Role In Disease Transmission Research Articles

Spatial network clustering reveals elk population structure and local variation in prevalence of chronic wasting disease

AbstractSpatial organization plays prominent roles in disease transmission, genetics, and demography of wildlife populations and is therefore an important consideration not only for wildlife management, but also for inference about populations and processes. We used hierarchical agglomerative clustering of a spatial graph network to partition Wind Cave National Park (WICA) into five regions used by 163 female elk (Cervus elaphus) marked with global positioning system collars during 2005–08 and 2011–13. We grouped elk based on differential use of the five regions, developed a priori models for inter‐group variation in the occurrence of chronic wasting disease (CWD), and used Akaike's information criterion to compare models and stratify regions. Previous descriptions of elk population structure, which have been based on social contact or overlap of individual ranges, have distinguished spatially disjunct population subsets. Constructing hierarchical partitions of the landscape enabled us to also discern and describe overlapping and nested subsets. During 2016–18, apparent park‐wide prevalence of CWD was 0.18 (90% CI = [0.146, 0.182]); however, prevalence within three spatial strata used primarily by different elk ranged from 0.03 ([0.008, 0.074]) to 0.29 ([0.211, 0.375]). In context with published estimates of recruitment, predation, and anthropogenic mortality, such differences in prevalence equate to increasing local abundance of elk in southwestern WICA, stable to declining abundance in the west/northwest, and rapidly declining abundance in the east. Despite the modest size of WICA (11,357 ha), park‐wide averages conflate effects of elk distribution and disease, obscuring spatial patterns with profound implications for study and management of elk and CWD. Graph networks have been used widely in ecology to describe such phenomena as social relationships, connectivity of habitat patches, animal movements, and the spread of disease. Extension to partitioning of geographic range is straightforward but entails different considerations. We discuss allocation of sampling effort, construction of an initial partition, specification of a model for graph cohesion, selection of a clustering algorithm, and identification of useful partitions.

Morphological and molecular differentiation between Culicoides oxystoma and Culicoides kingi (Diptera: Ceratopogonidae) in Tunisia

BackgroundCulicoides kingi and Culicoides oxystoma belong to the Schultzei group of biting midges. These two species are vectors of disease in livestock of economic importance. As described in the literature, morphological identification for discrimination between them is still unclear. However, species-specific identification is necessary to solve taxonomic challenges between species and to understand their roles in disease transmission and epidemiology. This study aims to develop accurate tools to discriminate C. oxystoma from C. kingi using traditional morphometry and polymerase chain reaction-restriction fragment length polymorphism (PCR RFLP) assays for use in developing countries.MethodsSpecimens were collected from the region of Kairouan in central Tunisia. A total of 446 C. oxystoma/C. kingi individuals were identified using traditional morphometric analyses combined with PCR–RFLP of the cytochrome c oxidase subunit I gene. Thirteen morphometric measurements were performed from the head, wings, and abdomen of slide-mounted specimens, and six ratios were calculated between these measurements. Multivariate analyses of the morphometric measurements were explored to identify which variables could lead to accurate species identification.ResultsFour variables, namely antennae, wings, spermathecae, and palpus length, were suitable morphometric characteristics to differentiate between the species. Digestion with the SspI restriction enzyme of the PCR product led to good discriminative ability. Molecular procedures and phylogenetic analysis confirmed the efficiency of this simple and rapid PCR–RFLP method.ConclusionsThis study highlights for the first time in Tunisia the presence of C. oxystoma and its discrimination from C. kingi using abdominal measurements and the PCR–RFLP method. This approach could be applied in future epidemiological studies at the national and international levels.Graphical

Transmission and Transmissibility of SARS-CoV-2: What We Know and What We Not

Declared as a pandemic on March 11, 2020, COVID -19 has made it essential for the entire world to control and ensure safety measures for such infections in the future. To take any measures, one must be sure of the route of transmission of the agent causing Pandemic. With so many controversies in its mode of spread, COVID-19 has raised questions for the researchers to confirm its various modes of spread. Many of these modes can be overlooked; it is necessary to emphasize and illustrate them. The aim of this paper is to provide a brief overview of the various modes of COVID-19 transmission. According to the published literature, COVID-19 is primarily transmitted from person to person through oral and respiratory aerosols, with droplets from the virus-infected environment playing a minor role in disease transmission. The infection is particularly dangerous for healthcare workers and the elderly with comorbidities.

Socio-demographic and Clinical Profile of Covid-19 in Children

Introduction: The corona virus disease 2019 (COVID-19) is a pandemic disease. Infection by COVID-19 in children is not so common but gradually the numbers of children affected with COVID-19 are increasing day by day. The epidemiological importance and clinical pattern in children with COVID-19 is now a challenge to be described by the clinicians. Objectives: To describe socio-demographic and clinical characteristics of COVID-19 infected children. Material and Methods: This cross sectional observational study was conducted among 58 COVID-19 children who were admitted in COVID-19 dedicated Kurmitola General Hospital (KGH), Dhaka from March 2020 to July 2020. Their signs, symptoms, sex, age distribution, laboratory results and familial contact were analyzed. Results: Among 58 most of the children (63.8%) were in school going age (5-15years). The number of female (39) was more than male (19) and female-male ratio was 1:0.48. Most of the children (75.9%) came from urban lower middle socioeconomic group. About 84.4% children were affected from family member. Among all, (8.6%) patients had no symptoms. Main symptoms of the children were cough (36.2%), only fever (22.4%), fever with cough (8.62%) and diarrhoea (5.2%). About 12.06% of the children had additional symptoms including sore throat, nasal congestion, fatigue, headache, body ache, vomiting, abdominal pain, convulsion and rash, 6.9% had respiratory distress and one child came with convulsion. About 12.1% patients showed lymphopenia, 18.9% showed leucopenia, 13.8% patient had neutrophillia. C-Reactive Protein (CRP) and serum ferritin were high in only 12.1% and 8.6% cases respectively. There were 29.3% patients who had normal Chest X-Ray and 58.6% had mild lesion, 8.6% had bilateral consolidation and 3.4% had patchy opacities. Conclusions: COVID-19 is not so common in children and usually presents with mild form or no sign symptoms clinically and by laboratory analysis. But it is noteworthy that they may play role in transmission of disease. JAFMC Bangladesh. Vol 16, No 2 (December) 2020: 72-75

High-Throughput Sequencing for Examining Salmonella Prevalence and Pathogen—Microbiota Relationships in Barn Swallows

Studies in both humans and model organisms suggest that the microbiome may play a significant role in host health, including digestion and immune function. Microbiota can offer protection from exogenous pathogens through colonization resistance, but microbial dysbiosis in the gastrointestinal tract can decrease resistance and is associated with pathogenesis. Little is known about the effects of potential pathogens, such as Salmonella, on the microbiome in wildlife, which are known to play an important role in disease transmission to humans. Culturing techniques have traditionally been used to detect pathogens, but recent studies have utilized high throughput sequencing of the 16S rRNA gene to characterize host-associated microbial communities (i.e., the microbiome) and to detect specific bacteria. Building upon this work, we evaluated the utility of high throughput 16S rRNA gene sequencing for potential bacterial pathogen detection in barn swallows (Hirundo rustica) and used these data to explore relationships between potential pathogens and microbiota. To accomplish this, we first compared the detection of Salmonella spp. in swallows using 16S rRNA data with standard culture techniques. Second, we examined the prevalence of Salmonella using 16S rRNA data and examined the relationship between Salmonella-presence or -absence and individual host factors. Lastly, we evaluated host-associated bacterial diversity and community composition in Salmonella-present vs. -absent birds. Out of 108 samples, we detected Salmonella in six (5.6%) samples based on culture, 25 (23.1%) samples with unrarefied 16S rRNA gene sequencing data, and three (2.8%) samples with both techniques. We found that sex, migratory status, and weight were correlated with Salmonella presence in swallows. In addition, bacterial community composition and diversity differed between birds based on Salmonella status. This study highlights the value of 16S rRNA gene sequencing data for monitoring pathogens in wild birds and investigating the ecology of host microbe-pathogen relationships, data which are important for prediction and mitigation of disease spillover into domestic animals and humans.

Current Finding of Helminth Morphology Cause Infectious Disease

<p><strong>In Indonesia, the prevalence of helminthiasis is still high, especially in children. The frequency is 60-70% in populations at risk. The lack of use of family latrines causes soil contamination with feces around the yard. There are still few articles that review the morphology of worms that cause infectious diseases in Indonesia. Whereas knowledge of morphology is important to understand the life cycle of worms that play a role in disease transmission in humans and mammals. This article aims to discuss the latest findings regarding the morphology of worms that cause infectious diseases in humans. It can be concluded that at the adult stage, worms can be sexed. Usually, the female type has a relatively larger size than the male. On the head (anterior) there are 3 lips that have sensor papillae, one on the mediodorsal and 2 on the ventrolateral. Between the 3 lips there is a bucal cavity which is triangular in shape and functions as a mouth.</strong></p><p><em><strong>Keywords - </strong>Morphology, Helminth, Infectious disease</em></p>

91Is rainfall associated with paediatric acute gastroenteritis in an affluent setting? A 21-Year Retrospective Investigation

Abstract Background Although many literatures demonstrated heavy rainfall was associated with an increased risk of acute gastroenteritis via contaminated food and water, we hypothesized there is no association between rainfall and paediatric acute gastroenteritis in a setting with high-standard food and water hygiene. Methods Intestinal infection-related hospital admissions data during 1998-2018 for children under 5 years of age in Hong Kong were collected. Meteorological data were collected from the Hong Kong Observatory. A distributed lag nonlinear model was employed to examine the associations between meteorological factors and the risk of hospital admissions due to acute gastroenteritis. Results Rainfall did not exhibit a statistically significant association with the risk of paediatric admission due to acute gastroenteritis but low temperature, low and high relative humidity did. The risk was 6.3% higher (95% confidence interval: 0.3% to 12.6%) when temperature was at 15.1oC (i.e. the 5th percentile). The adjusted relative risk was statistically significantly higher when relative humidity was ≤73.0% or ≥ 84.0%. Conclusions Text: We suggest rainfall playing a minor role in disease transmission via contaminated food and water in affluent societies like Hong Kong. Instead, we speculate low temperature and humidity extremes have greater impact on transmission through increased stability and infectivity of enteric viruses. Key messages Weather plays a minor role in food and water contamination in affluent societies. Low temperature and humidity extremes might improve survival of enteric viruses.

Environmental parameters associated with incidence and transmission of pathogenic Vibrio spp.

Vibrio spp. thrive in warm water and moderate salinity, and they are associated with aquatic invertebrates, notably crustaceans and zooplankton. At least 12 Vibrio spp. are known to cause infection in humans, and Vibrio cholerae is well documented as the etiological agent of pandemic cholera. Pathogenic non-cholera Vibrio spp., e.g., Vibrio parahaemolyticus and Vibrio vulnificus, cause gastroenteritis, septicemia, and other extra-intestinal infections. Incidence of vibriosis is rising globally, with evidence that anthropogenic factors, primarily emissions of carbon dioxide associated with atmospheric warming and more frequent and intense heatwaves, significantly influence environmental parameters, e.g., temperature, salinity, and nutrients, all of which can enhance growth of Vibrio spp. in aquatic ecosystems. It is not possible to eliminate Vibrio spp., as they are autochthonous to the aquatic environment and many play a critical role in carbon and nitrogen cycling. Risk prediction models provide an early warning that is essential for safeguarding public health. This is especially important for regions of the world vulnerable to infrastructure instability, including lack of 'water, sanitation, and hygiene' (WASH), and a less resilient infrastructure that is vulnerable to natural calamity, e.g., hurricanes, floods, and earthquakes, and/or social disruption and civil unrest, arising from war, coups, political crisis, and economic recession. Incorporating environmental, social, and behavioural parameters into such models allows improved prediction, particularly of cholera epidemics. We have reported that damage to WASH infrastructure, coupled with elevated air temperatures and followed by above average rainfall, promotes exposure of a population to contaminated water and increases the risk of an outbreak of cholera. Interestingly, global predictive risk models successful for cholera have the potential, with modification, to predict diseases caused by other clinically relevant Vibrio spp. In the research reported here, the focus was on environmental parameters associated with incidence and distribution of clinically relevant Vibrio spp. and their role in disease transmission. In addition, molecular methods designed for detection and enumeration proved useful for predictive modelling and are described, namely in the context of prediction of environmental conditions favourable to Vibrio spp., hence human health risk.

Shedding and Genetic Diversity of Leptospira spp. From Urban Stray Dogs in Klang Valley, Malaysia

Leptospirosis is an endemic zoonoses of global proportions. Stray dogs have been postulated to play a role in disease transmission; however, supporting information are still limited. Roaming behavior may not only predispose the dogs to infection, but could also contribute to disease spread. In this study, the susceptibility of urban stray dogs in shedding Leptospira spp. was determined. Blood, urine, and tissue samples of kidney and liver were collected from 100 dogs from 2 animal control facilities. Serological testing using microscopic agglutination test (MAT) were performed on blood against 20 leptospiral serovars with a cut-off titre of ≥ 1:100. Samples were cultured onto semi-solid Ellinghausen and McCullough modified by Johnson and Harris (EMJH) media. Isolates were identified using molecular polymerase chain reaction (PCR) using 2 primers (16s rRNA and LipL32) and hyperimmune serum (HIS) MAT. The seroprevalence for the dogs positive for leptospirosis was 32% (n=32/100) with the following detected serovars: Javanica (n=13), Bataviae (n=10), Icterohaemorrhagiae (n=3), Autumnalis (n=2), Canicola (n=1), Pyrogenes (n=1), Copenhageni (n=1), and Australis (n=1). Six Leptospira spp. isolated were procured from urine (n=2), kidney (n=2) and liver (n=2). All 6 isolates belonged to L. interrogans, a pathogenic variant of Leptospira spp. Serotyping and phylogenetic analysis suggested serovar Bataviae (n=5) and serovar Canicola (n=1). Presence of vaccinal serovars (Icterohaemorrhagiae and Canicola) suggested potential post-vaccination antibodies but the predominance of non-vaccinal serovars (Javanica and Bataviae) indicate the possibility of current infection or post-exposure. Isolation of Leptospira spp. directly from urine sample not only suggested an active infection but highlighted the potential shedding capability among these stray dogs. These findings further strengthen speculations that urban stray dogs could play a role in transmission and dissemination of leptospirosis through their constant movement. The urine of infected dogs may contaminate the environment, posing a major public health threat.

Big bees spread disease: body size mediates transmission of a bumble bee pathogen.

Trait variation can have important consequences for the outcomes of species interactions. Even though some traits vary as much within species as across related species, models and empirical studies typically do not consider the role of intraspecific trait variation for processes such as disease transmission. For example, many pollinator species are in decline because of a variety of stressors including pathogens, but the role of intraspecific trait variation in mediating disease dynamics is rarely considered. For example, pollinator body size could affect pathogen transmission via differences in resistance, foraging behavior and physiology. We tested effects of body size on pollinator pathogen transmission using the common eastern bumble bee Bombus impatiens in field tents, introducing an infected "donor" microcolony of large or small workers with an uninfected average-sized "recipient" microcolony and allowing bees to forage for 9-16d. Small donor bees had nearly 50% higher infection intensity (cells/0.02 μL) than large donor bees, but large donor bees were twice as likely to transmit Crithidia bombi to recipient bees. Both behavioral and physiological mechanisms may underlie this apparent paradox. Compared to small bees, large bees foraged more and produced more feces; simulations showed that foraging and defecation rates together had stronger effects on transmission than did donor infection intensity. Thus, effects of bee size on contact rates and pathogen supply may play significant roles in disease transmission, demonstrating the multifaceted impacts of traits on transmission dynamics.

Micropathogen community identification in ticks (Acari: Ixodidae) using third-generation sequencing.

Ticks are important vectors that facilitate the transmission of a broad range of micropathogens to vertebrates, including humans. Because of their role in disease transmission, it has become increasingly important to identify and characterize the micropathogen profiles of tick populations. The objective of the present study was to survey the micropathogens of ticks by third-generation metagenomic sequencing using the PacBio Sequel platform. Approximately 46.481 Gbp of raw micropathogen sequence data were obtained from samples from four different regions of Heilongjiang Province, China. The clean consensus sequences were compared with host sequences and filtered at 90% similarity. Most of the identified genomes represent previously unsequenced strains. The draft genomes contain an average of 397,746 proteins predicted to be associated with micropathogens, over 30% of which do not have an adequate match in public databases. In these data, Anaplasma phagocytophilum and Coxiella burnetii were detected in all samples, while Borrelia burgdorferi was detected only in Ixodes persulcatus ticks from G1 samples. Viruses are a key component of micropathogen populations. In the present study, Simian foamy virus, Pustyn virus and Crimean-Congo haemorrhagic fever orthonairovirus were detected in different samples, and more than 10–30% of the viral community in all samples comprised unknown viruses. Deep metagenomic shotgun sequencing has emerged as a powerful tool to investigate the composition and function of complex microbial communities. Thus, our dataset substantially improves the coverage of tick micropathogen genomes in public databases and represents a valuable resource for micropathogen discovery and for studies of tick-borne diseases.

Trends in Incidence and Transmission Patterns of COVID-19 in Valencia, Spain

Limited information on the transmission and dynamics of SARS-CoV-2 at the city scale is available. To describe the local spread of SARS-CoV-2 in Valencia, Spain. This single-center epidemiological cohort study of patients with SARS-CoV-2 was performed at University General Hospital in Valencia (population in the hospital catchment area, 364 000), a tertiary hospital. The study included all consecutive patients with COVID-19 isolated at home from the start of the COVID-19 pandemic on February 19 until August 31, 2020. Cases of SARS-CoV-2 infection confirmed by the presence of IgM antibodies or a positive polymerase chain reaction test result on a nasopharyngeal swab were included. Cases in which patients with negative laboratory results met diagnostic and clinical criteria were also included. The primary outcome was the characterization of dissemination patterns and connections among the 20 neighborhoods of Valencia during the outbreak. To recreate the transmission network, the inbound and outbound connections were studied for each region, and the relative risk of infection was estimated. In total, 2646 patients were included in the analysis. The mean (SD) age was 45.3 (22.5) years; 1203 (46%) were male and 1442 (54%) were female (data were missing for 1); and the overall mortality was 3.7%. The incidence of SARS-CoV-2 cases was higher in neighborhoods with higher household income (β2 [for mean income per household] = 0.197; 95% CI, 0.057-0.351) and greater population density (β1 [inhabitants per km2] = 0.228; 95% CI, 0.085-0.387). Correlations with meteorological variables were not statistically significant. Neighborhood 3, where the hospital and testing facility were located, had the most outbound connections (14). A large residential complex close to the city (neighborhood 20) had the fewest connections (0 outbound and 2 inbound). Five geographically unconnected neighborhoods were of strategic importance in disrupting the transmission network. This study of local dissemination of SARS-COV-2 revealed nonevident transmission patterns between geographically unconnected areas. The results suggest that tailor-made containment measures could reduce transmission and that hospitals, including testing facilities, play a crucial role in disease transmission. Consequently, the local dynamics of SARS-CoV-2 spread might inform the strategic lockdown of specific neighborhoods to stop the contagion and avoid a citywide lockdown.

Mosquitoes (Diptera: Culicidae) from Villages and Forest Areas of Rural Communes in Khanh Hoa and Binh Phuoc Provinces, Vietnam.

This study presents the diversity of mosquitoes collected from communes, endemic with malaria and dengue, located in Khanh Hoa and Binh Phuoc Provinces, Vietnam. A total of 10,288 mosquitoes were collected in the village and forested sites using standard larval dippers, cow-baited traps, ultra-violet light traps, and mechanical aspirators. Mosquito taxa were identified morphologically and species complexes/groups were further characterized molecularly. Five genera of mosquitoes were morphologically identified: Anopheles Meigen (21 species), Aedes Meigen (2 species), Culex Linnaeus (5 species), Mansonia Blanchard sp., and Armigeres Theobald sp. The PCR-based identification methods allowed the distinction of members of Maculatus Group, Funestus Group, and Dirus Complex; and DNA barcodes enabled the further identification of the Barbirostris Complex. Data reported here include the first report of An. saeungae Taai & Harbach and An. wejchoochotei Taai & Harbach from Vietnam, and re-emphasizes the significance of using molecular data in an integrated systematic approach to identify cryptic species and better understand their role in disease transmission.

Escaping a Pandemic: Utilizing an Escape Room to Increase Learner Engagement in Infection Prevention and Control Education

Background : Healthcare professionals attempting to provide education understand the significance of active learner engagement and its impact on outcomes; however, engaging learners in reoccurring mandatory training that lack motivating factors is difficult. Deploying Escape Rooms as voluntary education to augment mandatory annual trainings has increased learner engagement among Clinical and Non-Clinical staff. Participants were given a pandemic, novel flu scenario and asked to select appropriate personal protective equipment prior to entering the Escape Room. Once inside, objectives included collaborating as a team to mitigate the spread of disease, evaluating environmental surfaces that play a role in disease transmission, and demonstrating at least 3 moments of hand hygiene while completing job duties. In debriefing, participants analyzed their performance and were asked to hypothesize how their roles would change during a pandemic. Methods : The Escape Room ran every half hour over four days for teams of 3-5, providing 48 opportunities for interactive learning. The scenario consisted of collecting nasal swabs and demographic information from six patients. After pre-briefing, participants had 10 minutes to complete the scenario. Teams of participants completed pre- and post-simulation surveys with multiple choice and open-ended questions. Results : Voluntary education increased from an average of 20, clinical discipline participants per training to 189 clinical and non-clinical learners. In subsequent simulations, employees who attended the Escape Room actively contributed to high-consequence infectious disease policies and procedures while employees who did not attend the Escape Room were disengaged in the ongoing pandemic preparations. Conclusions : Although Escape Rooms were conceived as a social activity, they are quickly yielding themselves as a low-cost, high-impact and effective tool for healthcare education. Despite the low level of perceived pandemic threat at the time, the Pandemic Escape Room yielded a high volume of learners who frequently request additional Escape Room offerings.

Catch Composition of Dipteran flies in Old Oyo National Park, Nigeria

Dipteran flies play significant role in disease transmission to human, domestic and wild animals. The distribution and diversity of dipteran flies of medical and veterinary importance in Old Oyo national park and its significant importance were assessed in relation to altitude and ecology. Twelve Nzi traps were set at 50 m equidistance to capture dipteran flies between February and August 2019. A total of 1529 dipteran flies belonging to five families were captured. More dipteran flies (64.9%) were trapped during the dry season than wet season (35.1%) (X2 = 270.8; P < 0.0001; OR = 3.41). Of the total flies caught, 289 representing 18.9% were identified as haematophagus flies. Differences in the total haematophagus fly 2 abundance was not significant across the altitudinal levels (X2 = 0.432; P = 0.511; OR = 1.13). The relative apparent density (RAD) of 0.47, 0.22, 0.13, 0.09, 0.07 and 0.03 (flies/trap/day) was observed in Glossina, Hippobosca, Tabanus, Haematopota, Chrysops, Ancala and, respectively. The diversity index of 0.55 and 0.76 were determined for Glossina spp. and Tabanids respectively. The non-blood sucking flies in order of abundance are Musca domestica (43.6%), Fanniacanicularis (41.9%), Chrysomyia bezziana (8.9%), Lucilia sericata (5.6%). If the value-chain of ecotourism is to be promoted in the park, vector-borne arthropods need to be controlled through the use of integrated methods.
 Keywords: Ecological survey, haematophagus flies, Old Oyo national Park, RAD

Tick Microbiomes in Neotropical Forest Fragments Are Best Explained by Tick-Associated and Environmental Factors Rather than Host Blood Source

The composition of tick microbiomes varies both within and among tick species. Whether this variation is intrinsic (related to tick characteristics) or extrinsic (related to vertebrate host and habitat) is poorly understood but important, as microbiota can influence the reproductive success and vector competence of ticks. We aimed to uncover what intrinsic and extrinsic factors best explain the microbial composition and taxon richness of 11 species of neotropical ticks collected from eight species of small mammals in 18 forest fragments across central Panama. Microbial richness varied among tick species, life stages, and collection sites but was not related to host blood source. Microbiome composition was best explained by tick life stage, with bacterial assemblages of larvae being a subset of those of nymphs. Collection site explained most of the bacterial taxa with differential abundance across intrinsic and extrinsic factors. Francisella and Rickettsia were highly prevalent, but their proportional abundance differed greatly among tick species, and we found both positive and negative cooccurrence between members of these two genera. Other tick endosymbionts (e.g., Coxiella and Rickettsiella) were associated with specific tick species. In addition, we detected Anaplasma and Bartonella in several tick species. Our results indicate that the microbial composition and richness of neotropical ticks are principally related to intrinsic factors (tick species and life stage) and collection site. Taken together, our analysis informs how tick microbiomes are structured and can help anchor our understanding of tick microbiomes from tropical environments more broadly.IMPORTANCE Blood-feeding arthropod microbiomes often play important roles in disease transmission, yet the factors that structure tick microbial communities in the Neotropics are unknown. Utilizing ticks collected from live animals in neotropical forest fragments, this study teases apart the contributions of intrinsic and extrinsic tick-associated factors on tick microbial composition as well as which specific microbes contribute to differences across tick species, tick life stages, the mammals they fed on, and the locations from where they were sampled. Furthermore, this study provides revelations of how notable tick-associated bacterial genera are interacting with other tick-associated microbes as well as the forest animals they encounter.

A novel fluorescence immunochromatographic assay strip for the diagnosis of schistosomiasis japonica

BackgroundSchistosomiasis japonica is a severe zoonosis. Domestic animals are the primary source of infection and play an important role in disease transmission. Surveillance and diagnosis play key roles in schistosomiasis control; however, current techniques for the surveillance and diagnosis of the disease have limitations. In this study, we developed a novel fluorescence immunochromatographic assay (FICA) strip to detect anti-Schistosoma japonicum antibodies in host serum.MethodsA FICA strip was developed for the diagnosis of Schistosoma japonicum in domestic animals. Streptococcus protein G (SPG) and soluble egg antigen (SEA) were transferred onto a nitrocellulose (NC) membrane to form the control line (C) and the test line (T), respectively. With fluorescence activity as well as binding activity to multispecies IgG, the recombinant protein rSPG-RFP was expressed and employed as an antibody indicator in the FICA strips.ResultsThe dual gene fusion plasmid was verified by PCR and restriction enzyme digestion. The expressed recombinant protein was 39.72 kDa in size, which was consistent with the predicted molecular weight. The western blot results showed binding activity between rSPG-RFP and IgGs from different hosts. Fluorescence microscopy also showed the fluorescence activity of the protein present. The affinity constant (Ka) values of rSPG-RFP with rabbit, donkey, mouse and goat IgG were 1.9 × 105, 4.1 × 105, 1.7 × 105 and 5.4 × 105, respectively. Moreover, based on the recombinant protein, the test strip for detecting S. japonicum in buffaloes could distinguish positive from negative serum. The lower limit of detection of the FICA strip was 1:10,000. Compared with ELISA, the FICA strips exhibited similar results in the diagnosis of infection in clinical bovine serum samples, with a kappa value of 0.9660 and P < 0.01. The cross-reactivities of the FICA strips with Haemonchus contortus and Schistosoma turkestanicum (30.15% and 91.66%, respectively) were higher than those of ELISA (26.98% and 87.5%, respectively).ConclusionsBased on the rSPG-RFP protein that we developed, strip detection can be completed within 15 min. Heightened sensitivity allows the strip to accurately identify schistosome antibodies in serum. In conclusion, this method is convenient, feasible, rapid and effective for detecting S. japonicum.Graphical

Leptospira spp. Antibody in Wild Boars (Sus scrofa), Hunting Dogs (Canis lupus familiaris), and Hunters of Brazil.

Hunting activities are a potential risk factor for human infection with Leptospira spp. and, although wild boar seroprevalence has been studied, there are no concurrent serosurveys of wild boars (Sus scrofa), hunting dogs (Canis lupus familiaris), and hunters. The aim of our study was to assess the seroprevalence of Leptospira spp. antibodies in free-ranging wild boars, hunting dogs, and hunters, and risk factors associated with exposure in southern and central-western Brazil. Leptospira spp. antibodies were serologically detected using the microscopic agglutination test, with a total 30 serovars. Overall, 12.2% (9/74) of wild boars and 10.6% (16/170) of hunting dogs were seropositive for at least one serovar and all hunters 0.0% (0/49) were seronegative for Leptospira spp. Seropositivity was statistically higher in 42.1% (8/19) wild boars from natural areas when compared to 2.4% (1/41) from anthropized areas (P<0.001), with prevalence ratio of 17.14 (95% confidence interval: 2.29-128.36). Despite the limited sample size, our findings showed that hunters may be less exposed to Leptospira spp. than are wild boars, particularly in natural areas where Leptospira spp. may be maintained by wild reservoirs. In addition to acting as sentinels, hunting dogs may play a role in disease transmission of sylvatic leptospiral serovars.

Chemical composition and acaricidal activity of Eucalyptus globulus essential oil against the vector of tropical bovine piroplasmosis, Rhipicephalus (Boophilus) annulatus.

Ticks are of great economic importance to humans and animals due to their role in disease transmission. The application of synthetic, chemical acaricides on the animal and/or the environment (the most used tick control method globally) has led to the selection of tick populations that are resistant. Their adverse effects on ecology andhuman and animal health cannot be overemphasised. As a result, the search for alternatives that are natural and can overcome these adverse effects are strongly indicated. Using gas chromatography-mass spectrometry (GC-MS) and adult immersion test (AIT), this study evaluated the chemical composition and acaricidal activity, respectively, of Eucalyptus globulus essential oil (EO) on Rhipicephalus (Boophilus) annulatus ticks. This is a major tick species implicated for the transmission of bovine piroplasmosis in Nigeria. The acaricidal activity was evaluated using different concentrations (0.625, 1.25, 2.5, 5 and 10%) of E. globulus EO. Amitraz (1 and 2%) and cypermethrin (2%) served as the positive control and 2% dimethylsulfoxide in distilled water was the negative control. Three replicates of 10 engorged female ticks each were immersed in the test samples for 2min and the experiment was done twice. The GC-MS analysis identified the major constituents of E. globulus EO as eucalyptol (1,8-cineole) (78%), menthol (20%) and menthone (3%). Eucalyptus globulus EO caused 97% acaricidal mortality at 10% concentration. The lower concentrations reduced tick fecundity up to 90% in a dose-dependent manner. This study provides support for plant EOs as alternative tick control strategy for humans and animals.

Soybean mosaic disease (SMD): a review

ABSTRACT Soybean Mosaic Disease (SMD) is one of the most serious, devastating, and widespread diseases of Glycine max (L.) Merry. caused by Soybean Mosaic Virus (SMV). It is more prevalent in low-lying and warm areas of soybean cultivation. SMV is also associated with severe mosaic, epinasty, and premature death of Passiflora spp. By soybean (Glycine max) seed, the transmission of soybean mosaic virus is at very rear chances. The studies and investigations made in the field of resolving the issues of transmission of soybean mosaic virus suggest that infected seed plays a vital role in disease transmission, but still there are no proper investigations to study the roles of several factors that may influence the SMV seed transmission. These are virus classification, virus transmission and establishment, symptoms of damage, electron microscopy, viral morphology, and control, which have been reviewed in this review article from currently available sources.