Global Warming

Title: Bugs Like It Hot: Record Heat Kicks Insects Into High Gear
Date: July 23, 2012
Source: USA Today

Abstract: As if this summer isn't bad enough already, the unusual warmth is turning bugs extra frisky.

"We're calling it a breeding bonanza," says Missy Henriksen of the National Pest Management Association.

Across the country, as a result of record heat, pests from grasshoppers to crickets and ants to bees are arriving earlier and in greater numbers than usual, entomologists at HomeTeam Pest Defense say.

"We're seeing an increase in a lot of different pests right now," company entomologist Russ Horton says.

Pest controllers are battling grasshoppers in Texas, ants in Florida, and crickets and bees across the country, he says.

"Insects develop more rapidly with higher temperatures," says entomologist David Denlinger of Ohio State University. He adds that insects did well this past winter given the lack of intense cold.

Through June, the USA was sweating through its warmest year on record, according to the National Climatic Data Center.

Insects such as grasshoppers and crickets can be a nuisance to homeowners, but they are "very devastating" in the agricultural world, Horton says.

As harvesting season nears, the ongoing hot, dry weather could have grasshoppers and similar insects feeding in greater-than-normal numbers on alfalfa, tobacco and some vegetable crops, says Lee Townsend, an entomologist at the University of Kentucky.

"Grasshoppers should be abundant, because the bacteria and fungi that normally provide natural control are not very effective under hot, dry conditions," Townsend says.

Grasshoppers are already plentiful in New Jersey because of the hot weather, says entomologist George Hamilton of Rutgers University.

And the most annoying summer pest of all, mosquitoes, are enjoying the warmth, despite the record drought.

"Mosquitoes can breed in as little as a quarter- to half-inch of water," Henriksen says.

Texas and Florida are two spots where mosquitoes are particularly bad, Horton says, because those two states have been both unusually warm and rather wet this year.

Forty-seven human West Nile virus infections, which mosquitoes spread, have been reported this year to the Centers for Disease Control and Prevention. One man in Texas died from the virus.

Drought can drive insects into homes: Ants, for instance, Henriksen says, will come into homes to find water.

"If they're not finding it outside, they'll come inside," she says.

If the warmth stays into the fall, insects will continue to do well until the frost comes, Denlinger predicts.

And beyond that, "if we have another mild winter, we'll continue to see more pests out there," Horton says (USA Today, 2012)

Title: Hot, Dry Weather Heightens West Nile Virus Risk
Date: July 26, 2012
USA Today

Abstract: Hot, dry weather in the Midwest has created the perfect conditions for mosquitoes that carry 
West Nile virus.

The Culex mosquito breeds in still-damp ditches and underground storm water basins.

Indiana, Ohio and Illinois are reporting higher rates of infected mosquitoes compared with past years. More infected mosquitoes means a higher West Nile risk for humans. Illinois and Oklahoma report earlier-than-usual cases of human infection.

What's more, the dry weather means the pesky floodwater mosquito is scarce. That makes people think mosquitoes aren't a problem and gives the Culex mosquito a chance to sneak up and bite.

Health officials urge people to wear insect repellent though they may not be noticing biting mosquitoes (USA Today, 2012).

Title: Hot, Dry Weather Heightens West Nile Virus Risk
Date: July 26, 2012
USA Today

West Nile virus is spreading faster than it has in years, and the pace of the mosquito-borne disease is getting worse, health officials report.
States are reporting more cases than usual, says Marc Fischer, a specialist in mosquito-borne diseases with the Centers for Disease Control and Prevention (
CDC) in Fort Collins, Colo. "There's been a lot of mosquito activity in most states" this year, Fischer says.

Texas is getting the worst of it.

Sixteen people have died of West Nile virus this summer in Texas. That's out of 381 cases of the illness. "We're on track to have the worst year ever," says Christine Mann, spokeswoman for the Department of State Health Services in Austin.

Nationwide there have been at least 693 cases and 28 deaths, according to the CDC and state numbers released Tuesday. That's up from 390 cases and eight deaths last week.

A mild winter and ample spring rains allowed the mosquito population to build up early. Heat and scant rainfall are creating stagnant water pools, which make great breeding grounds, says Michael Merchant, an entomologist at the Texas AgriLife Extension Service in Dallas.

Thirty-two states have had cases of West Nile, the CDC says.

Louisiana has had six deaths in 68 cases, Oklahoma one death in 55 cases, and Mississippi one death in 59 cases. In Arizona, there's been one death in seven cases.

California had 23 cases, one of which was fatal, andSouth Dakota had one fatality in 37 cases.

It's going to get worse, says David Dausey, a professor of public health at Mercyhurst University in Erie, Pa. He says climate change means warmer winters, milder springs and hotter summers, all of which "create a longer season for mosquitoes to breed and ideal conditions for them to survive." That will mean more West Nile and, public health workers worry, other mosquito-borne diseases such as yellow fever, malaria and dengue fever, Dausey says.

Most people who are infected with the West Nile Virus, 70% to 80%, never know they have it. Twenty percent to 30% develop West Nile fever, with headaches, fever, joint pains, vomiting or diarrhea and rash.

Less than 1% of those infected with the virus develop West Nile neuroinvasive disease involving inflammation of the brain, spinal cord or the tissue surrounding the brain. About 10% of those will die, Fischer says. People over 50 and those with compromised immune systems are more likely to develop this forms (USA Today, 2012).

Title: Parasites May Get Nastier With Climate Swings: Study
Date: August 12, 2012

Abstract: Parasites look set to become more virulent because of climate change, according to a study showing that frogs suffer more infections from a fungus when exposed to unexpected swings in temperatures.

Parasites, which include tapeworms, the tiny organisms that cause malaria and funguses, may be more nimble at adapting to climatic shifts than the animals they live on since they are smaller and grow more quickly, scientists said.

"Increases in climate variability are likely to make it easier for parasites to infect their hosts," Thomas Raffel of Oakland University in the United States told Reuters, based on findings about frogs and a sometimes deadly skin fungus.

"We think this could exacerbate the effects of some disease," he said of the report he led with colleagues at the University of South Florida. It will be published in Monday's edition of the journal Nature Climate Change.

A U.N. panel of experts says that global warming is expected to add to human suffering from more heatwaves, floods, storms, fires and droughts, and have effects such as spreading the ranges of some diseases.

And climate change, blamed on greenhouse gases released by burning fossil fuels, is also likely to mean more swings in temperatures.

"Few...studies have considered the effects of climate variability or predictability on disease, despite it being likely that hosts and parasites will have differential responses to climatic shifts," they wrote.

The scientists exposed Cuban treefrogs in 80 laboratory incubators to varying temperatures and infections of a fungus, Batrachochytrium dendrobatidis, that is often deadly for the amphibians.

In one experiment, frogs kept at a temperature of 25 degrees Celsius (77F) for four weeks suffered far more infections when they were shifted to incubators at 15C (59F) and exposed to the fungus than frogs already used to living at 15C.

"If you shift the temperature a frog is more susceptible to infection than a frog that is already adapted to that temperature," Raffel said.

In another test, frogs that were exposed to predictable daily temperature variations between 15 and 25 Celsius, typical of shifts from night to day, were much better at resisting the fungus.

Based on factors including their size, life expectancy and factors such as their metabolisms, the scientists said frogs probabably took 10 times as long as fungus to get used to unexpected temperature changes, a process known as acclimation.

Raffel said that more tests were needed of other parasites and hosts to confirm the findings. "This study was only done on an single tropical frog species," he said.

He said he was unaware of studies about how other parasites such as malaria, for instance, might be affected by temperature swings that affect both its mosquito and human hosts. "It's an open question," he said.

Still, he said that there was speculation that cold-blooded creatures such as frogs, insects, reptiles or fish might be more susceptible to parasites as temperature shifted than warm-blooded birds and mammals (Reuters, 2012)

Title: Brain-Eating Amoeba And Other Diseases That Could Spread With Climate Change
Date: September 21, 2012
Source: Care2

Abstract:  Global warming is the greatest threat facing our planet today.

Scientists have been telling us this for a while: a warming planet alters weather patterns, water supplies, seasonal growth for plants and a sustainable way of life for us and the world’s wildlife.

But have you considered how climate change can affect your health?

Experts note that climate change may also be impacting certain environmentally sensitive diseases, and not in a good way. Read on, if you dare!

According to the Environmental Protection Agency (EPA),

Changes in climate may enhance the spread of some diseases. Disease-causing agents, called pathogens, can be transmitted through food, water, and animals such as deer, birds, mice, and insects. Climate change could affect all of these transmitters.

Translated, that means certain diseases will be able to proliferate due to rapid changes in water, heat and air quality. Here are just five examples. More can be found on the EPA site.

1. Salmonella
Let’s start with salmonella bacteria, the most frequently reported cause of food-borne illness. You may remember that two years ago,
 a salmonella outbreak caused by contaminated chicken eggs sickened more than 1,600 people across the United States, sending many victims to the hospital with severe infections.

Salmonella is a rod-shaped bacilli that can cause diarrheal illness in humans by passing from the feces of people or animals to other people or other animals.

What’s the global warming connection? Higher air temperatures can increase cases of salmonella and other bacteria-related food poisoning because bacteria grow more rapidly in warm environments. As if that were not bad enough, flooding and heavy rainfall can cause overflows from sewage treatment plants into fresh water sources. Overflows could also contaminate certain food crops, as was suspected with Taylor Farms lettuce last year.

2. Giardia
Giardiasis, caused by the parasite Giardia intestinalis,  is an infection of the small intestine and is the most common cause of water-borne, parasitic illness in the U.S.  Up to 2.5 million cases of this disease 
are reported each year in the U.S., and up to 20 percent of the world’s population is chronically infected.

As a backpacker, I spend much of my summer exploring wilderness areas and I know I am at risk of contracting giardiasis if I  drink from contaminated fresh water lakes, so I always treat my water. But giardiasis is also a common cause of outbreaks of diarrhea in day-care centers because of the high probability of fecal-oral contamination from children.

In general, giardiasis occurs where there is inadequate sanitation or treatment of drinking water. The most common manifestations of giardiasis are diarrhea and abdominal pain, particularly cramping; the symptoms and signs of giardiasis do not begin for at least seven days following infection, but can occur as long as three or more weeks later. And as I know from several hiker friends, the recovery period can be really long.

What’s the global warming connection? Heavy rainfall or flooding can increase water-borne parasites such as Giardia intestinalis that are sometimes found in drinking water, and it can cause stormwater runoff that may contaminate water bodies such as lakes and beaches, that  are used for recreation.

3. Lyme Disease
Lyme disease is spread 
through the bite of a blacklegged tick that is infected with Borrelia burgdorferi. Typical symptoms of Lyme disease include fever, headache, fatigue and a characteristic skin rash. Most people recover after taking antibiotics, while up to 20 percent of sufferers experience symptoms that can continue for years.

However, if you want to find out how terrible and life-changing this disease can be, read about author Amy Tan’s experience: an outdoor bucolic wedding in upstate New York led to hallucinations, the inability to drive and a life of constant anxiety.

The Centers for Disease Control and Prevention (CDC) reports that in 2010, the most recent data available, there were over 20,000 confirmed cases in North America. In the United States, most infections occur in the Northeast and mid-Atlantic, from northeastern Virginia to Maine; in north central states, mostly in Wisconsin and Minnesota; and on the west coast, particularly northern California.

What’s the global warming connection? The geographic range of ticks that carry Lyme disease is expanding as air temperatures rise. Patrick Leighton is a researcher at the University of Montreal:

From Scientific American:

“Currently, the areas where we are seeing a larger tick population is in the eastern part of the country along the U.S. border,” said Leighton, who observed that ranges for ticks are expanding by roughly 45 kilometers per year. He said the spread was linked to established Lyme disease hosts like white-tailed deer, suitable forest habitat and warmer temperatures.

“If you look historically, increases in temperature have been important [for Lyme disease],” he said. “The main thing that our study showed was that under warmer climate conditions, ticks move faster.”

4. West Nile Virus
West Nile virus is a disease spread by mosquitoes. West Nile virus was first discovered in the United States in the summer of 1999 in New York. Since then, the virus has spread throughout the United States. This is a type of virus known as a flavivirus. Researchers believe 
West Nile virus is spread when a mosquito bites an infected bird and then bites a person.

The milder version of the disease, generally called West Nile fever, may cause abdominal pain, diarrhea, fever, muscle aches, nausea, rash or a sore throat. These symptoms usually last for 3 – 6 days, but there is a much more serious form of the disease that can be life-threatening.

However, on the positive side, many people who are bitten by mosquitoes that carry West Nile virus do not notice any symptoms at all.

What’s the global warming connection? In 2002, a new strain of West Nile virus, which can cause serious, life-altering disease, emerged in the United States. Higher temperatures are favorable to the survival of this new strain; since 2012 is the hottest year on record in the United States according to the National Climatic Data Center, it’s probably not a coincidence that some of the states hit hardest by West Nile have also felt the brunt of the heat.

5. Brain-Eating Amoeba
This one may be the scariest of all.

From The Advisory Board Company:

CDC researchers say that the two Louisiana individuals who died last year from a brain-eating primary amoebic meningoencephalitis (PAM) contracted the infection after using neti-pots with tap water harboring the bacteria, according to a study in Clinical Infectious Diseases.

The victims’ deaths, the first recorded PAM cases in the U.S., were linked to the presence of Naegleria fowleri in the tap water they used to regularly clear their sinuses with neti pots, the study says. The municipal tap water tested negative for the bacteria, but one victim’s tankless water heater and the other’s sink and faucet tested positive for the bacteria.

What are the symptoms of PAM? In the first case, a 28-year-old man developed a severe headache, neck stiffness, back pain, confusion, fever and vomiting and became extremely disoriented. The second victim was a 51-year-old woman who suffered from nausea, vomiting, loss of appetite, fatigue, fever and neck stiffness.

What’s the global warming connection? The CDC believes that as temperatures increase, these bacteria can colonize in household plumbing and tap water. CDC researchers say there has been a shift north in the geographic pattern of where PAM cases are reported, perhaps due to a climate change or localized heat waves.

As always with the possibility of disease, the best approach is not to stay home and avoid all contact with insects. Rather, be careful! Personally, I’m not so fond of white-tailed deer any more, and I always check for those ticks after a hike in the park. Stay safe! (Care2, 2012).