Analysing The Hepatitis Infections Biology Essay

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

Healthy people create a healthy society. It is considered that illness, poverty and ignorance are three main enemies that stand against the progress or the development of any society. The government of any society put the health of its people first, as a priority because people will produce more wealth if they are healthy. World Health Organization (WHO) has stated in its report that liver diseases are spreading rapidly in both developed and developing countries. (Dusheiko, 1998).

Doctors in Pakistan are progressively more concerned that the recycle of syringes and use of blood without screening could amplify an increase in cases of hepatitis.

1.1 Importance of liver:

The liver is the largest, heaviest and one of the most important internal organs. Dark red in color, it weighs 1-1.5 kg and is located behind the lower right part of your ribs. It stores vitamins, sugars, fats and other nutrients from the food you eat and then releases them to the body when needed. It also builds basic chemicals that your body needs to stay healthy. Last but not least; it removes waste products, harmful bacteria and toxic chemicals from your blood. In other words - it is the powerhouse, recycling, and disposal plant of the body. Life is not possible without the liver.

1.2 Hepatitis:

There are at least five forms of hepatitis known to scientists and all of them cause inflammation, or swelling, of the liver. Doctors call the different forms hepatitis A, B, C, D and E. Each form of the disease is contracted by human in different ways and often exhibits unique symptoms. (Gallagher, 2005). The development of jaundice is a characteristic element of liver disease; only blood test can correctly diagnose the hepatitis. (Lemon, 1994, Stapleton and Lemon, 1994).

It is predicted that hepatitis has infected billions of people. Out of them more than 350 million are untreatable. However, liver diseases are avoidable but poorly understood (Ahmed,1999).

According to a survey conducted by some students of rural sociology in Agriculture University Faisalabad in 2004 in all 78.8 percent of the respondents of Faisalabad were not have awareness of Hepatitis, whereas 21.2 percent of respondents were aware of Hepatitis. Most of the respondents (67.5 percent) had no knowledge about source of transmission of Hepatitis, whereas 32.5 percent of them had knowledge about source of transmission. This present study showed that blood transfusion was a major risk factor in transmission of virus.

1.2.1 Hepatitis A:

Type A Hepatitis is one of the oldest diseases those are known to human beings. It is a self limited disease which results in fluminant hepatitis and the proportion of death by this disease is a very small number of patients. Yet, it is a considerable cause of anguish and socio-economic deprivations in many areas of the world. (Hollinger and Ticehurst, 1996).

Hepatitis A virus (HAV) is usually transmitted by the faecal-oral route. (lemon, 1997, Stapleton, 1995). Infections occur in early life, in the areas where cleanliness is poor and living conditions are crammed full.

Hepatitis A is a viral disease, and antibiotics are not valuable in the treatment of the infection. Therapy can only be helpful and intended at maintaining comfort and sufficient nutritional balance. Recovery without therapy is generally the rule. (Hollinger and Ticehurst, 1996). The rate in males is about 20% higher than in females. (Previsani and Lavanchy 2004). Risk factors of hepatitis A remain unknown in almost 50% of cases.(Koff 1998).

1.2.2 Hepatitis B:

Hepatitis B is a serious and common infection liver disease. It is affecting millions of people throughout the world. (Previsani and Lavanchy 2004).

The development of chronic hepatic insufficiency, cirrhosis and hepatocellular carcinoma (HCC) are included in the severe pathological consequences of persistent HBV infection. In addition, the disease can be transmitted by HBV for many years. The Infection of this disease occurs very frequently in early childhood and mostly leads to the chronic carrier state.

Chronic hepatitis B is an infection with a varied nature history, has been found most frequently in Asia-Pacific region (Fattovich, 2003). In Pakistan, the prevalence of hepatitis B virus (HBV) in normal individuals has varied in various regions. Three percent prevalence was noted in normal individuals of Karachi (Qasmi et al. 2000).

There are over 4 million sensitive clinical cases of HBV every year, and out of which 25% are carriers. One million people die because of chronic active hepatitis and cirrhosis of primary liver cancer in a year. Hepatitis B is also called serum hepatitis, type B hepatitis, or homologous serum jaundice. (Previsani and Lavanchy 2004).

While replicating in hepatocytes, the HBV interferes with the functions of the liver. Then the immune system is activated to make a specific reaction to fight and possibly eliminate the infectious agent. As a result of pathological damage, the liver becomes swollen.

By appearance, one should not judge the infected people because most infected people look completely healthy and do not have any acute sings of disease, however may be highly infectious.

1.2.3 Hepatitis C:

Unlike other forms of hepatitis, HCV is difficult for the immune system to over come, and so the disease can cause serious, long term liver damage, including cirrhosis, liver cancer, and even live failure- all three of which can be fatal. (Jenkins, 2000).

HCV is identified by Choo (Choo et al, 1989). It is a rapidly emerging as a major health problem in developing countries including Pakistan.

Most people infected with HCV have no symptoms of hepatitis. They generally stay oblivious that they have infection during the first 10 to 20 years of virus unless they have blood test. As a result of dying liver cells or leakage of these enzymes, these people will generally be found that they have some elevations of liver enzymes in their blood. (Seeff, 1995).

Super infection of hepatitis C with hepatitis A may cause fulminate liver failure, super infection of hepatitis C with hepatitis B increases the rate of progression of liver disease. Due to the shared risk factors among people acquiring Hepatitis A, B and C, and the serious consequences of super infections, NIH (National Institute of Hepatitis, USA).Veterans Health Administration have recommended that all current chronic hepatitis C patients that have not shown immunity to Hepatitis A or B be vaccinated.

The president of Pakistan Medical Association, Dr Umar Ayub Khan said that according to a rough estimate, about 15.6% of the population is infected with hepatitis. The persons who visited public hospitals, about three million have hepatitis B or C. The number might be ruinous if the whole population was screened.

1.2.4 Hepatitis D:

Hepatitis delta (D) virus is a defective virus in that it can not replicate without the aid of another virus, the hepatitis B virus. Despite this requirement, it is not particularly prevalent in South-East Asia, a major center of hepatitis B infection. Hepatitis D and B co infection in the same individual does not lead to a much higher incidence of acute or chronic liver disease than does infection with hepatitis B virus alone. By contrast, hepatitis D virus infection of a person previously infected with B virus is often correlated with acute disease followed cirrhosis of the liver. (Edward et al, 2008).

1.2.5 Hepatitis E:

Like hepatitis A virus, hepatitis E virus is spread by contaminated water and possibly by food. It is found throughout the world and has caused significant epidemics in India and Russia through problems with drinking water. The disease caused by this virus is usually mild. Recovery from acute infection is generally complete and there is no evidence of chronic infection following the acute phase. (Edward et al, 2008).

1.3 Limitations of the Study:

This study was started with the objective to find out the risk factors of five types of hepatitis those are hepatitis A, B, C, D and E. However, during the survey it was found that hepatitis A is a very minor disease and 90% of the patients do not need any type of treatment and will be all right after taking proper rest or by minor treatment. Hepatitis D can only develop in the presence hepatitis B. In Pakistan cases of Hepatitis D and E are very rare. During two months survey period, no patient of hepatitis A, D and E admitted in the DHQ hospital. Due to this reason the scope of the study was changed and now. I data about the hepatitis B and C patients and third category is the category of healthy persons has been analyzed.

1.4 Objective:

The objective of this thesis is to study the risk factors of hepatitis which is a liver disease. In this study the risk factors of two types of hepatitis (B, and C) are studied by taking information of hepatitis patients from liver center of DHQ hospital Faisalabad admitted during February and March 2009. A survey of patients in DHQ during these two months was conducted to get data on the factors which were expected to be the risk factors. This study will create awareness among people and provide assistance to the government policy maker, administrators and researchers with regard to control of the prevalence of Hepatitis and help in formulation of policies for improvement in the health department to the appropriate information and treatment compliance in the light of statistical results of this study.

From statistical point of view the parametric and non parametric classification techniques among the available one’s to study categorical dependent variable data are explored and the technique which gives better classification is recommended. The available techniques, those were applied to this data set, were logistic regression and classification trees. Logistic regression is a parametric technique and classification trees are non parametric techniques. The classification tree has three growing methods CART (Classification and Regression Tree, CHAID (Chi Square Automatic Interaction Detection) and QUEST (Quick Unbiased Efficient Statistical Tree). A comparison among logistic regression, CHAID, CART and QUEST is made. Statistical properties of these techniques are evaluated to form the basis of recommendations.

1.5 Need of the Study:

Statistically the objective of this study is to compare the parametric and non parametric classification techniques in case when the dependent variable has more than two categories and all the predictors are categorical. In the literature, the comparison of parametric and non parametric classification techniques can be found but it is just done firstly for the binary dependent variable and secondly in all previous studies predictors are all continuous or a mixture of continuous and categorical variables. In this study all the predictors are categorical and dependent variable has three categories. So the comparison is made in case when the dependent variable has three categories and all the predictors are categorical.