Now, it is well- known that the virus is mainly transmitted via fecal-oral route which results from contamination of food and water by fecal matter and direct contact with infected individuals. Initially another icteric agent, Hepatitis B virus, was isolated in 1973 by Robert H. Purcell. This is followed by isolation of HAV from marmoset liver explant cultures in 1979(5). Understanding of HAV had started after WWII because of its massive impact on the soldiers and civilians under the contamination favored conditions of war. HAV was first visualized under electron microscope at the National Institutes of Health in the feces of volunteers who have had HAV infection (1, 2).
Acquired immune deficiency syndrome, or AIDS, is a recently recognized disease entity. It is caused by infection with the human immunodeficiency virus (HIV), which attacks selected cells in the immune system (see IMMUNITY) and produces defects in function. These defects may not be apparent for years. They lead in a relentless fashion, however, to a severe suppression of the immune system's ability to resist harmful organisms. This leaves the body open to an invasion by various infections, which are therefore called opportunistic diseases, and to the development of unusual cancers.
It is characterized by high level viremia and initial innate defences (release of acute phase proteins, pro inflammatory cytokines, activation of natural killer cells) which is not sufficient to eradicate the virus. (1,3) Subsequent progression into early stage describes the period from seroconversion through to viral load set point. (3) Dendritic cell mediated cytotoxic T cell response is partially responsible for this reduction in viral RNA, which is an important prognostic marker for AIDS progression. (1,4) An earlier study (5) reported infection, depletion and dysfunction in mDCs and pDCs in advanced stages of HIV -1 infection. It was yet to be clearly elucidated if these changes occurred earlier on in HIV-1 infection or were an end outcome from long term viral exposure.
Diseases caused by pneumonia was not previously diagnosed clearly, consequently, the information about its pathological effects based on simple estimates (Garibaldi, 1995 ; Niederman, et al 1998 cited in American Thoracic Society, 2001). Whitney (2000) investigate that strains of bacteria have resistance to antibiotics made treatment more complicated. The main point is pneumococci becoming more resistant to common antibiotics. Whitney (2000) mainly argued that there are dramatic increases in the proportion of pneumococci that are resistant to antibiotics and other antimicrobial agents tested. This essay will firstly summarize this article and then follow by foundation and finally will discuss the impact.
In less than three years yellow fever decimated his troops to less than 5,000. This was so damaging that napoleon decided to sell the land to the United States and this is how we acquired the Louisiana Purchase . This and other epidemics of this extant are the reason scientists conducting immense research to prevent catastrophes of this nature from occurring again. The Flavivirus has been studied for years and there are some features that distinguish it from other viruses. First of all, these viruses are considered arboviruses.
The Horror of AIDS Virus AIDS is a communicable disease that has the ability to damage the immune system. A communicable disease is a type of disease that can spread from a person to a person. The immune system is a structure that conducts several processes to prevent from getting a disease. “The origins of HIV date back to the late nineteenth or early twentieth century in west-central Africa. AIDS and its cause, HIV, were first identified and recognized in the early 1980s” (What Is AIDS... 1).
Typhoid Fever Typhoid fever is an intestinal illness, which can result in great suffering and even death. At first it was commonly confused with other fever causing illnesses until 1869 when William Jenner performed a careful analysis and found differences in the different types of typhus fevers. In this paper, I will discuss the bacteria that causes typhoid fever, discuss the signs, symptoms, method of transmission, past and current epidemics, and whether or not there has been a decrease in outbreaks in the past few years. Typhoid fever is caused by the bacterium Salmonella typhi, a member of the genus Salmonella, which is included in the Enterobacteriaceae family. Salmonella typhi cells are aerobic, gram negative rods that affect the gastrointestinal tracts of humans, and occasionally the bloodstream.
Liver disease has seemed to plague our society for many, many years. Studies have shown that hepatitis and jaundice reports have confirmed that the virus has been an infectious liver disease, as early as the 8th century. The body’s immune system tries it’s best to fight the virus with cells called lymphocytes, which causes damage to the liver even more. Fibrosis starts to occur in the liver because the liver has been scarred, causing the blood flow to become slower and eventually causes Cirrhosis. Once the blood begins backing up and leaking into other organs, the liver has difficulties in manufacturing proteins, regulating the transport of fat storage, controlling the production and excretion of cholesterol becomes more difficult to do.
West Nile Virus has emerged in recent years throughout the temporate zones of Europe and North America. Causing a variety of conditions in its hosts, the most serious manifestation of WN virus infection is fatal encephalitis (inflammation of the brain) in humans and horses, and many birds. History While many forms of encephalitis exist, West Nile Virus was first isolated and identified in the West Nile District of Uganda in 1937. The virus, which was seemingly isolated to North Eastern Africa, became recognized as a cause of severe human meningoencephalitis (inflammation of the spinal cord and brain) in elderly patients during an outbreak in Israel in 1957. In addition to the human victims of this disease, the virus was found Egypt and France during 1960s to have fatal effects within horses.
Patients that were infected by SARS were noted to have atypical pneumonia. They presented with high fevers and respiratory issues that quickly developed into pneumonia within a few days (Zhong et al., 2003). Through serological and nasopharyngeal aspirate testing, the coronavirus (CoV) was determined to be the cause of SARS (Zhong et al., 2003). It was also determined that the persons that were originally exposed to the virus had contact with animals, most likely to prepare food, at a produce market in the province of Guangdong (Zhong et al., 2003). The virus had started with the animals, crossed over to humans, and mutated.