Temperature suitability for malaria climbing the Ethiopian Highlands
While the effect of climate change on the prevalence of malaria in the highlands of Eastern Africa has been the topic of protracted debate, temperature is widely accepted as a fundamentally important environmental factor constraining its transmission. Air temperatures below approximately 18 °C and 1...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2017-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/aa64e6 |
| _version_ | 1827870896089464832 |
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| author | Bradfield Lyon Tufa Dinku Anita Raman Madeleine C Thomson |
| author_facet | Bradfield Lyon Tufa Dinku Anita Raman Madeleine C Thomson |
| author_sort | Bradfield Lyon |
| collection | DOAJ |
| description | While the effect of climate change on the prevalence of malaria in the highlands of Eastern Africa has been the topic of protracted debate, temperature is widely accepted as a fundamentally important environmental factor constraining its transmission. Air temperatures below approximately 18 °C and 15 °C, respectively, prohibit the development of the Plasmodium falciparum and P. vivax parasites responsible for the majority of malaria cases in Ethiopia. Low temperatures also impede the development rates of the Anopheles mosquito vectors. While locations of sufficiently high elevation have temperatures below these transmission thresholds, a fundamental question is how such temperature ‘threshold elevations’ are changing with time. A lack of high quality, high spatial resolution climate data has previously prohibited a rigorous investigation. Using a newly developed national temperature dataset for Ethiopia that combines numerous in-situ surface observations with downscaled reanalysis data, we here identify statistically significant increases in elevation for both the 18 °C and 15 °C thresholds in highland areas between 1981–2014. Substantial interannual and spatial variations in threshold elevations are identified, the former associated with the El Niño Southern-Oscillation and the latter with the complex climate of the region. The estimated population in locations with an upward trend in the 15 °C threshold elevation is approximately 6.5 million people (2.2 million for 18 °C). While not a direct prediction of the additional population made vulnerable to malaria through a shift to higher temperature, our results underscore a newly acquired ability to investigate climate variability and trends at fine spatial scales across Ethiopia, including changes in a fundamental constraint on malaria transmission in the Ethiopian Highlands. |
| first_indexed | 2024-03-12T16:03:20Z |
| format | Article |
| id | doaj.art-1d420bd2ec724afa9dae473448fe0c7e |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T16:03:20Z |
| publishDate | 2017-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-1d420bd2ec724afa9dae473448fe0c7e2023-08-09T14:31:16ZengIOP PublishingEnvironmental Research Letters1748-93262017-01-0112606401510.1088/1748-9326/aa64e6Temperature suitability for malaria climbing the Ethiopian HighlandsBradfield Lyon0Tufa Dinku1Anita Raman2Madeleine C Thomson3University of Maine , 210 Sawyer Hall, Orono, ME 04469, United States of America; Author to whom any correspondence should be addressed.International Research Institute , Columbia University, 61 Route 9 W, Palisades, NY 10964, United States of AmericaInternational Research Institute , Columbia University, 61 Route 9 W, Palisades, NY 10964, United States of America; Current address: United Nations Climate Change Support Team , 405 East 42nd Street, New York, NY, 10017, United States of AmericaInternational Research Institute , Columbia University, 61 Route 9 W, Palisades, NY 10964, United States of AmericaWhile the effect of climate change on the prevalence of malaria in the highlands of Eastern Africa has been the topic of protracted debate, temperature is widely accepted as a fundamentally important environmental factor constraining its transmission. Air temperatures below approximately 18 °C and 15 °C, respectively, prohibit the development of the Plasmodium falciparum and P. vivax parasites responsible for the majority of malaria cases in Ethiopia. Low temperatures also impede the development rates of the Anopheles mosquito vectors. While locations of sufficiently high elevation have temperatures below these transmission thresholds, a fundamental question is how such temperature ‘threshold elevations’ are changing with time. A lack of high quality, high spatial resolution climate data has previously prohibited a rigorous investigation. Using a newly developed national temperature dataset for Ethiopia that combines numerous in-situ surface observations with downscaled reanalysis data, we here identify statistically significant increases in elevation for both the 18 °C and 15 °C thresholds in highland areas between 1981–2014. Substantial interannual and spatial variations in threshold elevations are identified, the former associated with the El Niño Southern-Oscillation and the latter with the complex climate of the region. The estimated population in locations with an upward trend in the 15 °C threshold elevation is approximately 6.5 million people (2.2 million for 18 °C). While not a direct prediction of the additional population made vulnerable to malaria through a shift to higher temperature, our results underscore a newly acquired ability to investigate climate variability and trends at fine spatial scales across Ethiopia, including changes in a fundamental constraint on malaria transmission in the Ethiopian Highlands.https://doi.org/10.1088/1748-9326/aa64e6temperature trendsEast Africamalaria |
| spellingShingle | Bradfield Lyon Tufa Dinku Anita Raman Madeleine C Thomson Temperature suitability for malaria climbing the Ethiopian Highlands Environmental Research Letters temperature trends East Africa malaria |
| title | Temperature suitability for malaria climbing the Ethiopian Highlands |
| title_full | Temperature suitability for malaria climbing the Ethiopian Highlands |
| title_fullStr | Temperature suitability for malaria climbing the Ethiopian Highlands |
| title_full_unstemmed | Temperature suitability for malaria climbing the Ethiopian Highlands |
| title_short | Temperature suitability for malaria climbing the Ethiopian Highlands |
| title_sort | temperature suitability for malaria climbing the ethiopian highlands |
| topic | temperature trends East Africa malaria |
| url | https://doi.org/10.1088/1748-9326/aa64e6 |
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