Could Climate Change Cause Deadly Epidemics?

If people aren’t as concerned about climate change as they should be, one reason may be that the gradual rise of temperatures and ocean waters seems to give us plenty of time to take mitigating measures, such as seawalls to protect coastal cities and genetically-engineered crops that would be able to flourish in the altered environment. It’s harder to understand that climate change may endanger us in other ways that will be more difficult to combat. For example, it may cause a slew of deadly diseases, which are now seen mostly in poorer regions in the tropics, to spread to developed nations in temperate zones.

Could Climate Change Cause Deadly Epidemics

The latest concern: A newly-published study in BMC Public Health looked at dengue fever, a virus spread by mosquitoes that sickens 50 million people and kills about 12,000 people worldwide each year, mostly in tropical areas.

The researchers found that dengue eventually could become a significant health problem in parts of Europe, including Mediterranean and Adriatic coastal areas that are popular with tourists. Europe is becoming hotter and more humid, conditions that foster the growth of the mosquitoes.

The researchers studied data from Mexico about the occurrence of dengue fever and the effect of climate variables such as temperature, humidity and rainfall, as well as socioeconomic factors, such as population density and income, on the spread of the disease. They then used that data to model the infection rate in various regions of Europe over the next century. In some places, they predicted that rate of dengue fever cases will quintuple, to up to 10 cases per 100,000 inhabitants.

Almost all of the excess risk will fall on the coastal areas of the Mediterranean and Adriatic seas and the northeastern part of Italy, particularly the Po Valley, University of East Anglia medical school professor Paul Hunter said in a press release.

That comes after a 2013 study warned that people in the United States are also at risk from dengue due to climate change. Traditionally, America has only had a few hundred reported cases of dengue each year, usually involving international travelers. But the Natural Resources Defense Council says that the mosquito that transmits dengue now is found in 28 states.

Another 2014 study found that climate change may be increasing the spread of Lyme disease.

Source: discovery news

75% seasonal, pandemic flu sufferers have no symptoms

Researchers have said that around 1 in 5 of the population were infected in both recent outbreaks of seasonal flu and the 2009 H1N1 influenza pandemic, but just 23 per cent of these infections caused symptoms.

The Flu Watch study tracked five successive cohorts of households across England over six influenza seasons between 2006 and 2011. The researchers calculated nationally representative estimates of the incidence of influenza infection, the proportion of infections that were symptomatic, and the proportion of symptomatic infections that led to medical attention.

Participants provided blood samples before and after each season for influenza serology, and all participating households were contacted weekly to identify any cases of cough, cold, sore throat or ‘flu-like illness’. Any person reporting such symptoms was asked to submit a nasal swab on day 2 of illness to test for a variety of respiratory viruses using Real-Time, Polymerase Chain Reaction (RT-PCR) technology.

The results show that on average 18per cent of the unvaccinated community were infected with influenza each winter season-19per cent during prepandemic seasons and 18per cent during the 2009 pandemic. But most (77per cent) of these infections showed no symptoms, and only around 17per cent of people with PCR-confirmed influenza visited their doctor. Compared with some seasonal flu strains, the 2009 pandemic strain caused substantially milder symptoms.

The study has been published in The Lancet Respiratory Medicine journal.
source: zee news

Flu season kicks in, affect younger adults

The new flu season is ramping up across the U.S. with growing reports of illness — particularly in the south — chiefly caused by the H1N1 bug that is more likely to sicken younger adults than the elderly, health officials said Friday.

Flu activity is increasing nationwide and is already high in six states: Texas, Louisiana, Mississippi, Alabama, Oklahoma and Missouri, officials with the Centers for Disease Control and Prevention said.

For the first time since the 2009 influenza pandemic, H1N1 is the dominant circulating flu strain early in the season, CDC officials said. While most flu strains predominantly sicken the elderly and those with existing health problems, that strain mostly sickens younger adults, those ages 18 to 49, and middle-aged folks, ages 49 to 64.

CDC officials warned earlier this week that they have already received “a number” of reports of serious respiratory illness and death in young and middle-aged adults, including many infected with H1N1 flu. In Texas, where flu is widespread in all areas, a 17-year-old with underlying health problems died, health officials said.

“It’s a reminder that flu can be a serious disease,” said Dr. Joseph Bresee, a CDC flu expert.

So far, there have been no significant changes in the H1N1 flu viruses to suggest they’re spreading more easily or have become more virulent, but CDC officials said they’re monitoring for any signs.

It’s still too soon to tell how serious this year’s flu season will be, or how well this year’s vaccine matches the strains that are actually going around, Bresee said. But, he added, a flu shot is still the best way to avoid illness.

CDC recommends that everyone older than 6 months get a flu shot every year. Federal officials reported earlier this month that flu vaccinations kept nearly 80,000 people out of the hospital last year and prevented 6.6 million cases of the flu.

On average, CDC says 200,000 people are hospitalized with flu each season — ranging from 158,000 people hospitalized in 1990-1991 to 431,000 in 1997-1998. Flu vaccine also may prevent other conditions, such as heart disease, studies show. Flu season typically peaks in January and February.

Still, many Americans, particularly young adults, tend not to get vaccinated.

Source: Nbc news