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Bird flu vs. West Nile Virus Nowadays people all over the word, especially in America and Asia are suffering from dangerous diseases that are communicated from animals to people. Two of them are bird flu are West Nile virus. In this paper these diseases will be described and compared.
The disease known as "bird flu" is the infectious disease of birds caused by one of the A type flu virus strains, which is similar to a virus of the usual human flu. Scientists assume that the key role in infection distribution is played by migrant birds especially which fly between China and Far East regions of Russia. It is considered that all birds are susceptible to the given infection though some kinds are less susceptible, than the other. A migrating waterfowl - more often wild ducks - are the natural reservoir of a virus of the bird flu and these birds are less susceptible to the infection. The poultry, including hens and turkeys is especially susceptible to epidemics. The virus usually does not affect other kinds of animals except for birds and pigs. ("Agricultural Workers at Increased Risk of Infection with Animal Flu Viruses") Out of 15 subtypes of a virus of the bird flu virus H 5 N 1 causes special anxiety of representatives of the Worldwide Public Health Services Organization. ("Agricultural Workers at Increased Risk of Infection with Animal Flu Viruses") It is a highly pathogenic virus dangerous to people: H 5 N 1 changes very quickly H 5 N 1 has propensity to receive genes from the viruses infecting other kinds of animals, the populations of this subtype have high pathogenicity and can cause heavy disease and even a lethal outcome at people (in the countries of Asia since 2003 at least 94 persons died from a virus of the bird flu).
Contact with sick birds is the basic way of infection of people the bird flu. Average death-rate among patients exceeds 50 %. And the main part of sick dies in the countries of Southeast Asia (China, Thailand, and Vietnam). First symptoms of bird flu H 5 N 1: raised temperature, a fever, head and muscular pains, an ache in the joints, raised speed of symptoms severity increasing, affection of the lower part of respiratory ways with possible development of a primary virus pneumonia is characteristic at the height of disease (2 - 3 day of illness) Cough, short wind, frustration of voice (dysphonia) begins. Patients, as a rule, die of virus pneumonia and hypostasis of lungs.
The survival of sick with the bird flu in many respects is defined by duly rendering of the qualified medical care. ("Dee Birds to Be" 2005) Anti-virus preparations, some of which can be used for treatment and preventive maintenance are clinically effective against flu strains at adults and children who are not having accompanying diseases, however have restrictions. ("Dee Birds to Be" 2005) Some of these preparations are also very expensive also their deliveries are limited. Experience in production of a vaccine from the bird flu is also worthy, especially as to annual changes in structure of a vaccine, caused by mutation. However, it takes at least four months to make a new vaccine capable to give protection against new subtypes of a virus in the significant amounts. (Janet 1999) To this day the effective vaccine against the virus H 5 N 1 of bird flu does not exist. Flu pandemic can arise on the average three-four times every century when a new subtype of a virus appear and spreads quickly. (Janet 1999) In 20 century after a big flu pandemic in 1918 - 1919 (Spanish influenza) which became the reason of death of 40 - 50 million person worldwide, pandemic in 1957 - 1958 and 1968 - 1969 happened. (Janet 1999) Experts state that one more flu pandemic is inevitable and probably will arise soon enough.
Experts-virologists predict that the bird's flu pandemic can affect almost one third of population on the Earth. Now scientists hope on the development of a vaccine which could prevent distribution of H 5 N 1 virus and future infective episodes affecting birds and people. Development of such vaccine is very complex, and now there is no vaccine which could protect the person from the bird's flu. Vaccines against standard viruses of a human flu are made by injection of harmless virus strains in the chicken embryo in the egg, together with pathogenic strain. Genes of two strains are mixed up, and some part of posterity receives two superficial albumen's from pathogenic strain, and other chickens receive genes of a harmless virus. This strain is singled out and multiplied in millions eggs, then are cleaned, killed and marked as a vaccine.
But this process does not work concerning H 5 N 1 virus of the bird flu. As this virus is lethal for chickens, it kills embryos after the injection of eggs. For overcoming this barrier the new technology is used, and already there are messages about the development of new vaccines in the number of the countries, including China. But, considering high ability of the DNA of these viruses to mutation, it is possible to say, that the virus of the bird flu is always one step ahead of both a man and a bird. West Nile Virus, the causative agent of the Western Nile fever is one of representatives of Flavivirus sort of Flaviviridae family, which received the greatest distribution in Africa, Western Asia and Near East countries. For the first time it was revealed in 1937 in a fever woman in area of the Western Nile (Uganda), and received its name in this connection.
In the beginning of the 1950 the virus was isolated from patients, birds and mosquitoes in Egypt. Later it became obvious, that West Nile Virus is, possibly, the most widespread representative of Flaviviruses. It caused sporadic cases and infective episodes at people and animals in the Europe. In 1999 there was first information appeared about the detection of the virus in the territory of the USA. The main carriers of a virus of the West Nile Virus are the mosquitoes, eating blood of the infected birds. Notwithstanding what the virus has been found out in 43 kinds of mosquitoes, more often it is met at mosquitoes of Culex sort. ("West Nile Virus Threatening Wildlife") The basic carriers of a virus are wild birds.
In tissues and bodies of the infected ducks and pigeon virus is kept for 20 - 100 days. Migrating birds, apparently, are carriers of the pathogen of disease in the moderate climatic zones of Eurasia during spring flights. Less often the West Nile Virus was found out in mammals (including mice, hamsters, camels, cattle, horses, dogs and a man). However unlike birds mammals usually do not participate in a cycle of transfer of a virus in ecosystem. ("Bracing for Another Battle") For a virus of the Western Nile two basic types of circulation are characteristic: a rural cycle (the wild birds living in boggy territories, and mosquitoes); a city cycle (ecologically connected with the person kinds of birds and mosquitoes eating blood of birds and a man, mainly Culex pipes / molested ). ("Bracing for Another Battle") Mosquitoes get a virus basically from the infected birds. After the incubator period (10 - 14 days) the West Nile virus of can be transferred to the person and other animals during stings of the infected mosquitoes as the activator is kept in their salivary glands. Multiplication of a virus in an organism of a man leads to development (after 3 - 6 -days of incubator period) of the clinical symptoms of the West Nile Virus. ("Bracing for Another Battle") More often it proceeds as flu-similar infection, accompanied by a fever (from moderated up to high), within 3 - 5 days, a headache (more often frontal), myalgia, arthralgia, weakness, sometimes conjunctivitis, typhoid maculopapular rash (approximately in half of cases), an anorexia, a nausea, pains in a stomach, a diarrhea and respiratory symptomatology.
Rather seldom aseptic al meningitis or meningoencephalitis (less than 15 %) happens. ("West Nile Virus Threatening Wildlife") From laboratory data it is possible to note insignificant increase of ESR and little leucocytosis. At patients with affect of the central nervous system at lumbar puncture a spinal liquid is transparent, with insignificant pleocytosis and the raised content of albumen. For West Nile fever full recovering without the long or constant residual is characteristic. Lethal cases are observed mainly at patients of 50 years old and older. ("West Nile Virus Still") No treatment is necessary for mild West Nile virus infection, and no definite treatment is found for severe infection. Treatment includes supportive care in a hospital to help the body fight the disease on its own.
Supportive care is frequently used when no cure exists for a disease. ("West Nile Virus Still") Supportive treatment includes intravenous (IV) fluids; help with breathing (using a ventilator), if needed; and prevention of secondary infections, such as pneumonia or a urinary tract infection. ("West Nile Virus Still") After analyzing two infections the following conclusion can be made: two viruses are very much alike according to their symptoms. The main symptoms of the both viruses are raised temperature, a fever, head and muscular pains. Both of them also can cause pneumonia as secondary infection. But West Nile fever runs differently: it cause also the brain fever. Also West Nile fever has its light form that cant be said about bird flu that always causes death. The ways of infection are also a bit different though very similar: bird flu infection is transferred from migrant birds to poultry and then to a man.
The basic carriers of a West Nile virus are also wild birds that makes it similar to birds flu but a man gets the disease through mosquitoes. Also there are no vaccines from these two diseases found yet. So, viruses have much in common because both of them have similar consequences and the both are equally dangerous for people all over the world and our scientists must do their best in their multiple attempts to find the way to struggle with these viruses. Works Cited "Agricultural Workers at Increased Risk of Infection with Animal Flu Viruses. " Journal of Environmental Health 68. 7 (2006) "Bracing for Another Battle with West Nile Virus. " USA Today (Society for the Advancement of Education) June 2003 "Dee Birds to Be Tested for Flu. " Daily Post (Liverpool, England) 15 Oct. 2005 Janet, Peter. "Your Health: How the Flu Makes Its Way from Wild Ducks, to Livestock, to You. " National Wildlife Dec. -Jan. 1999 "West Nile Virus Still on the Move. " USA Today (Society for the Advancement of Education) Sept. 2005 "West Nile Virus Threatening Wildlife. " USA Today (Society for the Advancement of Education) 133. 2712 (2004)
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Research essay sample on Bird Flu Vs West Nile Virus
