Yellow fever is a viral disease of typically short duration. In most cases, symptoms include fever, chills, loss of appetite, nausea, muscle pains particularly in the back, and headaches. Symptoms typically improve within five days. In about 15% of people, within a day of improving the fever comes back, abdominal pain occurs, and liver damage begins causing yellow skin. If this occurs, the risk of bleeding and kidney problems is increased.
Hepatitis is inflammation of the liver tissue. Some people with hepatitis have no symptoms, whereas others develop yellow discoloration of the skin and whites of the eyes (jaundice), poor appetite, vomiting, tiredness, abdominal pain, and diarrhea. Hepatitis is acute if it resolves within six months, and chronic if it lasts longer than six months. Acute hepatitis can resolve on its own, progress to chronic hepatitis, or (rarely) result in acute liver failure. Chronic hepatitis may progress to scarring of the liver (cirrhosis), liver failure, and liver cancer.
Hepatitis C is an infectious disease caused by the hepatitis C virus (HCV) that primarily affects the liver; it is a type of viral hepatitis. During the initial infection people often have mild or no symptoms. Occasionally a fever, dark urine, abdominal pain, and yellow tinged skin occurs. The virus persists in the liver in about 75% to 85% of those initially infected. Early on chronic infection typically has no symptoms. Over many years however, it often leads to liver disease and occasionally cirrhosis. In some cases, those with cirrhosis will develop serious complications such as liver failure, liver cancer, or dilated blood vessels in the esophagus and stomach.
Hepatology is the branch of medicine that incorporates the study of liver, gallbladder, biliary tree, and pancreas as well as management of their disorders. Although traditionally considered a sub-specialty of gastroenterology, rapid expansion has led in some countries to doctors specializing solely on this area, who are called hepatologists.
Hepatitis A is an infectious disease of the liver caused by Hepatovirus A (HAV); it is a type of viral hepatitis. Many cases have few or no symptoms, especially in the young. The time between infection and symptoms, in those who develop them, is between two and six weeks. When symptoms occur, they typically last eight weeks and may include nausea, vomiting, diarrhea, jaundice, fever, and abdominal pain. Around 10–15% of people experience a recurrence of symptoms during the six months after the initial infection. Acute liver failure may rarely occur, with this being more common in the elderly.
Hepatitis E is inflammation of the liver caused by infection with the hepatitis E virus (HEV); it is a type of viral hepatitis. Hepatitis E has mainly a fecal-oral transmission route that is similar to hepatitis A, although the viruses are unrelated. In retrospect, the earliest known epidemic of hepatitis E occurred in 1955 in New Delhi, but the virus was not isolated until 1983 by Russian scientists investigating an outbreak in Afghanistan. HEV is a positive-sense, single-stranded, nonenveloped, RNA icosahedral virus and one of five known human hepatitis viruses: A, B, C, D, and E.
Viral hepatitis is liver inflammation due to a viral infection. It may present in acute form as a recent infection with relatively rapid onset, or in chronic form.
Liver disease is a type of damage to or disease of the liver. Whenever the course of the problem lasts long, chronic liver disease ensues.
A vertically transmitted infection is an infection caused by pathogens that use mother-to-child transmission, that is, transmission directly from the mother to an embryo, fetus, or baby during pregnancy or childbirth. It can occur when the mother has a pre-existing disease or becomes infected during pregnancy. Nutritional deficiencies may exacerbate the risks of perinatal infections.
The schedule of childhood immunizations in the United States is given by the Centers for Disease Control and Prevention (CDC). The vaccination schedule is broken down by age: birth to six years of age, seven to eighteen, and adults nineteen and older. Childhood Immunizations are key in preventing children for diseases that were once epidemics.
Infectious canine hepatitis (ICH) is an acute liver infection in dogs caused by Canine mastadenovirus A, formerly called Canine adenovirus 1 (CAV-1). CAV-1 also causes disease in wolves, coyotes, and bears, and encephalitis in foxes. The virus is spread in the feces, urine, blood, saliva, and nasal discharge of infected dogs. It is contracted through the mouth or nose, where it replicates in the tonsils. The virus then infects the liver and kidneys. The incubation period is 4 to 7 days.
Astroviruses are a type of virus that was first discovered in 1975 using electron microscopes following an outbreak of diarrhea in humans. In addition to humans, astroviruses have now been isolated from numerous mammalian animal species and from avian species such as ducks, chickens, and turkey poults. Astroviruses are 28–35 nm diameter, icosahedral viruses that have a characteristic five- or sixpointed star-like surface structure when viewed by electron microscopy. Along with the Picornaviridae and the Caliciviridae, the Astroviridae comprise a third family of nonenveloped viruses whose genome is composed of plus-sense, single-stranded RNA. Astrovirus has a non-segmented, single stranded, positive sense RNA genome within a non-enveloped icosahedral capsid. Human astroviruses have been shown in numerous studies to be an important cause of gastroenteritis in young children worldwide. In animals, Astroviruses also cause infection of the gastrointestinal tract but may also result in encephalitis, hepatitis (avian) and nephritis (avian).
Waterborne diseases are conditions caused by pathogenic micro-organisms that are transmitted in water. These diseases can be spread while bathing, washing, drinking water, or by eating food exposed to contaminated water. While diarrhea and vomiting are the most commonly reported symptoms of waterborne illness, other symptoms can include skin, ear, respiratory, or eye problems.
Liver cancer, also known as hepatic cancer and primary hepatic cancer, is cancer that starts in the liver. Cancer which has spread from elsewhere to the liver, known as liver metastasis, is more common than that which starts in the liver. Symptoms of liver cancer may include a lump or pain in the right side below the rib cage, swelling of the abdomen, yellowish skin, easy bruising, weight loss and weakness.
Hepatitis B is an infectious disease caused by the hepatitis B virus (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection. Many people have no symptoms during the initial infection. In acute infection, some may develop a rapid onset of sickness with vomiting, yellowish skin, tiredness, dark urine and abdominal pain. Often these symptoms last a few weeks and rarely does the initial infection result in death. It may take 30 to 180 days for symptoms to begin. In those who get infected around the time of birth 90% develop chronic hepatitis B while less than 10% of those infected after the age of five do. Most of those with chronic disease have no symptoms; however, cirrhosis and liver cancer may eventually develop. Cirrhosis or liver cancer occur in about 25% of those with chronic disease.
Rabies is a viral disease that causes inflammation of the brain in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, confusion, and loss of consciousness. Once symptoms appear, the result is nearly always death. The time period between contracting the disease and the start of symptoms is usually one to three months, but can vary from less than one week to more than one year. The time depends on the distance the virus must travel along peripheral nerves to reach the central nervous system.
Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs), are infections that are commonly spread by sexual activity, especially vaginal intercourse, anal sex and oral sex. STIs often do not initially cause symptoms, which results in a greater risk of passing the disease on to others. Symptoms and signs of STIs may include vaginal discharge, penile discharge, ulcers on or around the genitals, and pelvic pain. STIs can be transmitted to an infant before or during childbirth, which may result in poor outcomes for the infant. Some STIs can cause infertility.
The 2009 Gujarat hepatitis B outbreak was a cluster of hepatitis B cases that appeared in Modasa, northern Gujarat, India in 2009. Over 125 people were infected and up to 49 people died. Several doctors were investigated and arrested after the outbreaks.
Viruses are a major cause of human waterborne and water-related diseases. Waterborne diseases are caused by water that is contaminated by human and animal urine and feces that contain pathogenic microorganisms. A subject can get infected through contact with or consumption of the contaminated water. Viruses affect all living organisms from single cellular plants, bacteria and animal to the highest forms of plants and animals including human beings. Within a specific kingdom the localization of viruses colonizing the host can vary: Some human viruses, for example, HIV, colonizes only the immune system, while influenza viruses on the other hand can colonize either the upper respiratory tract or the lower respiratory tract depending on the type. Different viruses can have different routes of transmission; for example, HIV is directly transferred by contaminated body fluids from an infected host into the tissue or bloodstream of a new host while influenza is airborne and transmitted through inhalation of contaminated air containing viral particles by a new host. Research has also suggested that solid surface plays a role in the transmission of water viruses. In a experiments that used E.coli phages, Qβ, fr, T4, and MS2 confirmed that viruses survive on a solid surface longer compared to when they are in water. Because of this adaptation to survive longer on solid surfaces, viruses now have a prolonged opportunities to infect humans. Enteric viruses primarily infect the intestinal tract through ingestion of food and water contaminated with viruses of fecal origin. Some viruses can be transmitted through all three routes of transmission.
2014 Odisha hepatitis outbreak refers to an outbreak of mainly Hepatitis E and also Hepatitis A which began in the town of Sambalpur in Odisha, India. The cause of the outbreak was suspected to be the contamination to drinking water supplied by the Public Health Engineering Department (PHED).
