Climate change can have a number of impacts on health, including the transmission of diseases. Some diseases, such as those transmitted by mosquitoes, may become more prevalent in certain regions as the climate becomes warmer and wetter. Other diseases, such as those transmitted by food or water, may become more common as a result of changes in agricultural practices or the availability of clean water.
There are a number of interventions that can help to prevent the transmission of diseases in a changing climate. These include:
- Mosquito control measures: This can include the use of insecticides, the release of mosquito-eating fish, and the use of mosquito nets.
- Improved sanitation: Access to clean water and proper sanitation facilities can help to prevent the transmission of waterborne diseases.
- Education: Providing information about how to prevent the transmission of diseases, such as proper hand-washing techniques, can help to reduce the spread of illness.
- Immunization: Vaccines can help to protect against a number of diseases and are an important tool for disease prevention.
- Surveillance: Tracking the spread of diseases and identifying outbreaks early can help to control the spread of illness and prevent outbreaks from becoming epidemics.
By implementing these and other interventions, it may be possible to mitigate the impact of climate change on disease transmission.
Dengue is the fastest-growing mosquito-borne disease in the world, and as climate change accelerates, many vulnerable populations will continue to be disproportionately impacted by this virus. Having shown floods to result in significantly increased dengue vector abundance, we hope to encourage actionable interventions to limit infection risk in light of these extreme climate events.
Cameron Nosrat
The primary vector for mosquito-borne diseases such as dengue fever is Aedes aegypti. The effects of climate change-related weather anomalies on mosquito populations, on the other hand, are poorly understood. Cameron Nosrat of Stanford University in the United States and colleagues published a study in PLOS Neglected Tropical Diseases that suggests that early interventions may prevent disease transmission even as extreme climate events increase the abundance of Aedes aegypti populations.
Temperature and rainfall have a big impact on Aedes aegypti abundance, and climate change will likely increase the frequency of extreme weather events like floods, droughts, heat waves, and cold waves. Researchers conducted a retrospective cohort study in Kenya to determine the impact of extreme rainfall and temperature on mosquito abundance and the risk of dengue infections in order to better understand the specific effects of weather anomalies on the dynamics of vector-borne disease transmission.
Using satellite-derived climate data, the authors classified extreme climate events as being in the upper or lower 10% of historical averages for rainfall and temperatures. The researchers then used trapping methods to monitor Aedes aegypti abundance and new dengue fever cases via blood samples collected from a cohort of 7,653 children.
Flood seasons increased Aedes aegypti egg and adult abundance significantly. Extreme weather events and increased Aedes aegypti abundance, on the other hand, did not correlate with an increase in the number of confirmed dengue fever cases. Human behavior can influence infection risk by altering the relationship between mosquito abundance and disease transmission. Preventive measures implemented in the study sites may have contributed to lower dengue transmission. The lack of long-term Kenya climate data was a major limitation of the study; however, the authors believe their study effectively examines the influence of weather anomalies on various life stages of Aedes aegypti abundance.
According to the authors, “Dengue is the fastest-growing mosquito-borne disease in the world, and as climate change accelerates, many vulnerable populations will continue to be disproportionately impacted by this virus. Having shown floods to result in significantly increased dengue vector abundance, we hope to encourage actionable interventions to limit infection risk in light of these extreme climate events.”
“Our team has pursued a simple idea: to take cancer cells and transform them into cancer killers and vaccines,” said corresponding author Khalid Shah, MS, Ph.D., director of the Center for Stem Cell and Translational Immunotherapy (CSTI) and the vice chair of research in the Department of Neurosurgery at the Brigham and faculty at Harvard Medical School and Harvard Stem Cell Institute (HSCI). “Using gene engineering, we are repurposing cancer cells to develop a therapeutic that kills tumor cells and stimulates the immune system to both destroy primary tumors and prevent cancer.”
Cancer vaccines are an active area of research for many labs, but the approach that Shah and his colleagues have taken is distinct. Instead of using inactivated tumor cells, the team repurposes living tumor cells, which possess an unusual feature. Like homing pigeons returning to roost, living tumor cells will travel long distances across the brain to return to the site of their fellow tumor cells. Taking advantage of this unique property, Shah’s team engineered living tumor cells using the gene editing tool CRISPR-Cas9 and repurposed them to release tumor cell killing agent. In addition, the engineered tumor cells were designed to express factors that would make them easy for the immune system to spot, tag, and remember, priming the immune system for a long-term anti-tumor response.
The team tested their repurposed CRISPR-enhanced and reverse-engineered therapeutic tumor cells (ThTC) in different mice strains including the one that bore bone marrow, liver, and thymus cells derived from humans, mimicking the human immune microenvironment. Shah’s team also built a two-layered safety switch into the cancer cell, which, when activated, eradicates ThTCs if needed. This dual-action cell therapy was safe, applicable, and efficacious in these models, suggesting a roadmap toward therapy. While further testing and development is needed, Shah’s team specifically chose this model and used human cells to smooth the path of translating their findings for patient settings.
“Throughout all of the work that we do in the Center, even when it is highly technical, we never lose sight of the patient,” said Shah. “Our goal is to take an innovative but translatable approach so that we can develop a therapeutic, cancer-killing vaccine that ultimately will have a lasting impact in medicine.” Shah and colleagues note that this therapeutic strategy is applicable to a wider range of solid tumors and that further investigations of its applications are warranted.
