scholarly journals The SARS-CoV-2 Reproduction Number R0 in Cats

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2480
Author(s):  
Jose L. Gonzales ◽  
Mart C. M. de Jong ◽  
Nora M. Gerhards ◽  
Wim H. M. Van der Poel
Keyword(s):  
Virus Infection ◽  
Potential Risk ◽  
Reproduction Number ◽  
Close Contact ◽  
Domestic Cats ◽  
Natural Conditions ◽  
Household Transmission ◽  
Exhaled Air

Domestic cats are susceptible to SARS-CoV-2 virus infection and given that they are in close contact with people, assessing the potential risk cats represent for the transmission and maintenance of SARS-CoV-2 is important. Assessing this risk implies quantifying transmission from humans-to-cats, from cats-to-cats and from cats-to-humans. Here we quantified the risk of cat-to-cat transmission by reviewing published literature describing transmission either experimentally or under natural conditions in infected households. Data from these studies were collated to quantify the SARS-CoV-2 reproduction number R0 among cats. The estimated R0 was significantly higher than one, hence cats could play a role in the transmission and maintenance of SARS-CoV-2. Questions that remain to be addressed are the risk of transmission from humans-to-cats and cats-to-humans. Further data on household transmission and data on virus levels in both the environment around infected cats and their exhaled air could be a step towards assessing these risks

scholarly journals The SARS-CoV-2 reproduction number R0 in cats

2021 ◽  
Author(s):  
Jose L Gonzales ◽  
Mart C.M. De Jong ◽  
Nora M Gerhards ◽  
Wim H.M. Van der Poel
Keyword(s):  
Virus Infection ◽  
Potential Risk ◽  
Reproduction Number ◽  
Close Contact ◽  
Domestic Cats ◽  
Natural Conditions ◽  
Household Transmission ◽  
Exhaled Air

Domestic cats are susceptible to SARS-CoV-2 virus infection and given that they are in close contact with people, assessing the potential risk cats represent for the transmission and maintenance of SARS-CoV-2 is important. Assessing this risk implies quantifying transmission from humans-to-cats, from cats-to-cats and from cats-to-humans. Here we quantified the risk of cat-to-cat transmission by reviewing published literature describing transmission either experimentally or under natural conditions in infected households. Data from these studies were collated to quantify the SARS-CoV-2 reproduction number R0 among cats. The estimated R0 was significantly higher than 1, hence cats could play a role in the transmission and maintenance of SARS-CoV-2. Questions that remain to be addressed are the risk of transmission from humans-to-cats and cats-to-humans. Further data on household transmission and data on virus levels in both the environment around infected cats and their exhaled air could be a step towards assessing these risks.

scholarly journals Seasonal stability of SARS-CoV-2 in biological fluids

2021 ◽  
Author(s):  
Taeyong Kwon ◽  
Natasha N Gaudreault ◽  
Juergen A Richt
Keyword(s):  
Breast Milk ◽  
Potential Risk ◽  
Half Life ◽  
Close Contact ◽  
Biological Fluids ◽  
Seasonal Pattern ◽  
Climatic Conditions ◽  
Natural Conditions ◽  
Winter Conditions ◽  
Different Types

Transmission of SARS-CoV-2 occurs by close contact with infected persons through droplets, the inhalation of infectious aerosols and the exposure to contaminated surface. Previously, we determined the virus stability on different types of surfaces under indoor and seasonal climatic conditions. SARS-CoV-2 survived the longest on surfaces under winter conditions, followed by spring/fall and summer conditions, suggesting the seasonal pattern of stability on surfaces. However, under natural conditions, the virus is secreted in various biological fluids from infected humans. In this respect, it remains unclear how long the virus survives in various types of biological fluids. This study explored the SARS-CoV-2 stability in human biological fluids under different environmental conditions and estimated the half-life. The virus was stable for up to 21 days in nasal mucus, sputum, saliva, tear, urine, blood, and semen; it remained infectious significantly longer under winter and spring/fall conditions than under summer conditions. In contrast, the virus was only stable up to 24 hours in feces and breast milk. These findings demonstrate the potential risk of infectious biological fluids in SARS-CoV-2 transmission and have implications for its seasonality.

scholarly journals Seasonal Stability of SARS-CoV-2 in Biological Fluids

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 540
Author(s):  
Taeyong Kwon ◽  
Natasha N. Gaudreault ◽  
Juergen A. Richt
Keyword(s):  
Breast Milk ◽  
Potential Risk ◽  
Half Life ◽  
Close Contact ◽  
Biological Fluids ◽  
Seasonal Pattern ◽  
Climatic Conditions ◽  
Natural Conditions ◽  
Winter Conditions ◽  
Different Types

The transmission of SARS-CoV-2 occurs by close contact with infected persons through droplets, the inhalation of infectious aerosols, and the exposure to contaminated surfaces. Previously, we determined the virus stability on different types of surfaces under indoor and seasonal climatic conditions. SARS-CoV-2 survived the longest on surfaces under winter conditions, followed by spring/fall and summer conditions, suggesting the seasonal pattern of stability on surfaces. However, under natural conditions, the virus is secreted in various biological fluids from infected humans. In this respect, it remains unclear how long the virus survives in various types of biological fluids. This study explores SARS-CoV-2 stability in virus-spiked human biological fluids under different environmental conditions by determining the virus half-life. The virus was stable for up to 21 days in nasal mucus, sputum, saliva, tear, urine, blood, and semen; it remained infectious significantly longer under winter and spring/fall conditions than under summer conditions. In contrast, the virus was only stable up to 24 h in feces and breast milk. These findings demonstrate the potential risk of infectious biological fluids in SARS-CoV-2 transmission and have implications for its seasonality.

scholarly journals Diagnosis of sialodacryoadenitis virus infection of rats in a virulent enzootic outbreak

1981 ◽  
Vol 15 (4) ◽  
pp. 339-342 ◽  
Author(s):  
P. Carthew ◽  
R. P. Slinger
Keyword(s):  
Virus Infection ◽  
Antibody Response ◽  
Clinical Signs ◽  
Sprague Dawley ◽  
Hypertensive Rats ◽  
Natural Conditions ◽  
Breeding Colony ◽  
Serological Screening ◽  
Sprague Dawley Rats ◽  
Natural Outbreak

In a natural outbreak of sialodacryoadenitis virus it was observed that the incidence of clinical signs in spontaneous-hypertensive rats was 100%, and that these signs were of a severity not observed before in other strains of rats. Rats free of the virus were introduced so that the progress of the disease could be studied under natural conditions of spontaneous spread from the enzootically-affected breeding colony. The pathogenesis of the infection in these Sprague-Dawley rats has been recorded over a period of 10 days after their introduction to the colony, and the results of extensive serological screening have shown that the antibody response of the spontaneous-hypertensive rats to the virus is lower than in other strains of rat.

Borna disease virus infection in Italian children. A potential risk for the developing brain?

Apmis ◽  
2008 ◽  
Vol 116 ◽  
pp. 70-73 ◽  
Author(s):  
ANNA-MARIA PATTI ◽  
ANTONELLA VULCANO ◽  
ELISA CANDELORI ◽  
RENATO DONFRANCESCO ◽  
HANNS LUDWIG ◽  
...  
Keyword(s):  
Virus Infection ◽  
Disease Virus ◽  
Potential Risk ◽  
Developing Brain ◽  
Borna Disease Virus ◽  
Italian Children ◽  
Borna Disease

scholarly journals High variability in transmission of SARS-CoV-2 within households and implications for control

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259097
Author(s):  
Damon J. A. Toth ◽  
Alexander B. Beams ◽  
Lindsay T. Keegan ◽  
Yue Zhang ◽  
Tom Greene ◽  
...  
Keyword(s):  
Test Data ◽  
Attack Rate ◽  
Serological Test ◽  
Close Contact ◽  
Antibody Test ◽  
High Variability ◽  
Test Accuracy ◽  
Household Transmission ◽  
Wide Range ◽  
Test Specificity

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a high risk of transmission in close-contact indoor settings, which may include households. Prior studies have found a wide range of household secondary attack rates and may contain biases due to simplifying assumptions about transmission variability and test accuracy. Methods We compiled serological SARS-CoV-2 antibody test data and prior SARS-CoV-2 test reporting from members of 9,224 Utah households. We paired these data with a probabilistic model of household importation and transmission. We calculated a maximum likelihood estimate of the importation probability, mean and variability of household transmission probability, and sensitivity and specificity of test data. Given our household transmission estimates, we estimated the threshold of non-household transmission required for epidemic growth in the population. Results We estimated that individuals in our study households had a 0.41% (95% CI 0.32%– 0.51%) chance of acquiring SARS-CoV-2 infection outside their household. Our household secondary attack rate estimate was 36% (27%– 48%), substantially higher than the crude estimate of 16% unadjusted for imperfect serological test specificity and other factors. We found evidence for high variability in individual transmissibility, with higher probability of no transmissions or many transmissions compared to standard models. With household transmission at our estimates, the average number of non-household transmissions per case must be kept below 0.41 (0.33–0.52) to avoid continued growth of the pandemic in Utah. Conclusions Our findings suggest that crude estimates of household secondary attack rate based on serology data without accounting for false positive tests may underestimate the true average transmissibility, even when test specificity is high. Our finding of potential high variability (overdispersion) in transmissibility of infected individuals is consistent with characterizing SARS-CoV-2 transmission being largely driven by superspreading from a minority of infected individuals. Mitigation efforts targeting large households and other locations where many people congregate indoors might curb continued spread of the virus.

scholarly journals Household transmission of SARS-CoV-2 in Norway; a prospective, longitudinal study showing increased transmissibility of the Alpha variant (B.1.1.7) compared with other variants

2021 ◽  
Author(s):  
Cathinka Halle Julin ◽  
Anna Hayman Robertson ◽  
Olav Hungnes ◽  
Gro Tunheim ◽  
Terese Bekkevold ◽  
...  
Keyword(s):  
Risk Factors ◽  
Longitudinal Study ◽  
Close Contact ◽  
Questionnaire Data ◽  
Primary Case ◽  
Prospective Longitudinal Study ◽  
Household Contacts ◽  
Household Transmission ◽  
Alpha Variant ◽  
Prospective Longitudinal

ABSTRACT Background We studied the secondary attack rate (SAR), risk factors, and precautionary practices of household transmission in a prospective longitudinal study. Moreover, we compared household transmission between the Alpha (B.1.1.7) variant and non-variants of concern (non-VOCs). Methods We recruited households of confirmed COVID-19 cases from May 2020 to May 2021. Households received 8 home visits over 6 weeks. Biological samples and questionnaire data were collected. Results We recruited 70 confirmed COVID-19 cases and 146 household contacts. Transmission occurred in 60% of the households; the overall SAR for household contacts was 49.6%. The SAR was significantly higher for the Alpha variant (77.8%) compared with non-VOC variants (42.5%) and was associated with a higher viral load. SAR was higher in household contacts aged ≥40 years (64%) than in younger contacts (40-47%), and for contacts of cases with loss of taste/smell. Close contact prior to confirmation of infection tended to give a higher SAR. A significantly lower SAR was found for sleeping separately from the primary case after confirmation of infection. Conclusion We found substantial household transmission, particularly for the Alpha variant. Precautionary practices seem to reduce SAR; however, prevention of transmission within households may become difficult with more transmissible variants.

scholarly journals A Mathematical Model for Nipah Virus Infection

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Assefa Denekew Zewdie ◽  
Sunita Gakkhar
Keyword(s):  
Virus Infection ◽  
Reproduction Number ◽  
Initial Conditions ◽  
Nipah Virus ◽  
Virus Transmission ◽  
Globally Asymptotically Stable ◽  
Dead Bodies ◽  
Manifold Theory ◽  
The Impact ◽  
The Given

It has been reported that unprotected contact with the dead bodies of infected individuals is a plausible way of Nipah virus transmission. An SIRD model is proposed in this paper to investigate the impact of unprotected contact with dead bodies of infected individuals before burial or cremation and their disposal rate on the dynamics of Nipah virus infection. The model is analyzed, and the reproduction number is computed. It is established that the disease-free state is globally asymptotically stable when the reproduction number is less than unity and unstable if it is greater than unity. By using the central manifold theory, we observe that the endemic equilibrium is locally stable near to unity. It is concluded that minimizing unsafe contact with the infected dead body and/or burial or cremation as fast as possible contributes positively. Further, the numerical simulations for the given choice of data and initial conditions illustrate that the endemic state is stable and the disease persists in the community when the reproduction number is greater than one.

scholarly journals Occurrence of Antibodies against SARS-CoV-2 in the Domestic Cat Population of Germany

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 772
Author(s):  
Anna Michelitsch ◽  
Donata Hoffmann ◽  
Kerstin Wernike ◽  
Martin Beer
Keyword(s):  
Neutralizing Antibodies ◽  
Large Scale ◽  
Close Contact ◽  
Companion Animals ◽  
Cross Reactivity ◽  
Human Infection ◽  
Domestic Cat ◽  
Domestic Cats ◽  
Serum Samples ◽  
Transmission Cycle

Domestic cats (Felis catus) are popular companion animals that live in close contact with their human owners. Therefore, the risk of a trans-species spreading event between domestic cats and humans is ever-present. Shortly after the emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid spread around the world, the role of domestic cats in the transmission cycle was questioned. In the present study, the first large-scale survey of antibody occurrence in the domestic cat population in Germany was conducted, in order to assess the incidence of naturally occurring human to cat transmission of SARS-CoV-2. A total of 920 serum samples, which were collected from April to September of 2020, were screened by an indirect multispecies ELISA. Positive samples were verified using an indirect immunofluorescence test (iIFT) and additionally tested for neutralizing antibodies. Furthermore, serum samples were screened for antibodies against feline coronavirus (FCoV), in order to rule out cross-reactivity in the described test systems. Overall, 0.69% (6/920) of serum samples were found to be positive for antibodies against SARS-CoV-2 by ELISA and iIFT. Two of these reactive sera also displayed neutralizing antibodies. No cross-reactivity with FCoV-specific antibodies was observed. The finding of SARS-CoV-2 antibody-positive serum samples in the domestic cat population of Germany, during a period when the incidence of human infection in the country was still rather low, indicates that human-to-cat transmission of SARS-CoV-2 happens, but there is no indication of SARS-CoV-2 circulation in cats.

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