African horse sickness and the overwintering of Culicoides spp. in the Iberian peninsula.

The research article investigates the presence and seasonal distribution of two potential vectors of African Horse Sickness (AHS) virus – Culicoides imicola and C. obsoletus – in the Iberian Peninsula, and how they might impact the persistence and spread of the disease in Europe.

Investigation Methodology

• The researchers used light trap collections to study the presence and distribution of the two vectors of AHS – Culicoides imicola and C.obsoletus in the Iberian peninsula.
• The exploration covered different latitudes and took into account the seasonal distributions of these potential vectors.

Findings : Culicoides Imicola

• Culicoides imicola was detected as far north as 41 degrees N, but not at 43 degrees N (Asturias, Spain).
• There is a seasonal pattern to their distribution with adults present for just a few months of the year in the northern parts of their spread, with a more continuous presence further south.

Findings : Culicoides Obsoletus

• C. obsoletus showed a broader presence, being identified at all latitudes explored.
• This species was found during all months of the year, demonstrating resilience against cold winter conditions. Its distribution aligns with that in southern Britain.

Implications for AHS

• The researchers compared these findings with data from the AHS outbreak that occurred from 1987-1990 in the Iberian peninsula.
• This comparison helped deduce the potential for AHS to persist yearly and to spread more widely in the palaearctic regions of Europe, facilitated by these potential vectors.

Conclusions

• The findings shed light on the possible role of these Culicoides species in the propagation of African Horse Sickness, especially their potential to aid the disease’s survival through winter and facilitate its spread across different regions of Europe.
• The understanding of the vectors’ behaviors and distributions can inform preventive strategies and response mechanisms to control and contain AHS outbreaks.