health approach.

Cutaneous leishmaniasis (CL), a neglected tropical disease, is a major public health concern in Yemen, with Leishmania tropica identified as the main causative agent. This study aims to investigate the occurrence and distribution of Leishmania parasites in domestic and wild animals in CL endemic areas in the western highlands of Yemen. A cross-sectional study was conducted in the Utmah District of western Yemen. Blood and skin scraping specimens were collected from 122 domestic and wild animals and tested for the Leishmania DNA using internal transcribed spacer 1 (ITS1) nested polymerase chain reaction. Phylogenetic analyses were performed on 20 L. tropica sequences obtained from animals in this study and 34 sequences from human isolates (collected concurrently from the same study area) retrieved from the GenBank. Overall, L. tropica was detected in 16.4% (20/122) of the examined animals, including 11 goats, two dogs, two bulls, one cow, one donkey, one rabbit, one rat and one bat. None of the examined cats and sheep was positive. The animal sequences were segregated into four different L. tropica haplotypes, with the majority of the animal (15/20) and human (32/34) sequences composed of one dominant haplotype/genotype. These findings represent the first confirmed evidence of natural L. tropica infections in different kinds of domestic and wild animals in western Yemen, suggesting these animals potentially have a role in the transmission of CL in Yemen. Therefore, a One Health approach is required for the effective prevention and control of this devastating disease among endemic populations.

Japanese encephlu emergence in Australia: the potential population at risk.

Japanese encephalitis virus (JEV), an RNA virus transmitted by Culex mosquitoes, primarily cycles between aquatic birds and mosquitoes with pigs as amplifying hosts, posing a significant global encephalitis threat. The emergence and spread of the JEV in new epidemiological regions, such as recent cases in Australia and nonendemic areas like Pune, India, raise significant concerns. With an estimated 68 000 clinical cases and 13 600 to 20 400 deaths annually, JEV poses a substantial global health threat. The virus primarily affects children, with a case-fatality ratio of 20-30% and long-term neurological sequelae in survivors. The changing epidemiology, influenced by factors like bird migration, climate change, and increased urbanization, contributes to the geographic expansion of JEV. The recent outbreaks underscore the potential for the virus to establish itself in nonendemic regions, posing a threat to populations previously considered at low-risk. With limited treatment options and high rates of neurological complications, continued surveillance, traveler vaccination, and research into treatments are crucial to mitigate the impact of JEV on human health. The evolving scenario necessitates proactive measures to prevent and control the spread of the virus in both endemic and newly affected areas.

The Occurrence and Diversity of Tick-Borne Pathogens in Small Mammals from Serbia.

Background: Despite abundance of small mammals in Serbia, there is no information on their role in the epidemiology of tick-borne diseases (TBDs). This retrospective study aimed to identify different tick-borne pathogens (TBPs) in small mammals in Serbia collected during 2011. Materials and Methods: A total of 179 small mammals were collected from seven different localities in Serbia. The five localities belong to the capital city of Serbia-Belgrade: recreational areas-Ada Ciganlija, Titov gaj, and Kosutnjak as well as mountainous suburban areas used for hiking-Avala and Kosmaj. The locality Veliko Gradiste is a tourist place in northeastern Serbia, whereas the locality Milosev Do is a remote area in western Serbia with minor human impact on the environment. Results: The results of the presented retrospective study are the first findings of Rickettsia helvetica, Rickettsia monacensis, Neoehrlichia mikurensis, Borrelia afzelii, Borrelia miyamotoi, Babesia microti, Hepatozoon canis, and Coxiella burnetii in small mammals in Serbia. The presence of R. helvetica was confirmed in two Apodemus flavicollis, the presence of one of the following pathogens, R. monacensis, B. afzelii, H. canis, Ba. microti, and N. mikurensis was confirmed in one A. flavicollis each, whereas the presence of B. miyamotoi was confirmed in one Apodemus agrarius. Coinfection with B. afzelii and Ba. microti was confirmed in one A. flavicollis. DNA of C. burnetii was detected in 3 of 18 pools. Conclusions: The results confirm that detected pathogens circulate in the sylvatic cycle in Serbia and point to small mammals as potential reservoir hosts for the detected TBPs. Further large-scale studies on contemporary samples are needed to clarify the exact role of particular small mammal species in the epidemiology of TBDs caused by the detected pathogens.

Is the European badger a new host for Dirofilaria immitis? The first records in Greece.

Dirofilaria immitis is a ubiquitous nematode parasite with zoonotic potential, transmitted by mosquitoes, that causes heartworm disease in various animal species. Dogs are the parasite's typical final host, and wild carnivores represent the parasite's reservoir in nature. Studies on D. immitis infections in wild animals are essential to assess infection pressure for domestic animals, and until now, there has been only one infection case reported in a European badger (Meles meles). The current report describes the first two European badger cases with cardiovascular dirofilariosis in Greece. Two adult male badgers were rescued in Heraklion and Chania, Crete Island, and admitted to "ANIMA -Wildlife Rehabilitation Centre" in Athens. The detailed clinical examination revealed that the first badger suffered from severe broncho-pneumonitis while the second one displayed clinical signs associated with severe brain trauma. Blood samples were taken for haematology and biochemistry analyses during their short hospitalisation period. In addition, different routine diagnostic tests were carried out, including heartworm antigen testing (ELISA) and the modified Knott's test for microfilariae. Both badgers were positive in both tests. The animals died a few hours after their admission and the detailed necropsies followed, revealed the presence of three parasites in each animal's right heart, morphologically identified as adults of D. immitis. These findings add the European badger in the list of additional potential reservoir hosts for D. immitis and highlight the potential role of wildlife for companion animals and human health.

A Tomato-Free Period Delays and Reduces Begomovirus Disease in Processing Tomato Fields in a Complex Agroecosystem in Central Brazil.

A mandatory tomato-free period (TFP) was implemented in the state of Goiás, Brazil, in 2007 to help manage diseases caused by whitefly-transmitted begomoviruses. The impact of the TFP was examined in five locations across three states in Central Brazil from 2013 to 2016. Surveys revealed significant differences in begomovirus disease incidence among locations, i.e., low in Guaíra-TFP and Patos de Minas-TFP; moderate-high in Itaberaí-TFP and Morrinhos-TFP; and high in the non-TFP (NTFP) control, Cristalina-NTFP. PCR tests and DNA sequencing were used to validate the symptoms and showed that all collected symptomatic plant samples were infected with tomato severe rugose virus (ToSRV), a common indigenous bipartite begomovirus. Early season surveys (20 to 40 days after transplants [DAT]) in Itaberaí-TFP and Morrinhos-TFP revealed significantly less begomovirus disease in fields established sooner after the TFP (0 to 2 months) compared with incidences in (i) equivalent early planted fields in the Cristalina-NTFP control and (ii) fields established longer after the end of the TFP (>2 to 5 months). Whitefly infestation of crops was detected year-round in all locations and years, and all tested adults were classified in the Bemisia tabaci MEAM1 cryptic species. Infestation levels were significantly higher during the summer but did not vary significantly among locations. Results of monthly monitoring of adult whiteflies for general begomovirus and ToSRV were positively correlated and were indicators of disease incidence in the field. Notably, ToSRV was not detected in whiteflies collected from nontomato plants during the TFP, and there was a longer lag period before detection in whiteflies collected from processing tomatoes for Itaberaí-TFP and Morrinhos-TFP compared with Cristalina-NTFP. Taken together with the low levels of ToSRV infection detected in potential nontomato reservoir hosts at all locations, our results revealed low levels of primary inoculum during the TFP. Thus, even in a complex agroecosystem with year-round whitefly infestation of crops, the TFP was beneficial due to delayed and reduced begomovirus disease pressure during a critical stage of plant development (first month) and for favoring low levels of primary inoculum. Thus, we concluded that the TFP should be part of a regional integrated pest management (IPM) program targeting ToSRV in Brazil.

Diversity and host specificity of Borrelia burgdorferi's outer surface protein C (ospC) alleles in synanthropic mammals, with a notable ospC allele U absence from mixed infections.

Interactions among pathogen genotypes that vary in host specificity may affect overall transmission dynamics in multi-host systems. Borrelia burgdorferi, a bacterium that causes Lyme disease, is typically transmitted among wildlife by Ixodes ticks. Despite the existence of many alleles of B. burgdorferi's sensu stricto outer surface protein C (ospC) gene, most human infections are caused by a small number of ospC alleles ["human infectious alleles" (HIAs)], suggesting variation in host specificity associated with ospC. To characterize the wildlife host association of B. burgdorferi's ospC alleles, we used metagenomics to sequence ospC alleles from 68 infected individuals belonging to eight mammalian species trapped at three sites in suburban New Brunswick, New Jersey (USA). We found that multiple allele ("mixed") infections were common. HIAs were most common in mice (Peromyscus spp.) and only one HIA was detected at a site where mice were rarely captured. ospC allele U was exclusively found in chipmunks (Tamias striatus), and although a significant number of different alleles were observed in chipmunks, including HIAs, allele U never co-occurred with other alleles in mixed infections. Our results suggest that allele U may be excluding other alleles, thereby reducing the capacity of chipmunks to act as reservoirs for HIAs.

Concurrent colonization of rodent kidneys with multiple species and serogroups of pathogenic Leptospira.

Rodents are important reservoir hosts of pathogenic leptospires in the US Virgin Islands. Our previous work determined that trapped rodents were colonized with Leptospira borgpetersenii serogroup Ballum (n = 48) and/or Leptospira kirschneri serogroup Icterohaemorrhagiae (n = 3). In addition, nine rodents appeared to be colonized with a mixed population comprising more than one species/serogroup. The aim of this study was to validate this finding by characterizing clonal isolates derived from cultures of mixed species. Cultures of presumptive mixed species (designated LR1, LR5, LR37, LR57, LR60, LR61, LR68, LR70, and LR72) were propagated in different media including Hornsby-Alt-Nally (HAN) media, incubated at both 29℃ and 37℃, and T80/40/LH incubated at 29℃. Polyclonal reference antisera specific for serogroup Ballum and Icterohaemorrhagiae were used to enrich for different serogroups followed by subculture on agar plates. Individual colonies were then selected for genotyping and serotyping. Of the nine cultures of mixed species/serogroups, a single clonal isolate was separated in five of them: L. borgpetersenii serogroup Ballum in LR1, LR5, and LR37, and L. kirschneri serogroup Icterohaemorrhagiae in LR60 and LR72. In four of the cultures with mixed species (LR57, LR61, LR68, and LR70), clonal isolates of both L. borgpetersenii serogroup Ballum and L. kirschneri serogroup Icterohaemorrhagiae were recovered. Our results definitively establish that rodents can be colonized with more than one species/serogroup of Leptospira concurrently. The identification and characterization of multiple species/serogroups of Leptospira from individual reservoir hosts of infection are essential to understand the epidemiology and transmission of disease to both human and domestic animal populations.IMPORTANCEPathogenic Leptospira, the causative agent of human and animal leptospirosis, comprise a diverse genus of species/serogroups which are inherently difficult to isolate from mammalian hosts due to fastidious growth requirements. Molecular evidence has indicated that reservoir hosts of Leptospira may shed multiple species concurrently. However, evidence of this phenomena by culture has been lacking. Culture is definitive and is essential for comprehensive characterization of recovered isolates by high-resolution genome sequencing and serotyping. In this work, a protocol using recently developed novel media formulations, in conjunction with reference antisera, was developed and validated to demonstrate the recovery of multiple species/serogroups of pathogenic Leptospira from the same host. The identification and characterization of multiple species/serogroups of Leptospira from individual reservoir hosts of infection are essential to understand the epidemiology and transmission of disease to both human and domestic animal populations.

Ticks (Acari: Ixodida) on synanthropic small and medium-sized mammals in areas of the northeastern United States infested with the Asian longhorned tick, Haemaphysalis longicornis.

The northeastern United States (US) is a hotspot for tick-borne diseases. Adding to an already complex vector landscape, in 2017 large populations of the invasive Haemaphysalis longicornis, the Asian longhorned tick, were detected in New Jersey (NJ) and later found to be widespread from Connecticut to Georgia. In its native range in northeastern Asia, H. longicornis is considered an important vector of deadly pathogens to humans, companion animals, and livestock. To identify the primary hosts of H. longicornis, we surveyed synanthropic small and medium-sized mammals in three different sites in suburban New Brunswick, NJ. Specifically, we collected approximately 9,000 tick specimens belonging to nine species from 11 different species of mammals sampled between May and September 2021. We found that H. longicornis feeds more frequently on rodents than previously thought, and that this invasive tick is likely exposed to important enzootic and zoonotic pathogens. Overall, we obtained detailed information about the seasonal dynamics and feeding patterns of six tick species common in the northeastern US, Haemaphysalis longicornis, Amblyomma americanum, Dermacentor variabilis, Ixodes scapularis, Ixodes texanus and Ixodes cookei. We found that unlike I. scapularis that feeds on mammals of all sizes, H. longicornis feeds on hosts following the general pattern of A. americanum, favoring larger species such as skunks, groundhogs, and raccoons. However, our survey revealed that unlike A. americanum, H. longicornis reaches high densities on Virginia opossum. Overall, the newly invasive H. longicornis was the most numerous tick species, both on multiple host species and in the environment, raising significant questions regarding its role in the epidemiology of tick-borne pathogens, especially those affecting livestock, companion animals and wildlife. In conclusion, our findings provide valuable insights into the tick species composition on mammalian hosts in NJ and the ongoing national expansion of H. longicornis.

Impact of climate change on vector- and rodent-borne infectious diseases.

Background: Endemic and imported vector- and rodent-borne infectious agents can be linked to high morbidity and mortality. Therefore, vector- and rodent-borne human diseases and the effects of climate change are important public health issues. Methods: For this review, the relevant literature was identified and evaluated according to the thematic aspects and supplemented with an analysis of surveillance data for Germany. Results: Factors such as increasing temperatures, changing precipitation patterns, and human behaviour may influence the epidemiology of vector- and rodent-borne infectious diseases in Germany. Conclusions: The effects of climatic changes on the spread of vector- and rodent-borne infectious diseases need to be further studied in detail and considered in the context of climate adaptation measures.

Domestic Animals as Potential Reservoirs of Zoonotic Viral Diseases.

Zoonoses are diseases and infections naturally transmitted between humans and vertebrate animals. Over the years, zoonoses have become increasingly significant threats to global health. They form the dominant group of diseases among the emerging infectious diseases (EID) and currently account for 73% of EID. Approximately 25% of zoonoses originate in domestic animals. The etiological agents of zoonoses include different pathogens, with viruses accounting for approximately 30% of all zoonotic infections. Zoonotic diseases can be transmitted directly or indirectly, by contact, via aerosols, through a vector, or vertically in utero. Zoonotic diseases are found in every continent except Antarctica. Numerous factors associated with the pathogen, human activities, and the environment play significant roles in the transmission and emergence of zoonotic diseases. Effective response and control of zoonotic diseases call for multiple-sector involvement and collaboration according to the One Health concept.

Two Years into the COVID-19 Pandemic: Lessons Learned.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and virulent human-infecting coronavirus that emerged in late December 2019 in Wuhan, China, causing a respiratory disease called coronavirus disease 2019 (COVID-19), which has massively impacted global public health and caused widespread disruption to daily life. The crisis caused by COVID-19 has mobilized scientists and public health authorities across the world to rapidly improve our knowledge about this devastating disease, shedding light on its management and control, and spawned the development of new countermeasures. Here we provide an overview of the state of the art of knowledge gained in the last 2 years about the virus and COVID-19, including its origin and natural reservoir hosts, viral etiology, epidemiology, modes of transmission, clinical manifestations, pathophysiology, diagnosis, treatment, prevention, emerging variants, and vaccines, highlighting important differences from previously known highly pathogenic coronaviruses. We also discuss selected key discoveries from each topic and underline the gaps of knowledge for future investigations.

Circulation of zoonotic flaviviruses in wild passerine birds in Western Spain.

We explore the presence of zoonotic flaviviruses (West Nile virus (WNV) and Usutu virus (USUV)) neutralizing antibodies in rarely studied passerine bird species. We report, for the first time in Europe, WNV-specific antibodies in red avadavat and cetti's warbler, and USUV in yellow-crowned bishop. The evidence of WNV and USUV circulating in resident and migratory species has implications for both animal and public health. Future outbreaks in avian reservoir hosts may occur and passerines should be considered as priority target species in flavivirus surveillance programmes.

Transmission models indicate Ebola virus persistence in non-human primate populations is unlikely.

Infectious diseases that kill their hosts may persist locally only if transmission is appropriately balanced by susceptible recruitment. Great apes die of Ebola virus disease (EVD) and have transmitted ebolaviruses to people. However, understanding the role that apes and other non-human primates play in maintaining ebolaviruses in Nature is hampered by a lack of data. Recent serological findings suggest that few non-human primates have antibodies to EVD-causing viruses throughout tropical Africa, suggesting low transmission rates and/or high EVD mortality (Ayouba A et al. 2019 J. Infect. Dis.220, 1599-1608 (doi:10.1093/infdis/jiz006); Mombo IM et al. 2020 Viruses12, 1347 (doi:10.3390/v12121347)). Here, stochastic transmission models of EVD in non-human primates assuming high case-fatality probabilities and experimentally observed or field-observed parameters did not allow viral persistence, suggesting that non-human primate populations are highly unlikely to sustain EVD-causing infection for prolonged periods. Repeated introductions led to declining population sizes, similar to field observations of apes, but not viral persistence.

Apparent density, trypanosome infection rates and host preference of tsetse flies in the sleeping sickness endemic focus of northwestern Uganda.

BACKGROUND: African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies. METHODOLOGY: We deployed 109 biconical traps in 10 villages in two districts of northwestern Uganda to obtain information on the apparent density, trypanosome infection status and blood meal sources of tsetse flies. A subset (272) of the collected samples was analyzed for detection of trypanosomes species and sub-species using a nested PCR protocol based on primers amplifying the Internal Transcribed Spacer (ITS) region of ribosomal DNA. 34 blood-engorged adult tsetse midguts were analyzed for blood meal sources by sequencing of the mitochondrial cytochrome c oxidase 1 (COI) and cytochrome b (cytb) genes. RESULTS: We captured a total of 622 Glossina fuscipes fuscipes tsetse flies (269 males and 353 females) in the two districts with apparent density (AD) ranging from 0.6 to 3.7 flies/trap/day (FTD). 10.7% (29/272) of the flies were infected with one or more trypanosome species. Infection rate was not significantly associated with district of origin (Generalized linear model (GLM), χ2 = 0.018, P = 0.895, df = 1, n = 272) and sex of the fly (χ2 = 1.723, P = 0.189, df = 1, n = 272). However, trypanosome infection was highly significantly associated with the fly's age based on wing fray category (χ2 = 22.374, P < 0.001, df = 1, n = 272), being higher among the very old than the young tsetse. Nested PCR revealed several species of trypanosomes: T. vivax (6.62%), T. congolense (2.57%), T. brucei and T. simiae each at 0.73%. Blood meal analyses revealed five principal vertebrate hosts, namely, cattle (Bos taurus), humans (Homo sapiens), Nile monitor lizard (Varanus niloticus), African mud turtle (Pelusios chapini) and the African Savanna elephant (Loxodonta africana). CONCLUSION: We found an infection rate of 10.8% in the tsetse sampled, with all infections attributed to trypanosome species that are causative agents for AAT. However, more verification of this finding using large-scale passive and active screening of human and tsetse samples should be done. Cattle and humans appear to be the most important tsetse hosts in the region and should be considered in the design of control interventions.

Antigen-Specific Urinary Immunoglobulin in Reservoir Hosts of Leptospirosis.

Domestic and wildlife animal species act as reservoir hosts of leptospirosis, a global zoonotic disease affecting more than 1 million people annually and causing significant morbidity and mortality in domestic animals. In contrast to incidental hosts which present with an array of clinical manifestations, reservoir hosts are typically asymptomatic and can shed leptospires from chronically infected kidneys via urine for extended periods of time. Renal excretion of leptospires occurs despite evidence of a humoral and cellular immune response and is reflective of the unique biological equilibrium that exists between certain animal species and specific serovars of Leptospira. Here, we demonstrate that urinary excretion of leptospires is accompanied by the presence of antigen-specific urinary immunoglobulin. In rats experimentally infected with L. interrogans serovar Copenhageni using the intraperitoneal or conjunctival route of inoculation, urinary immunoglobulin (Ig) G specific for protein antigens was detectable within 1 week. Rat urinary IgG was not bound to urinary-derived leptospires. In cattle that were naturally exposed to, and infected with, L. borgpetersenii serovar Hardjo, urinary IgA specific for protein antigens was detected. Collectively, these results demonstrate that urinary excretion of immunoglobulin specific for leptospires is a hallmark of reservoir hosts of infection.

SARS-CoV-2 in animals: From potential hosts to animal models.

Within only one year after the first detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), nearly 100 million infections were reported in the human population globally, with more than two million fatal cases. While SARS-CoV-2 most likely originated from a natural wildlife reservoir, neither the immediate viral precursor nor the reservoir or intermediate hosts have been identified conclusively. Due to its zoonotic origin, SARS-CoV-2 may also be relevant to animals. Thus, to evaluate the host range of the virus and to assess the risk to act as potential animal reservoir, a large number of different animal species were experimentally infected with SARS-CoV-2 or monitored in the field in the last months. In this review, we provide an update on studies describing permissive and resistant animal species. Using a scoring system based on viral genome detection subsequent to SARS-CoV-2 inoculation, seroconversion, the development of clinical signs and transmission to conspecifics or humans, the susceptibility of diverse animal species was classified on a semi-quantitative scale. While major livestock species such as pigs, cattle and poultry are mostly resistant, companion animals appear moderately susceptible, while several model animal species used in research, including several Cricetidae species and non-human primates, are highly susceptible to SARS-CoV-2 infection. By natural infections, it became obvious that American minks (Neovison vison) in fur farms, e.g., in the Netherlands and Denmark are highly susceptible resulting in local epidemics in these animals.

Genetic diversity of Anaplasma bacteria: Twenty years later.

The genus Anaplasma (family Anaplasmataceae, order Rickettsiales) includes obligate intracellular alphaproteobacteria that multiply within membrane-bound vacuoles and are transmitted by Ixodidae ticks to vertebrate hosts. Since the last reclassification of Anaplasmataceae twenty years ago, two new Anaplasma species have been identified. To date, the genus includes eight Anaplasma species (A. phagocytophilum, A. marginale, A. centrale, A. ovis, A. bovis, A. platys, A. odocoilei, and A. capra) and a large number of unclassified genovariants that cannot be assigned to known species. Members of the genus can cause infection in humans and a wide range of domestic animals with different degrees of severity. Long-term persistence which, in some cases, is manifested as cyclic bacteremia has been demonstrated for several Anaplasma species. Zoonotic potential has been shown for A. phagocytophilum, the agent of human granulocytic anaplasmosis, and for some other Anaplasma spp. that suggests a broader medical relevance of this genus. Genetic diversity of Anaplasma spp. has been intensively studied in recent years, and it has been shown that some Anaplasma spp. can be considered as a complex of genetically distinct lineages differing by geography, vectors, and host tropism. The aim of this review was to summarize the current knowledge concerning the natural history, pathogenic properties, and genetic diversity of Anaplasma spp. and some unclassified genovariants with particular attention to their genetic characteristics. The high genetic variability of Anaplasma spp. prompted us to conduct a detailed phylogenetic analysis for different Anaplasma species and unclassified genovariants, which were included in this review. The genotyping of unclassified genovariants has led to the identification of at least four distinct clades that might be considered in future as new candidate species.

Investigation of possible alternate animal reservoir hosts of Opisthorchis viverrini.

Chronic opisthorchiasis caused by Opisthorchis viverrini (O. viverrini) adversely affects human health and is associated with a fatal bile duct cancer (cholangiocarcinoma). Although cats and dogs are known animal reservoir hosts of opisthorchiasis, there is limited information about whether other fish-eating animals are fluke reservoirs. Wetlands along Chi River of Thailand have abundant intermediate host snails and fish for O. viverrini and diverse other animal species. This led to our investigation into whether other fish-eating animals can also become infected and be alternate reservoir hosts for human opisthorchiasis. Our preliminary study focused on the O. viverrini infection status of crab-eating or long-tailed macaques roaming in Kosumpi National Forest Park in Chi River Basin, Kosumpisai District of Mahasarakam Province, and rodents, small residential mammals and fish-eating birds living in Lawa wetland complex of Khon Kaen Province. Fecal samples of each animal were collected and modified formalin ether concentration technique was applied to identify infections. Additionally, participatory epidemiology was used to retrieve information from local communities on opisthorchiasis transmission in these animals. No O. viverrini infection was found in any fecal samples suggesting that monkeys, rodents, small residential mammals and birds in these two wetlands probably do not serve as alternate reservoir hosts of O. viverrini.