Current relevance of arbovirus infections in transfusion medicine

Arboviruses are maintained in nature through biological transmission between susceptible vertebrate hosts by haematophagous (blood feeding) arthropods, such as mosquitoes, ticks, midges and sandflies.Biological transmission can also be transovarian (from an infected female to offspring) and venereal (from a vertically infected male directly to a female vector).Originally, this large group of viruses was called ARBORviruses, a short laboratory name coined in part by William C. Reeves from the words ARthropod BORne viruses; however, the middle 'R' was later dropped to avoid potential misidentification with trees (arbor in Latin).The earliest attempts to isolate arboviruses were initiated during the 1930s when Murray Valley encephalitis, Rift Valley fever, St Louis encephalitis, Russian spring-summer encephalitis, Western, Eastern and Venezuelan equine encephalitis viruses were discovered [1,2].Today, around 520 arboviruses have been catalogued of which over 100 infect humans.This large group of RNA viruses is quite heterogenous both in terms of their genetic features as well as in the variety of disease they cause.Currently, the term arbovirus has long lost its taxonomic significance and is only suggestive of the common arthropodborne transmission strategy.At present, arboviruses are classified among six virus families: Flaviviridae (genus Flavivirus), Togaviridae (genus Alphavirus), Bunyaviridae (genus Orthobunyavirus, Nairovirus, Phlebovirus), Reoviridae (genus Orbivirus, Coltivirus, Seadornavirus-proposed), Rhabdoviridae (genus Vesiculovirus) and Orthomyxoviridae (genus Thogotovirus).An abbreviated list of medically important arboviruses is presented in Table 1.Other arboviruses for which the available information is insufficient, or which do not seem to cause a disease (although data for pathogenicity may become available in the future) were not considered for this review.Typically, the arbovirus transmission cycle in nature involves enzootic amplification (between the arthropod and small rodents or birds) which at times can spill over domestic animals or humans (West Nile, Rift Valley fever, Japanese encephalitis viruses) or human-arthropod-human urban transmission in the case of Dengue and Chikungunya infection (the latter can also be maintained in nature through enzootic (sylvatic) amplification between mosquitoes and non-human primates.For the most part, various arboviral infections result in mild or no apparent clinical symptoms, with a brief viraemia followed by specific immune response.Whenever there is a clinical presentation, several general syndromes could predominate in individual patients:(1) Self-limited viral fever with or without exanthema and non-specific flu-like symptoms (classical Dengue, West Nile fever, Rift Valley fever, Chikungunya viruses).( 2) Febrile illness with skin rash, arthralgia and ⁄ or arthritis, myalgia, fatigue, lethargy (Chikungunya, Ross River, Barmah Forest and Sindbis-related viruses, such as Ockelbo and Pogosta viruses).(3) Viral encephalitis, aseptic meningitis, flaccid paralysis (West Nile, St Louis encephalitis, Eastern, Western and Venezuelan equine encephalitis, Murray River Valley, Japanese encephalitis and tick-borne encephalitis Virus (TBEV).(4) Viral haemorrhagic fever, fulminent hepatitis or jaundice (Dengue, Yellow Fever, Rift Valley fever, Crimean-Congo haemorrhagic fever viruses).Disease manifestation in infected individuals varies accordingly with respect to host factors such as immune status with homologous or heterologous viruses, immunosuppression, age, race, etc. Secondary Dengue infection caused by a different serotype from the primary infection is considered as a higher risk for Dengue haemorrhagic fever ⁄ Dengue shock syndrome (DHF ⁄ DSS) especially in young children.On the other hand, certain level of heterologous immunity against one or more previous Dengue episodes may have a net positive effect on the outcome of a secondary ⁄ tertiary infection [3-5].African ancestry and Afro-Brazilian-Cuban-Caribbean ethnicity are protective against DHF ⁄ DSS compared to Caucasians [6-8].Recently, arbovirus incursions have increased on a global scale with a tendency to cause large epidemics; West Nile and Chikungunya virus infections are just few wellpublicized examples.Others such as Dengue and Japanese

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.