|
Humans have died over the years because of diseases carried by insects. The number is not small either as millions have perished from these diseases over time. Man struggles to overcome these diseases but it is a long, expensive and hard fight especially in areas of extreme poverty. Some insects infect man directly and some indirectly. Animals infested with insects are among the worse as humans ingest food from these animals and are infected with disease.
There are many ways that insects can transmit disease even without transferring germs. There are various mites and worms that will invade tissues. Allergies can flare from bites of bees, body lice, and bites of chiggers and ticks. Some flies will be called mechanical carries as they pick up germs by biting a diseased animal and then bite a healthy person thus contaminating them with disease. There are germs on garbage and other filth that a fly can crawl on it or walk on it and carry disease to humans. Fleas carry disease after ingest plague organisms.
Mosquitoes are of the insect order Diptera and this group of insects can cause more destruction in terms of human deaths and illness. Mosquitoes are all over this earth except in the polar regions. They are carriers of malayan filariasis, bancroftian, dengue, yellow fever and malaria and some kinds of encephalitis. The species of mosquitoes that carry human malaria are the dapple-winged Anopheles. The cells The greatest outbreaks of malaria are in the temperate regions and the Tropics. Anywhere there exists a mild climate and abundant water mosquitoes will bread and multiply. People tend to spend more time outside in these areas. Screened porches and houses do not necessarily keep out these mosquitoes. In the United States there are at least a dozen species of Anopheles mosquitoes. There are many species of the Anopheles that exist in other parts of the world. Some carry malaria and others do not. The mosquito known as the yellow-fever mosquito is a semi domestic. Yellow fever is still a serious threat in many places in the world. An infected monkey or even man can spread this virus. It can be found breeding in water and various places such as old tires, vases or cans. The female is the one that bites.
A breed of mosquito called Culex tarsalis and several other species of mosquitoes are transmitters of Encephalitis. This is one of several kinds of viruses that attack the central nervous systems of vertebrates. In the Tropics and subtropics Elephantiasis a disfiguring malady of humans is caused by mosquitoes.
Sand flies are blood suckers and carry at least a few serious diseases. In some South American countries the veruga or Oroya fever is carried by sand flies, or as the 8-Day fever of the regions of China, India, Iraq, or the Mediterranean region. This is a mild febrile disease. There is a skin disorder called Oriental sore that is carried by sand flies. Where there are crevices in rocks and walls and damp animal and vegetable wastes the flies will breed. Moth flies breed in sewage and carry disease. Black flies of the family Simuliidae are small humpbacked gnats exist in the United States and in many other countries. Humans can be severely allergic to them or have severe dermatitis. These flies are hosts for early stages of roundworm that can cause onchoceriasis by getting in the eyes and even have caused blindness in some cases. Horse and deer flies are aggressive bloodsuckers who prefer livestock but will bite humans with painful bites. These flies carry tularemia on their beaks. Tsetse flies carry African sleeping sickness. These dangerous flies are in tropical and subtropical Africa and much is done to stop their
Developing.
House flies will live in the human home and lay eggs and have a new generation within two weeks. They will breed in fermenting vegetable and animal matter. They are known to have spread tuberculosis, parasitic worms, yaws, trachome and cholera. Blow flies are known as the blue bottle or the green bottle flies and carry much of the same disease-producing organisms as the house fly. There is a fly in the tropical Americas called the Dermatobia. It will infest man causing maggots to pop out of the eggs and burrow in the skin.
A breed of mosquito called Culex tarsalis and several other species of mosquitoes are transmitters of Encephalitis. This is one of several kinds of viruses that attack the central nervous systems of vertebrates. In the Tropics and subtropics Elephantiasis a disfiguring malady of humans is caused by mosquitoes.
Fleas have parasitic habits in the adult stage only. They are able to move rapidly among hairs or feathers of their hosts with their wingless adult laterally compressed bodies and strong, spiny legs. If a human is bit there will be an immediate area of inflammation. The human flea is called Pulex irritas as it can live in clothing instead of fur. Rat, cat and dog fleas will carry disease from the host to humans. In the Tropics there is a flea called the chigoe that will bury themselves in the skin, especially feet and cause an ulcer like crater. There are species of fleas that carry the bubonic plague and murine typhus to humans living in warm climates. Bubonic plague is the most serious disease that the flea has causes.
Caterpillars need to be mentioned even though they do carry disease as they can cause many painful injuries. The sting of the caterpillar can be very painful. The puss caterpillar can give a severe sting that gives a human the symptoms of paralysis. Ants, wasps and bees will sting man sometimes causing a very allergic reaction requiring medical attention. The brown-tail moth stings and will irritate the skin and eyes of many humans.
The bed bug is of an order of insects called the Hemiptera. This order includes wingless bed bugs, winged, biting, blood sucking, assassin, bugs, conenoses and their relatives. These bugs live in areas of filth in houses, hotels and in public transportation areas. They will retreat to mattresses, joints of wood, cracks, and can fit into very tight crevices. It has not been proved that these bugs are carriers of disease but that they are the causative agents of several diseases such as plague, relapsing fever, infectious jaundice, lymphocytic choriomeningitis and tularemia. They have been known vectors of Rocky Mountain Spotted Fever. Some of these bugs will attack humans.
There are three kinds of sucking lice that will infest man, the head, body, and crab lice. The crab lice prefer hairy parts of the human body and will cause intense itching. The other lice have caused the disease, "red death" in the Middle Ages. The body louse can adapt readily to the human host. Louse-born typhus, like plague, has been one of the worst vermin-infestations of humanity. Epidemics have spread because of lice.
Ticks are mites are a class of arthropods of the Acarina. They have four instead of three legs in the nymphal and adult stages and lack a separate thoracic region as true insects have in their bodies. Half of the species of ticks feeds upon man. Scabies is caused by the itch mite. Grocer's itch and harvester's rash are caused by mites that infest grain and stored-food products. There is a tropical rate mite and a house-mouse-infesting mite that causes infestation of houses.
Chiggers belong to the mite family Trombiculidae. Scrub typhus is caused by certain species of chiggers. It is passed from one generation of mites to the next through the eggs. Certain species of chiggers will even attack man.
There are many more insects that will be carriers of human diseases, too numerous to mention.
Scientists are working all the time to find ways to prevent insects from carrying disease to humans. One method is to destroy the insect vector, by using drugs to kill or by immunization making the human host immune to the insect bites.
| 
