Abstract. The reference genomes of Culex laticinctus, Culex modestus, Culex perexiguus, and Culex theileri offer crucial resources for exploring the geneti

At a Feb. 5 Hennepin County committee meeting, the Metropolitan Mosquito Control District reported a record West Nile year in the district and outlined program changes including expanded drone use, large-scale larval control and a shift to community tire drop-off events to reduce staff burden.

The globally distributed arbovirus West Nile virus (WNV) continues to expand across Europe, with rising numbers of human cases and an increasingly broad geographic distribution. WNV is primarily transmitted by mosquitoes of the genus Culex. Out of nine WNV lineages, human pathogenicity has been clearly established for lineages 1 and 2, but differences in their transmission dynamics, such as minimal infectious dose and transmission efficiency, remain poorly understood. In this study, we investigated how viral lineage, mosquito species, and blood meal titer influence the vector competence of two primary WNV vectors from Europe, Cx. pipiens biotype pipiens and Cx. torrentium, as well as the invasive mosquito species Aedes albopictus. Female mosquitoes were fed with increasing blood meal titers containing either of the WNV lineages. After an incubation period of 14 days at a mean temperature of 24{degrees}C, mosquito body titers were quantified, and the presence of infectious viral particles in the saliva was assessed. Our results revealed a clear difference between the two lineages. Lineage 2 resulted in higher transmission efficiencies across all three species and required lower infectious doses to cause transmission. Among the tested species, Cx. torrentium proved to be a highly competent vector (max. transmission efficiency = 30%, minimum infectious dose = 105 TCID50/mL), despite its underrepresentation in research. These findings provide detailed insights into how viral lineage, mosquito species, and blood meal titer might shape WNV transmission, informing future risk assessments and efforts to mitigate WNV transmission in Europe.

The globally distributed arbovirus West Nile virus (WNV) continues to expand across Europe, with rising numbers of human cases and an increasingly broad geographic distribution. WNV is primarily transmitted by mosquitoes of the genus Culex. Out of nine WNV lineages, human pathogenicity has been clearly established for lineages 1 and 2, but differences in their transmission dynamics, such as minimal infectious dose and transmission efficiency, remain poorly understood. In this study, we investigated how viral lineage, mosquito species, and blood meal titer influence the vector competence of two primary WNV vectors from Europe, Cx. pipiens biotype pipiens and Cx. torrentium, as well as the invasive mosquito species Aedes albopictus. Female mosquitoes were fed with increasing blood meal titers containing either of the WNV lineages. After an incubation period of 14 days at a mean temperature of 24{degrees}C, mosquito body titers were quantified, and the presence of infectious viral particles in the saliva was assessed. Our results revealed a clear difference between the two lineages. Lineage 2 resulted in higher transmission efficiencies across all three species and required lower infectious doses to cause transmission. Among the tested species, Cx. torrentium proved to be a highly competent vector (max. transmission efficiency = 30%, minimum infectious dose = 105 TCID50/mL), despite its underrepresentation in research. These findings provide detailed insights into how viral lineage, mosquito species, and blood meal titer might shape WNV transmission, informing future risk assessments and efforts to mitigate WNV transmission in Europe.

Lin et al. show that in the setting of type I IFN signaling deficiency, IL-1R and MyD88 signaling in hematopoietic cells drives WNV pathogenesis. Infected myeloid cells, including monocytes and macrophages, and inflammasome activation contribute to gut barrier injury, liver damage, cytokine accumulation in serum, and brain injury.

Abstract. The Chicago metropolitan area is a hotspot for human West Nile virus (WNV) cases. Despite extensive surveillance and research, predicting WNV cas

In August 2025, West Nile virus (WNV) was detected for the first time in Belgium through a monitoring programme in wild birds, with three corvids testing positive by RT-qPCR. In September and October, four additional infected birds were identified. Whole genome sequencing classified the strain as WNV lineage 2, consistent with strains circulating elsewhere in Europe. These detections provide evidence of local WNV circulation with important implications for animal and public health preparedness and surveillance during the 2026 mosquito season.

The post The Unlikely Predatory Shrimp Battling West Nile Virus appeared first on A-Z Animals. Quick Take Triops maintained evolutionary stasis for 300 million years and outlasted dinosaurs . These crustaceans will eat practically anything, including shrimp, potatoes, and lunch...