Potential Risk Of Pathogen Transmission Research Articles

Phytophthora and Phytopythium species associated with walnut dieback in plantations of northern Patagonia, Argentina

AbstractThe walnut industry in Argentina has grown in recent years, especially in northern Patagonia. However, this expansion has also brought new challenges, including the emergence of diseases threatening the health and productivity of walnut plantations. One of the most important diseases affecting walnut crops worldwide is ‘ink disease’ or ‘walnut dieback'. The aim of this study was to characterize ink disease, identify the aetiological agents, and estimate its incidence in walnut orchards of northern Patagonia, Argentina. Symptomatic trees were observed in the seven surveyed walnut orchards, showing a range of symptoms, including chlorosis and wilting, stem cankers and desiccation. In vivo assay and molecular analyses revealed that not only Phytophthora (P.) but also Phytopythium (Ph.) species are the causal agents of the disease, with P. drechsleri, Ph. mercuriale and Ph. vexans being the most virulent over the commonly used rootstock Juglans hindsii. Notably, Ph. vexans was the most frequently isolated pathogen, suggesting its prevalence and potential impact on the regional walnut industry. Overall, this study provides critical insights into the prevalence and impact of Phytophthora and Phytopythium species on walnut health in northern Patagonia. The presence of multiple pathogenic oomycete species raises concerns about the health of walnut orchards, as well as the potential risk of pathogen transmission to other fruit crops in the region. The findings will help growers to develop better cultural practices and implement measures to guarantee the sustainability of the walnut industry in Patagonia.

A systematic analysis of nosocomial outbreaks of nosocomial infections after gastrointestinal endoscopy

Esophagogastroduodenoscopy (EGD), endoscopic retrograde cholangiopancreatography (ERCP) and colonoscopy (CLN) come with a potential risk of pathogen transmission. Unfortunately, up to now data on the causes and the distribution of pathogens is rather sparse.We performed a systematic review of the medical literature using the Worldwide Outbreak Database, the PubMed, and Embase. We then checked so-retrieved articles for potential sources of the outbreak, the spectrum of pathogens, the attack rates, mortality and infection control measures.In total 73 outbreaks (EGD: 24, ERCP: 42; CLN: 7) got included. The corresponding attack rates were 3.5%, 7.1% and 12.8% and mortality rates were 6.3%, 12.7% and 10.0% respectively. EGD was highly associated with transmission of enterobacteria including a large proportion of multi-drug resistant strains. ERCP led primarily to transmission of non-fermenting gram-negative rods. The most frequent cause was human failure during reprocessing regardless of the type of endoscope.Staff working in the field of endoscopy should always be aware of the possibility of pathogen transmission in order to detect and terminate those events at the early most time point. Furthermore, proper ongoing education of staff involved in the reprocessing and maintenance of endoscopes is crucial. Single-use devices may be an alternative option and lower the risk of pathogen transmission, but on the downside may also increase costs and waste.

The psychometric properties and gender invariance of the Italian version of the Perceived Vulnerability to Disease Questionnaire (I-PVDQ) during the COVID-19 pandemic

BackgroundThe Perceived Vulnerability to Disease Questionnaire (PVDQ) measures beliefs associated with personal susceptibility to infectious diseases and behaviors or perceptions in the presence of potential risk of pathogen transmission. Given the onset of the Severe Acute Respiratory Syndrome Coronavirus 2 global pandemic, otherwise known as the COVID-19 pandemic, the construct being measured may function differently based on affective, behavioral, and cognitive changes along with the need to change norms and lifestyles in a global context. The present study aims to test the psychometric properties and the gender invariance of the Italian adaptation of the PVDQ to confirm that the scale can be used with Italian-speaking people, and that it functions effectively during a pandemic.MethodsA total of 509 participants filled out an online questionnaire including the Italian version of the I-PVDQ (I-PVDQ) and several measures of psychological constructs. Reliability and factor analyses (single and multigroup) were conducted. Bayesian correlation tests and Bayesian independent sample t-tests were used to assess the validity of I-PVDQ.ResultsExploratory factor analysis supported the two-factor structure of the I-PVDQ, and factor loadings loaded appropriately onto perceived infectability (PI) and germ aversion (GA). In terms of invariance, the scale showed configural, metric, scalar, and strict invariance across genders. Decisive evidence in favor of correlation with the measure of COVID-19 related fears for both PI and GA was found. There was strong evidence for observed correlations with COVID-19 related constructs such as intolerance to uncertainty, psychological inflexibility, resilience, stress, and anxiety. Women showed higher GA than men, while there were no gender differences in PI.ConclusionsTaken together, these results suggest that the I-PVDQ confirms the psychometric properties of the original version and that can be used to detect PVD when it is affected by environmental circumstances since its functioning is preserved during a pandemic.

Optimization of human platelet lysate production and pathogen reduction in a public blood transfusion center.

Human platelet lysate (HPL) has been proposed as a safe and efficient xeno-free alternative to fetal bovine serum (FBS) for large-scale culturing of cell-based medicinal products. However, the use of blood derivatives poses a potential risk of pathogen transmission. To mitigate this risk, different pathogen reduction treatment (PRT) practices can be applied on starting materials or on final products, but these methods might modify the final composition and the quality of the products. We evaluated the impact of applying a PRT based on riboflavin and ultraviolet irradiation on the raw materials used to manufacture an improved Good Manufacturing Practices (GMP)-grade HPL product in a public blood center. Growth promotion and the levels of growth factors and proteins were compared between an inactivated product (HPL4-i) and a non-inactivated product (HPL4). Stability studies were performed at 4°C, -20°C, and -80°C. The application of a PRT on the starting materials significantly altered the protein composition of HPL4-i as compared with HPL4. Despite this, the growth promoting rates were unaffected when compared with FBS used as a control. While all products were stable at -20°C and -80°C for 24 months, a significant decrease in the activity of HPL4-i was observed when stored at 4°C. Our results show that the application of a PRT based on riboflavin and ultraviolet light on starting materials used in the manufacture of HPL modifies the final composition of the product, yet its cell growth promoting activity is maintained at levels similar to those of non-inactivated products.

High overlap of zoonotic helminths between wild mammalian predators and rural dogs - an emerging One Health concern?

The concept of One Health emphasizes the interdependence of human, animal and environmental health and is of growing significance, in part owing to the problems related to emerging infectious diseases of wildlife origin. Wild mammalian predators are a potential risk factor for transmission of zoonotic pathogens to domesticated animals and humans. This is especially relevant in rural areas, where transmission of zoonotic pathogens can occur particularly efficiently when free-ranging dogs are present. The main aim of this study was to determine helminth infections among wild mammalian predators and evaluate the overlap between helminth faunas of wild mammals and dogs. Scat samples of predators were collected in coastal areas of Western Estonia and genetic methodology applied for the correct identification of predator species from their scat. Parasitic helminths of mammalian predators in the scat samples were analysed and compared with dog data from a previous study. High helminth prevalence (~90%) was found in dominant predator species in the area, namely the red fox (Vulpes vulpes) and golden jackal (Canis aureus). Moreover, the helminth fauna of both wild species, including potentially zoonotic helminths, overlapped largely with that of rural dogs in the same area. The results, together with the ones from earlier parasitological studies among humans in Estonia, emphasize the potential risk of pathogen transmission from wild mammalian predators to dogs and from dogs to humans, making parasitic diseases of wildlife a One Health concern.

Spatial Heterogeneity of Sympatric Tick Species and Tick-Borne Pathogens Emphasizes the Need for Surveillance for Effective Tick Control.

Three tick species that can transmit pathogen causing disease are commonly found parasitizing people and animals in the mid-Atlantic United States: the blacklegged tick (Ixodes scapularis Say), the American dog tick (Dermacentor variabilis [Say]), and the lone star tick (Amblyomma americanum [L.]) (Acari: Ixodidae). The potential risk of pathogen transmission from tick bites acquired at schools in tick-endemic areas is a concern, as school-aged children are a high-risk group for tick-borne disease. Integrated pest management (IPM) is often required in school districts, and continued tick range expansion and population growth will likely necessitate IPM strategies to manage ticks on school grounds. However, an often-overlooked step of tick management is monitoring and assessment of local tick species assemblages to inform the selection of control methodologies. The purpose of this study was to evaluate tick species presence, abundance, and distribution and the prevalence of tick-borne pathogens in both questing ticks and those removed from rodent hosts on six school properties in Maryland. Overall, there was extensive heterogeneity in tick species dominance, abundance, and evenness across the field sites. A. americanum and I. scapularis were found on all sites in all years. Overall, A. americanum was the dominant tick species. D. variabilis was collected in limited numbers. Several pathogens were found in both questing ticks and those removed from rodent hosts, although prevalence of infection was not consistent between years. Borrelia burgdorferi, Ehrlichia chaffeensis, Ehrlichia ewingii, and Ehrlichia "Panola Mountain" were identified in questing ticks, and B. burgdorferi and Borrelia miyamotoi were detected in trapped Peromyscus spp. mice. B. burgdorferi was the dominant pathogen detected. The impact of tick diversity on IPM of ticks is discussed.

Health profile of free-range wild boar (Sus scrofa) subpopulations hunted in Santa Catarina State, Brazil.

Wild boars represent a potential dissemination source of important pathogens to public and animal health, since they can host several pathogens. This study aimed to evaluate the health profile of wild boars hunted for population control in the state of Santa Catarina (SC), south of Brazil. For this study, tissue and blood samples were collected from 61 wild boars hunted from October 2017 to November 2018. All 61 serum samples were screened for antibodies by different assays, presenting the following seroprevalence: 52.4% for porcine circovirus type 2 (PCV2); 21.3% for Leptospira spp.; 19.7% for Mycoplasma hyopneumoniae; 13.1% for hepatitis E virus (HEV); and 9.8% for influenza A virus (IAV). No seroreaction was observed for Brucella spp. and classical swine fever virus (CSFV). At necropsy, the main lesions observed were evidence of pulmonary metastrongylid parasites, haemorrhagic lymph nodes and white-spotted liver. Histopathological analyses mainly showed interstitial pneumonia, bronchopneumonia and bronchi-associated lymphoid tissue (BALT) hyperplasia. There was a significant association between metastrongylid parasitism and BALT hyperplasia in lungs. Pathological findings of wild boars indicate that the assessed individuals were not exposed to notifiable diseases, such as CSFV, African swine fever virus and foot-and-mouth disease, which cause economic damage by non-tariff trade barriers. However, the detection of antibodies against PCV2 and M.hyopneumoniae, pathogens that impact commercial production, indicates the circulation of these agents, with frequency variation in wild populations. This shows the potential risk of pathogen transmission among domestic swine populations and free-living ones. The detection of antibodies against zoonotic agents such as HEV, IAV and Leptospira spp., other than characterizing the pathogens' circulation in these populations, suggests a potential risk to public health and pig farming, depending on the interactions established with the environment, humans and domestic swine.

In vivo degradation of polyurethane foam with 55 wt % polyethylene glycol.

Most topical hemostatic agents are based on animal-derived products like collagen and gelatin. They carry the potential risk of pathogen transmission while adjustments in the production process of these materials are limited. A synthetic hemostatic agent based on polyurethane (PU) and polyethylene glycol (PEG) was developed to overcome these disadvantages. The goal of this study was to compare the degradation process of this biomaterial to collagen and gelatin hemostatic agents. Samples of the test materials were implanted subcutaneously in both rats and rabbits. The animals were sacrificed at certain time intervals up to three years and the explanted samples were microscopically assessed. The histological examination showed a comparable pattern of degradation for the different test materials. Remnants of gelatin and collagen were seen up to 26 and 39 weeks, respectively. For PU, it took up to three years before micro-particles of the material were no longer detected. All biomaterials showed a good biocompatibility and no severe foreign body reactions occurred. The good biocompatibility and predictable pattern of resorption indicate that PU can be used as a topical hemostatic agent. However, a degradation time comparable to collagen and gelatin would be favorable.

Molecular identification and thermoresistance to boiling of Nocardia farcinica and Nocardia cyriacigeorgica from bovine bulk tank milk

Two strains of Nocardia spp. were isolated from bovine milk of two individual bulk tank. Molecular identification classified the strains as Nocardia farcinica and Nocardia cyriacigeorgica. The thermorresistance to boiling of the isolates was carried out and was observed bacterial growth after boiling. Our findings indicate the potential risk of pathogen transmission to humans through contaminated milk with Nocardia spp.

In vivo hemostatic efficacy of polyurethane foam compared to collagen and gelatin

Topical hemostatic agents are used in all surgical disciplines. Most of these hemostats are based on animal-derived products like collagen and gelatin. They carry the potential risk of pathogen transmission. A newly developed biodegradable, fully synthetic hemostatic agent based on polyurethane foam (PU) with 55 % polyethylene glycol (PEG) would prevent these potential risks. The hemostatic efficacy of this new agent was compared to gelatin and collagen in humans who underwent extraction of an upper and lower molar (split-mouth model). After extraction of a molar in the maxilla and mandible, a PU foam and collagen or gelatin were inserted in the extraction socket for 2 min. Hereafter, the agents were removed and stored in ethylenediaminetetraacetic acid to stop coagulation. Then, the concentration of coagulation parameters thrombin-antithrombin III (TAT) complexes, fibrinogen, and thromboxane B2 (TxB2) in blood extracts from the agents was measured. The concentrations were also determined in baseline blood samples which were collected from the extraction socket. The concentrations of TAT and TxB2 were significantly increased, and fibrinogen concentration was significantly reduced compared to baseline wound blood concentrations indicating enhanced hemostasis. No significant differences were seen in the concentrations of these coagulation parameters in the three different hemostatic agents. These results show that PU combined with 55 % PEG is a promising alternative for the animal-derived hemostatic agents. The synthetic hemostatic agent could replace the animal-derived products like collagen and gelatin and therewith prevent the potential risk of pathogen transmission.

Looking for the gold standard: assessment of the effectiveness of four traps for monitoring mosquitoes in Italy

Several kinds of traps are available for the collection of Culicidae species creating nuisance problems and/or a potential risk of pathogen transmission. The choice of the most appropriate sampling device should take into consideration the objective of the monitoring activity (e.g., faunistic research, vector control evaluation, arbovirus surveillance, etc.), the ecological and behavioral characteristics of the target mosquito species, and the ecology of the sampling areas. However, there are few factual criteria technical personnel can rely on to choose the most suitable sampling method, particularly when the targets are represented by mosquito species in temperate areas. We carried out a Latin square experiment in three ecologically different settings in Mantua municipality (northern Italy) to compare the performance of four different traps targeting host-seeking mosquitoes: two traps specifically designed for mosquito monitoring purposes (Centers for Disease Control and Prevention CO(2) trap and Biogents BG Eisenhans de Luxe trap) and two designed to reduce mosquito densities in outdoor domestic settings (Activa Acti Power Trap PV 440 and Activa Acti Power Trap MT 250 Plus). Overall, 1,930 specimens belonging to nine species were collected and differences in the performance of the four traps with reference to their ability to detect overall species diversity, as well as to collect single species, were highlighted. These observations, coupled with an analysis of the costs associated with the trap's purchase, operation, and servicing, provide useful indications for the implementation of mosquito monitoring in temperate areas.

Does fibrinogen concentrate reduce blood products use in major obstetric haemorrhage?

In July 2009, the Irish Blood Transfusion Service replaced cryoprecipitate with fibrinogen concentrate to reduce the potential risk of pathogen transmission. Fibrinogen concentrate appears to have similar efficacy in treatment...

Fibrinogen concentrate for management of bleeding

Fibrinogen concentrate for management of bleeding

154 EVALUATION OF THE EFFECTIVENESS OF TREATMENT WITH TRYPSIN IN MURINES EMBRYOS EXPERIMENTALLY EXPOSED TO BOVINE HERPES VIRUS TYPE-1 (BoHV-1) BY THE NESTED-PCR TECHNIQUE

The cryopreservation of bovine embryos has allowed an increase in their commercialization causing concern about the transmission of pathogens through the production and transfer of in vitro embryos. The International Society of Embryo Transfer (IETS) suggests the treatment of embryos with trypsin or antibiotics in alternating washes with culture medium in order to remove and/or inactivate infectious agents that may interfere with the final product. The aim of this study was to evaluate the effectiveness of trypsin treatment in the elimination and/or removal of bovine herpes virus type-1 (BoHV-1), Colorado strain, in murine embryos. Viral detection was made by n-PCR and cytopathic effect in Madin Darby bovine kidney (MDBK) cells. Six- to 8-wk-old female mice (Swiss) were superovulated and mated with fertile males of the same strain. After 24 h, the zygotes (n = 262) were divided into 3 groups: control group submitted to sequential wash (CSW), the group exposed to the virus (30 μL; 106.5 virus mL–1) and submitted to sequential wash (ESW), and the group exposed to the virus and submitted to the trypsin treatment (ETT). All the groups of zygotes and the last sequential wash drops were tested by nested-PCR and inoculated in MDBK cells to allow observation of cytopathic effects. All groups except for CSW showed positive results for the nested-PCR for both zygotes and for the last wash drops. A cytopathic effect was observed in all groups except for CSW, demonstrating the viability of the virus after treatment. These results demonstrated that trypsin treatment was not effective in eliminating or removal of BoHV-1. The need for such studies is fundamentally important when considering the potential risk of pathogen transmission by reproductive biotechnologies.

Potential risk of pathogen transmission by acaricide-poisoned ticks

Many aspects of tick poisoning with acaricides have yet to be elucidated. One of them is the influence of acaricide poisoning on tick infectivity to their hosts. To clarify this problem, we should know how tick poisoning develops after acaricide application. Data obtained during more than three decades of work with ticks of various species and with acaricides of different groups are presented in the paper. The first important phenomenon found was the gradual and progressive development of toxic symptoms after acaricide application, with death of the treated ticks delayed for days or even weeks (‘slow-death syndrome’). The development of symptoms was much faster after the application of fenthion, an organophosphorous acaricide, when compared to DDT, a chlorinated hydrocarbon. The larger the adult ticks of a particular species, the more refractory they were to acaricide action. The duration of the development of toxic symptoms directly correlates with the degree of species-specific refractoriness. A special index T LD 50 ( T LC 50 ) was introduced for comparing the duration of the poisoning development between different tick species, populations etc. The index determines the time when the final mortality is reached after using the LD 50 of a particular acaricide. Another index, T LD 90 , was used for practical purposes. The values of these indices decreased with increasing age of tick populations. The prolonged duration of poisoning was also observed in nymphal ticks of species with a prolonged life-span and the ability to overwinter ( Ixodes, Haemaphysalis) but not in ticks characterized by a short life-span ( Dermacentor). During the entire period of poisoning, from acaricide application until tick death, the individual tick passes through six stages defined by its locomotor capabilities. The stages are the same for nymphs and adults of both hard and soft ticks after treatment with various acaricides. When ticks are at the initial stages of poisoning (1st to 3rd stage for DDT or 1st to 2nd for fenthion), they can attach to hosts and imbibe blood. The average body weight of such ticks after repletion corresponded to that of control ticks. Engorged nymphal ticks normally molted to adults, engorged females normally oviposited, and their progeny did not differ from the progeny of control females. This second important phenomenon, called ‘overcoming the poisoning’, was observed in all studied species of ticks from several genera. Thus, the slow development of tick poisoning creates a potential for ticks to attach to hosts and to gorge blood, and for infected ticks to transmit pathogens to those hosts, while the ability to overcome the poisoning allows the ticks to survive and makes possible the subsequent transstadial and transovarial passage of pathogens. These data can be considered as strong circumstantial evidence of the risk that ticks can present to humans and animals at the initial stages of poisoning after acaricide treatment.