scholarly journals Shedding and Transmission Modes of Severe Fever With Thrombocytopenia Syndrome Phlebovirus in a Ferret Model

2019 ◽  
Vol 6 (8) ◽  
Author(s):  
Kwang-Min Yu ◽  
Hye-Won Jeong ◽  
Su-Jin Park ◽  
Young-Il Kim ◽  
Min-Ah Yu ◽  
...  
Keyword(s):  
Virus Transmission ◽  
Body Fluids ◽  
Personal Contact ◽  
Infection Model ◽  
Nasal Discharge ◽  
Indirect Contact ◽  
Virus Shedding ◽  
Transmission Modes ◽  
Severe Fever ◽  
Urine Specimens

Abstract Background Although human-to-human transmission of severe fever with thrombocytopenia syndrome phlebovirus (SFTSV) via direct contact with body fluids has been reported, the role of specific body fluids from SFTSV-infected hosts has not been investigated in detail. Methods To demonstrate the virus transmission kinetics in SFTSV-infected hosts, we adapted the ferret infection model and evaluated the virus shedding periods, virus titers, and transmission modes from various specimens of infected ferrets. Results Large amounts of infectious SFTSV are shed through nasal discharge, saliva, and urine from SFTSV-infected ferrets. Virus could be detected from 2 dpi and persisted until 12 dpi in these specimens, compared with the relatively short virus-shedding period in sera. Further, transmission studies revealed that SFTSV can be transmitted to close direct and indirect contact naïve animals through various mediums, especially through contact with serum and urine. Further, ferrets contacted with human urine specimens from SFTSV-positive patients were successfully infected with SFTSV, suggesting that urine specimens could be a source of SFTSV infection in humans. Conclusions Our results demonstrate that the SFTSV can be shed in various body fluids for more than 12 days and that these specimens could be a source for direct or indirect transmission through close personal contact.

scholarly journals Modeling Ebola Virus Transmission Using Ferrets

mSphere ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Marc-Antoine de La Vega ◽  
Geoff Soule ◽  
Kaylie N. Tran ◽  
Kevin Tierney ◽  
Shihua He ◽  
...  
Keyword(s):  
Animal Model ◽  
Direct Contact ◽  
Ebola Virus ◽  
Infected Animal ◽  
Severe Disease ◽  
Virus Transmission ◽  
Metal Mesh ◽  
Indirect Contact ◽  
Specific Antibodies ◽  
Bodily Fluids

ABSTRACT Ebola virus (EBOV) has been responsible for sporadic outbreaks in Central Africa since 1976 and has the potential of causing social disruption and public panic as illustrated by the 2013–2016 epidemic in West Africa. Transmission of EBOV has been described to occur via contact with infected bodily fluids, supported by data indicating that infectious EBOV could be cultured from blood, semen, saliva, urine, and breast milk. Parameters influencing transmission of EBOV are, however, largely undefined in part due to the lack of an established animal model to study mechanisms of pathogen spread. Here, we investigated EBOV transmissibility in male and female ferrets. After intranasal challenge, an infected animal was placed in direct contact with a naive ferret and in contact with another naive ferret (separated from the infected animal by a metal mesh) that served as the indirect-contact animal. All challenged animals, male direct contacts, and one male indirect contact developed disease and died. The remaining animals were not viremic and remained asymptomatic but developed EBOV-glycoprotein IgM and/or IgG specific antibodies—indicative of virus transmission. EBOV transmission via indirect contact was frequently observed in this model but resulted in less-severe disease compared to direct contact. Interestingly, these observations are consistent with the detection of specific antibodies in humans living in areas of EBOV endemicity. IMPORTANCE Our knowledge regarding transmission of EBOV between individuals is vague and is mostly limited to spreading via direct contact with infectious bodily fluids. Studying transmission parameters such as dose and route of infection is nearly impossible in naturally acquired cases—hence the requirement for a laboratory animal model. Here, we show as a proof of concept that ferrets can be used to study EBOV transmission. We also show that transmission in the absence of direct contact is frequent, as all animals with indirect contact with the infected ferrets had detectable antibodies to the virus, and one succumbed to infection. Our report provides a new small-animal model for studying EBOV transmission that does not require adaptation of the virus, providing insight into virus transmission among humans during epidemics.

scholarly journals Characteristics of Three Person-to-Person Transmission Clusters of Severe Fever with Thrombocytopenia Syndrome in Southeastern China

2021 ◽  
Author(s):  
Mingyong Tao ◽  
Ying Liu ◽  
Feng Ling ◽  
Rong Zhang ◽  
Xuguang Shi ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Close Contact ◽  
Disease Onset ◽  
Virus Transmission ◽  
Secondary Case ◽  
Southeastern China ◽  
History Of ◽  
Severe Fever ◽  
Very High ◽  
Index Cases

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease worldwide. It can be transmitted from person to person, and the fatality rate is very high. During this study, three SFTS clusters including 12 associated cases were identified in three counties in Zhejiang Province from 2018 to 2020. The median age of the three index patients was 70 years, and that of secondary case patients was 59 years. Of note, the mortality rate of the index patients was 100%. The mortality rate of secondary case patients was 11%. The total secondary attack rate (SAR) was 30% (9/30). The SARs of cluster A, cluster B, and cluster C were 38% (3/8), 21% (3/14), and 38% (3/8), respectively. Additionally, the interval from onset to diagnosis was 4 days. The intervals from disease onset to confirmation of the index cases and secondary cases were 7 days and 4 days, respectively. All secondary case patients had a history of close contact with blood or body fluids of the index patients. These results indicate that SFTS patients should not be discharged until recovery. When SFTS patients die, the corpses should be transferred directly from the hospital to the crematorium for cremation by persons wearing proper protective equipment to prevent virus transmission.

scholarly journals Interannual cycles of Hantaan virus outbreaks at the human–animal interface in Central China are controlled by temperature and rainfall

2017 ◽  
Vol 114 (30) ◽  
pp. 8041-8046 ◽  
Author(s):  
Huaiyu Tian ◽  
Pengbo Yu ◽  
Bernard Cazelles ◽  
Lei Xu ◽  
Hua Tan ◽  
...  
Keyword(s):  
Focal Point ◽  
Virus Transmission ◽  
Disease Outbreaks ◽  
Climatic Conditions ◽  
Central China ◽  
Hantaan Virus ◽  
Infection Model ◽  
System Temperature ◽  
Human Infections ◽  
Long Timescales

Hantavirus, a rodent-borne zoonotic pathogen, has a global distribution with 200,000 human infections diagnosed annually. In recent decades, repeated outbreaks of hantavirus infections have been reported in Eurasia and America. These outbreaks have led to public concern and an interest in understanding the underlying biological mechanisms. Here, we propose a climate–animal–Hantaan virus (HTNV) infection model to address this issue, using a unique dataset spanning a 54-y period (1960–2013). This dataset comes from Central China, a focal point for natural HTNV infection, and includes both field surveillance and an epidemiological record. We reveal that the 8-y cycle of HTNV outbreaks is driven by the confluence of the cyclic dynamics of striped field mouse (Apodemus agrarius) populations and climate variability, at both seasonal and interannual cycles. Two climatic variables play key roles in the ecology of the HTNV system: temperature and rainfall. These variables account for the dynamics in the host reservoir system and markedly affect both the rate of transmission and the potential risk of outbreaks. Our results suggest that outbreaks of HTNV infection occur only when climatic conditions are favorable for both rodent population growth and virus transmission. These findings improve our understanding of how climate drives the periodic reemergence of zoonotic disease outbreaks over long timescales.

scholarly journals Environmental Restrictions: A New Concept Governing HIV-1 Spread Emerging from Integrated Experimental-Computational Analysis of Tissue-Like 3D Cultures

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1112 ◽  
Author(s):  
Samy Sid Ahmed ◽  
Nils Bundgaard ◽  
Frederik Graw ◽  
Oliver Fackler
Keyword(s):  
In Silico ◽  
Computational Analysis ◽  
Virus Transmission ◽  
Target Cells ◽  
Virus Spread ◽  
Transmission Modes ◽  
3D Collagen ◽  
Cell Densities ◽  
Hiv 1

HIV-1 can use cell-free and cell-associated transmission modes to infect new target cells, but how the virus spreads in the infected host remains to be determined. We recently established 3D collagen cultures to study HIV-1 spread in tissue-like environments and applied iterative cycles of experimentation and computation to develop a first in silico model to describe the dynamics of HIV-1 spread in complex tissue. These analyses (i) revealed that 3D collagen environments restrict cell-free HIV-1 infection but promote cell-associated virus transmission and (ii) defined that cell densities in tissue dictate the efficacy of these transmission modes for virus spread. In this review, we discuss, in the context of the current literature, the implications of this study for our understanding of HIV-1 spread in vivo, which aspects of in vivo physiology this integrated experimental–computational analysis takes into account, and how it can be further improved experimentally and in silico.

scholarly journals Development and Characterization of a Sin Nombre Virus Transmission Model in Peromyscus maniculatus

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 183 ◽  
Author(s):  
Bryce Warner ◽  
Derek Stein ◽  
Bryan Griffin ◽  
Kevin Tierney ◽  
Anders Leung ◽  
...  
Keyword(s):  
Peromyscus Maniculatus ◽  
Deer Mouse ◽  
Virus Transmission ◽  
Transmission Model ◽  
Deer Mice ◽  
Sin Nombre Virus ◽  
Infection Model ◽  
Main Driver ◽  
Heat Shock Responses

In North America, Sin Nombre virus (SNV) is the main cause of hantavirus cardiopulmonary syndrome (HCPS), a severe respiratory disease with a fatality rate of 35–40%. SNV is a zoonotic pathogen carried by deer mice (Peromyscus maniculatus), and few studies have been performed examining its transmission in deer mouse populations. Studying SNV and other hantaviruses can be difficult due to the need to propagate the virus in vivo for subsequent experiments. We show that when compared with standard intramuscular infection, the intraperitoneal infection of deer mice can be as effective in producing SNV stocks with a high viral RNA copy number, and this method of infection provides a more reproducible infection model. Furthermore, the age and sex of the infected deer mice have little effect on viral replication and shedding. We also describe a reliable model of direct experimental SNV transmission. We examined the transmission of SNV between deer mice and found that direct contact between deer mice is the main driver of SNV transmission rather than exposure to contaminated excreta/secreta, which is thought to be the main driver of transmission of the virus to humans. Furthermore, increases in heat shock responses or testosterone levels in SNV-infected deer mice do not increase the replication, shedding, or rate of transmission. Here, we have demonstrated a model for the transmission of SNV between deer mice, the natural rodent reservoir for the virus. The use of this model will have important implications for further examining SNV transmission and in developing strategies for the prevention of SNV infection in deer mouse populations.

scholarly journals Favipiravir at high doses has potent antiviral activity in SARS-CoV-2−infected hamsters, whereas hydroxychloroquine lacks activity

2020 ◽  
Vol 117 (43) ◽  
pp. 26955-26965 ◽  
Author(s):  
Suzanne J. F. Kaptein ◽  
Sofie Jacobs ◽  
Lana Langendries ◽  
Laura Seldeslachts ◽  
Sebastiaan ter Horst ◽  
...  
Keyword(s):  
Antiviral Drug ◽  
Virus Transmission ◽  
Small Animal ◽  
Antiviral Effect ◽  
Viral Disease ◽  
Scientific Basis ◽  
Infection Model ◽  
High Dose ◽  
High Doses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spread around the globe after its emergence in Wuhan in December 2019. With no specific therapeutic and prophylactic options available, the virus has infected millions of people of which more than half a million succumbed to the viral disease, COVID-19. The urgent need for an effective treatment together with a lack of small animal infection models has led to clinical trials using repurposed drugs without preclinical evidence of their in vivo efficacy. We established an infection model in Syrian hamsters to evaluate the efficacy of small molecules on both infection and transmission. Treatment of SARS-CoV-2−infected hamsters with a low dose of favipiravir or hydroxychloroquine with(out) azithromycin resulted in, respectively, a mild or no reduction in virus levels. However, high doses of favipiravir significantly reduced infectious virus titers in the lungs and markedly improved lung histopathology. Moreover, a high dose of favipiravir decreased virus transmission by direct contact, whereas hydroxychloroquine failed as prophylaxis. Pharmacokinetic modeling of hydroxychloroquine suggested that the total lung exposure to the drug did not cause the failure. Our data on hydroxychloroquine (together with previous reports in macaques and ferrets) thus provide no scientific basis for the use of this drug in COVID-19 patients. In contrast, the results with favipiravir demonstrate that an antiviral drug at nontoxic doses exhibits a marked protective effect against SARS-CoV-2 in a small animal model. Clinical studies are required to assess whether a similar antiviral effect is achievable in humans without toxic effects.

scholarly journals SARS-CoV-2 Infection in One Cat and Three Dogs Living in COVID-19-Positive Households in Madrid, Spain

2021 ◽  
Vol 8 ◽  
Author(s):  
Guadalupe Miró ◽  
Javier Regidor-Cerrillo ◽  
Rocio Checa ◽  
Carlos Diezma-Díaz ◽  
Ana Montoya ◽  
...  
Keyword(s):  
Clinical Signs ◽  
Nasal Discharge ◽  
Virus Shedding ◽  
Clinical Exam ◽  
Reverse Transcription Pcr ◽  
Infection Dynamics ◽  
Variant Lineage ◽  
Biochemical Profiles ◽  
Alpha Variant ◽  
Complete Blood Counts

In this study, we describe SARS-CoV-2 infection dynamics in one cat and three dogs from households with confirmed human cases of COVID-19 living in the Madrid Community (Spain) at the time of expansion (December 2020 through June 2021) of the alpha variant (lineage B.1.1.7). A thorough physical exam and nasopharyngeal, oropharyngeal, and rectal swabs were collected for real-time reverse-transcription PCR (RT-qPCR) SARS-CoV-2 testing on day 0 and in successive samplings on days 7, 14, 21, and 47 during monitoring. Blood was also drawn to determine complete blood counts, biochemical profiles, and serology of the IgG response against SARS-CoV-2. On day 0, the cat case 1 presented with dyspnea and fever associated with a mild bronchoalveolar pattern. The dog cases 2, 3, and 4 were healthy, but case 2 presented with coughing, dyspnea, and weakness, and case 4 exhibited coughing and bilateral nasal discharge 3 and 6 days before the clinical exam. Case 3 (from the same household as case 2) remained asymptomatic. SARS-CoV-2 detection by RT-qPCR showed that the cat case 1 and the dog case 2 exhibited the lowest cycle threshold (Ct) (Ct < 30) when they presented clinical signs. Viral detection failed in successive samplings. Serological analyses revealed a positive IgG response in cat case 1 and dog cases 3 and 4 shortly after or simultaneously to virus shedding. Dog case 2 was seronegative, but seroconverted 21 days after SARS-CoV-2 detection. SARS-CoV-2 genome sequencing was attempted, and genomes were classified as belonging to the B.1.1.7 lineage.

scholarly journals Detection of Haemophilus influenzae type b antigens in body fluids, using specific antibody-coated staphylococci

1977 ◽  
Vol 5 (1) ◽  
pp. 81-85
Author(s):  
M Suksanong ◽  
A S Dajani
Keyword(s):  
Cerebrospinal Fluid ◽  
Haemophilus Influenzae ◽  
Protein A ◽  
Body Fluids ◽  
Haemophilus Influenzae Type ◽  
Haemophilus Influenzae Type B ◽  
Bacterial Cells ◽  
Type B ◽  
Initiation Of Therapy ◽  
Urine Specimens

Protein A-rich staphylococci coated with Haemophilus influenzae type b antiserum agglutinate specifically with homologous bacterial cells or with cell-free supernatant fluids of cultures of the organism. Antibody-coated staphylococci were used to detect soluble antigens in body fluids of patients infected with H. influenzae type b. Cerebrospinal fluid from 36 cases of meningitis caused by this orgainsm showed positive coagglutination tests in 86% of patients prior to initiation of therapy. Antigens could be detected in 46% of sterile cerebrospinal fluid specimens obtained from the same cases 1 to 10 days after therapy. Soluble antigens were also detectable in sera (58%) and urine specimens (67%) of patients with H. influenzae type b septicemia, when such specimens were tested within 10 days of onset of illness. No antigen could be detected in body fluids beyond 10 days. The coagglutination test was positive in 57% of all body fluids examined; contercurrent immunoelectrophoresis (CCIE) was positive in only 27%. All specimens positive by CCIE were also positive by coagglutination. No false-positive reactions were noted by either test in body fluids from controls. The coagglutination test is simple, specific, and more sensitive than the CCIE method and could be a valuable tool for detecting antigens in body fluids of patients with various infections.

scholarly journals THE CHILD’S RIGHT TO MAINTAIN CONTACT WITH BOTH PARENTS IN THE AGE OF PANDEMIC

2021 ◽  
Author(s):  
Ana Radina
Keyword(s):  
Social Services ◽  
Legal Framework ◽  
Family Context ◽  
Personal Contact ◽  
Short Term ◽  
Indirect Contact ◽  
The Family ◽  
The Right ◽  
Medical Perspective

The COVID-19 pandemic and the accompanying extraordinary measures engaged restrictions of fundamental human rights and liberties to an unprecedented scale. Inevitably, this had implications in the family context as well. Even though children are not considered to be an endangered category from a medical perspective, they are adversely affected by the pandemic in practically all aspects of life, in the short-term and in the long-term. One of the child’s rights directly affected is the right to maintain direct contact with both parents on a regular basis. Digital means of communication can somewhat mitigate the lack of personal contact, however, not everyone has access to the necessary technologies and there might be various disagreements about exercising such indirect contact. The closure of judiciary and social services placed the burden of resolving contact related disputes almost entirely upon parents. This paper aims to examine the relevant legal framework and measures taken in relation to the child’s right to maintain contact with both parents in the circumstances of the pandemic, with particular focus on the Croatian context and the response of the Croatian authorities to the challenges arising from this extraordinary situation, and to identify actions which could be taken in order to improve the child’s unfavourable position.

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