Thursday 16 April 2015

VIDEO RODENT





ASSIGNMENT GROUP RODENT

STUDENT OF DIPLOMA IN ENVIRONMENTAL HEALTH UNISEL

COURSE MPD 3223 VECTOR & PEST CONTROL

The Human Itch (SCABIES)







REFERENCE : YOUTUBE 


MITES

SCABIES MITES  



MITES

Mites, along with ticks, are small arthropods belonging to the subclass Acari (also known as Acarina) and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology. In soil ecosystems, mites are favored by high organic matter content and by moist conditions, wherein they actively engage in the fragmentation and mixing of organic matter.


Types of Mites

The majority of mite species are harmless to humans, but a few species of mites can colonize humans directly, act as vectors for disease transmission, or cause or contribute to allergenic diseases.

v  Mites which colonize human skin are the cause of several types of skin itchy rashes, such as grain itch, grocer's itch, and scabies. Sarcoptes scabiei is a parasitic mite responsible for scabies which is one of the three most common skin disorders in children.
v  Demodex mites, which are common cause of mange in dogs and other domesticated animals, have also been implicated in the human skin disease rosacea, although the mechanism by which demodex contributes to the disease is unclear.
v  Chiggers are known primarily for their itchy bite, but they can also spread disease in some limited circumstances, such as scrub typhus. The house-mouse mite is the only known vector of the disease rickettsialpox.
v  Dust mites cause several forms of allergic diseases, including hay fever, asthma and eczema, and are known to aggravate atopic dermatitis.

v  House dust mites are usually found in warm and humid locations, including beds. It is thought that inhalation of mites during sleep exposes the human body to some antigens that eventually induce hypersensitivity reaction.











                 The scabies mite Sarcoptes scabiei  



SCABIES

i)What is scabies?
Scabies is an infestation of the skin caused by the scabies mite Sarcoptes scabiei (see image). The mite is very tiny, 0.2 mm to 0.4 mm long, and cannot easily be seen without magnification. It occurs worldwide and in all races and social classes. Scabies is not an indication of poor hygiene.

ii)How scabies is spread?
Scabies is usually transmitted by direct skin-to-skin contact, or rarely, by underwear or bed clothes that have been freshly contaminated by an infested person. The mites can survive for only a few days off the human or animal body.

iii)Signs and symptoms
Scabies and other mites usually infest the skin especially where there are creases, such as:

v  between the fingers
v  on the front of the wrists
v  in the folds of the elbows, armpits and buttocks
v  genitals.


When mites have been transmitted from animals (such as dogs) to people, the mites are commonly found on areas of skin having contact with the animal, including forearms, chest and neck. However, mites from animals cannot breed on humans, so do not cause ongoing infestation. Scabies mites cause intense itching, especially at night. Thread-like ‘tunnels’, about 10 mm long, may be visible as grey lines in the skin, but they are often difficult to detect. Scabies infection may appear on the genitals as small itchy lumps.



                          Scabies skin infection


iv)Incubation period
(time between becoming infected and developing symptoms)
Itching begins 2 to 6 weeks after infestation in individuals not previously exposed to scabies and within 1 to 5 days in individuals previously exposed.

v)Infectious period
(time during which an infested person can transmit the infestation to others)
Until the mites and eggs are destroyed by treatment. People can be infectious even before the itching begins.

vi)Treatment
Skin disease caused by mites can easily be confused with other skin diseases. Treatment should not be undertaken until the diagnosis has been confirmed by a doctor, following examination of skin scrapings for mites. This is particularly important for babies, pregnant women or people who already have other forms of skin disease. Babies under 12 months of age need special treatment. Treatment involves application of insecticidal cream, lotion or solution as prescribed by a doctor. For see the Direction for the application of a topical scabicide (PDF 59KB) (opens in a new window) for detailed information on what you should do and how to apply topical scabicides.

vii)Prevention
v  Exclude people with scabies from childcare, preschool, school and work until one day after treatment commences.
v  All close (skin-to-skin) contacts and other people in the same household should be treated at the same time, even if no itching or other symptoms are present. By the time scabies is diagnosed in one person, many other people may have been infested. If everyone is not treated at the same time, treatment is likely to be unsuccessful.
v  Underwear, clothing, towels, bed linen and personal effects such as slippers, bed jackets, dressing gowns and knee rugs used by the affected person in the 72 hours prior to treatment should be laundered using a hot wash cycle (hotter than 50°C) or hot tumble dried to kill the mites. If items are unable to be laundered or hot tumble dried, place them in a sealed plastic bag and leave them for 72 hours before airing and reusing.

v  Mattresses and upholstered furniture can be vacuumed or gently ironed



                                                     Prevention for scabies 


References :
ii) http://en.wikipedia.org/wiki/Mite


Wednesday 15 April 2015

Tick Lifecycle.mp4







Reference : youtube 

TICKS

A TICKS

Ticks are small arachnids in the order Parasitiformes. Along with mites, they constitute the subclass Acarina. Ticks are ectoparasites (external parasites), living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians. Ticks are vectors of a number of diseases, including
v  Lyme disease
v  Q fever (rare; more commonly transmitted by infected excreta)
v  Colorado tick fever
v  Rocky Mountain spotted fever
v  African tick bite fever
v  Crimean Congo hemorrhagic fever
v  Tularemia
v  Tick-borne relapsing fever
v  Babesiosis
v  Ehrlichiosis
v  Tick-borne meningoencephalitis, as well as bovine anaplasmosis and
v  probably the Heartland virus. Some species, notably the Australian paralysis tick, are also intrinsically venomous and can cause paralysis.


LIFE CYCLE OF TICKS

You probably have a clear idea of what happens to a person or an animal if it doesn't get food ,it starves to death. Ticks can also starve to death, but often the process takes months or even years. However, without food, ticks can't do much. Ticks are a clear illustration of how food works as an energy source. Ticks need energy from blood in order to grow, develop and lay eggs. Without blood, ticks can't do any of this.

A tick begins its life as an egg. When the egg hatches, a six-legged larva emerges. Aside from its missing set of legs, the larva looks a lot like an adult tick. Its first host is usually a small mammal or a lizard, and it has to find a host in order to grow. After feeding, the larva drops to the ground to digest its food and begin to grow. After one to three weeks, the larva molts and becomes a nymph.

A tick nymph has eight legs and looks like a smaller version of an adult tick. It has to find another meal, usually from another small mammal, bird or lizard, before it can molt again. Once the nymph is finished eating, it drops to the ground to continue its development. Some species of soft tick molt several times, consuming a blood meal before each molt. After its final molt, the tick is an adult.

An adult tick has one job -- to reproduce. In hard ticks, the female tick attaches to a host and feeds, often for more than 24 hours, before mating. The male tick feeds before mating as well, but he's often a fraction of the size of the engorged female when mating takes place. Often, the male dies after mating, and the female dies after laying anywhere from 2,000 to 18,000 eggs. Soft ticks are an exception. Many species of soft tick eat several smaller blood meals and lay eggs several times. This is one reason soft ticks don't consume as much blood in one sitting or swell to the extent that hard ticks do.


Hard and soft ticks also have different methods for finding hosts, which we'll examine in the next section.





A hard tick lays her eggs


Types of Ticks

Of the three families of ticks, one is Nuttalliellidae which is comprises a single species, Nuttalliella namaqua. The remaining two families contain the hard ticks (Ixodidae) and the soft ticks (Argasidae). Ticks are closely related to the numerous families of mites, within the subclass Acarina .

The Ixodidae include over 700 species. They are known as 'hard ticks' because they differ from the Argasidae in having a scutum or hard shield. This shield generally can resist the force of a human's soft-soled footwear, especially on soft ground; it requires a hard sole on a hard surface to crush the tick. However, stepping on an engorged tick, filled with blood, kills it easily, though messily. In nymphs and adults of the Ixodidae, a prominent capitulum (head) projects forwards from the body; in this they differ from the Argasidae. They differ too, in their life cycle; Ixodidae that attach to a host will bite painlessly and generally unnoticed, and they remain in place until they engorge and are ready to change their skin; this process may take days or weeks. Some species drop off the host to moult in a safe place, whereas others remain on the same host and only drop off once they are ready to lay their eggs.

The Argasidae are known regionally as 'soft ticks' or 'tampans'. The family includes about 200 species, but the proper composition of the genera is under review. The following genera were accepted in 2010:
v  Antricola
v  Argas
v  Nothaspis
v  Ornithodoros
v  Otobius.

The most obvious distinctions between the Argasidae and the Ixodidae are that:

They have no scutum and the capitulum is concealed beneath the body.

The Argasidae also differ from the Ixodidae in their habits and ecology. Many of them feed primarily on birds, though some Ornithodoros for example feed on mammals and are extremely harmful. Both groups feed rapidly, typically biting painfully and gorging within minutes and none of the species will stick to the host in the way that hard ticks do. Unlike the Ixodidae that have no fixed dwelling place except on the host, they live in sand or in crevices or similar shelters near animal dens or nests, or in human dwellings where they might come out nightly to attack roosting birds, or emerge only when they smell carbon dioxide in the breath of their hosts and emerge from the sand to attack them. Species common in North America primarily parasitise birds, and very rarely attack humans or other mammals.

Tick Appearance
Tick's aren't actually insects -- they are arachnids, from the same family as spiders and mites. Although different types of ticks vary in size, they all lack wings and have a flat, oval body in some shade of brown. While adult and nymph-stage ticks are eight-legged creatures, tick larvae have only six legs.

Hard vs. Soft
If you've ever found a tick on yourself or removed one from your cat or dog, it's almost certainly a hard tick. These are the creatures who primarily feed on larger mammals, reptiles and birds. Soft ticks usually feed on smaller prey, such as bats, baby birds and mammals and little rodents. Soft ticks go through additional molting stages compared to their hard brethren, along with feeding more frequently.

Fed vs. Unfed
If the adult tick is still small and flat, it hasn't yet found a host whose blood it will suck. Once ticks do find a host and burrow in, they start swelling as they consume the blood meal. If not removed, the average tick takes a week to 12 days until it becomes engorged and drops off. Females feed for a longer period than males. Ticks don't fly, so they crawl onto their hosts from below or move among leaves, rocks and other objects until locating a suitable host. If you or your pets don't want to become a "suitable host," stay out of tick-infested areas. Examine yourself and your pet carefully when returning from a trip through the woods or a field to ensure you aren't bringing home ticks. Your pets can benefit from flea and tick preventatives available from your veterinarian.



Hard Ticks and Soft Ticks






The different between hard ticks and soft ticks 



Symptoms of Ticks infection

The most important symptoms are :
v  Itching at in the area of the bite
v  Swelling and in severe cases
v  Breathing problems
v  Coordination problems


Ticks bite 



Prevention of Ticks

i)Personal Protection

Tick bites are usually painless, the ticks are tiny, and consequently many people are unaware that they have been bitten. Ticks do not survive in hot, dry areas as it causes their bodies to dry. They can be active when temperatures are above 40F even in the winter.

GOOD SENSE TIPS
v  Wear light colored clothing, long sleeves and pants, tuck pants into socks. Long loose hair should be covered, braided or tied when venturing into areas where ticks are apt to be. Spray your clothing, etc. (also, see Repellent Sprays section).
v  When coming in from outside activities where you might have encountered ticks, throw clothing into the dryer set on high heat. This will ensure no ticks survive on your clothing. Remember to do a tick check, take a shower and wash your hair.
v  Keep pets that have outside exposure off furniture especially bedding.
v  Make certain that you have very fine pointed tweezers available.
v  Also, see the section on property protection and repellent sprays.

TICK CHECKS
v  Thorough tick checks should be done, daily or when coming in after outside activities when temperatures are warm and you have been in areas that you may have encountered ticks (ticks can be active even on warm winter days). Check dark, moist areas: hair, cracks behind ears, knees, elbows, underarms, crotch etc. (also see: Tick Removal section).
v  Check your pets for ticks when they come into the house (also, see Protecting Animals section).
v  Wear light colored clothing, long sleeves and pants, tuck pants into socks. Long loose hair should be covered, braided or tied when venturing into areas where ticks are apt to be. Spray your clothing, etc. (also, see Repellent Sprays section).

TICK REMOVAL
v  Ticks should be removed promptly. The longer it is attached the higher the chance of disease transmission. Remove it carefully to prevent disease transmission:
v  Using fine pointed tweezers, grasp the tick as close to the skin as possible without squeezing the tick's body.
v  Firmly pull it straight out (expect to feel some resistance). Save the tick for future testing by placing it in a plastic bag or in a small jar of alcohol. If a tick is to tested for spirochetes place it in a small jar or vial with a blade of grass to keep it alive. Be sure to note the date and site of the bite for future reference.

v  NEVER: squeeze the tick, burn it, or cover it with Vaseline or any other substance.

v  Remember to disinfect the site of the bite, wash your hands and disinfect your tweezers.

v  Contact your doctor.


ii)Repellant Sprays

DEET products can be used for exposed skin. Several controlled release DEET formulations have been developed which decrease skin absorbtion and increase protection time. Extended duration products include 3M Ultrathon, Skedaddle, and Sawyer's Controlled Release. Concentrations of DEET effective for mosquitoes, especially for children may not be effective against ticks, so tick checks are vital (see Repellent Sprays section).  US EPA information on DEET can be located at: http://www.epa.gov/pesticides/citizens/deet.htm

Permethrin 0.5% based sprays (on clothing only, not on skin, always follow manufacturers directions) for clothing, especially: shoes, socks, pants cuffs or on other fabrics such as mosquito netting, tents.  It is a synthetic pyrethroid insecticide rather than a true repellant, and works primarily by killing ticks on contact with treated clothes. It lasts up to 2 weeks and provides high levels of protection against ticks and mosquitos.

These products (Duranon Tick Repellent, Repell Permanone, Cutter Outdoorsman Gear Guard, Permethrin Tick Repellent)  usually can be found at sporting goods or garden supply stores. Once dry, Permethrin has a low level of mammalian toxicity, is poorly absorbed through the skin and is rapidly inactivated by the body.  Comment: to prevent exposure, do not spray permethrin on clothing on a windy day. Hint: if you regularly do yardwork, you might consider using a set of clothing that you have sprayed with permethrin.

Natural or Herbal Repellents and other products are marketed for protection against mosquitos, but are probably less effective against ticks. Applications of plant-derived repellents that might reduce tick attachment are less likely to deter a tick from walking across the skin to an untreated area.
If venturing into tick habitat, a combination of both DEET for skin and permethrin on clothing might be considered. Always follow guidelines for using repellant sprays before applying.
Consumers Report, June 2000, "Buzz-off!"  contains worthwhile information on insect repellants.


iii)Property Management

Ticks are most common in overgrown places where the ground is covered with leaf litter, weeds, and high grass, etc. These are the areas where they are protected from harsh drying effects of sun and wind, and are also where mice and deer live. Ticks can be found in the ecotone that surrounds your lawn area from the woods. Sometimes they can be found on well mowed lawns or in your home, because they dropped off animals or pets that crossed over or entered these areas.
The following methods are suggested to minimize ticks on your property:

v  Create tick free zones around your home by cutting back wooded areas and increasing the size of open lawn.
v  Keep grass mowed to 3 inches or less. This lowers humidity at ground level, making it difficult for ticks to survive.
v  Place play areas in sunshine.
v  Remove leaf litter, moist plant litter, brush, weeds and other debris that attract ticks.
v  Eliminate dense plant beds close to your home such as ivy and pachysandra.
v  Create borders (pebbles, cedar chips) to separate your lawn from the wooded area surrounding it.
v  Rock walls, woodpiles, and birdfeeders attract mice and chipmunks which hide, nest and eat spilled food from these sources. Do your best to keep these far from your home.
v  Keep garbage in tightly closed cans and don't leave pet food outside or purposely attract and feed wild animals.
v  Reduce plants that attract deer and plant those that they do not eat.
v  Scare tactics can be used to keep deer away.
v  Soap such as Irish Spring can be used to keep deer from eating plants.
v  Ten foot high deer fences can be used to keep them out of property.
v  See Tick control section for information about arcaricides and insecticides.
v  See Research section for the multiple other exciting methods under development.


iv)Tick Control

There are many methodologies to control ticks. Most of these are covered under the topics of Property Management or under Research.
Host reduction and exclusion: We have built homes in wooded areas, farmlands have decreased; the result of this is an increase in deer and mouse populations and an increase of human contact with ticks.

The deer are responsible for increasing the tick population. The mouse, followed by the chipmunk are responsible for the spread of many tick-borne pathogens, as they are the reservoirs for the disease organisms (as an example for the Lyme disease spirochete). Therefore, reducing exposure to these animals and reducing ticks on them seem a reasonable approach and are incorporated into much of the research and recommendations in the other sections.
Insecticidal soaps and Diatomaceous earth (silicon dioxide) due to its desiccation (drying) properties work against ticks.

Arcaricides are another approach that is quite controversial, use only those that are labeled for the control of ticks in residential landscape. They can be quite effective against nymphal ticks if application is done at the optimum date of mid-May to early June in the Northeast. A fall application may be used to control the adult I.scapularis. Comment: most people acquire Lyme disease from the nymphal ticks, due to their small size. Always read and follow EPA approved label on the product containers.

Cyfluthrin (Tempo). Chemical class: pyrethroid. For licensed applicator use only, is one of the most commonly used commercial products for tick control.


v)Protecting Animals

PETS
Check with your veterinarian for tick control products and/or a Lyme disease vaccine that they consider safe for your animal. Remember that exposing your pet to more than one type of treatment (collars, dips, baths or powders) within a short period of time might seriously harm your pet. For pets that go outdoors, check them carefully when they return inside.

Designate specific sleeping areas for your pets and check their bedding routinely for ticks (if they get on your furniture check it also). It is wise to vacuum their bedding, carpeting, and furniture they frequent, then dispose of the vacuum bag contents in outdoor trash can.

DEER
For information about "4 poster" feeder stations which reduce ticks on deer, see Research section.

MICE & CHIPMUNKS
Keep small animals, such as mice outside of your home by sealing small gaps. For information about bait boxes that reduce ticks on mice and chipmunks, see Research section.
You may also use Damminix, tubes stuffed with cotton balls treated with the pesticide permethrin. Mice make nesting materials from the cotton, thus reducing the ticks on the mice.


References :
i) http://en.wikipedia.org/wiki/Tick