Phylogenetic analysis of West Nile virus: first report of lineage 1 in donkey in Turkey

Molecular evidence of Wolbachia and Orthoflavivirus infection in field-collected mosquitoes in three provinces of Türkiye

BACKGROUND

Mosquitoes transmit various pathogens causing diseases like Zika, Dengue, West Nile and Chikungunya. They also harbour insect-specific viruses (ISVs) and Wolbachia, which can block arbovirus transmission. This study investigated the prevalence of Orthoflavivirus and Wolbachia in mosquito populations from three provinces in Türkiye.

METHODS

Mosquitoes were collected using CDC Miniature Light traps in 2022-2023. Morphologically identified specimens were pooled (1-10 individuals) and screened for Orthoflavivirus and Wolbachia via PCR and confirmed by Sanger sequencing. Infection prevalence was estimated using the maximum likelihood method. Mosquito taxa richness across provinces was estimated using the abundance-based, non-parametric Chao1 index.

RESULTS

Among 8766 mosquitoes (11 taxa) collected, Culex perexiguus, Ochlerotatus caspius and Anopheles claviger were most abundant. Anopheles flavivirus (AnFV) detected in one Oc. caspius pool, while Wolbachia sequences belonging to supergroup B were detected in An. claviger, Cx. pipiens s.l., Cx. perexiguus and Oc. caspius, with an overall infection prevalence of 0.0119 (95% CI: 0.008-0.0161). The richest mosquito fauna was detected in Ankara, followed by Adana, and Çankırı.

CONCLUSION

This study provides new insights into mosquito richness and the prevalence of Orthoflavivirus and Wolbachia in Türkiye, contributing to vector surveillance and the potential use of Wolbachia in mosquito control strategies.

An Overview of Infectious and Non-Infectious Causes of Pregnancy Losses in Equine

Equine breeding plays an essential role in the local economic development of many countries, and it has experienced rapid growth in China in recent years. However, the equine industry, particularly large-scale donkey farms, faces a significant challenge with pregnancy losses. Unfortunately, there is a lack of systematic research on abortion during equine breeding. Several causes, both infectious and non-infectious, of pregnancy losses have been documented in equines. The infectious causes are viruses, bacteria, parasites, and fungi. Non-infectious causes may include long transportation, ingestion of mycotoxins, hormonal disturbances, twinning, placentitis, umbilical length and torsion, etc. In current review, we discuss the transmission routes, diagnostic methods, and control measures for these infectious agents. Early detection of the cause and appropriate management are crucial in preventing pregnancy loss in equine practice. This review aims to provide a comprehensive understanding of the potential causes of abortion in equines, including infectious agents and non-infectious factors. It emphasizes the importance of continued research and effective control measures to address this significant challenge in the equine industry.

West Nile Virus Lineage 1 in Italy: Newly Introduced or a Re-Occurrence of a Previously Circulating Strain?

In Italy, West Nile virus (WNV) appeared for the first time in the Tuscany region in 1998. After 10 years of absence, it re-appeared in the areas surrounding the Po River delta, affecting eight provinces in three regions. Thereafter, WNV epidemics caused by genetically divergent isolates have been documented every year in the country. Since 2018, only WNV Lineage 2 has been reported in the Italian territory. In October 2020, WNV Lineage 1 (WNV-L1) re-emerged in Italy, in the Campania region. This is the first occurrence of WNV-L1 detection in the Italian territory since 2017. WNV was detected in the internal organs of a goshawk (Accipiter gentilis) and a kestrel (Falco tinnunculus). The RNA extracted in the goshawk tissue samples was sequenced, and a Bayesian phylogenetic analysis was performed by a maximum-likelihood tree. Genome analysis, conducted on the goshawk WNV complete genome sequence, indicates that the strain belongs to the WNV-L1 Western-Mediterranean (WMed) cluster. Moreover, a close phylogenetic similarity is observed between the goshawk strain, the 2008-2011 group of Italian sequences, and European strains belonging to the Wmed cluster. Our results evidence the possibility of both a new re-introduction or unnoticed silent circulation in Italy, and the strong importance of keeping the WNV surveillance system in the Italian territory active.