Any pet animal brought to the house, whether it is a puppy or a kitten, must first be examined using standard veterinary procedures-one of which is the proper de-worming of the pet. This can be accomplished by the use of a simple pill or two on the cat or dog. The internal parasites common in young pet are a species of intestinal worms simply known as the roundworms, which are elongated and threadlike creatures which are often seen wriggling about in the feces of the animal. These are nematode worms and this scientific name - nematode, is a Greek word rendered as nema-"thread," and tode-worm. Unlike the appearance of the flattened tapeworms and flukes, these so called roundworms are called "round" precisely because the body is not flattened and is rather cylindrical. Among all existing parasites, the roundworms remain the most common in occurrence and are the most widespread of all known internal parasites across the world. These roundworms even parasitize plants and no single animal species is without its own particular species specific roundworms; thus these parasites are very successful organisms and have adapted to a wide variety of host species. It is known that humans can be affected by at least fifty species of roundworms, among these about a dozen are very common parasites which can cause great disease, can lead to the disfigurement of the host, and even result in the death of the individual. A roundworm infection in fact, affects at least one out of every four people during an average lifetime. Roundworms have almost no parasitic equals and strictly from the evolutionary point of view can be seen as successful opportunists that have adapted and constantly seek to gain biological advantage at the expense of other organisms - in short, they are perfect parasites.
Another common internal parasitic worm in many parts of India, Africa, and large areas of southern Asia is the guinea worm-which may bring on severe symptoms in the victim. The infestations from the female guinea worm has been known to cause incapacitating symptoms that may affect even a whole quarter of the population in a village in these areas and such outbreaks are periodical in occurrence and can induce severe vomiting, diarrhea, and spells of dizziness. These symptoms make it hard for the adult population of such areas to work normally. The female guinea worm often reaches two to four feet in length-while the male worm is only an inch in length, the female worm wanders all over the body for sometime and it finally settles in the tissues lying beneath the skin. The female worm is like a coiled varicose vein in appearance and can often be spotted even during cursory examinations. These affected areas of the body and skin will erupt into blisters which may discharge a milky fluid when the area is immersed in water - this is something that will never occur in a varicose vein. This exuded fluid from the blisters will contains thousands of small larvae - which are there to ensure the perpetuation of the species. A tiny crustacean found in freshwater, called a cyclops is the next host when these larvae are released into water. When people swallow water contaminated with the larvae laden cyclops - the result will be the infection of a new human host by the worm. Physical symptoms include very painful inflammation and crippling muscle damage in the legs as the guinea worm almost always attacks the legs of the victim. This area of the body is by no means the only site of infection by the guinea worm.
Many million of Japanese people enjoy a dish of sliced raw fish in their diet and the consumption of raw fish is spreading as Japanese cuisine has spread worldwide. The fondness for sushi and sashimi is paid for dearly by many unfortunate Japanese diners every year, as several hundred Japanese diners contract a parasitic disease known as anisakiasis from eating contaminated raw fish. The disease has spread even to the united States though incidences of the condition is still not considered to be a serious worldwide problem in terms of the number of people it affects, the disease is also spreading to other countries as worldwide travel increases. The possible dangers inherent in contracting this disease must realized by any lovers of raw fish dishes. Physical symptoms that become apparent in only a few hours after the consumption of raw fish, is the presence of an excruciating pain in the abdominal region coupled with the vomiting of blood - these symptoms are the most prevalent symptoms ever to appear. Physically the larval parasite is about one and a half inch in size - this larva of the anisakis worm is ingested along with the raw meat. Once the parasite gains entry into the body of the host it immediately buries its anterior region or head in the tissues lining the inner areas of the stomach. Here it causes a bloody - two inch in diameter - ulcer, which is nasty in appearance and this ulcer can be detected by looking through a gastroscope-which is a medical tube that is stuck down into the throat and through to the stomach of the victim. The body of the worm is anchored via its head like protuberance right at the center of the inflamed and craterlike wound or ulcer, here the body of the larvae undulates in the stomach juices very much alive and feeding off its host. The worm can sometimes be removed by the careful use of pincers fixed to the end of the gastroscope and if this treatment is successful, there is no further need for medical intervention and the patient is free of the worm. However, this may not always work out and at other times the doctors must resort to the use of surgery on the affected tissues of the patient to remove the worm. In addition, sometimes the larvae of the worm can also attach itself to the wall of the small intestine much farther down along the digestive tract, and in these cases - surgery is the only option. The physical symptoms such as severe stabbing pain will not immediately appear when the worm is anchored in this way.
The infection from the anisakis larvae is relatively rare when one considers the sheers number of people who consume sushi and sashimi on a regular and daily basis, in fact any cases of infection with the anisakis larvae is rare and is not a very big health concern. Another intestinal roundworm parasite is very different in the ability to infect people in large areas of the tropical and subtropical areas of the world-the distribution of this common parasite is almost universal in these parts. The physiological characteristics of this small internal parasite give it the name-hookworm. In fact, the adult hookworms can only attain a full body length of about a half an inch. The name of the worm is sourced from rows of tiny hooks or attachment plates that lie within the mouth of this parasitic worm. As the worm sucks in tissue fluids and blood in the gut, these hooks and plates often bite down hard onto the intestinal wall of the host-and thus they are organs of attachment similar to those seen in other intestinal parasites. Crippling and severe anemia can often be the end result, particularly if the number of worms within the body is numerous in the body of a single individual. The anemia is one of the only serious legacies of this infestation. However, severe infestation in children can often lead to the appearance of other conditions and such children often have some sort of physical or mental retardation. The transmission of the worm larvae is through fecal matter similar to the transmission of so many other species of intestinal parasites. When the contaminated the human waste which contains microscopic eggs is deposited in soil, it leads to the maturation of the eggs and hundreds of tiny eggs are hatched into the soil. Infection of a new host occurs when the hookworm larvae staying in such soils burrow through the skin of individuals who walking barefoot on the ground. Once the larvae fain entry into the body of the new host, they quickly enter the bloodstream and are rapidly transported by the blood into the intestine - which is their final destination and where they will mature into adults, thus the cycle is perpetuated and the species survives.
The disease known as filariasis must be mentioned when talking about different crippling parasitic diseases; this extremely debilitating disease is caused by a species of roundworms called filaria. Areas of greatest prevalence include countries in western and central Africa, along with the countries in the Middle and the Far East, the disease is also prevalent in some parts of the New World, mainly in the southern part of the continent extending from Mexico to Brazil. The greatest medical concern is placed on two filarial worms which are practically close cousins and related species. The first filarial worm causes the condition known as river blindness and the other one causes the elephantiasis-both of these conditions cause severe injury to the human host. It is believed that more than a hundred million individuals may well be affected by the symptoms caused by these two filarial worms together around the world. The more dramatic in appearance and very debilitating is the disease called elephantiasis. The most noticeable feature of the condition is the immense swelling in the tissues of the host. The name elephantiasis is derived from the fact that the worm often affects the legs of the individual, these become so large in size that they begin to resemble the feet of an elephant-hence the name. Other areas of the body can also be affected and in particular the testicular tissues of men is a vulnerable spot, when this area is affected by the parasite, the testicles will assume gargantuan dimensions and grow extremely large-the size is such that the testicles cannot be hidden and sometimes the person may even be unable to move because of the weight of the swollen testes. For example, one unfortunate male elephantiasis patient found it impossible to walk or move about, unless he placed the huge testicles - which were the size of watermelons - in a wheelbarrow, he carted his own swollen testicles in front of him-in fact, testicles can even assume much larger sizes than this. At the same time, the parasite can also cause the swelling of women's breasts and make them grow to gigantic proportions. The reproductive activities of the female parasitic worm are the causative factor for the extreme swelling seen in the majority of untreated patients. The female worm looks like a coiled piece of string and grow to be about three or four inches in length when fully extended. The female worm will lie within the lymphatic glands or in the lymphatic ducts-in fact, the lymphatic system is the main site in the body that the worm causes the major damages. Thousands of tiny larvae are produced by these females every day. All of these thousands of tiny parasites are in the form of tiny and threadlike larvae which are called microfilaria -these larvae will be the main agents of the destruction and swelling in the host of the tissues. The numerous microfilaria swim about and proliferate through the lymphatic system leading to the clogging of lymphatic ducts, this will cause the accumulation of lymphatic fluid, which will finally lead to a swelling in the affected parts of the body. The transmission of the filarial worm is through an insect vector-namely the culex mosquito species and the bite of this mosquito transfers the worm from one infected human to another human host. The species of mosquito - Culex, is almost ubiquitous in all the areas covering most of the tropics and subtropics. The mosquito breeds in particularly filthy and long stagnant waters such as those in areas where raw sewage is kept. Control of the vector can eliminate incidences of this disease and therefore it is not surprising, that incidences of the disease have increased because of the growth of large cities without proper sanitation and without planning - the numbers of this mosquito species has greatly increased in some areas. The worm that causes elephantiasis also use to exist in certain areas of the southern United States, when it entered the country along with African slaves-however, the disease was eradicated in the country by the 1920s and outbreaks of this particular disease is rare in the country. It is still a scourge in some underdeveloped countries mainly lying in warmer parts of the world. Infected patients in whom parasitic reproduction has began are all capable of passing on the worm to others. Thus when a Culex mosquito uses its little proboscis to suck blood from an infected human host, it will also sucks up, along with the blood which is its meal, thousands of the larval microfilaria which can bring elephantiasis in another person - if he or she is unlucky enough to be bitten by this mosquito again. Larval development continues rapidly within the body of the mosquito itself and thus the mosquito is not only an insect vector for the disease it can also be something of an intermediate host. The parasite is transferred when the insect succeeds in biting another person again and thus the species of the worm is perpetuated by the human primary host as well as the insect intermediate host. Another filarial disease known as river blindness-is extremely dangerous and endemic primarily in the African continent. This disease is caused by a filarial worm related to the one that causes elephantiasis. This particular worm is however, transmitted by the bites of the black fly, which is an insect that lives and breeds in habitats that consist of fast-flowing streams and rivers-unlike the stagnant pools, mosquitoes like to breed in. The filarial worm that the bite of this black fly introduces into the unlucky host is a peculiar species of filarial parasitic worm - which almost always infiltrates the tissues in the eyes and tissues along the outer layers of the skin of the victim. In these regions of the body tiny worms in their thousands will be found, these are the snakelike microfilaria - the larval forms of the worm. This ocular infestation has a sad and common outcome, total blindness is common, only impaired vision will result if the host is lucky. The condition of individuals with worms affecting only the skin is not better then other patients. Social ostracism is often felt by patients as the microfilaria cause disfiguring and ugly lesions to appear on the skin. The itching sensation in the affected skin often turns so intense and persistent over time, that suicide is the only option of some patients. The blindness the worm causes is the reason why the disease is known as river blindness.