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Hantavirus reservoir Oligoryzomys longicaudatus spatial distribution sensitivity to climate change scenarios in Argentine Patagonia.

Carbajo AE, Vera C, González PL - Int J Health Geogr (2009)

Bottom Line: If temperature and precipitation trends remain at current levels for 60 years or double in the future 30 years, the probability of the rodent presence and the associated total area of potential distribution would diminish throughout Patagonia; the areas of potential distribution for colilargos would shift eastwards.These results suggest that future changes in Patagonia climate may lower transmission risk through a reduction in the potential distribution of the rodent reservoir.According to our model the rates of temperature and precipitation changes observed between 1967 and 1998 may produce significant changes in the rodent distribution in an equivalent period of time only in certain areas.

View Article: PubMed Central - HTML - PubMed

Affiliation: Unidad de Ecología de Reservorios y Vectores de Parásitos, Depto Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina.

ABSTRACT

Background: Oligoryzomys longicaudatus (colilargo) is the rodent responsible for hantavirus pulmonary syndrome (HPS) in Argentine Patagonia. In past decades (1967-1998), trends of precipitation reduction and surface air temperature increase have been observed in western Patagonia. We explore how the potential distribution of the hantavirus reservoir would change under different climate change scenarios based on the observed trends.

Methods: Four scenarios of potential climate change were constructed using temperature and precipitation changes observed in Argentine Patagonia between 1967 and 1998: Scenario 1 assumed no change in precipitation but a temperature trend as observed; scenario 2 assumed no changes in temperature but a precipitation trend as observed; Scenario 3 included changes in both temperature and precipitation trends as observed; Scenario 4 assumed changes in both temperature and precipitation trends as observed but doubled. We used a validated spatial distribution model of O. longicaudatus as a function of temperature and precipitation. From the model probability of the rodent presence was calculated for each scenario.

Results: If changes in precipitation follow previous trends, the probability of the colilargo presence would fall in the HPS transmission zone of northern Patagonia. If temperature and precipitation trends remain at current levels for 60 years or double in the future 30 years, the probability of the rodent presence and the associated total area of potential distribution would diminish throughout Patagonia; the areas of potential distribution for colilargos would shift eastwards. These results suggest that future changes in Patagonia climate may lower transmission risk through a reduction in the potential distribution of the rodent reservoir.

Conclusion: According to our model the rates of temperature and precipitation changes observed between 1967 and 1998 may produce significant changes in the rodent distribution in an equivalent period of time only in certain areas. Given that changes maintain for 60 years or double in 30 years, the hantavirus reservoir Oligoryzomys longicaudatus may contract its distribution in Argentine Patagonia extensively.

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Study area. Study area (rectangle), showing Argentine Patagonia and Oligoryzomys longicaudatus field records. Dashed lined rectangles and numbers indicate the subareas used to evaluate the changes in O. longicaudatus presence probability (see table 1).
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Figure 1: Study area. Study area (rectangle), showing Argentine Patagonia and Oligoryzomys longicaudatus field records. Dashed lined rectangles and numbers indicate the subareas used to evaluate the changes in O. longicaudatus presence probability (see table 1).

Mentions: Except for a few works in Chile [12,13], the knowledge of colilargo ecology is anecdotal or brief at best. The Patagonian region (Figure 1), has suffered in the last century many environmental challenges that affect the rodent's distribution. Sheep ranching doubled between 1900' and 1950' but has since declined [14]. Fire, considered a natural disturbance that shapes the south Andean forests, has also been influenced by humans since the late eighteen century [15]. Grazing and fire together with temperature and rainfall have a complex relation with multiple feedbacks that influence the establishment and growth of woods, shrubs and grasses [16,17], which in turn affect the colilargo populations. Eruptions in rodent populations (including colilargos) have been associated with bamboo flowering and subsequent seed production as well as with increased rainfall after El Niño [18]. Also population dynamics were associated with the Antarctic Oscillation Index and Southern Oscillation Index in Chile; El Niño events (negative SOI values) had a lagged positive effect on population growth [12]. In the United States not only the abundance of the reservoir but also increased risk of SNV transmission were related to rise in precipitation associated with El Niño [19]. Excepting this last study, most have focused mainly on temporal relationships between climate indexes and population time series. Changes in the spatial distribution, particularly over southern South America, have yet to be explored extensively.


Hantavirus reservoir Oligoryzomys longicaudatus spatial distribution sensitivity to climate change scenarios in Argentine Patagonia.

Carbajo AE, Vera C, González PL - Int J Health Geogr (2009)

Study area. Study area (rectangle), showing Argentine Patagonia and Oligoryzomys longicaudatus field records. Dashed lined rectangles and numbers indicate the subareas used to evaluate the changes in O. longicaudatus presence probability (see table 1).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2721831&req=5

Figure 1: Study area. Study area (rectangle), showing Argentine Patagonia and Oligoryzomys longicaudatus field records. Dashed lined rectangles and numbers indicate the subareas used to evaluate the changes in O. longicaudatus presence probability (see table 1).
Mentions: Except for a few works in Chile [12,13], the knowledge of colilargo ecology is anecdotal or brief at best. The Patagonian region (Figure 1), has suffered in the last century many environmental challenges that affect the rodent's distribution. Sheep ranching doubled between 1900' and 1950' but has since declined [14]. Fire, considered a natural disturbance that shapes the south Andean forests, has also been influenced by humans since the late eighteen century [15]. Grazing and fire together with temperature and rainfall have a complex relation with multiple feedbacks that influence the establishment and growth of woods, shrubs and grasses [16,17], which in turn affect the colilargo populations. Eruptions in rodent populations (including colilargos) have been associated with bamboo flowering and subsequent seed production as well as with increased rainfall after El Niño [18]. Also population dynamics were associated with the Antarctic Oscillation Index and Southern Oscillation Index in Chile; El Niño events (negative SOI values) had a lagged positive effect on population growth [12]. In the United States not only the abundance of the reservoir but also increased risk of SNV transmission were related to rise in precipitation associated with El Niño [19]. Excepting this last study, most have focused mainly on temporal relationships between climate indexes and population time series. Changes in the spatial distribution, particularly over southern South America, have yet to be explored extensively.

Bottom Line: If temperature and precipitation trends remain at current levels for 60 years or double in the future 30 years, the probability of the rodent presence and the associated total area of potential distribution would diminish throughout Patagonia; the areas of potential distribution for colilargos would shift eastwards.These results suggest that future changes in Patagonia climate may lower transmission risk through a reduction in the potential distribution of the rodent reservoir.According to our model the rates of temperature and precipitation changes observed between 1967 and 1998 may produce significant changes in the rodent distribution in an equivalent period of time only in certain areas.

View Article: PubMed Central - HTML - PubMed

Affiliation: Unidad de Ecología de Reservorios y Vectores de Parásitos, Depto Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina.

ABSTRACT

Background: Oligoryzomys longicaudatus (colilargo) is the rodent responsible for hantavirus pulmonary syndrome (HPS) in Argentine Patagonia. In past decades (1967-1998), trends of precipitation reduction and surface air temperature increase have been observed in western Patagonia. We explore how the potential distribution of the hantavirus reservoir would change under different climate change scenarios based on the observed trends.

Methods: Four scenarios of potential climate change were constructed using temperature and precipitation changes observed in Argentine Patagonia between 1967 and 1998: Scenario 1 assumed no change in precipitation but a temperature trend as observed; scenario 2 assumed no changes in temperature but a precipitation trend as observed; Scenario 3 included changes in both temperature and precipitation trends as observed; Scenario 4 assumed changes in both temperature and precipitation trends as observed but doubled. We used a validated spatial distribution model of O. longicaudatus as a function of temperature and precipitation. From the model probability of the rodent presence was calculated for each scenario.

Results: If changes in precipitation follow previous trends, the probability of the colilargo presence would fall in the HPS transmission zone of northern Patagonia. If temperature and precipitation trends remain at current levels for 60 years or double in the future 30 years, the probability of the rodent presence and the associated total area of potential distribution would diminish throughout Patagonia; the areas of potential distribution for colilargos would shift eastwards. These results suggest that future changes in Patagonia climate may lower transmission risk through a reduction in the potential distribution of the rodent reservoir.

Conclusion: According to our model the rates of temperature and precipitation changes observed between 1967 and 1998 may produce significant changes in the rodent distribution in an equivalent period of time only in certain areas. Given that changes maintain for 60 years or double in 30 years, the hantavirus reservoir Oligoryzomys longicaudatus may contract its distribution in Argentine Patagonia extensively.

Show MeSH
Related in: MedlinePlus