Very often, mosquitos, which act as vectors, infect birds with protozoans of the genus Plasmodium with their bites. This makes birds into vertebrate hosts of these parasites. In the case of this study, the house sparrow ( Passer domesticus ) has been found, for the first time, to be a host for a parasite from Africa, Plasmodium PAGRI02, which had not been previously described outside that continent. This is the outcome of a study which analysed blood samples from some 3000 sparrows in Andalusia and Extremadura, conducted by researchers at the UEx Zoology Department, in collaboration with the Doñana Biological Station (EBD-CSIC).
The scientists looked at the genomic DNA to sequence the parasites and described thirteen species of the pathogen Plasmodium in house sparrows, while five of these in Europe were identified as infected by the African lineage Plasmodium PAGRI02. "Undoubtedly, global environmental changes which affect communities of hosts and vectors are currently under way, which are encouraging the active transmission of this African parasite outside its native area", says the researcher Martina Ferraguti. Scientists are warning of the consequences that global change is already having on wildlife. Milder temperatures in winter help to develop stable and permanent populations of mosquitos, the principal vectors of avian malaria, throughout the year.
The house sparrow is a very well-studied bird in Europe and "in the records from more than 15,000 samples analysed all over Europe up to now, this is the first time we have encountered a tropical lineage of this parasite, which is already being transmitted actively in this country", explains Alfonso Marzal, a UEx researcher.
According to the researchers, the evidence of the active transmission of this African parasite in Europe is the principal novelty in this study, published in the journal Parasites & Vectors , published by BMC, a leader in medicine and tropical health. These results open up many new fields of research into the effect of the new parasite on European fauna and its transmission, as well as in the study of the communities of mosquitos which pass on the pathogen. Moreover, "this type of research constitutes a first step in the study of the transmission patterns of other tropical diseases which are making their way into Europe, such as dengue, zika, chikungunya and, of course, malaria itself", states Marzal.
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Parasites & Vectors