The Epidemiology of Viral Hepatitis

Hepatitis or liver inflammation can be self-limiting or progressive to scarring, cirrhosis, or liver cancer. The condition is mainly caused by Hepatitis although there are other factors such as toxic substances (alcohol) autoimmune diseases and certain types of infections (Swetha Samji, Buggs, & Roy, 2017). Typically, there are five major hepatitis viruses known as types A, B, C, D, and E. The five categories have been placed on higher priority globally due to the death and disease burden they cause as well as potential epidemic spread and outbreaks. Since most cases of hepatitis are because of viruses, the following discussion will focus on viral hepatitis.

Hepatitis Etiology

As noted, viral hepatitis is known to be caused mainly by HAV, HBV, HCV, HDV (which can only proliferate if it coexists with HBV), and HEV. There is another hepatitis virus referred to as HGV but is still not clear whether it is pathogenic in Humans. In US, endemic viruses are HAV, HBV, and HCV only and they are responsible for 90% of acute viral hepatitis in this region (Swetha Samji, Buggs, & Roy, 2017). Although HAV and HBV are the most common cause of acute hepatitis, chronic hepatitis is mainly caused by HCV in the USA. The data below shows patterns by which the viruses are transmitted. The + shows transmission frequency and therefore the more the symbols, the higher the incidence.

Signs and Symptoms

Acute viral hepatitis can lead to minor flu- like illness or fatal liver failure. At times hepatitis can be asymptomatic especially when is because of HAV and HBV, which show mild or unnoticeable signs. However, HBV and HEV produce severe symptoms, which may worsen in case B and D coexist (Swetha Samji, Buggs, & Roy, 2017). Sudden symptoms may include nausea, poor appetite, vomiting, pain in the upper part of the abdomen (liver location), and fever. Occasionally a patient may develop itchy red hives on skin and joint pains, especially if they get infected with HBV. In three to ten days of infection, a patient usually excretes dark urine and jaundice start to develop. In rare occurrences, symptoms may worsen and become severe due to the development of fulminant hepatitis (liver failure). Such cases happen in individuals with HBV and more so in those that have HDV. The condition is highly progressive as the liver fails to remove toxic substances resulting in their accumulation in blood and later in the brain, leading to hepatic encephalopathy (Swetha Samji, Buggs, & Roy, 2017). Liver failure because of the virus may be fatal, particularly in adults. Nonetheless, acute liver hepatitis symptoms usually vanish within 4 to 8 weeks even without treatment. Even so, people infected with the virus might become carriers especially HCV which may eventually stimulate development of liver cirrhosis or liver cancer.

Risk Factors

Risk factors do vary according to the type of hepatitis. Having multiple sex partner, unsafe sex including anal and drug abuse (due to injections) increase chances of getting infected with any of the viruses (Swetha Samji, Buggs, & Roy, 2017). Infants also have a higher chance of getting infected by the viruses from their mother with HBV and HCV. Lastly, engaging in activities that involve exchange of body fluids increases the risk of contracting hepatitis.

Prevalence of Hepatitis

According to data corrected by Lancet and colleagues using the Global Burden of Disease (GBD) Study approach, in 2013 viral hepatitis accounted for 1.43 million deaths which were a 63% rise compared to 0.89 million in 1990 (Messina et al., 2015). The biggest trend was observed in hepatitis caused by type C virus for which the rate of disability adjusted life years raised by 43% for the last two decades. However, the burden was to be unequally distributed worldwide as high levels of mortality were noticed in Asia, Africa, and Oceania as compared to Western countries.In the USA, hepatitis A and B have declined over the last two decades drastically according to CDC reports, but C shows a worrying trend and has gained much attention from American medical community recently (Messina et al., 2015). The graphs below show trends of the three forms of Hepatitis in the USA from 1980 to 2014.

Currently, studies show that hepatitis types B and C are the primary cause of liver cancers and cirrhosis across the world. In fact, together they have been found to cause chronic disease in hundreds of millions of persons globally, and they account for 75% of the total cases of liver diseases (Messina et al., 2015). In addition, statistics suggests that over 200 million people are infected with hepatitis C that is an overall incidence of about 3.3 percent of the world population. Epidemiology studies in various regions of the world revealed that hepatitis caused by C virus was lowest in the Northern European countries such as France, Britain, and German with a prevalence of less than 1% compared to that of the USA, which is approximately 2.5% (Messina et al., 2015). However, Southern Asian countries such as India and Japan were noted to have a rate that ranges 1.2% to 2.3%; alarming rates have only been observed in Africa in places such as Egypt that were found to reach 14.5% which is much higher than that of the USA.

Diagnosis

Physical examination of the condition entails physician pressing on the abdomen above the liver to determine whether it is tender and enlarged which indicates existence of acute viral hepatitis. A blood test is then carried out to determine whether the liver is damaged or functional. They are also done to establish the type of hepatitis virus causing the infection as they detect specific antibodies produced to fight them (Swetha Samji, Buggs, & Roy, 2017). In rare cases when the analysis is unclear physicians may conduct a biopsy and if acute hepatitis is found to be likely, the doctor may inquire more information from the patient about activities that may increase risk of contracting the virus. In addition, they may also ask about drug and alcohol abuse past to establish whether the virus is the cause of hepatitis detected.

Treatment

In most patients, special treatment is not required although in individuals with severe hepatitis require hospitalization. There is usually need to restrict diet and activities, but vitamin supplements are not necessary for treatment process (Swetha Samji, Buggs, & Roy, 2017). Alcohol should be avoided under all circumstances until a patient is fully recovered together with drugs that could accumulate in the body to harmful levels since the liver is unable to process them. In extreme severe hepatitis, antiviral drugs may be administrated. Nevertheless, a liver transplant is the effective treatment of fulminant hepatitis, especially in adults.

Prognosis

The most debated and notable type of hepatitis is that caused by virus C in modern world. About 5 to 20 percent of individuals with HCV develop liver cirrhosis within 20 years (Swetha Samji, Buggs, & Roy, 2017). Life expectancy and outlook for people with this virus rely on the extent of the liver damage and how well they respond to the treatment.

Preventative Measures

For hepatitis A and B, vaccination offers the best approach to prevention. However, there are no vaccines for HCV and HDV, but it has been observed that vaccination of HBV reduces risk of virus D infection (Swetha Samji, Buggs, & Roy, 2017). Other preventative measures include hygiene, practicing safe sex, and avoiding sharing personal effect as well as a proper screening of blood for transfusion.

References

Messina, J. P., Humphreys, I., Flaxman, A., Brown, A., Cooke, G. S., Pybus, O. G., & Barnes, E. (2015). Global distribution and prevalence of hepatitis C virus genotypes. Hepatology, 61(1), 77-87. Statistics & Surveillance | Division of Viral Hepatitis | CDC. (2017). Cdc.gov. Retrieved on August 22, 2017 from https://www.cdc.gov/hepatitis/statistics/index.htm

Swetha Samji, N. Buggs, A., & Roy, P. (2017). Viral Hepatitis: Background, Pathophysiology, Etiology. Emedicine.medscape.com. Retrieved on August 22, 2017 from http://emedicine.medscape.com/article/775507-overview#a4