Killing mosquitoes to fight off dengue

The wrong approach to wiping out the mosquitoes that cause dengue infections could lead to worse epidemics in the future, according to a study released on Tuesday.

Targeting only mosquito larvae, and not adults, with insecticides may work in the short run, but could result in higher resistance in the insects and less disease immunity among humans, especially in urban settings, the study finds.

Dengue is a mosquito-borne infection that causes severe, flu-like symptoms in some 50 million people every year, mainly in developing countries.

Global incidence of the disease, which is rarely fatal but often debilitating, has risen dramatically in recent decades, linked to both rapid urbanization and the impact of global warming.

There is no treatment, cure or vaccine - the only way to control the disease is to kill the mosquitoes that carry it.

The method prevailing in most countries - attempting to destroy breeding areas - is misguided, according to the study, published in The Lancet.

"Year-round larval control can be counterproductive, exacerbating epidemics in later years because of evolution of insecticide resistance and lost of herd immunity," the researchers say.

"The main conclusion is that when you compare all the proposals for controlling dengue, the most cost effective is killing adult mosquitoes," comments Eduardo Massad, a professor at the School of Medicine at the University of Sao Paulo.

Workouts work best when they're planned

Physical exercise should be an integral part of one's daily routine and preferably planned in advance, advises Herbert Loellgen, president of the German Society for Sports Medicine and Prevention. If there is no time for exercise in the morning, he says, then time should be found in the evening.

Loellgen says people who miss a training session should not reproach themselves but make sure to get their workout the next time around. It is important to continue to enjoy it and not trouble oneself with feelings of guilt, he points out. To stick to a training program, it can help to train with others.

Aside from enjoying the physical activity and having sufficient time to practice it, people should start slowly and gradually increase the intensity.

It is a good idea to devote about 70 percent of one's efforts to endurance training such as running, mountain hiking or cycling, which exercise multiple, large muscle groups.

Twenty percent should go to strength training and the remaining 10 percent to stretching exercises that improve flexibility and lower the risk of injurious falls in advanced age, Loellgen says.

Endurance training should be practiced at least twice a week - three or four times is better - for at least 15 to 30 minutes each time.

Loellgen recommends alternating the types of sport to enhance motivation and prevent uneven strain on muscles and joints.

Nutritional benefits to eating as a family

Kids who sit down to eat with their families are less likely to be overweight and eat unhealthy foods, according to US researchers who call for more shared meals.

In the first report to combine all existing studies on the issue, they found kids who eat with their parents at least three times a week had 12 percent lower odds of being overweight.

The children were also 20 percent less likely to eat junk food, 35 percent less likely to have eating problems like skipping meals or bingeing, and 24 percent more likely to eat vegetables and other healthy foods.

"Sitting down together as a family, there are nutritional benefits from that," says Amber Hammons, a psychologist at the University of Illinois at Urbana-Champaign, whose findings are published in the journal Pediatrics.

The new report is based on findings from nearly 183,000 children about 2 to 17 years of age.

While those studies yielded mixed results and weren't easy to compare, overall they show regular family meals are tied to better nutrition.

It's not clear why that is, Hammons says, but it's possible that parents may influence and monitor their kids more during shared meals.

As a result, the researchers encourage families to spend more time together around the dinner table.

"It doesn't have to be every day," Hammons says. "We know that families are very busy."

Reuters-DPA