Mosquitoes & West Nile Virus
(They carry other horrid diseases, too)
Date Created - 4 June, 2003
This is NOT an exhaustive research of mosquitoes or the diseases they carry. It is rather an attempt to gather basic information for personal protection and safety - I have bone marrow cancer which means I have a suppressed immune system, and for me basic information on how to avoid mosquito bites is critical.
I will try my best to update this page as this summer unfolds and new West Nile Virus information becomes available.
According to the American Mosquito Control Association - Mosquito Information reveals that mosquitoes feed primarily on nectar. Female mosquitoes mouthparts form a long piercing-sucking proboscis. Males differ from females by having feathery antennae and mouthparts not suitable for piercing skin. Only female mosquitoes require a blood meal (protein) and bite animals – warm or cold blooded – and birds. Acquiring a blood meal, i.e., protein, is essential for egg production.
Aedes and Ochlerotatus mosquitoes search for a blood meal early in the morning, at dusk (crepuscular feeders) and into the evening. They usually do not enter dwellings. Some are daytime biters especially on cloudy days and in shaded areas. (American Mosquito Control Association - Mosquito Information)
The Aedes japonicus species of mosquito seems to be the main carrier of the West Nile Virus (though other species of mosquitoes may also be identified). As such, it would be a good idea to learn the habits of the Aedes japonicus mosquito.
Adult species of Aedes japonicus rest in wooded areas and prefer to bite during the daytime. In the laboratory, they feed readily on chicks and mice, but not on reptiles or amphibians. Further studies on Aedes japonicus are needed to more clearly define their feeding preferences in a variety of situations.
Protection
As with other biting insects, the use of protective clothing (i.e., long-sleeved shirts and long pants) and insect repellent is recommended to prevent bites.
Only female mosquitoes bite and suck blood; they use the proteins in the blood to produce eggs. While mosquito larvae can develop in a variety of water habitats, those of the Aedes japonicus are found in small water containers, such as holes in rocks or trees, as well as the aforementioned used tires or other containers. Although many mosquitoes are most active at dusk or dawn, Aedes japonicus is a daytime feeder and is usually associated with wooded areas.
The two references above seem to indicate that the Aedes japonicus mosquito are most active at dusk or at dawn (but is 'a daytime feeder' and can be about any time of the day).
Scratching my head and wanders what other types of mosquitoes will end up carriers of real 'nasties.'
The sites above also indicate that the Aedes japonicus mosquito is 'usually associated with wooded areas.' I wasn't aware of that - will keep out of the woods unless I am wearing the recommended clothing and have applied recommended insect repellent. As a bare minimum for this summer (2003) I am wearing the recommended clothing - no shorts or short-sleeve shirts (with proper insect repellent handy as the situation warrants).
Question - What is the recommended insect repellent?
Apply insect repellent containing DEET (N,N-diethyl-meta-toluamide) to exposed skin whenever you are outdoors.
When possible, wear long-sleeves, long pants and socks when outdoors. Treating clothes with repellents containing permethrin or DEET will give extra protection, since mosquitoes may bite through thin clothing. Do not apply repellents containing permethrin directly to skin. Do not spray repellent containing DEET on the skin under your clothing.
The hours from dusk to dawn are peak mosquito biting times. Consider avoiding outdoor activities during these times -- or take extra care to use repellent and protective clothing during evening and early morning.
Mosquitoes lay their eggs in standing water. Limit the number of places around your home for mosquitoes to breed by getting rid of items that hold water.
PS: For as long as we have been together Queenie Bee Beate has been rabbiting on about not wearing perfume in the summer - that it attracts mosquitoes. She rabbits on about all sorts. But... way up at the top of the page - where it said mosquitoes feed on nectar - hmmmm... she is a very wise Queenie Bee... and maybe she has a point - so no perfume or after shave lotion (I don't use either). There may - or may not be something in that...
'Appropriate concentration.' I cringe when I read things like that - whatever in the world is the 'appropriate concentration?' I was spared uttering a few choice swear words as I read on at the MayoClinic.com webpage: 'It doesn't take a high concentration of mosquito repellent with DEET to provide an effective deterrent to mosquitoes. Typically, a 25 percent to 30 percent concentration of DEET is sufficient for both adults and children. This will provide protection for about 5 hours, while a product with 5 percent to 7 percent DEET protects for only about 1 to 2 hours.' (MayoClinic.com - Mosquito repellents: To DEET or not to DEET?)
That's the kind of information the public needs to make a wise choice of repellent. I am the sort who likes to see more than just one source of 'expert advice' and was happy with Health Canada's advice about DEET products.
Illinois Department of Public Health West Nile Virus Website reveals meaningful symptoms of West Nile Virus: 'Mild cases of West Nile infections may cause a slight fever or headache. More severe infections are marked by a rapid onset of a high fever with head and body aches, disorientation, tremors, convulsions and, in the most severe cases, paralysis or death. Usually symptoms occur from three to 14 days after the bite of an infected mosquito.'
West Nile Virus CDC Brochure advises: 'Most people who are infected with West Nile virus will not develop symptoms. Some people may become ill 3 to 15 days after the bite of an infected mosquito. Evidence suggests that a minority of infected persons will develop a mild illness with fever, headache, body aches, and sometimes skin rash and swollen glands. There are no known long-term effects due to mild illness.
West Nile virus infection infrequently results in a severe illness, however, known as West Nile encephalitis. Encephalitis is an inflammation of the brain that may be marked by headache, high fever, stiff neck, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis. A small number of cases have been fatal.'
The skin rash and swollen glands are added things to watch out for.
The above are more concise symptoms of having the West Nile Virus. The slight fever or headache is a bit 'iffy' but all the other heavy duty symptoms equate to 'get yourself to the hospital as soon as possible.'
I will update this section if I learn of any other symptoms to watch out for.
Following are reminders of important ways to reduce breeding sites of the mosquitoes associated with transmission of West Nile virus from State of New York Department of Health
Replace or repair broken screens and install new screens as needed;
Dispose of tin cans, plastic containers, ceramic pots or similar outdoor items that hold water;
Remove all discarded tires from your property;
Drill holes in the bottoms of recycling containers that are kept outdoors;
Clean clogged rain gutters and make sure they continue to work properly;
Turn over wheelbarrows and wading pools when not in use;
Change water in bird baths at least every four days;
Clear vegetation and debris from the edges of ponds;
Clean and chlorinate swimming pools, outdoor saunas and hot tubs;
Drain water from pool covers; and
Use landscaping to eliminate low spots where standing water accumulates.
Notice for mothers who are breast-feeding infants:
