Showing papers in "Vector-borne and Zoonotic Diseases in 2019"
TL;DR: It is of great importance to strengthen the monitoring of JEV as well as virus genotypes, especially in non-traditional epidemic areas, because the regional changes in JEV pose a great threat to human health, leading to huge disease burdens.
Abstract: Japanese encephalitis virus (JEV) is a representative virus of the JEV serogroup in genus Flavivirus, family Flaviviridae JEV is a mosquito-borne virus that causes Japanese encephalitis (JE), one of the most severe viral encephalitis diseases in the world JEV is divided into five genotypes (G1-G5), and each genotype has its own distribution pattern However, the distribution of different JEV genotypes has changed markedly in recent years JEV G1 has replaced G3 as the dominant genotype in the traditional epidemic areas in Asia, while G3 has spread from Asia to Europe and Africa and caused domestic JE cases in Africa G2 and G5, which were endemic in Malaysia, exhibited great geographical changes as well G2 migrated southward and led to prevalence of JE in Australia, while G5 emerged in China and South Korea after decades of silence Along with these changes, JE occurred in some non-traditional epidemic regions as an emerging infectious disease The regional changes in JEV pose a great threat to human health, leading to huge disease burdens Therefore, it is of great importance to strengthen the monitoring of JEV as well as virus genotypes, especially in non-traditional epidemic areas
53 citations
TL;DR: In South Korea, SFTS is an emerging disease, showing a rapid increase in reports since 2012, with high mortality, and reports of Lyme disease and Q fever cases have also been rapidly increasing during 2012-2017, although caution should be taken when interpreting these results, considering the likely influence of increased physician awareness and reporting of these diseases.
Abstract: Background: Bites with tick-borne pathogens can cause various bacterial, viral, or parasitic diseases in humans. Tick-transmitted diseases are known as contributing factors to the increasi...
48 citations
TL;DR: From 2006 through August 2017, a passive surveillance study of Ixodes ticks submitted from California, Oregon, and Washington was conducted by the TickReport program at the University of Southern California as discussed by the authors.
Abstract: From July 2006 through August 2017, a passive surveillance study of Ixodes ticks submitted from California, Oregon, and Washington was conducted by the TickReport program at the University...
45 citations
TL;DR: There has been substantial MERS-CoV research since 2012, but significant knowledge gaps persist, especially in epidemiology and natural history of the infection, and there have been few rigorous studies of baseline prevalence, transmission, and spectrum of disease.
Abstract: Background: Middle East respiratory syndrome coronavirus (MERS-CoV) was first identified in humans in 2012. A systematic literature review was conducted to synthesize current knowledge and...
41 citations
TL;DR: High-risk vector and host species identified in this study can be used to focus ASFV risk assessments in the U.S., guide targeted surveillance and control strategies, and proactively prepare for an AsFV incursion event.
Abstract: African swine fever virus (ASFV) continues to threaten global animal health and agricultural biosecurity. Mitigating the establishment of ASFV in the United States (U.S.) is contingent on (1) the identification of arthropod vectors and vertebrate hosts that are capable of viral maintenance and transmission in the U.S. and (2) knowledge of vector-host associations that may permit transmission. We aggregated data on vector competence, host competence and tick-host associations by systematic review of published articles and collection records to identify species that may support the invasion of ASFV in the U.S. Three species of competent soft ticks occur in the U.S., Ornithodoros coriaceus, Ornithodoros turicata, and Ornithodoros puertoricensis, however, vector competence for the majority of soft ticks in the U.S. remains unknown. Three species of competent vertebrate hosts currently occur in the U.S.: domestic pigs (Sus scrofa domesticus), feral hogs (Sus scrofa), and common warthogs (Phacochoerus africanus). Hierarchical hazard categories based on vector competence, tick-host contact rates, and vector abundance were used to semiquantitatively rank U.S. soft tick species by their relative risk for contributing to ASFV transmission to identify which soft tick species are a priority for future studies. High-risk vector and host species identified in this study can be used to focus ASFV risk assessments in the U.S., guide targeted surveillance and control strategies, and proactively prepare for an ASFV incursion event. Results indicate O. coriaceus, O. turicata, and O. puertoricensis demonstrate the highest relative risk for contributing to ASFV transmission in the U.S., however, many gaps in knowledge exist preventing the full evaluation of at least 30 soft tick species in the U.S. Further study is required to identify soft tick vectors that interact with feral swine populations, elucidate vector competence, and further understand the biology of soft tick species.
31 citations
TL;DR: Efficacy of fipronil seems comparable with DeltaDust, which exhibited a residual effect for ∼10 months in prior studies, and continued research is needed to optimize fipronsil treatments for plague management on prairie dog colonies.
Abstract: Plague, a flea-borne disease, hampers efforts to restore populations of black-footed ferrets (Mustela nigripes), which occupy colonies of prairie dogs (Cynomys spp.) in North America. Plag...
28 citations
TL;DR: Considering the biphasic character of S. suis meningitis and its frequently atypical outcome, all individuals with this condition should be optimally supervised by a multidisciplinary team, including an ENT specialist.
Abstract: Streptococcus suis, a prevalent porcine pathogen, may sporadically cause infections in humans, and has recently emerged as a cause of zoonoses in some professionals. The aim of this article was to review available data on epidemiology, etiopathogenesis, diagnostics, and management of the most common form of S. suis infection, purulent meningitis. Literature data show that S. suis is an important etiological factor of purulent meningitis, especially in subjects being occupationally exposed to contact with pigs and/or pork meat. Owing to growing incidence of S. suis meningitis, a history of such exposure should be verified in each patient presenting with typical meningeal symptoms. Whenever S. suis was confirmed as the etiological factor of purulent meningitis, therapeutic protocol should be adjusted appropriately, to avoid patient's exposure to potentially ototoxic antimicrobial agents and corticosteroids. Considering the biphasic character of S. suis meningitis and its frequently atypical outcome, all individuals with this condition should be optimally supervised by a multidisciplinary team, including an ENT specialist.
28 citations
TL;DR: Data from this study support multiple other contemporary studies that indicate infrequent detection of R. rickettsii in D. variabilis in North America.
Abstract: Dermacentor variabilis, a common human-biting tick found throughout the eastern half and along the west coast of the United States, is a vector of multiple bacterial pathogens. Historically, D. variabilis has been considered a primary vector of Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever. A total of 883 adult D. variabilis, collected between 2012 and 2017 from various locations in 12 states across the United States, were screened for rickettsial DNA. Tick extracts were evaluated using three real-time PCR assays; an R. rickettsii-specific assay, a Rickettsia bellii-specific assay, and a Rickettsia genus-specific assay. Sequencing of ompA gene amplicons generated using a seminested PCR assay was used to determine the rickettsial species present in positive samples not already identified by species-specific real-time assays. A total of 87 (9.9%) tick extracts contained R. bellii DNA and 203 (23%) contained DNA of other rickettsial species, including 47 (5.3%) with Rickettsia montanensis, 11 (1.2%) with Rickettsia amblyommatis, 2 (0.2%) with Rickettsia rhipicephali, and 3 (0.3%) with Rickettsia parkeri. Only 1 (0.1%) tick extract contained DNA of R. rickettsii. These data support multiple other contemporary studies that indicate infrequent detection of R. rickettsii in D. variabilis in North America.
26 citations
TL;DR: The prevalence of SFTSV in adult and nymph ticks was relatively high, compared with previous reports, andSFTSV was detected in ticks collected from both trail and nontrail areas in the national parks, and up to 800 meters above sea level.
Abstract: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging viral disease in East Asian countries, including China, Japan, and the Republic of Korea (ROK). The causative agent of SFTS is the SFTS virus (SFTSV), which is transmitted by ticks. To investigate the prevalence of SFTSV in the ROK, a total of 9744 ticks were collected from vegetation in five national parks between July and November 2015. Of the collected adult and nymph ticks, Haemaphysalis longicornis (68.44%) was the most abundant, followed by Haemaphysalis flava (29.66%), Ixodes nipponensis (1.56%), and Amblyomma testudinarium (0.34%). Collected larval ticks were of the genera Haemaphysalis (99.61%) and Ixodes (0.39%). One-step RT-PCR and nested PCR were used to detect SFTSV-specific genes from each individual adult and nymph tick and pooled larval ticks. SFTSV was detected in 4.77% (48/1006) in H. longicornis, 1.15% (5/436) in H. flava, 0% (0/23) in I. nipponensis, and 20% (1/5) in A. testudinarium. The infection rate of SFTSV in adult and nymph ticks was 3.61%. The prevalence of SFTSV in adult and nymph ticks was relatively high, compared with previous reports. In larval ticks, the minimum infection rate was 0.31%. SFTSV was detected in ticks collected from both trail and nontrail areas in the national parks, and up to 800 meters above sea level. The sequences obtained showed 99.4-99.7% homology with SFTS virus S segment sequences from Chinese and Japanese ticks.
25 citations
TL;DR: The results suggest that there may be a large number of host animals for GETV in the local area, and it is important to improve the monitoring of the incidence of GETV infection in domestic animals, in particular among pigs and beef cattle.
Abstract: We detected neutralizing antibodies of Getah virus (GETV) in serum specimens of domestic animals collected from Yunnan Province in China. Antibodies were detected in serum specimens of chicken, duck, dairy cattle, pig, and beef cattle. The positive rate of antibodies in pig and beef cattle was high (46–72%), with titers of 1:640–1:2560. These results suggest that there may be a large number of host animals for GETV in the local area. It is important to improve the monitoring of the incidence of GETV infection in domestic animals, in particular among pigs and beef cattle, by surveillance for animal illness and testing of sick animals.
24 citations
TL;DR: The results indicated that mosquitoes in China are widely infected with R. felis, the agent of human flea-borne spotted fever, and that R. bellii can also occur outside of the Americas and its usual tick hosts.
Abstract: To add to the limited information on Rickettsia in mosquitoes in China, we carried out a PCR survey on convenience samples of 3051 mosquitoes collected with hand nets in and around domestic dwellings in 25 provinces. Five species of mosquitoes were identified: Culex pipiens pallens (n = 1620), Aedes albopictus (806), Armigeres subalbatus (377), Anopheles sinensis (168), and Culex tritaeniorhynchus (80). A Rickettsia nested-PCR targeting the variable domain of gltA showed Rickettsia felis in four mosquito species of 16 provinces Cx. pipiens pallens (1.8%, 29/1620); Ae. albopictus (1.2%, 10/806); An. sinensis (1.2%, 2/168); and Ar. subalbatus (2.1%, 8/377). Rickettsia bellii was also widespread, occurring in 12 provinces and 2 species: Cx. pipiens pallens (4.3%, 69/1620) and An. sinensis (0.6%, 1/168). R. felis and R. bellii were found in almost similar numbers in female [1.5% (27/1809) and 1.2% (21/1809), respectively] as in male mosquitoes [1.8% (22/1242) and 4.0% (49/1242), respectively]. Our results indicated that mosquitoes in China are widely infected with R. felis, the agent of human flea-borne spotted fever, and that R. bellii can also occur outside of the Americas and its usual tick hosts.
TL;DR: HGA, LD, and tick-borne encephalitis (TBE) pathogens are actively circulating in these ecosystems and have the potential to coinfect vectors that might increase the risk of transmitting multiple pathogens to humans during host feeding by individual ticks.
Abstract: Introduction: Tick-borne encephalitis virus (TBEV) and Borrelia burgdorferi, the causative agent of Lyme disease (LD), are widespread in Western Ukraine. However, relatively little is know...
TL;DR: Serological data suggest henipavirus spillover from bats to livestock and human populations in Africa without reported clinical disease in any of these species, and potential sources for virus spillover are discussed.
Abstract: Nipah virus (NiV) and Hendra virus (HeV) are closely related members within the genus Henipavirus, family Paramyxoviridae, for which fruit bats serve as the reservoir. The initial emergence of NiV infections in pigs and humans in Malaysia, and HeV infections in horses and humans in Australia, posed severe impacts on human and animal health, and continues threatening lives of humans and livestock within Southeast Asia and Australia. Recently, henipavirus-specific antibodies have also been detected in fruit bats in a number of sub-Saharan African countries and in Brazil, thereby considerably increasing the known geographic distribution of henipaviruses. Africa is progressively being recognized as a new high prevalence zone for henipaviruses, as deduced from serological and molecular evidence of past infections in Madagascar, Ghana, Republic of Congo, Gulf of Guinea, Zambia, Tanzania, Cameroon, and Nigeria lately. Serological data suggest henipavirus spillover from bats to livestock and human populations in Africa without reported clinical disease in any of these species. All virus isolation attempts have been abortive, highlighting the need for further investigations. The genome of the Ghanaian bat henipavirus designated Ghana virus (GhV), which was detected in a pteropid Eidolon helvum bat, is the only African henipavirus that has been completely sequenced limiting our current knowledge on the genetic diversity and pathogenesis of African henipaviruses. In this review, we summarize the available data on the circulation of henipaviruses in Africa, discuss potential sources for virus spillover, and highlight existing research gaps.
TL;DR: WNV IgM antibodies positive were detected in acute serum specimens of patients clinically diagnosed with JEV infection in JEV-endemic areas, but no WNV neutralization antibodies were detected fourfold greater than that of the corresponding JEV antibodies.
Abstract: This study detected West Nile virus (WNV) infection in serum samples of patients clinically diagnosed with viral encephalitis in the Japanese encephalitis virus (JEV) endemic area (seven p...
TL;DR: The role that dogs play in Latin American countries where Chagas disease is endemic is described and the implementation of dog intervention could complement other control measures currently in place, mostly in periods when vector spraying has been interrupted.
Abstract: This review describes the role that dogs play in Latin American countries where Chagas disease is endemic. Multiple studies determined the high frequency with which canine populations are infected with Trypanosoma cruzi. The infection prevalence of dogs is greater than that of humans and the presence of infected dogs in households is associated with a higher risk of human infection. Dog infectiousness to triatomine vectors is several-fold higher than that of humans, thereby underscoring their major role in the domestic transmission of T. cruzi. Insecticide spraying of houses is in most cases efficacious but the lack of sustainability hinders this vector-focused strategy. Multi-pronged approaches have been adopted to improve control measures but dog intervention was never included. Experimental evaluation of systemic insecticides or deltamethrin-impregnated collars suggested that dog intervention leading to triatomine killing could curb domestic transmission of T. cruzi. Larger field studies are required to determine its applicability and efficacy. However, the implementation of dog intervention could complement other control measures currently in place, mostly in periods when vector spraying has been interrupted.
TL;DR: Investigation of spleen samples from moose in southern Sweden shows that Swedish moose are exposed to pathogens that in some instances are more commonly found in regions with warmer climate, and highlights the importance of also considering moose as sentinels of vector-borne pathogens.
Abstract: Climate change, with warmer temperatures and altered precipitation patterns, has affected the distribution of vectors and vector-borne diseases. In the northern hemisphere, vectors are spreading north, and with them, pathogens of zoonotic and animal health impact. Eurasian moose (Alces alces alces) are physiologically and anatomically adapted for cold climate, and are rarely considered ideal hosts of vectors, apart from deer keds (Lipoptena cervi). To investigate the presence of vector-borne pathogens, spleen samples from 615 moose were collected in southern Sweden from 2008 to 2015. The samples were analyzed with a high-throughput PCR method for 24 bacterial, and 12 parasitic pathogens. Anaplasma (82%), Borrelia (3%), Babesia (3%), and Bartonella (1%) DNA was found, showing that moose are exposed to, and can act as hosts of some of these pathogens, which can have an impact of both animal and human health. These results show that Swedish moose are exposed to pathogens that in some instances are more commonly found in regions with warmer climate, and highlights the importance of also considering moose as sentinels of vector-borne pathogens. Further research is needed to understand the effect of these pathogens on the health of individual moose and to elucidate whether climate change and moose population density interact to create the pattern observed.
TL;DR: Sand flies are sensitive to environmental modification and species diversity is greater in regions that have experienced less anthropization, and the high abundance of Ps.
Abstract: This study examined sand fly diversity and the natural infection of sand flies by Leishmania in three localities in Rondonia State: Santo Antonio and Sao Vicente farm, which are anthropize...
TL;DR: The results support that the emergence of BSF in the residential park was a consequence of the increase of the local capybara population, which in turn, provided the increment of the A. sculptum population.
Abstract: The bacterium Rickettsia rickettsii causes Brazilian spotted fever (BSF), a highly lethal disease that is transmitted by Amblyomma sculptum ticks in areas where capybaras (Hydrochoerus hydrochaeris) are the tick's major hosts. In this study, we evaluated the expansion of a capybara population in a residential park in Sao Paulo state, and the implications of such expansion to the occurrence of ticks and BSF. The capybara population was quantified during 2004-2013. In 2012, there was a BSF human case in the area, culminating in the complete fencing of the residential park and the official culling of all capybaras. Quantification of ticks in the environment was performed by dry ice traps from 2005 to 2018. Domestic dogs in 2006-2011 and capybaras in 2012 were serologically tested for the presence of anti-R. rickettsii antibodies. Our results show that capybara numbers increased ≈5 times from 2004 (41 capybaras) to 2012 (230 capybaras). Dry ice traps collected A. sculptum and Amblyomma dubitatum. The number of A. dubitatum adult ticks was generally higher than A. sculptum adults during 2005-2006; however, during 2012-2013, A. sculptum outnumbered A. dubitatum by a large difference. During 2016-2018 (after capybara culling), the number of both species fell close to zero. The low numbers of A. sculptum adult ticks during 2005-2006 coincided with relatively low capybara numbers (<80). Thereafter, in 2012, we counted the highest numbers of both A. sculptum ticks and capybaras (230 animals). All 40 canine blood samples were seronegative to R. rickettsii, in contrast to the 48.3% seropositivity (83/172) among capybaras. Our results support that the emergence of BSF in the residential park was a consequence of the increase of the local capybara population, which in turn, provided the increment of the A. sculptum population. Culling the entire capybara population eliminated the risks of new BSF cases.
TL;DR: The results revealed that zoonotic agents were common in dogs from the Castellón province, and Animals from rural areas and sheltered dogs were particularly at risk of these infections.
Abstract: The diversity and frequency of enteric parasites in dog populations in the Castellon province (Eastern Spain) were assessed using a prospective cross-sectional epidemiological survey. A to...
TL;DR: Cx.
Abstract: Introduction: Sindbis virus (SINV) is a mosquito-borne Alphavirus known to infect birds and cause intermittent outbreaks among humans in Fenno-Scandia. In Sweden, the endemic area has mainly been i ...
TL;DR: This is the first evidence of the DENV-2 genome in bats in from the Colombian Caribbean, and shows a high similarity with serotype-2 dengue virus (DENV- 2).
Abstract: Natural infection of dengue virus (DENV) in bats is an unexplored field in Colombia. To detect the presence of DENV in bats, a descriptive prospective study using a nonprobabilistic sampling was carried out; 286 bats in 12 sites were caught. Sample tissues of different animals were obtained; the RNA was obtained from tissues and a nested-RT-PCR was carried out and detected amplicons of 143 fragment of the NS5 gene were sequenced by the Sanger method. In nonhematophagous bats Carollia perspicillata and Phyllostomus discolor captured in Ayapel and San Carlos (Cordoba), respectively, an amplicon corresponding to NS5 was detected. The amplicons showed a high similarity with serotype-2 dengue virus (DENV-2). This is the first evidence of the DENV-2 genome in bats in from the Colombian Caribbean.
TL;DR: Seropositivity to zoonotic pathogens is common among Alaskans with the highest to Cryptosporidium spp.
Abstract: Background: Due to their close relationship with the environment, Alaskans are at risk for zoonotic pathogen infection. One way to assess a population's disease burden is to determine the ...
TL;DR: Cat seroprevalence was higher in this Midwestern location than has previously been reported elsewhere in the United States, and this population was more likely to be Leptospira spp.
Abstract: By the nature of their environment and behavior, free-roaming cats are at increased risk of exposure to a wide range of pathogens compared with client-owned cats. Consequently, free-roaming cats can act as a reservoir for possible zoonotic infections. In this study, 140 cats were prospectively recruited over a 12-month period from a free-roaming cat spay and neuter clinic and a local animal shelter in the state of Iowa. The presence of antileptospiral antibodies was measured using a microscopic agglutination test against six leptospiral serovars (canicola, pomona, icterhemorrhagiae, bratislava, hardjo, and grippotyphosa). In addition, serum samples were tested for the presence of antibodies against Toxoplasma gondii and Dirofilaria immitis using an ELISA and lateral flow immunoassay, respectively. Serum samples from 12/139 cats (8.6%) were positive for the leptospiral serovars tested, with bratislava having the highest prevalence. Cats were more likely to be positive in the spring than in the fall or summer. Positive titers to T. gondii and D. immitis were present in 42/140 cats (30%) and 9/140 cats (6.4%), respectively. Cats >72 months of age were more likely to be seropositive to T. gondii than cats in younger age groups. Feline Leptospira spp. seroprevalence was higher in this Midwestern location than has previously been reported elsewhere in the United States. Contrary to previously reported seasonal trends, this population was more likely to be Leptospira spp. seropositive in the spring rather than fall or summer. Seroprevalence of D. immitis in this geographical location was substantially lower than previous reports of free-roaming cats in the United States.
TL;DR: The distribution of SFTS natural foci was under the influence of multidimensional environmental factors and slope and maximum temperature of warmest month were the key environmental risk factors.
Abstract: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging natural focus, tick-borne disease caused by a novel bunyavirus named SFTS virus (SFTSV). The main purpose of this study was to analyze the environmental risk factors and geographic distribution of SFTS natural foci in Jiangsu Province. A retrospective space-time analysis by SaTScan software was used to detect clusters at the town level. The maximum entropy modeling method was applied to construct the ecological niche model and analyze the environmental risk factors, and then to draw the predicted risk map. The performance of the model was assessed using the area under the curve (AUC) and known occurrence locations. During the years 2010-2016, a total of 140 laboratory-confirmed indigenous SFTS cases occurred in Jiangsu Province, with 66 occurrence locations. The reported number of SFTS cases increased year by year and SFTS cases occurred from April to October with a peak between May and August each year. Three clusters detected by space-time scan statistical analysis were connected together and shared the similar ecological environmental characteristic of hilly landscape. Fifteen environmental variables with different percent contribution can influence the ecological niche model in different degrees, whereas slope (suitable range: 0.1-4) and maximum temperature of warmest month (suitable range: 32.8-34.2°C) as the key environmental factors contributed 46.1% and 23.2%, respectively. The model had high accuracy on prediction with the averaged training AUC of 0.926. Within a predicted risk map, potential areas at high risk and 10 previously unidentified endemic regions were recognized. The distribution of SFTS natural foci was under the influence of multidimensional environmental factors. Slope and maximum temperature of warmest month were the key environmental risk factors. These results provide a valuable basis for the selection of prevention and control strategies, and the identification of potential risk areas.
TL;DR: These analyses indicate that California, Texas, Georgia, and Florida are high-priority candidates for proactive risk reduction strategies and areas of California, Florida, and much of the southwestern United States were classified as high risk for ASFV establishment and spillover should an introduction event occur.
Abstract: African swine fever virus (ASFV) causes a high-consequence foreign animal disease that has emerged along international trade routes. Owing to high lethality and resulting trade sanctions, establishment of this disease in the United States would have devastating economic consequences. ASFV can be transmitted by soft ticks in the genus Ornithodoros or directly between swine, including domestic, feral, and wild swine. Consequently, the spatial risk of ASFV establishment depends on where susceptible animals, with or without competent vectors, co-occur. We synthesized county-level historical records of soft tick occurrence, current maps of feral swine distribution, and domestic swine inventory to evaluate the risk of ASFV establishment and spillover in the United States. Areas of California, Florida, and much of the southwestern United States were classified as high risk for ASFV establishment and spillover should an introduction event occur. Our analyses indicate that California, Texas, Georgia, and Florida are high-priority candidates for proactive risk reduction strategies. Domestic swine are often produced in high-biosecurity environments, mitigating health risks associated with contacting infected hosts and vectors. However, small-scale and organic pig producers in much of the southern United States remain more vulnerable to disease emergence.
TL;DR: The presence of R. typhi in fleas from cats suggests that in Galveston, there exists a small but measurable risk to humans who come into contact with flea-infested cats.
Abstract: Murine typhus is a flea-borne typhus group rickettsiosis caused by Rickettsia typhi. Once a prevalent disease in the United States, the use of dichlorodiphenyltrichloroethane in the 1940s broke the classic rat-rat flea cycle of transmission, and the remaining endemic foci are now believed to be associated with opossums and the cat flea (Ctenocephalides felis). In Galveston, Texas murine typhus has re-emerged as a cause of febrile illness, and 7% of fleas collected from opossums are infected with R. typhi. In this study, we sought to explore the prevalence of rickettsiae associated with fleas on cats, as these animals have been speculated to play a role in the epidemiology of murine typhus. Fleas were collected from feral cats entering a local veterinary clinic as part of a trap, spay, neuter, and release program. Fleas were identified and subjected to analysis by PCR and sequencing. An estimation of the minimum infection rate (MIR) of pooled samples was performed. Three hundred fourteen fleas (all C. felis) were collected from 24 cats. Sequences for the outer membrane protein B gene revealed R. typhi in one pool (MIR 0.3%), Rickettsia felis in four pools (MIR 1.3%), Rickettsia asembonensis in one pool (MIR 0.3%), and "Candidatus R. senegalensis" in six pools (MIR 2.0%). Results were confirmed by sequencing portions of the rickettsial citrate synthase and 17-kD protein gene. In this study, the presence of R. typhi in fleas from cats suggests that in Galveston, there exists a small but measurable risk to humans who come into contact with flea-infested cats. Despite this, we believe that the low prevalence from cat-collected fleas, compared with that previously detected from opossums, makes cats less likely to play a role in the maintenance of R. typhi in this region. The significance of other identified flea-borne rickettsiae is yet to be elucidated.
TL;DR: The study indicated that HEV is widespread in industrial farms in Bulgaria and presented high seroprevalence in pigs and showed age dependency, and the National Health Authorities should raise awareness of HEV and its zoonotic potential.
Abstract: Hepatitis E virus (HEV) has been isolated from humans and several animals' species. During the last years, the knowledge of HEV infection dramatically changed and enriched. The aim of this...
TL;DR: The prevalence of CTFV is confirmed in D. andersoni ticks within the Bitterroot Valley, which has remained at levels found in the 1950s and 60s, and evidence of reassortment was observed between strains within the valley.
Abstract: The Rocky Mountain wood tick, Dermacentor andersoni, has long been known to transmit human pathogens. Within the Bitterroot Valley, Ravalli County, Montana, these agents include Rickettsia rickettsii, Francisella tularensis, and Colorado tick fever virus (CTFV). Found in the western United States where wood ticks occur, CTFV causes a biphasic, febrile illness in humans and persists in enzootic cycles involving the ticks and small mammals. CTFV belongs to the genus Coltivirus, family Reoviridae, whose genome consists of 12 double-stranded RNA segments. Previous studies revealed the presence of CTFV-infected ticks and rodents in select locations within the valley in the 1960s and 1970s, using animal and cell culture methods for detection. We aimed to determine the range and prevalence of the virus in adult questing ticks throughout the valley using molecular tools and to examine the genomic variation between virus strains. Adult D. andersoni ticks were collected during 2002-2003 and 2009-2013. RNA extractions and reverse transcription-polymerase chain reaction were performed on 921 ticks, of which 61 ticks were positive for CTFV, resulting in a 6.6% prevalence of infection. Four genetic loci, one from each of the segments 9, 10, 11, and 12, within the viral genome were sequenced. Reassortment was detected between CTFV sequence strains within the valley. This study confirmed the prevalence of CTFV in D. andersoni ticks within the Bitterroot Valley, which has remained at levels found in the 1950s and 60s. Additional CTFV sequences were obtained and evidence of reassortment was observed between strains within the valley.
TL;DR: A Flavivirus survey on 183 hunting dogs was conducted in Campania region, Southern Italy and the seroprevalence value of 40.43% (74/183, 95% confidence intervals [CIs] 33.37–47.49) detected flavivirus in dogs detected in the region.
Abstract: A Flavivirus survey on 183 hunting dogs was conducted in Campania region, Southern Italy. The seroprevalence value of 40.43% (74/183, 95% confidence intervals [CIs] 33.37-47.49) detected in our study using a competitive enzyme-linked immunosorbent serologic assay (cELISA) proves a considerable level of Flavivirus exposition of these animals. Among the 74 cELISA-positive sera, seroneutralization (SN) test showed that 24 sera resulted positive for Usutu virus with an overall prevalence of 13.11% (24/183) (95% CI 8.27-17.95), but none of cELISA-positive samples resulted positive for West Nile virus. Data analysis showed a significant difference of cELISA seropositivity risk factors in case of presence of farm animals in contact with hunting dogs and for dogs living in a rural environment but not for gender, age, management, hunting season, and hunting abroad. A RT-PCR assay was performed to detect the Flavivirus RNA, but none of the blood samples tested positive. This study documents the first report regarding the circulation of Flavivirus in hunting dog in Southern Italy and suggests the dog as an interesting target to monitor Flavivirus circulation.
TL;DR: The results indicate that the total number of JE cases in China in 2013 was significantly higher compared with those in 2011 and 2012, and the incidence rate increased substantially in those aged 15 years and older.
Abstract: Background: A Japanese encephalitis (JE) epidemic occurred in 2013 in China. The aim of this study was to determine the spatial–temporal pattern of JE cases in adults occurring in 2013, as...