The Sindbis virus was first identified in 1952 in the city of Sindbis, Egypt. It belongs to the genus Alphavirus and its main vectors are mosquitoes of the genus Culex. The main hosts of this virus are birds, but it can occasionally also be transmitted to humans when bitten by an infected mosquito. In people it is usually asymptomatic, but sometimes it can cause fever, skin rashes and muscle, joint or headache pain.
Now, Spanish researchers have identified for the first time in Spain the presence of the Sindbis virus (SINV) in mosquitoes in the southwest of the country. The finding has been published in the journal One Health and constitutes a key advance in understanding the circulation of this zoonotic virus in southern Europe.
The research has been carried out by teams of scientists from the Carlos III Health Institute and the Doñana Biological Station (EBD-CSIC) dependent on the Higher Council for Scientific Research (CSIC). The researchers analyzed 31,920 mosquitoes, grouped in 1,149 lots, captured in 2022 in western Andalusia, and found the Sindbis virus in 137 lots (11.92%).
The virus was present in five different mosquito species, with Culex perexiguus having the highest infection rate. In addition, it was detected in different locations in the provinces of Málaga, Seville, Huelva and Cádiz, the latter standing out with the highest infection rate.
Migratory birds have introduced the Sindbis virus into Spain
The genomic analysis of the strains detected in Spain has revealed that they all belong to genotype I, previously detected in other areas of Europe and Africa. The Spanish strains showed low genetic variation and were closely related to strains from Algeria and Kenya, suggesting that the virus has recently been introduced into our country by migratory birds, possibly from the north (Algeria) or central Africa.
This discovery has been possible thanks to the collaboration with the West Nile Virus Surveillance and Control Program in Vectors of the Government of Andalusia and highlights the importance of surveillance programs in the early detection of emerging pathogens. Future studies are necessary to determine the importance that this virus may have for public health in Spain.
The virus was present in five different species of mosquitoes and was detected in different locations in the provinces of Málaga, Seville, Huelva and Cádiz.
“The importance of this finding lies in the possibility of investigating the importance that this virus may have in Public Health, if it is causing infections in humans and taking into account the knowledge acquired to improve the differential diagnosis with other arboviruses,” Rafael Gutiérrez pointed out. López and Ana Vázquez, from the National Center of Microbiology (CNM) of the ISCIII, two of the main authors of the study in a note published by the CSIC.
“The study demonstrates the circulation of a virus with potential public health importance long before human cases have been detected, so it is very important to know the possible expansion of this virus in Spain and establish the real impact it may have on the health of the population,” add María José Ruiz López and Jordi Figuerola, from the Department of Conservation Biology and Global Change at the Doñana Biological Station.
Source: Higher Council for Scientific Research (CSIC)
