Leta i den här bloggen

torsdag 24 juli 2025

Chikungunya-purkauksista jälleen uusia tietoja 2025 . Vektori myös AEDES-lajeja

 https://www.sciencedirect.com/science/article/pii/S1071909125000348?via%3Dihub

  • Tämån vuoden artikkelista olennaista tietoa CHIKV viruksesta ja vektorista.  
  •  LÄHDETIEDOT: 

    Chikungunya virus infection: A scoping review highlighting pediatric systemic and neurologic complications

    , , ,

Epidemiology

Aedes aegypti and Aedes albopictus are the primary vectors responsible for the transmission of several medically significant arboviruses, including dengue, Zika, yellow fever, and chikungunya viruses.4 Aedes aegypti, originally native to Africa, has expanded globally via maritime trade and now predominantly inhabits tropical and subtropical urban regions. It demonstrates endophilic behavior and a strong preference for human hosts, contributing to its high vectorial capacity in densely populated areas.5,6 In contrast, Aedes albopictus, native to Asia, has successfully colonized both tropical and temperate climates.
 
 Its ability to produce cold-resistant diapausing eggs enables overwintering in cooler Environmental temperature plays a critical role in modulating CHIKV transmission. Higher temperatures have been shown to accelerate viral replication within the mosquito and reduce the extrinsic incubation period, thereby enhancing infectivity.12,13 Consequently, climate change may facilitate the expansion of Aedes vectors into regions previously unsuitable for sustained transmission. This phenomenon has already manifested in parts of Europe, where local cases of CHIKV and other arboviral infections have recently 
emerged.14, 15, 16Microbiology
Chikungunya virus (CHIKV) is an enveloped, single-stranded, positive-sense RNA virus belonging to the Alphavirus genus within the Togaviridae family. Its envelope glycoproteins (gp.) , E1 and E2, form heterodimers that organize into trimeric spikes on the virion surface, mediating host cell entry. E1 contains a hydrophobic fusion peptide crucial for membrane fusion, while E2 facilitates receptor binding and is the principal target of host neutralizing antibodies. During maturation, the precursor protein p62—comprising E2 and E3—is processed in the trans-Golgi network (TGN), with E3 remaining associated with E2 until final virion assembly is complete. CHIKV engages host cell receptors including glycosaminoglycans (gag)  and the adhesion molecule Mxra8, which promotes viral attachment and internalization. Entry is predominantly mediated by clathrin-dependent endocytosis and macropinocytosis, both of which require endosomal acidification.17,18
emerged.14, 15, 16 environments, facilitating its global spread since the 1960s.6,7
 
In addition to viral and host factors, the mosquito’s microbiota significantly influences CHIKV replication and transmission. The gut microbiome can alter virus dynamics following a blood meal19 and modulate the vector's innate immune response.20 Among the microbial inhabitants, Wolbachia—an intracellular, maternally transmitted bacterium present in approximately 60 % of insect species—has emerged as a potential tool for vector control. While Aedes albopictus naturally harbors Wolbachia, Aedes aegypti does not.21 However, experimental introduction of Wolbachia into A. aegypti has been shown to suppress CHIKV replication, likely through immune priming mechanisms.21,22 

Clinical manifestations

Chikungunya virus (CHIKV) is associated with high attack rates during outbreaks (35–75 %), such as during the Réunion Island epidemic, where laboratory-confirmed cases totaled 16,050 and estimated cases reached 244,000 (35 % attack rate).28,29 CHIKV infection presents age-dependent clinical features and severity, ranging from mild febrile illness in children to severe multisystem disease in neonates and chronic sequelae in adults. Recognizing these patterns is essential to guide diagnosis, monitoring, and management.

Systemic manifestations

Overall, systemic chikungunya presents a spectrum of disease severity. While adults bear the brunt of chronic rheumatologic sequelae, neonates face the most acute risk of life-threatening complications, and children typically experience intermediate, self-limited illness with some risk of complications in infancy.

Neonates

They are at the highest risk for severe systemic disease, especially those born to viremic mother
 

Inga kommentarer:

Skicka en kommentar