No abstract

Since the first evidence of human parvovirus B19 (B19V) infection in late 80s, several studies have been conducted to clarify the spectrum of clinical diseases in Brazil. B19V infection is prevalent in the general population and has exhibited a cyclical pattern of occurrence every 4–5 years, with the predominance of genotype 1 over 3b. During epidemic periods the wide range of clinical conditions, such as ertythema infectiosum, arthropathy, transient aplastic crisis, nonimmune hydrops fetalis and B19V-hepatitis were diagnosed. However, many infections are likely asymptomatic or have a self-limiting clinical course and are not readly diagnosed. Besides, the similarity of the symptoms of ertythema infectiosum to other rash diseases and the broadly circulation of arboviruses makes differential diagnosis more difficult. In this article, we provide a historical comprehensive overview of the research on parvovirus B19 conducted in Brazil, with a focus on the clinical and epidemiological aspects of the infection.

COVID-19 pandemic affected the global population in an unprecedented scale, with long-term consequences of SARS CoV-2 infection now emerging as a serious concern. Cognitive dysfunction is often reported in post-COVID patients, but its underlying mechanisms remain unknown. Here we demonstrated that brain exposure to SARS-CoV-2 spike (S) protein through its infusion into the lateral ventricle of adult mice induced late cognitive impairment, hippocampal synapse loss, and microglial engulfment of presynaptic terminals. Additionally, TLR4 blockage prevented Sassociated detrimental effects on memory in mice and TLR4 single nucleotide polymorphism (SNP) rs10759931 was associated with late cognitive outcome in mild COVID-19-recovered patients. Collectively, these findings indicate that S protein directly impacts the brain and identify TLR4 as a key target to prevent cognitive dysfunction. To our knowledge, this is the first animal model that recapitulates postCOVID cognitive impairment, opening new avenues for developing new strategies to prevent or treat the neurological outcomes of COVID-19.