scholarly journals Investigation of Cyprinid Herpesvirus 3 (CyHV-3) Disease Periods and Factors Influencing CyHV-3 Transmission in A Low Stocking Density Infection Trial

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 2
Author(s):  
Isaiah Tolo ◽  
Przemyslaw Bajer ◽  
Tiffany Wolf ◽  
Sunil Mor ◽  
Nicholas Phelps
Keyword(s):  
Incubation Period ◽  
Disease Modeling ◽  
Stocking Density ◽  
Direct Transmission ◽  
Viral Loads ◽  
Koi Herpesvirus ◽  
Indirect Transmission ◽  
Cyprinid Herpesvirus 3 ◽  
Environmental Disease ◽  
Kinetics Of

Cyprinid herpesvirus 3 (CyHV-3) is the etiological agent of koi herpesvirus disease (KHVD) and important pathogen of aquaculture and wild populations of common carp worldwide. Understanding the relative contributions of direct and indirect transmission of CyHV-3 as well as the factors that drive CyHV-3 transmission can clarify the importance of environmental disease vectors and is valuable for informing disease modeling efforts. To study the mechanisms and factors driving CyHV-3 transmission we conducted infection trials that determined the kinetics of KHVD and the contributions of direct and indirect forms of CyHV-3 transmission, as well as the contributions of contact rate, viral load, pathogenicity and contact type. The incubation period of KHVD was 5.88 + 1.75 days and the symptomatic period was 5.31 + 0.87 days. Direct transmission was determined to be the primary mechanism of CyHV-3 transmission (OR = 25.08, 95%CI = 10.73–99.99, p = 4.29 × 10−18) and transmission primarily occurred during the incubation period of KHVD. Direct transmission decreased in the symptomatic period of disease. Transmissibility of CyHV-3 and indirect transmission increased during the symptomatic period of disease, correlating with increased viral loads. Additionally, potential virulence-transmission tradeoffs and disease avoidance behaviors relevant to CyHV-3 transmission were identified.

scholarly journals Asymptomatic COVID-19 Adult Outpatients identified as Significant Viable SARS-CoV-2 Shedders 

2021 ◽  
Author(s):  
Marie Glenet ◽  
Anne-Laure Lebreil ◽  
Laetitia Heng ◽  
Yohan N’Guyen ◽  
Ittah Meyer ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Control Measures ◽  
Upper Respiratory Tract ◽  
Rna Detection ◽  
Viral Loads ◽  
Infection Control Measures ◽  
Infected Adult ◽  
Asymptomatic Adult ◽  
Upper Respiratory ◽  
Kinetics Of

Abstract Differential kinetics of RNA loads and infectious viral levels in the upper respiratory tract between asymptomatic and symptomatic SARS-CoV-2 infected adult outpatients remain unclear limiting recommendations that may guide clinical management, infection control measures and occupational health decisions. In the present investigation, 496 (2.5%) of 17,911 French adult outpatients were positive for an upper respiratory tract SARS-CoV-2 RNA detection by a quantitative RT-PCR assay, of which 180 (36.3%) were COVID-19 asymptomatic. Of these adult asymptomatic viral shedders, 84.4% had mean to high RNA viral loads (Ct values<30) which median value was significantly higher than that observed in symptomatic subjects (P=0.029), and 50.6% were positive by cell culture assays of their upper respiratory tract specimens. Our findings indicate that COVID-19 asymptomatic adult outpatients are significant viable SARS-CoV-2 shedders in their upper respiratory tract playing a major potential role as SARS-CoV-2 transmitters in various epidemiological transmission chains, promoting COVID-19 resurgence in populations.

OPTIMAL CONTROL OF VECTOR-BORNE DISEASE WITH DIRECT TRANSMISSION

2015 ◽  
Vol 76 (13) ◽  
Author(s):  
Nurul Aida Nordin ◽  
Rohanin Ahmad ◽  
Rashidah Ahmad
Keyword(s):  
Dynamical System ◽  
Optimal Control ◽  
Optimal Control Theory ◽  
Existence And Uniqueness ◽  
Blood Donation ◽  
Direct Transmission ◽  
Vector Borne Disease ◽  
Indirect Transmission ◽  
Vector Borne ◽  
Vector Control Strategy

This paper introduces the usage of three controls as a way to reduce the occurrence of vector-borne disease. The governing equation of the dynamical system used in this paper describes both direct and indirect transmission mode of vector-borne disease. This means that the disease can be transmitted in two different ways. First, it can be transmitted through mosquito bites and the other is through human blood transfusion. The three controls that are incorporated in the dynamical system include a measurement of basic practice for blood donation procedure, self-prevention effort and vector control strategy by health authority. The optimality system of the three controls is characterized using optimal control theory and the existence and uniqueness of the optimal control are established. Then, the effect of the incorporation of the three controls is investigated by performing numerical simulation. 

scholarly journals Factors Associated With Viral Load Kinetics of Middle East Respiratory Syndrome Coronavirus During the 2015 Outbreak in South Korea

2020 ◽  
Author(s):  
Jeong-Sun Yang ◽  
Min-Gyu Yoo ◽  
Hye-Ja Lee ◽  
Han Byul Jang ◽  
Hee-Dong Jung ◽  
...  
Keyword(s):  
Viral Load ◽  
Middle East ◽  
Symptom Onset ◽  
Healthcare Workers ◽  
Middle East Respiratory Syndrome ◽  
Viral Loads ◽  
Hospitalization Period ◽  
Using Data ◽  
Kinetics Of ◽  
Respiratory Specimens

Abstract We conducted a retrospective study of Middle East respiratory syndrome coronavirus (MERS-CoV) viral load kinetics using data from patients hospitalized with MERS-CoV infection between 19 May and 20 August 2015. Viral load trajectories were considered over the hospitalization period using 1714 viral load results measured in serial respiratory specimens of 185 patients. The viral load levels were significantly higher among nonsurvivors than among survivors (P = .003). Healthcare workers (P = .001) and nonspreaders (P &lt; .001) had significantly lower viral loads. Viral RNA was present on the day of symptom onset and peaked 4–10 days after symptom onset.

Acidification of drinking water inhibits indirect transmission, but not direct transmission of Campylobacter between broilers

2012 ◽  
Vol 105 (4) ◽  
pp. 315-319 ◽  
Author(s):  
B.A.D. van Bunnik ◽  
W.E.A. Katsma ◽  
J.A. Wagenaar ◽  
W.F. Jacobs-Reitsma ◽  
M.C.M. de Jong
Keyword(s):  
Drinking Water ◽  
Direct Transmission ◽  
Indirect Transmission

Ultrasonic Pulse Velocity for In Situ Measurement of Compressive Strength of Concrete

2007 ◽  
Vol 18-19 ◽  
pp. 55-61 ◽  
Author(s):  
C.A. Chidolue ◽  
B.A. Chidolue ◽  
S.N. Umenwaliri
Keyword(s):  
Aggregate Size ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Direct Transmission ◽  
Indirect Transmission ◽  
Mix Proportion ◽  
Compressive Strength Of Concrete ◽  
A Site

In this study, pulse velocities calculated from the time taken by pulses emitted by a transducer to traverse a known thickness of the concrete is utilized in building up a correlation between pulse velocity and strength of concrete cubes and between pulse velocity and age of concrete. Three different arrangements of transmitters and receivers were studied to cover the varieties of problems likely to be encountered on a site. These are direct transmission, semi-direct transmission and indirect transmission. For a particular mix proportion and aggregate size a calibration curve was obtained for in-situ testing of concrete. These curves can be used to determine the relative in-situ strength of similar members or structures.

scholarly journals Real-Time PCR Investigation of Potential Vectors, Reservoirs, and Shedding Patterns of Feline Hemotropic Mycoplasmas

2007 ◽  
Vol 73 (12) ◽  
pp. 3798-3802 ◽  
Author(s):  
Barbara Willi ◽  
Felicitas S. Boretti ◽  
Marina L. Meli ◽  
Marco V. Bernasconi ◽  
Simona Casati ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Late Phase ◽  
Direct Transmission ◽  
Tissue Samples ◽  
Indirect Transmission ◽  
Rodent Population ◽  
Hemotropic Mycoplasma ◽  
Cat Fleas ◽  
Insight Into

ABSTRACT Three hemotropic mycoplasmas have been identified in pet cats: Mycoplasma haemofelis, “Candidatus Mycoplasma haemominutum,” and “Candidatus Mycoplasma turicensis.” The way in which these agents are transmitted is largely unknown. Thus, this study aimed to investigate fleas, ticks, and rodents as well as saliva and feces from infected cats for the presence of hemotropic mycoplasmas, to gain insight into potential transmission routes for these agents. DNA was extracted from arthropods and from rodent blood or tissue samples from Switzerland and from salivary and fecal swabs from two experimentally infected and six naturally infected cats. All samples were analyzed with real-time PCR, and some positive samples were confirmed by sequencing. Feline hemotropic mycoplasmas were detected in cat fleas and in a few Ixodes sp. and Rhipicephalus sp. ticks collected from animals but not in ticks collected from vegetation or from rodent samples, although the latter were frequently Mycoplasma coccoides PCR positive. When shedding patterns of feline hemotropic mycoplasmas were investigated, “Ca. Mycoplasma turicensis” DNA was detected in saliva and feces at the early but not at the late phase of infection. M. haemofelis and “Ca. Mycoplasma haemominutum” DNA was not amplified from saliva and feces of naturally infected cats, despite high hemotropic mycoplasma blood loads. Our results suggest that besides an ostensibly indirect transmission by fleas, direct transmission through saliva and feces at the early phase of infection could play a role in the epizootiology of feline hemotropic mycoplasmas. Neither the investigated tick nor the rodent population seems to represent a major reservoir for feline hemotropic mycoplasmas in Switzerland.

Koi herpesvirus represents a third cyprinid herpesvirus (CyHV-3) in the family Herpesviridae

2005 ◽  
Vol 86 (6) ◽  
pp. 1659-1667 ◽  
Author(s):  
Thomas B. Waltzek ◽  
Garry O. Kelley ◽  
David M. Stone ◽  
Keith Way ◽  
Larry Hanson ◽  
...  
Keyword(s):  
Dna Polymerase ◽  
Major Capsid Protein ◽  
Biological Data ◽  
Lower Vertebrate ◽  
Channel Catfish Virus ◽  
Koi Herpesvirus ◽  
Cyprinid Herpesvirus 3 ◽  
The Family ◽  
Fish Viruses ◽  
Herpesvirus 1

The sequences of four complete genes were analysed in order to determine the relatedness of koi herpesvirus (KHV) to three fish viruses in the family Herpesviridae: carp pox herpesvirus (Cyprinid herpesvirus 1, CyHV-1), haematopoietic necrosis herpesvirus of goldfish (Cyprinid herpesvirus 2, CyHV-2) and channel catfish virus (Ictalurid herpesvirus 1, IcHV-1). The genes were predicted to encode a helicase, an intercapsomeric triplex protein, the DNA polymerase and the major capsid protein. The results showed that KHV is related closely to CyHV-1 and CyHV-2, and that the three cyprinid viruses are related, albeit more distantly, to IcHV-1. Twelve KHV isolates from four diverse geographical areas yielded identical sequences for a region of the DNA polymerase gene. These findings, with previously published morphological and biological data, indicate that KHV should join the group of related lower-vertebrate viruses in the family Herpesviridae under the formal designation Cyprinid herpesvirus 3 (CyHV-3).

scholarly journals KINETICS OF VIRAL LOADS AND GENOTYPIC ANALYSIS OF ELEPHANT ENDOTHELIOTROPIC HERPESVIRUS-1 INFECTION IN CAPTIVE ASIAN ELEPHANTS (ELEPHAS MAXIMUS)

2013 ◽  
Vol 44 (1) ◽  
pp. 42-54 ◽  
Author(s):  
Jeffrey J. Stanton ◽  
Jian-Chao Zong ◽  
Crystal Eng ◽  
Lauren Howard ◽  
Joe Flanagan ◽  
...  
Keyword(s):  
Elephas Maximus ◽  
Asian Elephants ◽  
Viral Loads ◽  
Genotypic Analysis ◽  
Herpesvirus 1 ◽  
Kinetics Of

scholarly journals The Need for an Air Sterilization Unit Before Releasing Bio-Hazardous Agents as COVID-19 Virioli in Environment

2021 ◽  
Vol 2 (5) ◽  
pp. 350-351
Author(s):  
Liviu Popa-Simil
Keyword(s):  
Close Contact ◽  
Abiotic Factors ◽  
Direct Transmission ◽  
Survival Times ◽  
Biotic And Abiotic Factors ◽  
Indirect Transmission

Transmission of many viruses occurs by direct transmission during a close contact between two hosts, or by an indirect transmission through the environment, where biotic and abiotic factors may act independently or connected to assure survival of viruses released in the environment, and further direct or intermediary carrier (rats, cats, dogs, squirrels, dears, etc.) transmission back to humans. It is supposed that virioli as SARS-CoV-2 may have exceptional survival times in cold, clean, dark environments traveling short to very long distances, especially in the air or in water, “waiting” for a host to multiply.

scholarly journals Kinetics of Nucleocapsid, Spike and Neutralizing Antibodies, and Viral Load in Patients with Severe COVID-19 Treated with Convalescent Plasma

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1844
Author(s):  
Thomas P. Thomopoulos ◽  
Margherita Rosati ◽  
Evangelos Terpos ◽  
Dimitris Stellas ◽  
Xintao Hu ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Rna Binding ◽  
Neutralizing Antibody ◽  
Binding Domain ◽  
High Morbidity ◽  
Viral Loads ◽  
Effective Treatment Modality ◽  
Meta Analyses ◽  
Humoral Responses ◽  
Kinetics Of

COVID-19 is an ongoing pandemic with high morbidity and mortality. Despite meticulous research, only dexamethasone has shown consistent mortality reduction. Convalescent plasma (CP) infusion might also develop into a safe and effective treatment modality on the basis of recent studies and meta-analyses; however, little is known regarding the kinetics of antibodies in CP recipients. To evaluate the kinetics, we followed 31 CP recipients longitudinally enrolled at a median of 3 days post symptom onset for changes in binding and neutralizing antibody titers and viral loads. Antibodies against the complete trimeric Spike protein and the receptor-binding domain (Spike-RBD), as well as against the complete Nucleocapsid protein and the RNA binding domain (N-RBD) were determined at baseline and weekly following CP infusion. Neutralizing antibody (pseudotype NAb) titers were determined at the same time points. Viral loads were determined semi-quantitatively by SARS-CoV-2 PCR. Patients with low humoral responses at entry showed a robust increase of antibodies to all SARS-CoV-2 proteins and Nab, reaching peak levels within 2 weeks. The rapid increase in binding and neutralizing antibodies was paralleled by a concomitant clearance of the virus within the same timeframe. Patients with high humoral responses at entry demonstrated low or no further increases; however, virus clearance followed the same trajectory as in patients with low antibody response at baseline. Together, the sequential immunological and virological analysis of this well-defined cohort of patients early in infection shows the presence of high levels of binding and neutralizing antibodies and potent clearance of the virus.

Sign in / Sign up

Export Citation Format

Share Document