Wednesday, July 23, 2014

Unfounded mosquito rumors repelled

Keep safe while RVing: Unfounded mosquito rumors repelled
by Russ and Tina DeMaris
West Nile virus is present in almost every corner of our country, and this is the peak season. An analysis from the U.S. Centers for Disease Control and Prevention (CDC) on U.S. West Nile virus found that most cases were reported during July, August and September. The CDC says the mosquito-borne disease is underreported and undertreated.
 
West Nile virus can do nasty things to those infected with it. According to Wikipedia, one stage is somewhat like a miserable flu: "Fever, headache, chills, diaphoresis (excessive sweating), weakness, lymphadenopathy (swollen lymph nodes), and drowsiness. Occasionally there is a short-lived truncal rash and some patients experience gastrointestinal symptoms including nausea, vomiting, loss of appetite, or diarrhea. All symptoms are resolved within 7-10 days, although fatigue can last for some weeks and lymphadenopathy can take up to two months to resolve."
 
That's not something any of us would want to spoil our RV travel with — but it can be worse. Wiki says, "The more dangerous encephalitis is characterized by similar early symptoms but also a decreased level of consciousness, sometimes approaching near-coma. Deep tendon reflexes are hyperactive at first, later diminished. There are also extrapyramidal disorders. Recovery is marked by a long convalescence with fatigue."
 
There are no "shots" you can take to ward off West Nile. And if you get the virus, there isn't much your doctor can do for you — spell that: no cure — only supportive measures. Yes, some people do die from West Nile. So what's the best thing to do? Don't get it in the first place. The medical community, including the CDC, says the best bet is to use a bug repellent — usually the best working contain DEET. But a lot of rumors persist about DEET.  
 
For you, here are the myths and myth busters:
 
Myth: Some popular skin creams and "natural" repellent products are safer than DEET.
Fact: "DEET has been shown to be an extremely safe and effective repellent," said Lyle R. Petersen, M.D., director of the CDC's division of vector-borne infectious diseases. (Vector: an organism, often an invertebrate arthropod [e.g., insects], that transmits a pathogen from reservoir to host.) University of Florida scientists Jonathan Day and Roxanne Rutledge wrote: "Natural is a word that is sometimes used to promote 'safe' products. Unfortunately, the wording can be misleading for the uninformed individual. 'Natural' products are usually essential oils distilled from plants.… These oils can be toxic and irritating in high concentrations. 'Natural' repellents are not necessarily safe repellents." DEET is one of the most widely tested consumer products of any type and has been used reliably by consumers for more than 50 years. According to a New England Journal of Medicine article (Fradin and Day, 2002), DEET "has a remarkable safety profile."
 
Myth: Garlic, bananas and vitamin B ward off mosquitoes.
Fact: "There is no scientific evidence that eating garlic, vitamins, onions, or any other food will make a person repellent to mosquitoes," said Day and Rutledge of the University of Florida. "It is also unlikely that B-1 skin patches will work either," Day says. DEET is regarded as the "gold standard" against which other repellents are tested.
 
Myth: New devices are effective against mosquitoes.
Fact: "There is no evidence that wearing devices that emit sound will repel mosquitoes," say Day and Rutledge. "Bug zappers do not control mosquitoes and can reduce the populations of beneficial insects," says Ken Gioeli, University of Florida natural resource agent. Some experts suggest that zappers actually attract mosquitoes to your property.
 
Myth: Dryer sheets and other home remedies repel bugs.
Fact: "The truth is although many home remedies and oddball uses of everyday products do serve to repel mosquitoes somewhat, they don't work very effectively for very long," writes Barbara Mikkelson on the popular Website, Snopes.com.
 
Myth: DEET is smelly and oily.
Fact: Fifty years of product development has yielded DEET-based products that are pleasant to use — they have a pleasant "feel" on the skin and fresh fragrances. Some even go on as a dry formulation similar to spray deodorant that is powder-like.
 
Myth: Higher concentrations mean better protection.
Fact: Higher concentrations of DEET mean longer protection, not better. A 5% product will provide about 90 minutes of protection and a 100% product protects for about 10 hours. Protection time increases as the concentration increases. So, the longer you are outside, the higher the concentration you should use. However, protecting against ticks requires at least 20% DEET, and no other repellent works as well against ticks. Most folks who are going outside for a backyard barbecue should choose a product that protects them for up to two hours, a repellent in the 10% range. It's often fine to use a concentration below 30% for most outdoor activities. When you are exposed for long periods to hordes of mosquitoes, though, a 100% product is advisable.
 
Myth: I don't need repellent unless I'm headed out into a wooded or waterfront location.
Fact: Mosquitoes can be anywhere, even in a city, and many carry disease. Most people who have contracted West Nile virus were bitten by mosquitoes lurking in their own yards. Cases of malaria have occurred in recent years in Washington, D.C., and other mosquito-borne diseases sometimes occur elsewhere in the United States.
 
Myth: DEET is an insecticide.
Fact: DEET does not kill mosquitoes, as insecticides do. It repels them by confusing their ability to locate humans. 
 
Myth: DEET causes seizures in children.
Fact: Scientific reviews do not show a causal relationship between DEET and seizures (Murphy, et al., 1997; Bell, et al., 2002). This myth stems from a handful of isolated reports in both adults and children that cannot be definitively linked to DEET. Experts report that 2% of typical children have one or more seizures from unknown causes by age 10. A multi-year review of adverse events yielded a handful of neurological cases (given millions of product uses per year) that could not be tied to use of DEET-based repellents. These neurological adverse events were not more common in children than in other age groups and were not tied to concentration of DEET in the products.
 
Myth: Some popular skin creams and "natural" repellents work as well as DEET.
Fact: Scientifically controlled studies show very few repellents are as effective as DEET (Fradin and Day, 2002). The CDC urges consumers to pick only repellents with EPA registrations to assure appropriate efficacy. The most effective, according to the CDC, are DEET, picaridin, oil of lemon eucalyptus or PMD (recommended with limitations), and IR3535.

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