Reactivation of Epstein-Barr virus in SFTSV infected patients

Background:Severe fever with thrombocytopenia syndrome(SFTS)is an emerging hemorrhagic fever caused by a tick-borne bunyavirus SFTSV with case fatality up to 30%.The reactivation of Epstein-Barr virus(EBV)has been proven to occur in individuals with various immune suppression conditions.Methods:Here,we diagnosed 22 SFTSV infected patients with PCR in a hospital in Shandong Province,China in 2020.To understand the consequences of SFTSV infection leading to EBV reactivation,we examined EBV reactivation in SFTSV-infected patients with PCR and RT-PCR.Results:We found that EBV was reactivated in 18.2%(4/22)of SFTS patients,suggesting that EBV reactivation is common in SFTS patients.Compared with SFTS patients without EBV reactivation,SFTS patients with EBV-reactivation had a significantly lower median level of serum albumin(32.45 g/L vs.26.95 g/L,p=0.03)and a significantly higher median number of urine red blood cells(0 cells/μL vs.9 cells/μL,p=0.04).Conclusion:SFTS infection can reactivate EBV in patients,which may make the clinical condition of patients worsen.

Global trends in COVID-19

The pandemic COVID-19 is certainly one of the most severe infectious diseases in human history.In the last 2 years,the COVID-19 pandemic has caused over 418.6 million confirmed cases and 5.8 million deaths world-wide.Young people make up the majority of all infected COVID-19 cases,but the mortality rate is relatively lower compared to older age groups.Currently,about 55.04%individuals have been fully vaccinated rapidly approaching to herd immunity globally.The challenge is that new SARS-CoV-2 variants with potential to evade immunity from natural infection or vaccine continue to emerge.Breakthrough infections have occurred in both SARS-CoV-2 naturally infected and vaccinated individuals,but breakthrough infections tended to exhibit mild or asymptomatic symptoms and lower mortality rates.Therefore,immunity from natural infection or vaccination can reduce SARS-CoV-2 pathogenicity,but neither can completely prevent SARS-CoV-2 infection/reinfection.Fortunately,the morbidity and mortality of COVID-19 continue to decline.The 7-day average cumulative case fatality of COVID-19 has decreased from 12.3%on the February 25,2020,to 0.27%on January 09,2022,which could be related to a decreased SARS-CoV-2 variant virulence,vaccine immunization,and/or better treatment of patients.In conclusion,elimination of SARS-CoV-2 in the world could be impossible or at least an arduous task with a long way to go.The best strategy to prevent COVID-19 pandemic is to expand inoculation rate of effective vaccines.As the population reaches herd immunity,the mortality rate of COVID-19 may continue to decrease,and COVID-19 could eventually become another common cold.

Oral and ocular transmission of severe fever with thrombocytopenia syndrome virus

Background:Severe fever with thrombocytopenia syndrome virus(SFTSV)is a tick-borne bunyavirus that could cause a severe hemorrhagic fever termed SFTS with a high fatality rate of up to 30%.Importantly,SFTSV is frequently transmitted from person-to-person and patients’blood or excreta are considered as the risk factors for transmission of SFTSV.However,the mechanism of person-to-person transmission of SFTSV is still elusive.Methods:In this study,wild-type(WT)C57BL/6 J mice and a lethal SFTSV mouse model IFNAR−/−A129 mice were utilized to evaluate whether SFTSV could be transmitted via oral or ocular routes.C57BL/6 J mice were inoculated with cell-cultured SFTSV via oral and ocular inoculation.IFNAR−/−A129 mice were inoculated with cell-cultured SFTSV or SFTSV infected mouse acute sera via oral and ocular inoculation.Results:We found that SFTSV antibody positive rates in C57BL/6 J mice were 70%(7/10)and 30%(3/10)in the oral inoculation group and ocular inoculation group,respectively on day 21 post SFTSV inoculation.The mortality rates of IFNAR−/−mice with oral and ocular inoculation of cell-cultured SFTSV were 100%and 83.33%(5/6),respectively on day 6 post inoculation.The mortality rates of IFNAR−/−mice with oral and ocular inoculation of SFTSV infected mouse acute serum were 100%and 66.67%(4/6),respectively on day 9 post inoculation.Conclusions:Together,our results show that SFTSV can be transmitted effectively through oral and ocular mem-brane,suggesting exposure to SFTS positive excreta may be a high-risk factor of nosocomial transmission of SFTSV in hospitals and/or families.Family members and healthcare workers should be protected properly during taking care of SFTS patients to prevent SFTSV nosocomial infection.