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A new study published in PNAS has provided insights regarding the origin and spread of European malaria.
The malaria-causing parasites Plasmodium vivax and Plasmodium falciparum were eradicated in Europe in the mid-twentieth century.
Now, researchers have recovered genetic data from European samples of malaria preserved on microscope slides in the 1940s.
The team performed second-generation sequencing on DNA extracted from 3 of the slides, which generated millions of sequences of malaria-causing parasites.
The researchers were then able to reconstruct the parasites’ mitochondrial genomes and compare them with those of present-day samples worldwide.
“The European sequence of P vivax is closely related to the most common strain currently found in Central and South America,” said study author Carles Lalueza-Fox, PhD, of the Institute of Evolutionary Biology (Consejo Superior de Investigaciones Científicas-Universitat Pompeu Fabra) in Barcelona, Spain.
“This suggests that the pathogen was introduced to the Americas by European colonists after Columbus. In contrast, the European sequence of P falciparum belongs to a strain which has only been found in India. This indicates that the pathogen of the most severe form of malaria was introduced to Europe from the Indian subcontinent, probably some 2500 years ago.”
The European samples the researchers analyzed were dated between 1942 and 1944. They originate from an old antimalarial center inaugurated in 1925 in Sant Jaume d’Enveja, on the Ebro Delta, located in Spain’s north-eastern region of Tarragona.
The center’s head, Ildefonso Canicio, spent decades treating malaria sufferers who worked in the area’s rice fields and ultimately contracted the disease himself.
Following Dr Canicio’s death in 1961, some of his slides, which were used for diagnostic purposes, were saved from destruction when they were recognized by his descendants, who allowed them to be used in the current study.
“It is still possible to see malaria-carrying parasites on the slides when they are studied under the microscope,” Dr Lalueza-Fox said. “However, the quantity of the pathogen’s DNA available in a single drop of blood is very limited, and when you add to that the issue of poor preservation after 70 years, it is clear why this type of study has never been carried out.”
Still, the researchers said this study has shown that historic specimens can be an important source of insight into the genetics of extinct or eradicated pathogens.
“Analyzing the nuclear genome in these pathogens will allow us to know more about the mutations which have made current-day strains resistant to different drugs, given that the European Plasmodium which has been retrieved is older than all of these treatments,” said study author Pere Gelabert, also of the Institute of Evolutionary Biology. 
Photo from the Institute
of Evolutionary Biology
A new study published in PNAS has provided insights regarding the origin and spread of European malaria.
The malaria-causing parasites Plasmodium vivax and Plasmodium falciparum were eradicated in Europe in the mid-twentieth century.
Now, researchers have recovered genetic data from European samples of malaria preserved on microscope slides in the 1940s.
The team performed second-generation sequencing on DNA extracted from 3 of the slides, which generated millions of sequences of malaria-causing parasites.
The researchers were then able to reconstruct the parasites’ mitochondrial genomes and compare them with those of present-day samples worldwide.
“The European sequence of P vivax is closely related to the most common strain currently found in Central and South America,” said study author Carles Lalueza-Fox, PhD, of the Institute of Evolutionary Biology (Consejo Superior de Investigaciones Científicas-Universitat Pompeu Fabra) in Barcelona, Spain.
“This suggests that the pathogen was introduced to the Americas by European colonists after Columbus. In contrast, the European sequence of P falciparum belongs to a strain which has only been found in India. This indicates that the pathogen of the most severe form of malaria was introduced to Europe from the Indian subcontinent, probably some 2500 years ago.”
The European samples the researchers analyzed were dated between 1942 and 1944. They originate from an old antimalarial center inaugurated in 1925 in Sant Jaume d’Enveja, on the Ebro Delta, located in Spain’s north-eastern region of Tarragona.
The center’s head, Ildefonso Canicio, spent decades treating malaria sufferers who worked in the area’s rice fields and ultimately contracted the disease himself.
Following Dr Canicio’s death in 1961, some of his slides, which were used for diagnostic purposes, were saved from destruction when they were recognized by his descendants, who allowed them to be used in the current study.
“It is still possible to see malaria-carrying parasites on the slides when they are studied under the microscope,” Dr Lalueza-Fox said. “However, the quantity of the pathogen’s DNA available in a single drop of blood is very limited, and when you add to that the issue of poor preservation after 70 years, it is clear why this type of study has never been carried out.”
Still, the researchers said this study has shown that historic specimens can be an important source of insight into the genetics of extinct or eradicated pathogens.
“Analyzing the nuclear genome in these pathogens will allow us to know more about the mutations which have made current-day strains resistant to different drugs, given that the European Plasmodium which has been retrieved is older than all of these treatments,” said study author Pere Gelabert, also of the Institute of Evolutionary Biology.
Photo from the Institute
of Evolutionary Biology
A new study published in PNAS has provided insights regarding the origin and spread of European malaria.
The malaria-causing parasites Plasmodium vivax and Plasmodium falciparum were eradicated in Europe in the mid-twentieth century.
Now, researchers have recovered genetic data from European samples of malaria preserved on microscope slides in the 1940s.
The team performed second-generation sequencing on DNA extracted from 3 of the slides, which generated millions of sequences of malaria-causing parasites.
The researchers were then able to reconstruct the parasites’ mitochondrial genomes and compare them with those of present-day samples worldwide.
“The European sequence of P vivax is closely related to the most common strain currently found in Central and South America,” said study author Carles Lalueza-Fox, PhD, of the Institute of Evolutionary Biology (Consejo Superior de Investigaciones Científicas-Universitat Pompeu Fabra) in Barcelona, Spain.
“This suggests that the pathogen was introduced to the Americas by European colonists after Columbus. In contrast, the European sequence of P falciparum belongs to a strain which has only been found in India. This indicates that the pathogen of the most severe form of malaria was introduced to Europe from the Indian subcontinent, probably some 2500 years ago.”
The European samples the researchers analyzed were dated between 1942 and 1944. They originate from an old antimalarial center inaugurated in 1925 in Sant Jaume d’Enveja, on the Ebro Delta, located in Spain’s north-eastern region of Tarragona.
The center’s head, Ildefonso Canicio, spent decades treating malaria sufferers who worked in the area’s rice fields and ultimately contracted the disease himself.
Following Dr Canicio’s death in 1961, some of his slides, which were used for diagnostic purposes, were saved from destruction when they were recognized by his descendants, who allowed them to be used in the current study.
“It is still possible to see malaria-carrying parasites on the slides when they are studied under the microscope,” Dr Lalueza-Fox said. “However, the quantity of the pathogen’s DNA available in a single drop of blood is very limited, and when you add to that the issue of poor preservation after 70 years, it is clear why this type of study has never been carried out.”
Still, the researchers said this study has shown that historic specimens can be an important source of insight into the genetics of extinct or eradicated pathogens.
“Analyzing the nuclear genome in these pathogens will allow us to know more about the mutations which have made current-day strains resistant to different drugs, given that the European Plasmodium which has been retrieved is older than all of these treatments,” said study author Pere Gelabert, also of the Institute of Evolutionary Biology.