Deforestation linked to rise in cases of emerging zoonotic malaria.
Research suggests environmental
changes are driving increase in Plasmodium knowlesi malaria – an
infection usually found only in monkeys – among people in Malaysia.
A steep rise in human cases of P.
knowlesi malaria in Malaysia is likely to be linked to deforestation and
associated environmental changes, according to new research published in Emerging Infectious Diseases The
study, led by the London School of Hygiene & Tropical Medicine, is the
first to explore how changes in land use are impacting the emergence of the
disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by
mosquitoes, which is common in forest-dwelling macaque monkeys. Although only
recently reported in humans, it is now the most common form of human malaria in
many areas of Malaysia, and has been reported across southeast Asia. In recent
years, Malaysia has seen widespread deforestation alongside rapid oil palm and
other agricultural expansion. It is thought changes in the way land is used
could be a key driver in the emergence of P. knowlesi, but until now
this has not been investigated in detail.
They found that the number of P.
knowlesi cases was strongly linked to deforestation in areas surrounding
the villages. This could be explained by a number of factors, including
humans coming into closer contact with the forest inhabited by the macaques and
the mosquito vectors, due to employment in tree clearance and expanding
agriculture. Another factor could be that as land use changes in this way,
macaque populations are becoming more densely concentrated in areas of forest
where humans are present.
Lead author Kimberly Fornace,
Research Fellow at the London School of Hygiene & Tropical Medicine, said:
“The dramatic rise in the number of P. knowlesi malaria cases in humans
in Malaysia in the past ten years has been most common in areas with
deforestation, as well as areas that are close to patches of forest where
humans, macaques and mosquitoes are coming into closer and more frequent
contact. This suggests that there is a higher risk of P. knowlesi
transmission in areas where land use is changing, and this knowledge will help
focus efforts on these areas and also predict and respond to future outbreaks.
Given our findings, we view deforestation as having distinct public health
consequences which need to be urgently addressed.”
The findings show the study region
had undergone significant environmental changes, with many villages
substantially affected by deforestation. During the five-year study alone, 39%
of the region’s villages lost more than 10% of the forest cover in their
surrounding 1km radius, and half of villages lost more than 10% within a 5km
radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during
the study period.
The findings also confirmed that P.
knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of
malaria may have been unreported as they were asymptomatic or resolved without
treatment. P. knowlesi can be mistaken for other forms of human malaria
in microscope diagnosis, however the authors adjusted for this uncertainty in
the study. They also highlight that the environmental data were limited as they
could not discriminate between types of forest or crops, meaning further work
is needed to investigate whether vegetation type is a risk factor for P.
knowlesi.
The research was carried out in
collaboration with the Infectious Disease Society Kota Kinabalu Sabah,
Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies
School of Health Research, Australia; Sabah Department of Health, Malaysia; and
the University of Glasgow, UK. FOR MORE INFORMATION SOURCE http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#VITA VIVENDA.
Deforestation linked to rise in cases of emerging zoonotic malaria
Research suggests environmental changes are driving increase in Plasmodium knowlesi malaria – an infection usually found only in monkeys – among people in Malaysia.A steep rise in human cases of P. knowlesi malaria in Malaysia is likely to be linked to deforestation and associated environmental changes, according to new research published in Emerging Infectious Diseases. The study, led by the London School of Hygiene & Tropical Medicine, is the first to explore how changes in land use are impacting the emergence of the disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by mosquitoes, which is common in forest-dwelling macaque monkeys. Although only recently reported in humans, it is now the most common form of human malaria in many areas of Malaysia, and has been reported across southeast Asia. In recent years, Malaysia has seen widespread deforestation alongside rapid oil palm and other agricultural expansion. It is thought changes in the way land is used could be a key driver in the emergence of P. knowlesi, but until now this has not been investigated in detail.
The study focused on the Kudat and Kota Marudu districts in Sabah, Malaysia, covering an area of more than 3,000km² with a population of approximately 120,000 people. Researchers used hospital records for 2008-2012 to collect data on the number of P. knowlesi malaria cases from villages in the districts. Information collected from satellite data helped the team to map the local forest, land use, and environmental changes around 450 villages, in order to correlate how these changes might affect human infection.
They found that the number of P. knowlesi cases was strongly linked to deforestation in areas surrounding the villages. This could be explained by a number of factors, including humans coming into closer contact with the forest inhabited by the macaques and the mosquito vectors, due to employment in tree clearance and expanding agriculture. Another factor could be that as land use changes in this way, macaque populations are becoming more densely concentrated in areas of forest where humans are present.
Lead author Kimberly Fornace, Research Fellow at the London School of Hygiene & Tropical Medicine, said: “The dramatic rise in the number of P. knowlesi malaria cases in humans in Malaysia in the past ten years has been most common in areas with deforestation, as well as areas that are close to patches of forest where humans, macaques and mosquitoes are coming into closer and more frequent contact. This suggests that there is a higher risk of P. knowlesi transmission in areas where land use is changing, and this knowledge will help focus efforts on these areas and also predict and respond to future outbreaks. Given our findings, we view deforestation as having distinct public health consequences which need to be urgently addressed.”
The findings show the study region had undergone significant environmental changes, with many villages substantially affected by deforestation. During the five-year study alone, 39% of the region’s villages lost more than 10% of the forest cover in their surrounding 1km radius, and half of villages lost more than 10% within a 5km radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during the study period.
The findings also confirmed that P. knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of malaria may have been unreported as they were asymptomatic or resolved without treatment. P. knowlesi can be mistaken for other forms of human malaria in microscope diagnosis, however the authors adjusted for this uncertainty in the study. They also highlight that the environmental data were limited as they could not discriminate between types of forest or crops, meaning further work is needed to investigate whether vegetation type is a risk factor for P. knowlesi.
This study was funded by the Biotechnology and Biosciences Research Council, Economic and Social Research Council, Medical Research Council, and Natural Environment Research Council, through the Environmental and Social Ecology of Human Infectious Diseases Initiative (ESEI).
The research was carried out in collaboration with the Infectious Disease Society Kota Kinabalu Sabah, Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies School of Health Research, Australia; Sabah Department of Health, Malaysia; and the University of Glasgow, UK.
- See more at: http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#sthash.9id9MmXX.dpuf
esearch suggests environmental changes are driving increase in Plasmodium knowlesi malaria – an infection usually found only in monkeys – among people in Malaysia.
A steep rise in human cases of P. knowlesi malaria in Malaysia is likely to be linked to deforestation and associated environmental changes, according to new research published in Emerging Infectious Diseases. The study, led by the London School of Hygiene & Tropical Medicine, is the first to explore how changes in land use are impacting the emergence of the disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by mosquitoes, which is common in forest-dwelling macaque monkeys. Although only recently reported in humans, it is now the most common form of human malaria in many areas of Malaysia, and has been reported across southeast Asia. In recent years, Malaysia has seen widespread deforestation alongside rapid oil palm and other agricultural expansion. It is thought changes in the way land is used could be a key driver in the emergence of P. knowlesi, but until now this has not been investigated in detail.
The study focused on the Kudat and Kota Marudu districts in Sabah, Malaysia, covering an area of more than 3,000km² with a population of approximately 120,000 people. Researchers used hospital records for 2008-2012 to collect data on the number of P. knowlesi malaria cases from villages in the districts. Information collected from satellite data helped the team to map the local forest, land use, and environmental changes around 450 villages, in order to correlate how these changes might affect human infection.
They found that the number of P. knowlesi cases was strongly linked to deforestation in areas surrounding the villages. This could be explained by a number of factors, including humans coming into closer contact with the forest inhabited by the macaques and the mosquito vectors, due to employment in tree clearance and expanding agriculture. Another factor could be that as land use changes in this way, macaque populations are becoming more densely concentrated in areas of forest where humans are present.
Lead author Kimberly Fornace, Research Fellow at the London School of Hygiene & Tropical Medicine, said: “The dramatic rise in the number of P. knowlesi malaria cases in humans in Malaysia in the past ten years has been most common in areas with deforestation, as well as areas that are close to patches of forest where humans, macaques and mosquitoes are coming into closer and more frequent contact. This suggests that there is a higher risk of P. knowlesi transmission in areas where land use is changing, and this knowledge will help focus efforts on these areas and also predict and respond to future outbreaks. Given our findings, we view deforestation as having distinct public health consequences which need to be urgently addressed.”
The findings show the study region had undergone significant environmental changes, with many villages substantially affected by deforestation. During the five-year study alone, 39% of the region’s villages lost more than 10% of the forest cover in their surrounding 1km radius, and half of villages lost more than 10% within a 5km radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during the study period.
The findings also confirmed that P. knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of malaria may have been unreported as they were asymptomatic or resolved without treatment. P. knowlesi can be mistaken for other forms of human malaria in microscope diagnosis, however the authors adjusted for this uncertainty in the study. They also highlight that the environmental data were limited as they could not discriminate between types of forest or crops, meaning further work is needed to investigate whether vegetation type is a risk factor for P. knowlesi.
This study was funded by the Biotechnology and Biosciences Research Council, Economic and Social Research Council, Medical Research Council, and Natural Environment Research Council, through the Environmental and Social Ecology of Human Infectious Diseases Initiative (ESEI).
The research was carried out in collaboration with the Infectious Disease Society Kota Kinabalu Sabah, Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies School of Health Research, Australia; Sabah Department of Health, Malaysia; and the University of Glasgow, UK.
- See more at: http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#sthash.9id9MmXX.dpuf
A steep rise in human cases of P. knowlesi malaria in Malaysia is likely to be linked to deforestation and associated environmental changes, according to new research published in Emerging Infectious Diseases. The study, led by the London School of Hygiene & Tropical Medicine, is the first to explore how changes in land use are impacting the emergence of the disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by mosquitoes, which is common in forest-dwelling macaque monkeys. Although only recently reported in humans, it is now the most common form of human malaria in many areas of Malaysia, and has been reported across southeast Asia. In recent years, Malaysia has seen widespread deforestation alongside rapid oil palm and other agricultural expansion. It is thought changes in the way land is used could be a key driver in the emergence of P. knowlesi, but until now this has not been investigated in detail.
The study focused on the Kudat and Kota Marudu districts in Sabah, Malaysia, covering an area of more than 3,000km² with a population of approximately 120,000 people. Researchers used hospital records for 2008-2012 to collect data on the number of P. knowlesi malaria cases from villages in the districts. Information collected from satellite data helped the team to map the local forest, land use, and environmental changes around 450 villages, in order to correlate how these changes might affect human infection.
They found that the number of P. knowlesi cases was strongly linked to deforestation in areas surrounding the villages. This could be explained by a number of factors, including humans coming into closer contact with the forest inhabited by the macaques and the mosquito vectors, due to employment in tree clearance and expanding agriculture. Another factor could be that as land use changes in this way, macaque populations are becoming more densely concentrated in areas of forest where humans are present.
Lead author Kimberly Fornace, Research Fellow at the London School of Hygiene & Tropical Medicine, said: “The dramatic rise in the number of P. knowlesi malaria cases in humans in Malaysia in the past ten years has been most common in areas with deforestation, as well as areas that are close to patches of forest where humans, macaques and mosquitoes are coming into closer and more frequent contact. This suggests that there is a higher risk of P. knowlesi transmission in areas where land use is changing, and this knowledge will help focus efforts on these areas and also predict and respond to future outbreaks. Given our findings, we view deforestation as having distinct public health consequences which need to be urgently addressed.”
The findings show the study region had undergone significant environmental changes, with many villages substantially affected by deforestation. During the five-year study alone, 39% of the region’s villages lost more than 10% of the forest cover in their surrounding 1km radius, and half of villages lost more than 10% within a 5km radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during the study period.
The findings also confirmed that P. knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of malaria may have been unreported as they were asymptomatic or resolved without treatment. P. knowlesi can be mistaken for other forms of human malaria in microscope diagnosis, however the authors adjusted for this uncertainty in the study. They also highlight that the environmental data were limited as they could not discriminate between types of forest or crops, meaning further work is needed to investigate whether vegetation type is a risk factor for P. knowlesi.
This study was funded by the Biotechnology and Biosciences Research Council, Economic and Social Research Council, Medical Research Council, and Natural Environment Research Council, through the Environmental and Social Ecology of Human Infectious Diseases Initiative (ESEI).
The research was carried out in collaboration with the Infectious Disease Society Kota Kinabalu Sabah, Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies School of Health Research, Australia; Sabah Department of Health, Malaysia; and the University of Glasgow, UK.
- See more at: http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#sthash.9id9MmXX.dpuf
esearch suggests environmental changes are driving increase in Plasmodium knowlesi malaria – an infection usually found only in monkeys – among people in Malaysia.
A steep rise in human cases of P. knowlesi malaria in Malaysia is likely to be linked to deforestation and associated environmental changes, according to new research published in Emerging Infectious Diseases. The study, led by the London School of Hygiene & Tropical Medicine, is the first to explore how changes in land use are impacting the emergence of the disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by mosquitoes, which is common in forest-dwelling macaque monkeys. Although only recently reported in humans, it is now the most common form of human malaria in many areas of Malaysia, and has been reported across southeast Asia. In recent years, Malaysia has seen widespread deforestation alongside rapid oil palm and other agricultural expansion. It is thought changes in the way land is used could be a key driver in the emergence of P. knowlesi, but until now this has not been investigated in detail.
The study focused on the Kudat and Kota Marudu districts in Sabah, Malaysia, covering an area of more than 3,000km² with a population of approximately 120,000 people. Researchers used hospital records for 2008-2012 to collect data on the number of P. knowlesi malaria cases from villages in the districts. Information collected from satellite data helped the team to map the local forest, land use, and environmental changes around 450 villages, in order to correlate how these changes might affect human infection.
They found that the number of P. knowlesi cases was strongly linked to deforestation in areas surrounding the villages. This could be explained by a number of factors, including humans coming into closer contact with the forest inhabited by the macaques and the mosquito vectors, due to employment in tree clearance and expanding agriculture. Another factor could be that as land use changes in this way, macaque populations are becoming more densely concentrated in areas of forest where humans are present.
Lead author Kimberly Fornace, Research Fellow at the London School of Hygiene & Tropical Medicine, said: “The dramatic rise in the number of P. knowlesi malaria cases in humans in Malaysia in the past ten years has been most common in areas with deforestation, as well as areas that are close to patches of forest where humans, macaques and mosquitoes are coming into closer and more frequent contact. This suggests that there is a higher risk of P. knowlesi transmission in areas where land use is changing, and this knowledge will help focus efforts on these areas and also predict and respond to future outbreaks. Given our findings, we view deforestation as having distinct public health consequences which need to be urgently addressed.”
The findings show the study region had undergone significant environmental changes, with many villages substantially affected by deforestation. During the five-year study alone, 39% of the region’s villages lost more than 10% of the forest cover in their surrounding 1km radius, and half of villages lost more than 10% within a 5km radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during the study period.
The findings also confirmed that P. knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of malaria may have been unreported as they were asymptomatic or resolved without treatment. P. knowlesi can be mistaken for other forms of human malaria in microscope diagnosis, however the authors adjusted for this uncertainty in the study. They also highlight that the environmental data were limited as they could not discriminate between types of forest or crops, meaning further work is needed to investigate whether vegetation type is a risk factor for P. knowlesi.
This study was funded by the Biotechnology and Biosciences Research Council, Economic and Social Research Council, Medical Research Council, and Natural Environment Research Council, through the Environmental and Social Ecology of Human Infectious Diseases Initiative (ESEI).
The research was carried out in collaboration with the Infectious Disease Society Kota Kinabalu Sabah, Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies School of Health Research, Australia; Sabah Department of Health, Malaysia; and the University of Glasgow, UK.
- See more at: http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#sthash.9id9MmXX.dpuf
A steep rise in human cases of P. knowlesi malaria in Malaysia is likely to be linked to deforestation and associated environmental changes, according to new research published in Emerging Infectious Diseases. The study, led by the London School of Hygiene & Tropical Medicine, is the first to explore how changes in land use are impacting the emergence of the disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by mosquitoes, which is common in forest-dwelling macaque monkeys. Although only recently reported in humans, it is now the most common form of human malaria in many areas of Malaysia, and has been reported across southeast Asia. In recent years, Malaysia has seen widespread deforestation alongside rapid oil palm and other agricultural expansion. It is thought changes in the way land is used could be a key driver in the emergence of P. knowlesi, but until now this has not been investigated in detail.
The study focused on the Kudat and Kota Marudu districts in Sabah, Malaysia, covering an area of more than 3,000km² with a population of approximately 120,000 people. Researchers used hospital records for 2008-2012 to collect data on the number of P. knowlesi malaria cases from villages in the districts. Information collected from satellite data helped the team to map the local forest, land use, and environmental changes around 450 villages, in order to correlate how these changes might affect human infection.
They found that the number of P. knowlesi cases was strongly linked to deforestation in areas surrounding the villages. This could be explained by a number of factors, including humans coming into closer contact with the forest inhabited by the macaques and the mosquito vectors, due to employment in tree clearance and expanding agriculture. Another factor could be that as land use changes in this way, macaque populations are becoming more densely concentrated in areas of forest where humans are present.
Lead author Kimberly Fornace, Research Fellow at the London School of Hygiene & Tropical Medicine, said: “The dramatic rise in the number of P. knowlesi malaria cases in humans in Malaysia in the past ten years has been most common in areas with deforestation, as well as areas that are close to patches of forest where humans, macaques and mosquitoes are coming into closer and more frequent contact. This suggests that there is a higher risk of P. knowlesi transmission in areas where land use is changing, and this knowledge will help focus efforts on these areas and also predict and respond to future outbreaks. Given our findings, we view deforestation as having distinct public health consequences which need to be urgently addressed.”
The findings show the study region had undergone significant environmental changes, with many villages substantially affected by deforestation. During the five-year study alone, 39% of the region’s villages lost more than 10% of the forest cover in their surrounding 1km radius, and half of villages lost more than 10% within a 5km radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during the study period.
The findings also confirmed that P. knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of malaria may have been unreported as they were asymptomatic or resolved without treatment. P. knowlesi can be mistaken for other forms of human malaria in microscope diagnosis, however the authors adjusted for this uncertainty in the study. They also highlight that the environmental data were limited as they could not discriminate between types of forest or crops, meaning further work is needed to investigate whether vegetation type is a risk factor for P. knowlesi.
This study was funded by the Biotechnology and Biosciences Research Council, Economic and Social Research Council, Medical Research Council, and Natural Environment Research Council, through the Environmental and Social Ecology of Human Infectious Diseases Initiative (ESEI).
The research was carried out in collaboration with the Infectious Disease Society Kota Kinabalu Sabah, Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies School of Health Research, Australia; Sabah Department of Health, Malaysia; and the University of Glasgow, UK.
- See more at: http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#sthash.9id9MmXX.dpuf
esearch suggests environmental changes are driving increase in Plasmodium knowlesi malaria – an infection usually found only in monkeys – among people in Malaysia.
A steep rise in human cases of P. knowlesi malaria in Malaysia is likely to be linked to deforestation and associated environmental changes, according to new research published in Emerging Infectious Diseases. The study, led by the London School of Hygiene & Tropical Medicine, is the first to explore how changes in land use are impacting the emergence of the disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by mosquitoes, which is common in forest-dwelling macaque monkeys. Although only recently reported in humans, it is now the most common form of human malaria in many areas of Malaysia, and has been reported across southeast Asia. In recent years, Malaysia has seen widespread deforestation alongside rapid oil palm and other agricultural expansion. It is thought changes in the way land is used could be a key driver in the emergence of P. knowlesi, but until now this has not been investigated in detail.
The study focused on the Kudat and Kota Marudu districts in Sabah, Malaysia, covering an area of more than 3,000km² with a population of approximately 120,000 people. Researchers used hospital records for 2008-2012 to collect data on the number of P. knowlesi malaria cases from villages in the districts. Information collected from satellite data helped the team to map the local forest, land use, and environmental changes around 450 villages, in order to correlate how these changes might affect human infection.
They found that the number of P. knowlesi cases was strongly linked to deforestation in areas surrounding the villages. This could be explained by a number of factors, including humans coming into closer contact with the forest inhabited by the macaques and the mosquito vectors, due to employment in tree clearance and expanding agriculture. Another factor could be that as land use changes in this way, macaque populations are becoming more densely concentrated in areas of forest where humans are present.
Lead author Kimberly Fornace, Research Fellow at the London School of Hygiene & Tropical Medicine, said: “The dramatic rise in the number of P. knowlesi malaria cases in humans in Malaysia in the past ten years has been most common in areas with deforestation, as well as areas that are close to patches of forest where humans, macaques and mosquitoes are coming into closer and more frequent contact. This suggests that there is a higher risk of P. knowlesi transmission in areas where land use is changing, and this knowledge will help focus efforts on these areas and also predict and respond to future outbreaks. Given our findings, we view deforestation as having distinct public health consequences which need to be urgently addressed.”
The findings show the study region had undergone significant environmental changes, with many villages substantially affected by deforestation. During the five-year study alone, 39% of the region’s villages lost more than 10% of the forest cover in their surrounding 1km radius, and half of villages lost more than 10% within a 5km radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during the study period.
The findings also confirmed that P. knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of malaria may have been unreported as they were asymptomatic or resolved without treatment. P. knowlesi can be mistaken for other forms of human malaria in microscope diagnosis, however the authors adjusted for this uncertainty in the study. They also highlight that the environmental data were limited as they could not discriminate between types of forest or crops, meaning further work is needed to investigate whether vegetation type is a risk factor for P. knowlesi.
This study was funded by the Biotechnology and Biosciences Research Council, Economic and Social Research Council, Medical Research Council, and Natural Environment Research Council, through the Environmental and Social Ecology of Human Infectious Diseases Initiative (ESEI).
The research was carried out in collaboration with the Infectious Disease Society Kota Kinabalu Sabah, Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies School of Health Research, Australia; Sabah Department of Health, Malaysia; and the University of Glasgow, UK.
- See more at: http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#sthash.9id9MmXX.dpuf
A steep rise in human cases of P. knowlesi malaria in Malaysia is likely to be linked to deforestation and associated environmental changes, according to new research published in Emerging Infectious Diseases. The study, led by the London School of Hygiene & Tropical Medicine, is the first to explore how changes in land use are impacting the emergence of the disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by mosquitoes, which is common in forest-dwelling macaque monkeys. Although only recently reported in humans, it is now the most common form of human malaria in many areas of Malaysia, and has been reported across southeast Asia. In recent years, Malaysia has seen widespread deforestation alongside rapid oil palm and other agricultural expansion. It is thought changes in the way land is used could be a key driver in the emergence of P. knowlesi, but until now this has not been investigated in detail.
The study focused on the Kudat and Kota Marudu districts in Sabah, Malaysia, covering an area of more than 3,000km² with a population of approximately 120,000 people. Researchers used hospital records for 2008-2012 to collect data on the number of P. knowlesi malaria cases from villages in the districts. Information collected from satellite data helped the team to map the local forest, land use, and environmental changes around 450 villages, in order to correlate how these changes might affect human infection.
They found that the number of P. knowlesi cases was strongly linked to deforestation in areas surrounding the villages. This could be explained by a number of factors, including humans coming into closer contact with the forest inhabited by the macaques and the mosquito vectors, due to employment in tree clearance and expanding agriculture. Another factor could be that as land use changes in this way, macaque populations are becoming more densely concentrated in areas of forest where humans are present.
Lead author Kimberly Fornace, Research Fellow at the London School of Hygiene & Tropical Medicine, said: “The dramatic rise in the number of P. knowlesi malaria cases in humans in Malaysia in the past ten years has been most common in areas with deforestation, as well as areas that are close to patches of forest where humans, macaques and mosquitoes are coming into closer and more frequent contact. This suggests that there is a higher risk of P. knowlesi transmission in areas where land use is changing, and this knowledge will help focus efforts on these areas and also predict and respond to future outbreaks. Given our findings, we view deforestation as having distinct public health consequences which need to be urgently addressed.”
The findings show the study region had undergone significant environmental changes, with many villages substantially affected by deforestation. During the five-year study alone, 39% of the region’s villages lost more than 10% of the forest cover in their surrounding 1km radius, and half of villages lost more than 10% within a 5km radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during the study period.
The findings also confirmed that P. knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of malaria may have been unreported as they were asymptomatic or resolved without treatment. P. knowlesi can be mistaken for other forms of human malaria in microscope diagnosis, however the authors adjusted for this uncertainty in the study. They also highlight that the environmental data were limited as they could not discriminate between types of forest or crops, meaning further work is needed to investigate whether vegetation type is a risk factor for P. knowlesi.
This study was funded by the Biotechnology and Biosciences Research Council, Economic and Social Research Council, Medical Research Council, and Natural Environment Research Council, through the Environmental and Social Ecology of Human Infectious Diseases Initiative (ESEI).
The research was carried out in collaboration with the Infectious Disease Society Kota Kinabalu Sabah, Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies School of Health Research, Australia; Sabah Department of Health, Malaysia; and the University of Glasgow, UK.
- See more at: http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#sthash.9id9MmXX.dpuf
esearch suggests environmental changes are driving increase in Plasmodium knowlesi malaria – an infection usually found only in monkeys – among people in Malaysia.
A steep rise in human cases of P. knowlesi malaria in Malaysia is likely to be linked to deforestation and associated environmental changes, according to new research published in Emerging Infectious Diseases. The study, led by the London School of Hygiene & Tropical Medicine, is the first to explore how changes in land use are impacting the emergence of the disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by mosquitoes, which is common in forest-dwelling macaque monkeys. Although only recently reported in humans, it is now the most common form of human malaria in many areas of Malaysia, and has been reported across southeast Asia. In recent years, Malaysia has seen widespread deforestation alongside rapid oil palm and other agricultural expansion. It is thought changes in the way land is used could be a key driver in the emergence of P. knowlesi, but until now this has not been investigated in detail.
The study focused on the Kudat and Kota Marudu districts in Sabah, Malaysia, covering an area of more than 3,000km² with a population of approximately 120,000 people. Researchers used hospital records for 2008-2012 to collect data on the number of P. knowlesi malaria cases from villages in the districts. Information collected from satellite data helped the team to map the local forest, land use, and environmental changes around 450 villages, in order to correlate how these changes might affect human infection.
They found that the number of P. knowlesi cases was strongly linked to deforestation in areas surrounding the villages. This could be explained by a number of factors, including humans coming into closer contact with the forest inhabited by the macaques and the mosquito vectors, due to employment in tree clearance and expanding agriculture. Another factor could be that as land use changes in this way, macaque populations are becoming more densely concentrated in areas of forest where humans are present.
Lead author Kimberly Fornace, Research Fellow at the London School of Hygiene & Tropical Medicine, said: “The dramatic rise in the number of P. knowlesi malaria cases in humans in Malaysia in the past ten years has been most common in areas with deforestation, as well as areas that are close to patches of forest where humans, macaques and mosquitoes are coming into closer and more frequent contact. This suggests that there is a higher risk of P. knowlesi transmission in areas where land use is changing, and this knowledge will help focus efforts on these areas and also predict and respond to future outbreaks. Given our findings, we view deforestation as having distinct public health consequences which need to be urgently addressed.”
The findings show the study region had undergone significant environmental changes, with many villages substantially affected by deforestation. During the five-year study alone, 39% of the region’s villages lost more than 10% of the forest cover in their surrounding 1km radius, and half of villages lost more than 10% within a 5km radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during the study period.
The findings also confirmed that P. knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of malaria may have been unreported as they were asymptomatic or resolved without treatment. P. knowlesi can be mistaken for other forms of human malaria in microscope diagnosis, however the authors adjusted for this uncertainty in the study. They also highlight that the environmental data were limited as they could not discriminate between types of forest or crops, meaning further work is needed to investigate whether vegetation type is a risk factor for P. knowlesi.
This study was funded by the Biotechnology and Biosciences Research Council, Economic and Social Research Council, Medical Research Council, and Natural Environment Research Council, through the Environmental and Social Ecology of Human Infectious Diseases Initiative (ESEI).
The research was carried out in collaboration with the Infectious Disease Society Kota Kinabalu Sabah, Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies School of Health Research, Australia; Sabah Department of Health, Malaysia; and the University of Glasgow, UK.
- See more at: http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#sthash.9id9MmXX.dpuf
A steep rise in human cases of P. knowlesi malaria in Malaysia is likely to be linked to deforestation and associated environmental changes, according to new research published in Emerging Infectious Diseases. The study, led by the London School of Hygiene & Tropical Medicine, is the first to explore how changes in land use are impacting the emergence of the disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by mosquitoes, which is common in forest-dwelling macaque monkeys. Although only recently reported in humans, it is now the most common form of human malaria in many areas of Malaysia, and has been reported across southeast Asia. In recent years, Malaysia has seen widespread deforestation alongside rapid oil palm and other agricultural expansion. It is thought changes in the way land is used could be a key driver in the emergence of P. knowlesi, but until now this has not been investigated in detail.
The study focused on the Kudat and Kota Marudu districts in Sabah, Malaysia, covering an area of more than 3,000km² with a population of approximately 120,000 people. Researchers used hospital records for 2008-2012 to collect data on the number of P. knowlesi malaria cases from villages in the districts. Information collected from satellite data helped the team to map the local forest, land use, and environmental changes around 450 villages, in order to correlate how these changes might affect human infection.
They found that the number of P. knowlesi cases was strongly linked to deforestation in areas surrounding the villages. This could be explained by a number of factors, including humans coming into closer contact with the forest inhabited by the macaques and the mosquito vectors, due to employment in tree clearance and expanding agriculture. Another factor could be that as land use changes in this way, macaque populations are becoming more densely concentrated in areas of forest where humans are present.
Lead author Kimberly Fornace, Research Fellow at the London School of Hygiene & Tropical Medicine, said: “The dramatic rise in the number of P. knowlesi malaria cases in humans in Malaysia in the past ten years has been most common in areas with deforestation, as well as areas that are close to patches of forest where humans, macaques and mosquitoes are coming into closer and more frequent contact. This suggests that there is a higher risk of P. knowlesi transmission in areas where land use is changing, and this knowledge will help focus efforts on these areas and also predict and respond to future outbreaks. Given our findings, we view deforestation as having distinct public health consequences which need to be urgently addressed.”
The findings show the study region had undergone significant environmental changes, with many villages substantially affected by deforestation. During the five-year study alone, 39% of the region’s villages lost more than 10% of the forest cover in their surrounding 1km radius, and half of villages lost more than 10% within a 5km radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during the study period.
The findings also confirmed that P. knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of malaria may have been unreported as they were asymptomatic or resolved without treatment. P. knowlesi can be mistaken for other forms of human malaria in microscope diagnosis, however the authors adjusted for this uncertainty in the study. They also highlight that the environmental data were limited as they could not discriminate between types of forest or crops, meaning further work is needed to investigate whether vegetation type is a risk factor for P. knowlesi.
This study was funded by the Biotechnology and Biosciences Research Council, Economic and Social Research Council, Medical Research Council, and Natural Environment Research Council, through the Environmental and Social Ecology of Human Infectious Diseases Initiative (ESEI).
The research was carried out in collaboration with the Infectious Disease Society Kota Kinabalu Sabah, Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies School of Health Research, Australia; Sabah Department of Health, Malaysia; and the University of Glasgow, UK.
- See more at: http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#sthash.9id9MmXX.dpuf
esearch suggests environmental changes are driving increase in Plasmodium knowlesi malaria – an infection usually found only in monkeys – among people in Malaysia.
A steep rise in human cases of P. knowlesi malaria in Malaysia is likely to be linked to deforestation and associated environmental changes, according to new research published in Emerging Infectious Diseases. The study, led by the London School of Hygiene & Tropical Medicine, is the first to explore how changes in land use are impacting the emergence of the disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by mosquitoes, which is common in forest-dwelling macaque monkeys. Although only recently reported in humans, it is now the most common form of human malaria in many areas of Malaysia, and has been reported across southeast Asia. In recent years, Malaysia has seen widespread deforestation alongside rapid oil palm and other agricultural expansion. It is thought changes in the way land is used could be a key driver in the emergence of P. knowlesi, but until now this has not been investigated in detail.
The study focused on the Kudat and Kota Marudu districts in Sabah, Malaysia, covering an area of more than 3,000km² with a population of approximately 120,000 people. Researchers used hospital records for 2008-2012 to collect data on the number of P. knowlesi malaria cases from villages in the districts. Information collected from satellite data helped the team to map the local forest, land use, and environmental changes around 450 villages, in order to correlate how these changes might affect human infection.
They found that the number of P. knowlesi cases was strongly linked to deforestation in areas surrounding the villages. This could be explained by a number of factors, including humans coming into closer contact with the forest inhabited by the macaques and the mosquito vectors, due to employment in tree clearance and expanding agriculture. Another factor could be that as land use changes in this way, macaque populations are becoming more densely concentrated in areas of forest where humans are present.
Lead author Kimberly Fornace, Research Fellow at the London School of Hygiene & Tropical Medicine, said: “The dramatic rise in the number of P. knowlesi malaria cases in humans in Malaysia in the past ten years has been most common in areas with deforestation, as well as areas that are close to patches of forest where humans, macaques and mosquitoes are coming into closer and more frequent contact. This suggests that there is a higher risk of P. knowlesi transmission in areas where land use is changing, and this knowledge will help focus efforts on these areas and also predict and respond to future outbreaks. Given our findings, we view deforestation as having distinct public health consequences which need to be urgently addressed.”
The findings show the study region had undergone significant environmental changes, with many villages substantially affected by deforestation. During the five-year study alone, 39% of the region’s villages lost more than 10% of the forest cover in their surrounding 1km radius, and half of villages lost more than 10% within a 5km radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during the study period.
The findings also confirmed that P. knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of malaria may have been unreported as they were asymptomatic or resolved without treatment. P. knowlesi can be mistaken for other forms of human malaria in microscope diagnosis, however the authors adjusted for this uncertainty in the study. They also highlight that the environmental data were limited as they could not discriminate between types of forest or crops, meaning further work is needed to investigate whether vegetation type is a risk factor for P. knowlesi.
This study was funded by the Biotechnology and Biosciences Research Council, Economic and Social Research Council, Medical Research Council, and Natural Environment Research Council, through the Environmental and Social Ecology of Human Infectious Diseases Initiative (ESEI).
The research was carried out in collaboration with the Infectious Disease Society Kota Kinabalu Sabah, Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies School of Health Research, Australia; Sabah Department of Health, Malaysia; and the University of Glasgow, UK.
- See more at: http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#sthash.9id9MmXX.dpuf
A steep rise in human cases of P. knowlesi malaria in Malaysia is likely to be linked to deforestation and associated environmental changes, according to new research published in Emerging Infectious Diseases. The study, led by the London School of Hygiene & Tropical Medicine, is the first to explore how changes in land use are impacting the emergence of the disease.
Plasmodium knowlesi is a zoonotic malaria parasite, transmitted between hosts by mosquitoes, which is common in forest-dwelling macaque monkeys. Although only recently reported in humans, it is now the most common form of human malaria in many areas of Malaysia, and has been reported across southeast Asia. In recent years, Malaysia has seen widespread deforestation alongside rapid oil palm and other agricultural expansion. It is thought changes in the way land is used could be a key driver in the emergence of P. knowlesi, but until now this has not been investigated in detail.
The study focused on the Kudat and Kota Marudu districts in Sabah, Malaysia, covering an area of more than 3,000km² with a population of approximately 120,000 people. Researchers used hospital records for 2008-2012 to collect data on the number of P. knowlesi malaria cases from villages in the districts. Information collected from satellite data helped the team to map the local forest, land use, and environmental changes around 450 villages, in order to correlate how these changes might affect human infection.
They found that the number of P. knowlesi cases was strongly linked to deforestation in areas surrounding the villages. This could be explained by a number of factors, including humans coming into closer contact with the forest inhabited by the macaques and the mosquito vectors, due to employment in tree clearance and expanding agriculture. Another factor could be that as land use changes in this way, macaque populations are becoming more densely concentrated in areas of forest where humans are present.
Lead author Kimberly Fornace, Research Fellow at the London School of Hygiene & Tropical Medicine, said: “The dramatic rise in the number of P. knowlesi malaria cases in humans in Malaysia in the past ten years has been most common in areas with deforestation, as well as areas that are close to patches of forest where humans, macaques and mosquitoes are coming into closer and more frequent contact. This suggests that there is a higher risk of P. knowlesi transmission in areas where land use is changing, and this knowledge will help focus efforts on these areas and also predict and respond to future outbreaks. Given our findings, we view deforestation as having distinct public health consequences which need to be urgently addressed.”
The findings show the study region had undergone significant environmental changes, with many villages substantially affected by deforestation. During the five-year study alone, 39% of the region’s villages lost more than 10% of the forest cover in their surrounding 1km radius, and half of villages lost more than 10% within a 5km radius. Overall, forest cover in Kudat and Kota Marudu declined by 4.8% during the study period.
The findings also confirmed that P. knowlesi is the most common cause of human malaria cases in the region.
The authors note that some cases of malaria may have been unreported as they were asymptomatic or resolved without treatment. P. knowlesi can be mistaken for other forms of human malaria in microscope diagnosis, however the authors adjusted for this uncertainty in the study. They also highlight that the environmental data were limited as they could not discriminate between types of forest or crops, meaning further work is needed to investigate whether vegetation type is a risk factor for P. knowlesi.
This study was funded by the Biotechnology and Biosciences Research Council, Economic and Social Research Council, Medical Research Council, and Natural Environment Research Council, through the Environmental and Social Ecology of Human Infectious Diseases Initiative (ESEI).
The research was carried out in collaboration with the Infectious Disease Society Kota Kinabalu Sabah, Malaysia; Hospital Queen Elizabeth Clinical Research Centre, Malaysia; Menzies School of Health Research, Australia; Sabah Department of Health, Malaysia; and the University of Glasgow, UK.
- See more at: http://www.lshtm.ac.uk/newsevents/news/2015/deforestation_malaria_link.html#sthash.9id9MmXX.dpuf
