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Åke Lundkvist
Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Uppsala University, 75121 Uppsala, Sweden

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Journal article
Published: 07 August 2021 in Viruses
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Highly pathogenic avian influenza (HPAI) viruses continue to circulate worldwide, causing numerous outbreaks among bird species and severe public health concerns. H5N1 and H5N8 are the two most fundamental HPAI subtypes detected in birds in the last two decades. The two viruses may compete with each other while sharing the same host population and, thus, suppress the spread of one of the viruses. In this study, we performed a statistical analysis to investigate the temporal correlation of the HPAI H5N1 and HPAI H5N8 subtypes using globally reported data in 2015–2020. This was joined with an in-depth analysis using data generated via our national surveillance program in Egypt. A total of 6412 outbreaks were reported worldwide during this period, with 39% (2529) as H5N1 and 61% (3883) as H5N8. In Egypt, 65% of positive cases were found in backyards, while only 12% were found in farms and 23% in live bird markets. Overall, our findings depict a trade-off between the number of positive H5N1 and H5N8 samples around early 2017, which is suggestive of the potential replacement between the two subtypes. Further research is still required to elucidate the underpinning mechanisms of this competitive dynamic. This, in turn, will implicate the design of effective strategies for disease control.

ACS Style

Fatma Amer; Ruiyun Li; Neveen Rabie; Mohamed El-Husseiny; Nahed Yehia; Naglaa Hagag; Mohamed Samy; Abdullah Selim; Mohamed Hassan; Wafaa Hassan; Abdel-Sattar Arafa; Åke Lundkvist; Momtaz Shahein; Mahmoud Naguib. Temporal Dynamics of Influenza A(H5N1) Subtype before and after the Emergence of H5N8. Viruses 2021, 13, 1565 .

AMA Style

Fatma Amer, Ruiyun Li, Neveen Rabie, Mohamed El-Husseiny, Nahed Yehia, Naglaa Hagag, Mohamed Samy, Abdullah Selim, Mohamed Hassan, Wafaa Hassan, Abdel-Sattar Arafa, Åke Lundkvist, Momtaz Shahein, Mahmoud Naguib. Temporal Dynamics of Influenza A(H5N1) Subtype before and after the Emergence of H5N8. Viruses. 2021; 13 (8):1565.

Chicago/Turabian Style

Fatma Amer; Ruiyun Li; Neveen Rabie; Mohamed El-Husseiny; Nahed Yehia; Naglaa Hagag; Mohamed Samy; Abdullah Selim; Mohamed Hassan; Wafaa Hassan; Abdel-Sattar Arafa; Åke Lundkvist; Momtaz Shahein; Mahmoud Naguib. 2021. "Temporal Dynamics of Influenza A(H5N1) Subtype before and after the Emergence of H5N8." Viruses 13, no. 8: 1565.

Journal article
Published: 02 June 2021 in Virology Journal
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Background The ongoing SARS-CoV-2 pandemic has spread rapidly worldwide and disease prevention is more important than ever. In the absence of a vaccine, knowledge of the transmission routes and risk areas of infection remain the most important existing tools to prevent further spread. Methods Here we investigated the presence of the SARS-CoV-2 virus in the hospital environment at the Uppsala University Hospital Infectious Disease ward by RT-qPCR and determined the infectivity of the detected virus in vitro on Vero E6 cells. Results SARS-CoV-2 RNA was detected in several areas, although attempts to infect Vero E6 cells with positive samples were unsuccessful. However, RNase A treatment of positive samples prior to RNA extraction did not degrade viral RNA, indicating the presence of SARS-CoV-2 nucleocapsids or complete virus particles protecting the RNA as opposed to free viral RNA. Conclusion Our results show that even in places where a moderate concentration (Ct values between 30 and 38) of SARS-CoV-2 RNA was found; no infectious virus could be detected. This suggests that the SARS-CoV-2 virus in the hospital environment subsides in two states; as infectious and as non-infectious. Future work should investigate the reasons for the non-infectivity of SARS-CoV-2 virions.

ACS Style

Janina Krambrich; Dario Akaberi; Jiaxin Ling; Tove Hoffman; Lennart Svensson; Marie Hagbom; Åke Lundkvist. SARS-CoV-2 in hospital indoor environments is predominantly non-infectious. Virology Journal 2021, 18, 1 -9.

AMA Style

Janina Krambrich, Dario Akaberi, Jiaxin Ling, Tove Hoffman, Lennart Svensson, Marie Hagbom, Åke Lundkvist. SARS-CoV-2 in hospital indoor environments is predominantly non-infectious. Virology Journal. 2021; 18 (1):1-9.

Chicago/Turabian Style

Janina Krambrich; Dario Akaberi; Jiaxin Ling; Tove Hoffman; Lennart Svensson; Marie Hagbom; Åke Lundkvist. 2021. "SARS-CoV-2 in hospital indoor environments is predominantly non-infectious." Virology Journal 18, no. 1: 1-9.

Journal article
Published: 31 May 2021 in Viruses
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The potential of rapid point-of-care (POC) tests has been subject of doubt due to an eventual risk of production errors. The aim was therefore to evaluate the two separate production lots of a commercial POC lateral flow test, intended for the detection of IgM and IgG against the SARS-CoV-2 spike protein (S1). Control samples consisted of serum from individuals with confirmed SARS-CoV-2 infection and pre-COVID-19 negative sera gathered from a biobank. The presence of anti-S1 IgM/IgG in the sera was verified by an in-house Luminex-based serological assay (COVID-19 SIA). One hundred samples were verified as positive for anti-S1 IgG and 74 for anti-S1 IgM. Two hundred samples were verified as negative for anti-S1 IgM/IgG. For the two lots of the POC-test, the sensitivities were 93.2% and 87.8% for IgM and 93.0% and 100% for IgG. The specificities were 100% for IgM and 99.5% for IgG. The positive predictive value was 100% for IgM and 98.9% and 99.0% for IgG. The negative predictive value was 97.6% and 95.7% for IgM, and 96.6% and 100% for IgG. The evaluated POC-test is suitable to assess anti-SARS-CoV-2 S1 IgM and IgG, as a measure of previous virus exposure on an individual level. The external validation of separate lots of rapid POC-tests is encouraged to ensure high sensitivity before market introduction.

ACS Style

Tove Hoffman; Linda Kolstad; Bengt Rönnberg; Åke Lundkvist. Evaluation of Production Lots of a Rapid Point-of-Care Lateral Flow Serological Test Intended for Identification of IgM and IgG against the N-Terminal Part of the Spike Protein (S1) of SARS-CoV-2. Viruses 2021, 13, 1043 .

AMA Style

Tove Hoffman, Linda Kolstad, Bengt Rönnberg, Åke Lundkvist. Evaluation of Production Lots of a Rapid Point-of-Care Lateral Flow Serological Test Intended for Identification of IgM and IgG against the N-Terminal Part of the Spike Protein (S1) of SARS-CoV-2. Viruses. 2021; 13 (6):1043.

Chicago/Turabian Style

Tove Hoffman; Linda Kolstad; Bengt Rönnberg; Åke Lundkvist. 2021. "Evaluation of Production Lots of a Rapid Point-of-Care Lateral Flow Serological Test Intended for Identification of IgM and IgG against the N-Terminal Part of the Spike Protein (S1) of SARS-CoV-2." Viruses 13, no. 6: 1043.

Journal article
Published: 26 May 2021 in Viruses
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Due to the current, rapidly increasing Coronavirus disease 2019 (COVID-19) pandemic, efficient and highly specific diagnostic methods are needed. The receptor-binding part of the spike (S) protein, S1, has been suggested to be highly virus-specific; it does not cross-react with antibodies against other coronaviruses. Three recombinant partial S proteins of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) expressed in mammalian or baculovirus-insect cells were evaluated as antigens in a Luminex-based suspension immunoassay (SIA). The best performing antigen (S1; amino acids 16-685) was selected and further evaluated by serum samples from 76 Swedish patients or convalescents with COVID-19 (previously PCR and/or serologically confirmed), 200 pre-COVID-19 individuals (180 blood donors and 20 infants), and 10 patients with acute Epstein-Barr virus infection. All 76 positive samples showed detectable antibodies to S1, while none of the 210 negative controls gave a false positive antibody reaction. We further compared the COVID-19 SIA with a commercially available enzyme immunoassay and a previously evaluated COVID-19 rapid antibody test. The results revealed an overall assay sensitivity of 100%, a specificity of 100% for both IgM and IgG, a quantitative ability at concentrations up to 25 BAU/mL, and a better performance as compared to the commercial assays, suggesting the COVID-19 SIA as a most valuable tool for efficient laboratory-based serology.

ACS Style

Tove Hoffman; Linda Kolstad; Johanna Lindahl; Bo Albinsson; Anders Bergqvist; Bengt Rönnberg; Åke Lundkvist. Diagnostic Potential of a Luminex-Based Coronavirus Disease 2019 Suspension Immunoassay (COVID-19 SIA) for the Detection of Antibodies against SARS-CoV-2. Viruses 2021, 13, 993 .

AMA Style

Tove Hoffman, Linda Kolstad, Johanna Lindahl, Bo Albinsson, Anders Bergqvist, Bengt Rönnberg, Åke Lundkvist. Diagnostic Potential of a Luminex-Based Coronavirus Disease 2019 Suspension Immunoassay (COVID-19 SIA) for the Detection of Antibodies against SARS-CoV-2. Viruses. 2021; 13 (6):993.

Chicago/Turabian Style

Tove Hoffman; Linda Kolstad; Johanna Lindahl; Bo Albinsson; Anders Bergqvist; Bengt Rönnberg; Åke Lundkvist. 2021. "Diagnostic Potential of a Luminex-Based Coronavirus Disease 2019 Suspension Immunoassay (COVID-19 SIA) for the Detection of Antibodies against SARS-CoV-2." Viruses 13, no. 6: 993.

Journal article
Published: 19 March 2021 in Viruses
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Diseases caused by flaviviruses, including dengue fever and Japanese encephalitis, are major health problems in Vietnam. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Hanoi city. A total of 475 dogs serum samples from 221 households in six districts of Hanoi were analyzed by a competitive enzyme-linked immunosorbent assay (cELISA) for antibodies to the pr-E protein of West Nile virus and other flaviviruses due to cross-reactivity. The overall flavivirus seroprevalence in the dog population was 70.7% (95% CI = 66.4–74.8%). At the animal level, significant associations between seropositive dogs and district location, age, breed and keeping practice were determined. At the household level, the major risk factors were rural and peri-urban locations, presence of pigs, coil burning and households without mosquito-borne disease experience (p < 0.05). Mosquito control by using larvicides or electric traps could lower seropositivity, but other measures did not contribute to significant risk mitigation of flavivirus exposure in dogs. These results will support better control of mosquito-borne diseases in Hanoi, and they indicate that dogs can be used as sentinels for flavivirus exposure.

ACS Style

Long Pham-Thanh; Thang Nguyen-Tien; Ulf Magnusson; Vuong Bui-Nghia; Anh Bui-Ngoc; Duy Le-Thanh; Åke Lundkvist; Minh Can-Xuan; Thuy Nguyen-Thi Thu; Hau Vu-Thi Bich; Hu Lee; Hung Nguyen-Viet; Johanna Lindahl. Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam. Viruses 2021, 13, 507 .

AMA Style

Long Pham-Thanh, Thang Nguyen-Tien, Ulf Magnusson, Vuong Bui-Nghia, Anh Bui-Ngoc, Duy Le-Thanh, Åke Lundkvist, Minh Can-Xuan, Thuy Nguyen-Thi Thu, Hau Vu-Thi Bich, Hu Lee, Hung Nguyen-Viet, Johanna Lindahl. Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam. Viruses. 2021; 13 (3):507.

Chicago/Turabian Style

Long Pham-Thanh; Thang Nguyen-Tien; Ulf Magnusson; Vuong Bui-Nghia; Anh Bui-Ngoc; Duy Le-Thanh; Åke Lundkvist; Minh Can-Xuan; Thuy Nguyen-Thi Thu; Hau Vu-Thi Bich; Hu Lee; Hung Nguyen-Viet; Johanna Lindahl. 2021. "Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam." Viruses 13, no. 3: 507.

Journal article
Published: 14 December 2020 in Viruses
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A crucial, but unresolved question concerning mosquito-borne virus transmission is how these viruses can remain endemic in regions where the transmission is halted for long periods of time, due to mosquito inactivity in, e.g., winter. In northern Europe, Sindbis virus (SINV) (genus alphavirus, Togaviridae) is transmitted among birds by Culex mosquitoes during the summer, with occasional symptomatic infections occurring in humans. In winter 2018–19, we sampled hibernating Culex spp females in a SINV endemic region in Sweden and assessed them individually for SINV infection status, blood-feeding status, and species. The results showed that 35 out of the 767 collected mosquitoes were infected by SINV, i.e., an infection rate of 4.6%. The vast majority of the collected mosquitoes had not previously blood-fed (98.4%) and were of the species Cx. pipiens (99.5%). This is the first study of SINV overwintering, and it concludes that SINV can be commonly found in the hibernating Cx. pipiens population in an endemic region in Sweden, and that these mosquitoes become infected through other means besides blood-feeding. Further studies on mosquito ecology and viral interactions are needed to elucidate the mechanisms of the persistence of these viruses over winter.

ACS Style

Alexander Bergman; Emma Dahl; Åke Lundkvist; Jenny C. Hesson. Sindbis Virus Infection in Non-Blood-Fed Hibernating Culex pipiens Mosquitoes in Sweden. Viruses 2020, 12, 1441 .

AMA Style

Alexander Bergman, Emma Dahl, Åke Lundkvist, Jenny C. Hesson. Sindbis Virus Infection in Non-Blood-Fed Hibernating Culex pipiens Mosquitoes in Sweden. Viruses. 2020; 12 (12):1441.

Chicago/Turabian Style

Alexander Bergman; Emma Dahl; Åke Lundkvist; Jenny C. Hesson. 2020. "Sindbis Virus Infection in Non-Blood-Fed Hibernating Culex pipiens Mosquitoes in Sweden." Viruses 12, no. 12: 1441.

Preprint content
Published: 29 October 2020
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Evidence suggests that SARS-CoV-2, as well as other coronaviruses, can be dispersed and potentially transmitted by aerosols directly or via ventilation systems. We therefore investigated ventilation openings in one COVID-19 ward and central ducts that expel indoor air from three COVID-19 wards at Uppsala University Hospital, Sweden, during April and May 2020. Swab samples were taken from individual ceiling ventilation openings and surfaces in central ducts. Samples were subsequently subjected to rRT-PCR targeting the N and E genes of SARS-CoV-2. Central ventilation HEPA filters, located several stories above the wards, were removed and portions analyzed in the same manner. In two subsequent samplings, SARS-CoV-2 N and E genes were detected in seven and four out of 19 room vents, respectively. Central ventilation HEPA exhaust filters from the ward were found positive for both genes in three samples. Corresponding filters from two other, adjacent COVID-19 wards were also found positive. Infective ability of the samples was assessed by inoculation of susceptible cell cultures but could not be determined in these experiments. Detection of SARS-CoV-2 in central ventilation systems, distant from patient areas, indicate that virus can be transported long distances and that droplet transmission alone cannot reasonably explain this, especially considering the relatively low air change rates in these wards. Airborne transmission of SARS-CoV-2 must be taken into consideration for preventive measures.

ACS Style

Karolina Nissen; Janina Krambrich; Dario Akaberi; Tove Hoffman; Jiaxin Ling; Åke Lundkvist; Erik Salaneck. Long-distance airborne dispersal of SARS-CoV-2 in COVID-19 wards. 2020, 1 .

AMA Style

Karolina Nissen, Janina Krambrich, Dario Akaberi, Tove Hoffman, Jiaxin Ling, Åke Lundkvist, Erik Salaneck. Long-distance airborne dispersal of SARS-CoV-2 in COVID-19 wards. . 2020; ():1.

Chicago/Turabian Style

Karolina Nissen; Janina Krambrich; Dario Akaberi; Tove Hoffman; Jiaxin Ling; Åke Lundkvist; Erik Salaneck. 2020. "Long-distance airborne dispersal of SARS-CoV-2 in COVID-19 wards." , no. : 1.

Journal article
Published: 21 September 2020 in Redox Biology
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The ongoing SARS-CoV-2 pandemic is a global public health emergency posing a high burden on nations’ health care systems and economies. Despite the great effort put in the development of vaccines and specific treatments, no prophylaxis or effective therapeutics are currently available. Nitric oxide (NO) is a broad-spectrum antimicrobial and a potent vasodilator that has proved to be effective in reducing SARS-CoV replication and hypoxia in patients with severe acute respiratory syndrome. Given the potential of NO as treatment for SARS-CoV-2 infection, we have evaluated the in vitro antiviral effect of NO on SARS-CoV-2 replication. The NO-donor S-nitroso-N-acetylpenicillamine (SNAP) had a dose dependent inhibitory effect on SARS-CoV-2 replication, while the non S-nitrosated NAP was not active, as expected. Although the viral replication was not completely abolished (at 200 μM and 400 μM), SNAP delayed or completely prevented the development of viral cytopathic effect in treated cells, and the observed protective effect correlated with the level of inhibition of the viral replication. The capacity of the NO released from SNAP to covalently bind and inhibit SARS-CoV-2 3CL recombinant protease in vitro was also tested. The observed reduction in SARS-CoV-2 protease activity was consistent with S-nitrosation of the enzyme active site cysteine.

ACS Style

Dario Akaberi; Janina Krambrich; Jiaxin Ling; Chen Luni; Göran Hedenstierna; Josef D. Järhult; Johan Lennerstrand; Åke Lundkvist. Mitigation of the replication of SARS-CoV-2 by nitric oxide in vitro. Redox Biology 2020, 37, 101734 -101734.

AMA Style

Dario Akaberi, Janina Krambrich, Jiaxin Ling, Chen Luni, Göran Hedenstierna, Josef D. Järhult, Johan Lennerstrand, Åke Lundkvist. Mitigation of the replication of SARS-CoV-2 by nitric oxide in vitro. Redox Biology. 2020; 37 ():101734-101734.

Chicago/Turabian Style

Dario Akaberi; Janina Krambrich; Jiaxin Ling; Chen Luni; Göran Hedenstierna; Josef D. Järhult; Johan Lennerstrand; Åke Lundkvist. 2020. "Mitigation of the replication of SARS-CoV-2 by nitric oxide in vitro." Redox Biology 37, no. : 101734-101734.

Journal article
Published: 14 September 2020 in Viruses
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Background: During the COVID-19 pandemic, the virus evolved, and we therefore aimed to provide an insight into which genetic variants were enriched, and how they spread in Sweden. Methods: We analyzed 348 Swedish SARS-CoV-2 sequences freely available from GISAID obtained from 7 February 2020 until 14 May 2020. Results: We identified 14 variant sites ≥5% frequency in the population. Among those sites, the D936Y substitution in the viral Spike protein was under positive selection. The variant sites can distinguish 11 mutational profiles in Sweden. Nine of the profiles appeared in Stockholm in March 2020. Mutational profiles 3 (B.1.1) and 6 (B.1), which contain the D936Y mutation, became the predominant profiles over time, spreading from Stockholm to other Swedish regions during April and the beginning of May. Furthermore, Bayesian phylogenetic analysis indicated that SARS-CoV-2 could have emerged in Sweden on 27 December 2019, and community transmission started on February 1st with an evolutionary rate of 1.5425 × 10−3 substitutions per year. Conclusions: Our study provides novel knowledge on the spatio-temporal dynamics of Swedish SARS-CoV-2 variants during the early pandemic. Characterization of these viral variants can provide precious insights on viral pathogenesis and can be valuable for diagnostic and drug development approaches.

ACS Style

Jiaxin Ling; Rachel A. Hickman; Jinlin Li; Xi Lu; Johanna F. Lindahl; Åke Lundkvist; Josef D. Järhult. Spatio-Temporal Mutational Profile Appearances of Swedish SARS-CoV-2 During the Early Pandemic. Viruses 2020, 12, 1026 .

AMA Style

Jiaxin Ling, Rachel A. Hickman, Jinlin Li, Xi Lu, Johanna F. Lindahl, Åke Lundkvist, Josef D. Järhult. Spatio-Temporal Mutational Profile Appearances of Swedish SARS-CoV-2 During the Early Pandemic. Viruses. 2020; 12 (9):1026.

Chicago/Turabian Style

Jiaxin Ling; Rachel A. Hickman; Jinlin Li; Xi Lu; Johanna F. Lindahl; Åke Lundkvist; Josef D. Järhult. 2020. "Spatio-Temporal Mutational Profile Appearances of Swedish SARS-CoV-2 During the Early Pandemic." Viruses 12, no. 9: 1026.

Other
Published: 01 September 2020
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Background and objectives Several antibody tests are available to detect SARS-CoV-2 specific antibodies, many of which address different antigens. Rapid point-of-care (POC) tests have been doubted due to an eventual risk of production errors, although it is unstudied whether such error would affect test sensitivity and/or specificity. We aimed to evaluate two separate production lots of a commercially available test intended for rapid detection of IgM and IgG against the N-terminal part of the SARS-CoV-2 spike protein (S1). Materials and methods Serum samples from individuals with confirmed SARS-CoV-2 infection, by RT-PCR and/or serology, and pre-COVID-19 negative control sera gathered from a biobank during 2018 were collected. The presence of anti-S1 IgM/IgG was verified by an in-house Luminex-based serological assay, serving as reference method. The index test was a commercially available rapid POC-test (the COVID-19 IgG/IgM Rapid Test Cassette [Zhejiang Orient Gene Biotech Co Ltd, Huzhou, Zhejiang, China/Healgen Scientific, LLC, U.S.A.]). Results One hundred samples were verified positive for anti-S1 IgG (median fluorescence intensity (MFI) ≥900) and 74 for anti-S1 IgM (MFI ≥700), confirmed by RT-PCR (n=90) and/or serology (n=89). None of the negative controls (n=200; MFI Conclusion The rapid POC-test used in this study is suitable to assess SARS-CoV-2 anti-S1 specific IgM/IgG, as a measure of previous virus exposure on an individual level. While the specificity was not affected by production lot, external validation of separate lots of rapid POC-tests is encouraged to ensure high sensitivity before market introduction.

ACS Style

Tove Hoffman; Linda Kolstad; Bengt Rönnberg; Åke Lundkvist. Evaluation of production lots of a rapid point-of-care lateral flow serological test intended for identification of IgM and IgG against the N-terminal part of the spike protein (S1) of SARS-CoV-2. 2020, 1 .

AMA Style

Tove Hoffman, Linda Kolstad, Bengt Rönnberg, Åke Lundkvist. Evaluation of production lots of a rapid point-of-care lateral flow serological test intended for identification of IgM and IgG against the N-terminal part of the spike protein (S1) of SARS-CoV-2. . 2020; ():1.

Chicago/Turabian Style

Tove Hoffman; Linda Kolstad; Bengt Rönnberg; Åke Lundkvist. 2020. "Evaluation of production lots of a rapid point-of-care lateral flow serological test intended for identification of IgM and IgG against the N-terminal part of the spike protein (S1) of SARS-CoV-2." , no. : 1.

Preprint content
Published: 02 July 2020
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We report repeated rRT-PCR detection and infective ability of Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) from a health care worker three days prior to mild COVID-19 symptoms. We propose that this provides evidence for potential early presymptomatic transmission of SARS-CoV-2 and that contagiousness may arise shortly after exposure.

ACS Style

Karolina Nissen; Marie Hagbom; Janina Krambrich; Dario Akaberi; Sumit Sharma; Jiaxin Ling; Tove Hoffman; Kåre Bondeson; Lennart Svensson; Åke Lundkvist; Erik Salaneck. Presymptomatic viral shedding and infective ability of Severe Acute Respiratory Syndrome coronavirus 2. 2020, 1 .

AMA Style

Karolina Nissen, Marie Hagbom, Janina Krambrich, Dario Akaberi, Sumit Sharma, Jiaxin Ling, Tove Hoffman, Kåre Bondeson, Lennart Svensson, Åke Lundkvist, Erik Salaneck. Presymptomatic viral shedding and infective ability of Severe Acute Respiratory Syndrome coronavirus 2. . 2020; ():1.

Chicago/Turabian Style

Karolina Nissen; Marie Hagbom; Janina Krambrich; Dario Akaberi; Sumit Sharma; Jiaxin Ling; Tove Hoffman; Kåre Bondeson; Lennart Svensson; Åke Lundkvist; Erik Salaneck. 2020. "Presymptomatic viral shedding and infective ability of Severe Acute Respiratory Syndrome coronavirus 2." , no. : 1.

Preprint content
Published: 01 July 2020
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Evidence suggests that SARS-CoV-2 can be dispersed and potentially transmitted by aerosols, directly or via ventilation systems. We report detection of SARS-CoV-2 RNA in COVID-19 ward ceiling vent openings as well as in ventilation exhaust filters and central ducts up to at least 56 meters from patient areas. As this ventilation system provides low air flow, we propose that viral particles may be readily dispersed in air over vast distances and that further investigations of infectivity of airborne SARS-CoV-2 must be performed.

ACS Style

Karolina Nissen; Janina Krambrich; Dario Akaberi; Tove Hoffman; Jiaxin Ling; Åke Lundkvist; Erik Salaneck. Long-distance airborne dispersal of SARS-CoV-2 in COVID-19 wards. 2020, 1 .

AMA Style

Karolina Nissen, Janina Krambrich, Dario Akaberi, Tove Hoffman, Jiaxin Ling, Åke Lundkvist, Erik Salaneck. Long-distance airborne dispersal of SARS-CoV-2 in COVID-19 wards. . 2020; ():1.

Chicago/Turabian Style

Karolina Nissen; Janina Krambrich; Dario Akaberi; Tove Hoffman; Jiaxin Ling; Åke Lundkvist; Erik Salaneck. 2020. "Long-distance airborne dispersal of SARS-CoV-2 in COVID-19 wards." , no. : 1.

Preprint content
Published: 18 April 2020
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The intricate lattice of Gn and Gc glycoprotein spike complexes at the surface of hantaviruses facilitates host-cell entry and is the primary target of the neutralizing antibody-mediated immune response. Here, through study of a neutralizing monoclonal antibody (mAb 4G2) generated in a bank vole reservoir host following infection with Puumala virus (PUUV), we provide molecular-level insights into how antibody-mediated targeting of the hantaviral glycoprotein lattice effectively neutralizes the virus. Crystallographic analysis reveals that mAb 4G2 binds to a multi-domain site on Gc in the pre-fusion state, and that Fab binding is incompatible with the conformational changes of the Gc that are required for host cell entry. Cryo-electron microscopy of PUUV-like particles treated with Fab 4G2 demonstrates that the antibody binds to monomeric Gc at breaks in the Gn-Gc lattice, highlighting the immunological accessibility of Gc monomers on the mature hantavirus surface and the plastic nature of the higher-order lattice assembly. This work provides a structure-based blueprint for rationalizing antibody-mediated targeting of hantaviruses.

ACS Style

Ilona Rissanen; Robert Stass; Stefanie A. Krumm; Jeffrey Seow; Ruben J.G. Hulswit; Guido C. Paesen; Jussi Hepojoki; Olli Vapalahti; Ake Lundkvist; Olivier Reynard; Viktor Volchkov; Katie J. Doores; Juha T. Huiskonen; Thomas A. Bowden. Molecular rationale for hantavirus neutralization by a reservoir host-derived monoclonal antibody. 2020, 1 .

AMA Style

Ilona Rissanen, Robert Stass, Stefanie A. Krumm, Jeffrey Seow, Ruben J.G. Hulswit, Guido C. Paesen, Jussi Hepojoki, Olli Vapalahti, Ake Lundkvist, Olivier Reynard, Viktor Volchkov, Katie J. Doores, Juha T. Huiskonen, Thomas A. Bowden. Molecular rationale for hantavirus neutralization by a reservoir host-derived monoclonal antibody. . 2020; ():1.

Chicago/Turabian Style

Ilona Rissanen; Robert Stass; Stefanie A. Krumm; Jeffrey Seow; Ruben J.G. Hulswit; Guido C. Paesen; Jussi Hepojoki; Olli Vapalahti; Ake Lundkvist; Olivier Reynard; Viktor Volchkov; Katie J. Doores; Juha T. Huiskonen; Thomas A. Bowden. 2020. "Molecular rationale for hantavirus neutralization by a reservoir host-derived monoclonal antibody." , no. : 1.

Journal article
Published: 26 March 2020 in Eurosurveillance
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Background Tick-borne encephalitis (TBE) is a potentially severe neurological disease caused by TBE virus (TBEV). In Europe and Asia, TBEV infection has become a growing public health concern and requires fast and specific detection. Aim In this observational study, we evaluated a rapid TBE IgM test, ReaScan TBE, for usage in a clinical laboratory setting. Methods Patient sera found negative or positive for TBEV by serological and/or molecular methods in diagnostic laboratories of five European countries endemic for TBEV (Estonia, Finland, Slovenia, the Netherlands and Sweden) were used to assess the sensitivity and specificity of the test. The patients’ diagnoses were based on other commercial or quality assured in-house assays, i.e. each laboratory’s conventional routine methods. For specificity analysis, serum samples from patients with infections known to cause problems in serology were employed. These samples tested positive for e.g. Epstein–Barr virus, cytomegalovirus and Anaplasma phagocytophilum, or for flaviviruses other than TBEV, i.e. dengue, Japanese encephalitis, West Nile and Zika viruses. Samples from individuals vaccinated against flaviviruses other than TBEV were also included. Altogether, 172 serum samples from patients with acute TBE and 306 TBE IgM negative samples were analysed. Results Compared with each laboratory’s conventional methods, the tested assay had similar sensitivity and specificity (99.4% and 97.7%, respectively). Samples containing potentially interfering antibodies did not cause specificity problems. Conclusion Regarding diagnosis of acute TBEV infections, ReaScan TBE offers rapid and convenient complementary IgM detection. If used as a stand-alone, it can provide preliminary results in a laboratory or point of care setting.

ACS Style

Bo Albinsson; Anu Jääskeläinen; Kairi Värv; Mateja Jelovšek; Corine GeurtsvanKessel; Sirkka Vene; Josef D. Järhult; Chantal Reusken; Irina Golovljova; Tatjana Avšič-Županc; Olli Vapalahti; Åke Lundkvist. Multi-laboratory evaluation of ReaScan TBE IgM rapid test, 2016 to 2017. Eurosurveillance 2020, 25, 1900427 .

AMA Style

Bo Albinsson, Anu Jääskeläinen, Kairi Värv, Mateja Jelovšek, Corine GeurtsvanKessel, Sirkka Vene, Josef D. Järhult, Chantal Reusken, Irina Golovljova, Tatjana Avšič-Županc, Olli Vapalahti, Åke Lundkvist. Multi-laboratory evaluation of ReaScan TBE IgM rapid test, 2016 to 2017. Eurosurveillance. 2020; 25 (12):1900427.

Chicago/Turabian Style

Bo Albinsson; Anu Jääskeläinen; Kairi Värv; Mateja Jelovšek; Corine GeurtsvanKessel; Sirkka Vene; Josef D. Järhult; Chantal Reusken; Irina Golovljova; Tatjana Avšič-Županc; Olli Vapalahti; Åke Lundkvist. 2020. "Multi-laboratory evaluation of ReaScan TBE IgM rapid test, 2016 to 2017." Eurosurveillance 25, no. 12: 1900427.

Other
Published: 24 March 2020
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ObjectivesComorbidities have significant indications for the disease outcome of COVID-19, however which underlying diseases that contribute the most to aggravate the conditions of COVID-19 patients is still largely unknown. SARS-CoV-2 viral clearance is a golden standard for defining the recovery of COVID-19 infections. To dissect the underlying diseases that could impact on viral clearance, we enrolled 106 COVID-19 patients who were hospitalized in the Zhongnan Hospital of Wuhan University, Wuhan, China between Jan 5 and Feb 25, 2020.MethodologyWe comprehensively analyzed demographic, clinical and laboratory data, as well as patient treatment records. Survival analyses with Kaplan-Meier and Cox regression modelling were employed to identify factors influencing the viral clearance negatively.ResultsWe found that increasing age, male gender, and angiotensin-converting enzyme 2 (ACE2) associated factors (including hypertension, diabetes, and cardiovascular diseases) adversely affected the viral clearance. Furthermore, analysis by a random forest survival model pointed out hypertension, cortisone treatment, gender, and age as the four most important variables.ConclusionsWe conclude that patients at old age, males, and/or having diseases associated with high expression of ACE2 will have worse prognosis during a COVID-19 infections.

ACS Style

Xiaoping Chen; Wenjia Hu; Jiaxin Ling; Pingzheng Mo; Yongxi Zhang; Qunqun Jiang; Zhiyong Ma; Qian Cao; Liping Deng; Shihui Song; Ruiying Zheng; Shicheng Gao; Hengning Ke; Xien Gui; Åke Lundkvist; Jinlin Li; Johanna F Lindahl; Yong Xiong. Hypertension and Diabetes Delay the Viral Clearance in COVID-19 Patients. 2020, 1 .

AMA Style

Xiaoping Chen, Wenjia Hu, Jiaxin Ling, Pingzheng Mo, Yongxi Zhang, Qunqun Jiang, Zhiyong Ma, Qian Cao, Liping Deng, Shihui Song, Ruiying Zheng, Shicheng Gao, Hengning Ke, Xien Gui, Åke Lundkvist, Jinlin Li, Johanna F Lindahl, Yong Xiong. Hypertension and Diabetes Delay the Viral Clearance in COVID-19 Patients. . 2020; ():1.

Chicago/Turabian Style

Xiaoping Chen; Wenjia Hu; Jiaxin Ling; Pingzheng Mo; Yongxi Zhang; Qunqun Jiang; Zhiyong Ma; Qian Cao; Liping Deng; Shihui Song; Ruiying Zheng; Shicheng Gao; Hengning Ke; Xien Gui; Åke Lundkvist; Jinlin Li; Johanna F Lindahl; Yong Xiong. 2020. "Hypertension and Diabetes Delay the Viral Clearance in COVID-19 Patients." , no. : 1.

Other
Published: 06 March 2020
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SummaryBackgroundViral clearance is one important indicator for the recovery of SARS-CoV-2 infected patients. Previous studies have pointed out that suboptimal T and B cell responses can delay viral clearance in MERS-CoV and SARS-CoV infected patients. The role of leukomonocytes in viral clearance of COVID-19 patients is not yet well defined.MethodsFrom January 26 to February 28, 2020, an observational study was launched at the Department of Infectious Diseases, Zhongnan Hospital of Wuhan University, Wuhan, China. We enrolled 25 laboratory-confirmed COVID-19 patients, whose throat-swab specimens were tested positive for SARS-CoV-2 infection by qRT-PCR. To investigate the factors that contribute to the viral clearance, we comprehensively analyzed clinical records, counts of lymphocyte subsets including CD3+, CD4+, CD8+ T cells, B cells and NK cells in the patients who successfully cleared SARS-CoV-2, and compared to those that failed to, after a standardized treatment of 8-14 days.FindingsIn 25 enrolled COVID-19 patients, lymphopenia was a common feature. After the treatment, 14 out of the 25 enrolled patients were tested negative for SARS-CoV-2. The patients that cleared the infection had restored the numbers of CD3+, CD4+, CD8+ T cells and B cells as compared to the still viral RNA positive patients, while the recovered patients had a higher count of leukomonocytes.ConclusionsBy comparison of leukomonocytes counts in COVID-19 patients at different stages of the disease, we found that CD3+, CD4+, CD8+ T cells and B cells appear to play important roles in viral clearance. The restoration of leukomonocytes counts from peripheral blood can be used as prognosis for the recovery of an COVID-19 infection. We propose that restoration of leukomonocytes counts can be added to the COVID-19 diagnostic guidance as a criterion for releasing and discharging patients.

ACS Style

Xiaoping Chen; Jiaxin Ling; Pingzheng Mo; Yongxi Zhang; Qunqun Jiang; Zhiyong Ma; Qian Cao; Wenjia Hu; Shi Zou; Liangjun Chen; Lei Yao; Mingqi Luo; Tielong Chen; Liping Deng; Ke Liang; Shihui Song; Rongrong Yang; Ruiying Zheng; Shicheng Gao; Xien Gui; Hengning Ke; Wei Hou; Åke Lundkvist; Yong Xiong. Restoration of leukomonocyte counts is associated with viral clearance in COVID-19 hospitalized patients. 2020, 1 .

AMA Style

Xiaoping Chen, Jiaxin Ling, Pingzheng Mo, Yongxi Zhang, Qunqun Jiang, Zhiyong Ma, Qian Cao, Wenjia Hu, Shi Zou, Liangjun Chen, Lei Yao, Mingqi Luo, Tielong Chen, Liping Deng, Ke Liang, Shihui Song, Rongrong Yang, Ruiying Zheng, Shicheng Gao, Xien Gui, Hengning Ke, Wei Hou, Åke Lundkvist, Yong Xiong. Restoration of leukomonocyte counts is associated with viral clearance in COVID-19 hospitalized patients. . 2020; ():1.

Chicago/Turabian Style

Xiaoping Chen; Jiaxin Ling; Pingzheng Mo; Yongxi Zhang; Qunqun Jiang; Zhiyong Ma; Qian Cao; Wenjia Hu; Shi Zou; Liangjun Chen; Lei Yao; Mingqi Luo; Tielong Chen; Liping Deng; Ke Liang; Shihui Song; Rongrong Yang; Ruiying Zheng; Shicheng Gao; Xien Gui; Hengning Ke; Wei Hou; Åke Lundkvist; Yong Xiong. 2020. "Restoration of leukomonocyte counts is associated with viral clearance in COVID-19 hospitalized patients." , no. : 1.

Other
Published: 01 January 2020 in Infection Ecology & Epidemiology
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The prevalence of COVID-19 antibodies on June 17–18, 2020 was investigated in two residential areas of Stockholm, Sweden. Among the residents in Norra Djurgårdsstaden, a newly built upper- and middle-class area of Stockholm, 4.1% of study participants had SARS-CoV-2-specific antibodies, while in Tensta, a highly segregated low-income area, 30% of the participants tested antibody positive.

ACS Style

Åke Lundkvist; Stefan Hanson; Björn Olsen. Pronounced difference in Covid-19 antibody prevalence indicates cluster transmission in Stockholm, Sweden. Infection Ecology & Epidemiology 2020, 10, 1 .

AMA Style

Åke Lundkvist, Stefan Hanson, Björn Olsen. Pronounced difference in Covid-19 antibody prevalence indicates cluster transmission in Stockholm, Sweden. Infection Ecology & Epidemiology. 2020; 10 (1):1.

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Åke Lundkvist; Stefan Hanson; Björn Olsen. 2020. "Pronounced difference in Covid-19 antibody prevalence indicates cluster transmission in Stockholm, Sweden." Infection Ecology & Epidemiology 10, no. 1: 1.

Research article
Published: 01 January 2020 in Infection Ecology & Epidemiology
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COVID-19 is the most rapidly growing pandemic in modern time, and the need for serological testing is most urgent. Although the diagnostics of acute patients by RT-PCR is both efficient and specific, we are also crucially in need of serological tools for investigating antibody responses and assessing individual and potential herd immunity. We evaluated a commercially available test developed for rapid (within 15 minutes) detection of SARS-CoV-2-specific IgM and IgG by 29 PCR-confirmed COVID-19 cases and 124 negative controls. The results revealed a sensitivity of 69% and 93.1% for IgM and IgG, respectively, based solely on PCR-positivity due to the absence of a serological gold standard. The assay specificities were shown to be 100% for IgM and 99.2% for IgG. This indicates that the test is suitable for assessing previous virus exposure, although negative results may be unreliable during the first weeks after infection. More detailed studies on antibody responses during and post infection are urgently needed.

ACS Style

Tove Hoffman; Karolina Nissen; Janina Krambrich; Bengt Rönnberg; Dario Akaberi; Mouna Esmaeilzadeh; Erik Salaneck; Johanna Lindahl; Åke Lundkvist. Evaluation of a COVID-19 IgM and IgG rapid test; an efficient tool for assessment of past exposure to SARS-CoV-2. Infection Ecology & Epidemiology 2020, 10, 1754538 .

AMA Style

Tove Hoffman, Karolina Nissen, Janina Krambrich, Bengt Rönnberg, Dario Akaberi, Mouna Esmaeilzadeh, Erik Salaneck, Johanna Lindahl, Åke Lundkvist. Evaluation of a COVID-19 IgM and IgG rapid test; an efficient tool for assessment of past exposure to SARS-CoV-2. Infection Ecology & Epidemiology. 2020; 10 (1):1754538.

Chicago/Turabian Style

Tove Hoffman; Karolina Nissen; Janina Krambrich; Bengt Rönnberg; Dario Akaberi; Mouna Esmaeilzadeh; Erik Salaneck; Johanna Lindahl; Åke Lundkvist. 2020. "Evaluation of a COVID-19 IgM and IgG rapid test; an efficient tool for assessment of past exposure to SARS-CoV-2." Infection Ecology & Epidemiology 10, no. 1: 1754538.

Research article
Published: 01 January 2020 in Infection Ecology & Epidemiology
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Anaplasma phagocytophilum (AP) has vast geographical and host ranges and causes disease in humans and domesticated animals. We investigated the role of northward migratory birds in the dispersal of tick-borne AP in the African-Western Palearctic. Ticks were collected from northward migratory birds trapped during spring migration of 2010 at two localities in the central Mediterranean Sea. AP DNA was detected by PCR (gltA and 16S rRNA) and variant determination was performed using ankA sequences. In total, 358 ticks were collected. One of 19 ticks determined as Ixodes was confirmed positive for AP DNA. The tick was collected from a woodchat shrike (Lanius senator senator) trapped in Greece, and molecularly determined to belong to the I. ricinus complex and sharing highest (95%) 16S RNA sequence identity to I. gibbosus. The ankA AP sequence exhibited highest similarity to sequences from rodents and shrews (82%) and ruminants (80%). Phylogenetic analyses placed it convincingly outside other clades, suggesting that it represents a novel AP variant. The divergent Ixodes species harboring a novel AP variant could either indicate an enzootic cycle involving co-evolution with birds, or dissemination from other regions by avian migration. None of the 331 Hyalomma marginatum sensu lato ticks, all immature stages, were positive for AP DNA, lending no evidence for the involvement of Hyalomma ticks transported by birds in the ecology of AP.

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Tove Hoffman; Peter Wilhelmsson; Christos Barboutis; Thord Fransson; Thomas G.T. Jaenson; Per-Eric Lindgren; Friederike D. Von Loewenich; Åke Lundkvist; Björn Olsen; Erik Salaneck. A divergent Anaplasma phagocytophilum variant in an Ixodes tick from a migratory bird; Mediterranean basin. Infection Ecology & Epidemiology 2020, 10, 1729653 .

AMA Style

Tove Hoffman, Peter Wilhelmsson, Christos Barboutis, Thord Fransson, Thomas G.T. Jaenson, Per-Eric Lindgren, Friederike D. Von Loewenich, Åke Lundkvist, Björn Olsen, Erik Salaneck. A divergent Anaplasma phagocytophilum variant in an Ixodes tick from a migratory bird; Mediterranean basin. Infection Ecology & Epidemiology. 2020; 10 (1):1729653.

Chicago/Turabian Style

Tove Hoffman; Peter Wilhelmsson; Christos Barboutis; Thord Fransson; Thomas G.T. Jaenson; Per-Eric Lindgren; Friederike D. Von Loewenich; Åke Lundkvist; Björn Olsen; Erik Salaneck. 2020. "A divergent Anaplasma phagocytophilum variant in an Ixodes tick from a migratory bird; Mediterranean basin." Infection Ecology & Epidemiology 10, no. 1: 1729653.

Clinical research article
Published: 01 January 2020 in Infection Ecology & Epidemiology
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The COVID-19 pandemic is growing and spread in the Swedish elderly care system during April 2020. The increasing number of employees on sick-leave due to COVID-19 created severe logistic problems. Some elderly care homes therefore started to screen their personnel to secure the safety of the elderly and to avoid unnecessary quarantine of potentially immune employees. Secondary data from a screening with a COVID-19 rapid test for detection of SARS-CoV-2-specific IgM and IgG of 1,005 employees in 22 elderly care homes in Stockholm, Sweden, were analyzed. Seropositive employees were found in 21 out of the 22 care homes. In total, 23% (231/1,005) of the employees tested positive for antibodies against SARS-CoV-2, and 14.3% (144/1,005) were found positive for IgM (either alone or combined with IgG), indicating recent or present infection. Of those that tested seropositive, 46.5% did not report any clinical symptoms, indicating pre- or asymptomatic infections. Reported symptoms with the highest correlation with seropositivity were fever and loss of smell and taste. These results suggest that antibody testing of employees in elderly care homes is valuable for surveillance of disease development and a crucial screening tool in the effort to decrease the death toll in this pandemic.

ACS Style

Johanna F. Lindahl; Tove Hoffman; Mouna Esmaeilzadeh; Björn Olsen; Reidar Winter; Stefan Amer; Christian Molnár; Ann Svalberg; Åke Lundkvist. High seroprevalence of SARS-CoV-2 in elderly care employees in Sweden. Infection Ecology & Epidemiology 2020, 10, 1789036 .

AMA Style

Johanna F. Lindahl, Tove Hoffman, Mouna Esmaeilzadeh, Björn Olsen, Reidar Winter, Stefan Amer, Christian Molnár, Ann Svalberg, Åke Lundkvist. High seroprevalence of SARS-CoV-2 in elderly care employees in Sweden. Infection Ecology & Epidemiology. 2020; 10 (1):1789036.

Chicago/Turabian Style

Johanna F. Lindahl; Tove Hoffman; Mouna Esmaeilzadeh; Björn Olsen; Reidar Winter; Stefan Amer; Christian Molnár; Ann Svalberg; Åke Lundkvist. 2020. "High seroprevalence of SARS-CoV-2 in elderly care employees in Sweden." Infection Ecology & Epidemiology 10, no. 1: 1789036.