Several studies suggest the potential for climate change to increase malaria incidence in cooler, marginal transmission environments. However, the effect of increasing temperature in warmer regions where conditions currently support endemic transmission has received less attention. We investigate how increases in temperature from optimal conditions (27 °C to 30 °C and 33 °C) interact with realistic diurnal temperature ranges (DTR: ± 0 °C, 3 °C, and 4.5 °C) to affect the ability of key vector species from Africa and Asia (Anopheles gambiae and An. stephensi) to transmit the human malaria parasite, Plasmodium falciparum. The effects of increasing temperature and DTR on parasite prevalence, parasite intensity, and mosquito mortality decreased overall vectorial capacity for both mosquito species. Increases of 3 °C from 27 °C reduced vectorial capacity by 51–89% depending on species and DTR, with increases in DTR alone potentially halving transmission. At 33 °C, transmission potential was further reduced for An. stephensi and blocked completely in An. gambiae. These results suggest that small shifts in temperature could play a substantial role in malaria transmission dynamics, yet few empirical or modeling studies consider such effects. They further suggest that rather than increase risk, current and future warming could reduce transmission potential in existing high transmission settings.
Malaria parasite data for Anopheles gambiae
This data file includes data on malaria infection in individual mosquitoes. For each temperature treatment we dissected midguts (on day 7 post infection) or salivary glands (day 15 post infection) from 20 individual mosquitoes within each temperature treatment if numbers permitted. The "Oocyst_data" tab includes data on whether or not a mosquito had oocysts on its midgut and overall oocyst burden. The "Sporozoite_data" tab includes information on whether or not an individual mosquito had sporozoites in its salivary glands. The "Data codes" tab includes information describing each column and how it is coded across both the "Oocyst_data" and "Sporozoite_data" tabs.
Anopheles_gambiae_parasitedata.xlsx
Malaria parasite data for Anopheles stephensi
This data file includes data on malaria infection in individual mosquitoes. For each temperature treatment we dissected midguts (on day 7 post infection) or salivary glands (day 15 post infection) from 20 individual mosquitoes within each temperature treatment if numbers permitted. The "Oocyst_data" tab includes data on whether or not a mosquito had oocysts on its midgut and overall oocyst burden. The "Sporozoite_data" tab includes information on whether or not an individual mosquito had sporozoites in its salivary glands. The "Data codes" tab includes information describing each column and how it is coded across both the "Oocyst_data" and "Sporozoite_data" tabs.
Anopheles_stephensi_parasitedata.xlsx
Mosquito Survival Data
This data file includes in the "Survival Data" tab the daily mortality events for the associated infection experiments. We have recorded number of mosquitoes alive vs. dead each day post-infection with human malaria. We also followed a blood-fed, uninfected control group to determine if the effects of temperature and diurnal temperature range had a different impact on the daily probability of mosquito survival for P. falciparum infected mosquitoes. Finally, we also recorded the number of mosquitoes that were dissected for midguts and salivary glands to assess parasite infection so that these cases could be censored in the downstream survival analysis. The "Data Codes" tab has descriptors for the various column headings and data labels.
SurvivalData.xlsx