Scientists concerned about effects of global warming on infectious diseases

May 22, 2007

As the Earth’s temperatures continue to rise, we can expect a signficant change in infectious disease patterns around the globe. Just exactly what those changes will be remains unclear, but scientists agree they will not be for the good.

"Environmental changes have always been associated with the appearance of new diseases or the arrival of old diseases in new places. With more changes, we can expect more surprises," says Stephen Morse of Columbia University, speaking May 22, 2007, at the 107th General Meeting of the American Society for Microbiology in Toronto.

In its April 2007 report on the impacts of climate change, the Intergovernmental Panel on Climate Change (IPCC) warned that rising temperatures may result in "the altered spatial distribution of some infectious disease vectors," and will have "mixed effects, such as the decrease or increase of the range and transmission potential of malaria in Africa."

"Diseases carried by insects and ticks are likely to be affected by environmental changes because these creatures are themselves very sensitive to vegetation type, temperature, humidity etc. However, the direction of change – whether the diseases will increase or decrease – is much more difficult to predict, because disease transmission involves many factors, some of which will increase and some decrease with environmental change. A combination of historical disease records and present-day ground-based surveillance, remotely sensed (satellite) and other data, and good predictive models is needed to describe the past, explain the present and predict the future of vector-borne infectious diseases," says David Rogers of Oxford University, also speaking at the meeting.

One impact of rising global temperatures, though, can be fairly accurately predicted, says Morse. In the mountains of endemic areas, malaria is not transmitted above a certain altitude because temperatures are too cold to support mosquitoes. As temperatures rise, this malaria line will rise as well.

"One of the first indicators of rising global temperatures could be malaria climbing mountains," says Morse.

Another change could be the flu season. Influenza is a year-round event in the tropics. If the tropical airmass around the Earth's equator expands, as new areas lose their seasons they may also begin to see influenza year-round.

And extreme weather events will also lead to more disease, unless we are prepared. As the frequency, intensity, and duration of extreme weather events change, water supplies become more at risk, according Joan Rose of Michigan State University.

"Hurricanes, typhoons, tornados and just high intensity storms have exacerbated an aging drinking and wastewater infrastructure, enhanced the mixing of untreated sewage and water supplies, re-suspended pathogens from sediments and displaced large populations to temporary shelters. We are at greater risk than ever before of infectious disease associated with increasing extreme weather events," says Rose.

There will also be indirect effects of climate change on infectious disease as well. For instance, says Morse, the effect of global warming on agriculture could lead to significant changes in disease transmission and distribution.

"If agriculture in a particular area begins to fail due drought, more people will move into cities," says Morse. High population densities, especially in developing countries, are associated with an increased transmission of a variety of diseases including HIV, tuberculosis, respiratory diseases (such as influenza) and sexually transmitted diseases.

"I’m worried about climate change and agree that something needs to be done," says Morse. "Otherwise, we can hope our luck will hold out."

Source: American Society for Microbiology

Explore further: Opioid abuse leads to heroin use and a hepatitis C epidemic, researcher says

Related Stories

Opioid abuse leads to heroin use and a hepatitis C epidemic, researcher says

February 22, 2018
Heroin is worse than other drugs because people inject it much sooner, potentially resulting in increased risk of injection-related epidemics such as hepatitis C and HIV, a Keck School of Medicine of USC study shows.

This disease kills half the people it infects. So why isn't more being done?

February 20, 2018
Every morning, Prasart Songsorn used to wake before dawn to head out to the fields before the tropical sun and oppressive humidity made it impossible to work. Prasart, who spent all his 56 years on his family's small rice ...

Past encounters with the flu shape vaccine response

February 20, 2018
New research on why the influenza vaccine was only modestly effective in recent years shows that immune history with the flu influences a person's response to the vaccine.

Home remedies: Lifestyle affects your heart health

February 19, 2018
Heart disease can be improved—or even prevented—by making certain lifestyle changes. The following changes can help anyone who wants to improve heart health:

It's OK to use nasal spray flu vaccine again, US panel says

February 21, 2018
It's OK for doctors to start using a kid-friendly nasal spray flu vaccine again, a federal panel said Wednesday.

Flu shot during pregnancy poses no harm to baby

February 20, 2018
(HealthDay)—There's some good news for expecting moms who are trying to weather a brutal flu season—a new study shows that getting the flu vaccine during pregnancy causes no harm to newborns.

Recommended for you

Ambitious global virome project could mark end of pandemic era

February 23, 2018
Rather than wait for viruses like Ebola, SARS and Zika to become outbreaks that force the world to react, a new global initiative seeks to proactively identify, prepare for and stop viral threats before they become pandemics.

Forecasting antibiotic resistance with a 'weather map' of local data

February 23, 2018
The resistance that infectious microbes have to antibiotics makes it difficult for physicians to confidently select the right drug to treat an infection. And that resistance is dynamic: It changes from year to year and varies ...

Scientists gain new insight on how antibodies interact with widespread respiratory virus

February 22, 2018
Scientists have found and characterized the activity of four antibodies produced by the human immune system that target an important protein found in respiratory syncytial virus (RSV), according to new research published ...

Study reveals how kidney disease happens

February 22, 2018
Monash researchers have solved a mystery, revealing how certain immune cells work together to instigate autoimmune kidney disease.

Building better tiny kidneys to test drugs and help people avoid dialysis

February 16, 2018
A free online kidney atlas built by USC researchers empowers stem cell scientists everywhere to generate more human-like tiny kidneys for testing new drugs and creating renal replacement therapies.

Expanding Hepatitis C testing to all adults is cost-effective and improves outcomes

February 16, 2018
According to a new study, screening all adults for hepatitis C (HCV) is a cost-effective way to improve clinical outcomes of HCV and identify more infected people compared to current recommendations. Using a simulation model, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.