Optimal temperature for malaria transmission is dramatically lower than previously predicted

• Published in: Ecology letters Vol. 16; no. 1; pp. 22 - 30
• Main Authors: Mordecai, Erin A., Paaijmans, Krijn P., Johnson, Leah R., Balzer, Christian, Ben-Horin, Tal, de Moor, Emily, McNally, Amy, Pawar, Samraat, Ryan, Sadie J., Smith, Thomas C., Lafferty, Kevin D.
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.01.2013; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Anopheles; Biological and medical sciences; Climate Change; Culicidae - parasitology; Culicidae - physiology; disease ecology; Disease transmission; Ecology; Female; Fundamental and applied biological sciences. Psychology; General aspects; Host-Parasite Interactions; Human protozoal diseases; Humans; Infectious diseases; Malaria; Malaria - transmission; Medical sciences; Models, Biological; Mosquitoes; Parasitic diseases; Plasmodium falciparum; Plasmodium falciparum - physiology; Protozoal diseases; Temperature; Temperature effects; Africa; Protozoa; Apicomplexa; Protozoal disease; Temperature; Disease; Malaria; Insecta; Transmission; Parasite; Environmental factor; Ecology; Parasitosis; Dynamical climatology; Infection; Climate change; Plasmodium falciparum; Anopheles; Arthropoda; Culicidae; Ectoparasite; Invertebrata; disease ecology; Vector; Diptera
• ISSN: 1461-023X; 1461-0248
• DOI: 10.1111/ele.12015

The ecology of mosquito vectors and malaria parasites affect the incidence, seasonal transmission and geographical range of malaria. Most malaria models to date assume constant or linear responses of mosquito and parasite life‐history traits to temperature, predicting optimal transmission at 31 °C. These models are at odds with field observations of transmission dating back nearly a century. We build a model with more realistic ecological assumptions about the thermal physiology of insects. Our model, which includes empirically derived nonlinear thermal responses, predicts optimal malaria transmission at 25 °C (6 °C lower than previous models). Moreover, the model predicts that transmission decreases dramatically at temperatures > 28 °C, altering predictions about how climate change will affect malaria. A large data set on malaria transmission risk in Africa validates both the 25 °C optimum and the decline above 28 °C. Using these more accurate nonlinear thermal‐response models will aid in understanding the effects of current and future temperature regimes on disease transmission.