Viremia after influenza infection
Pro Research Analysisby 
Searched over 200M research papers
Viremia After Influenza Infection: Insights and Implications
Introduction to Influenza-Induced Viremia
Viremia, the presence of viruses in the bloodstream, is a critical aspect of influenza pathogenesis. While traditionally associated with severe cases, recent studies have expanded our understanding of its occurrence and implications across different influenza strains and infection severities.
Detection and Occurrence of Viremia
Mouse Models and Tissue Distribution
Research using mouse models of influenza A/PR/8 virus infection has demonstrated that viral RNA can be detected in the blood and various tissues. Specifically, the nucleoprotein gene was found in the red blood cell fraction from 1 to 5 days post-inoculation, and in organs such as the lung, brain, liver, spleen, kidney, heart, and skeletal muscle for varying durations up to 14 days1. This suggests that viremia occurs during the acute phase of infection and that the virus can transiently express its genes in multiple organs.
Human Cases and Clinical Implications
In human studies, viremia has been detected in patients with severe influenza infections. For instance, during the 2009 H1N1 pandemic, viral RNA was found in the blood of patients with severe clinical presentations, indicating that viremia is associated with higher disease severity and potentially higher mortality rates, although the latter was not statistically significant3. Additionally, viremia was observed in children during an influenza outbreak in Japan, with viral RNA detected in peripheral blood mononuclear cells2.
Sporadic Nature in Experimental Infections
In experimental settings, such as in mice infected with lethal doses of influenza A (PR8 virus), viremia was observed sporadically. The incidence varied significantly, and it was noted that viremia typically occurred only after high viral concentrations were reached in the lungs4. This sporadic nature suggests that while viremia is not consistently present, it can occur under certain conditions of high viral load.
Viremia in Severe Influenza Strains
H5N1 and H1N1 Strains
Severe strains like H5N1 and pandemic H1N1/2009 have shown a higher propensity for causing viremia. In ferrets infected with H5N1, viral RNA was frequently detected in the blood before death, correlating with severe disease outcomes6. Similarly, in cases of severe H1N1/2009 infection, viremia was detected and associated with rapid disease progression and respiratory failure5.
Implications for Disease Severity and Prognosis
The presence of viremia in severe influenza cases has significant prognostic and therapeutic implications. It may serve as a predictive marker for severe disease, guiding more aggressive treatment strategies. For instance, antiviral agents with low serum levels may be ineffective in patients with viremia, necessitating alternative therapeutic approaches5.
Conclusion
Viremia is a notable feature of influenza infections, particularly in severe cases and specific strains like H5N1 and H1N1/2009. Its detection in blood and various tissues underscores its role in the pathogenesis and severity of the disease. Understanding the occurrence and implications of viremia can aid in better clinical management and treatment of influenza, potentially improving patient outcomes.
Sources and full results
Most relevant research papers on this topic
Viremia induced by influenza virus.
Viremia occurs during the acute phase of influenza A/PR/8 virus infection, with the virus present in various organs and transiently expressed in the blood, potentially influencing the pathogenesis of influenza.
Non-RCT
Animal Study[Viremia in influenza: detection by polymerase chain reaction].
Viremia in influenza infection is not uncommon, suggesting extra respiratory transmission may contribute to gastroenteritis, arthralgia, and myalgia symptoms.
Observational StudyClinical and Virological Factors Associated with Viremia in Pandemic Influenza A/H1N1/2009 Virus Infection
Viremia in pandemic influenza A/H1N1/2009 patients is strongly associated with disease severity and is strongly associated with the D222G/N mutation in the viral hemagglutinin protein.
Observational Study
Highly CitedViremia in mice with pulmonary influenza A virus infections.
Viremia occurs in mice with pulmonary influenza A virus infections, with a high incidence in mice killed after exposure to lethal doses, but its significance in pathogenesis and immune response remains unclear.
Non-RCTAnimal StudyEvidence of viremia in 2 cases of severe pandemic influenza A H1N1/09.
Virus viremia is present in severe 2009 H1N1 influenza cases, potentially indicating severe disease and affecting the effectiveness of low serum antiviral agents.
Case ReportViremia Associated with Fatal Outcomes in Ferrets Infected with Avian H5N1 Influenza Virus
Viremia is a bio-marker for fatal outcomes in ferrets infected with avian H5N1 influenza virus, with high virus load in the brain and low levels in the ileum being associated with death.
Non-RCTAnimal StudyA pantropic strain of influenza virus: generalized infection and viremia in the infant mouse.
Infant mice can easily support the multiplication of a neurotropic influenza A virus variant, NWS strain of Stuart-Harris, causing generalized infections and persistent viremia, with resistance developing with age.
Detection of Influenza A(H3N2) Virus RNA in Donated Blood
Influenza A(H3N2) virus RNA was identified in one blood donation in Brazil, posing a potential risk for viremia and transfusion transmission.
Observational Study
Rigorous JournalLethal H5N1 influenza viruses escape host anti-viral cytokine responses
Lethal H5N1 influenza viruses are resistant to antiviral cytokine responses, potentially explaining their high virulence in humans.
Non-RCTAnimal StudyHighly CitedHIV-1 Plasma Viremia not Increased in Patients Receiving Highly Active Antiretroviral Therapy After Influenza Vaccination
Influenza vaccination in patients with undetectable HIV-1 viremia achieved with highly active antiretroviral therapy does not appear to affect viral load.
Non-RCTTry another search
three-way decision
Thrombolytic therapy after cardiac arrest due to pulmonary embolism
water pollution
What are the implications of high fructose corn syrup on health?
What are the advantages of Al2O3/LaAlO3/SiO2 gate dielectric for SiC power MOSFETs?
The safety and efficacy of online therapy platforms in mental health care.