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Hpatitis A

Hpatitis A. Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus. Hepatitis A is one of several types of hepatitis viruses that cause inflammation that affects the functions of the live.

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Hpatitis A

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  1. Hpatitis A Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus. Hepatitis A is one of several types of hepatitis viruses that cause inflammation that affects the functions of the live. Every year, approximately 10 million people worldwide are infected with the virus.

  2. Hepatitis A Virus • Picornavirus (non-enveloped, positive standard  RNA viruses) • Humans are only natural host • Stable at low pH • Inactivated by high temperature (185°F or higher), formalin, chlorine

  3. HEPATITIS A VIRUS

  4. Causes The hepatitis virus is usually spread when a person ingests tiny amounts of contaminated fecal matter. The hepatitis A virus infects the liver cells and causes inflammation. The inflammation can impair liver function and cause other signs and symptoms of hepatitis A.

  5. Pathogenesis • Following ingestion, HAV enters the bloodstream through the epithelium of the oropharynx or intestine. The blood carries the virus to its target, the liver, and multiplies within hepatocytes and Kupffer cells (i.e., liver macrophages). • There is no apparent virus-mediated cytotoxicity, and liver pathology is likely immune-mediated. • Virions are secreted into the bile and released in stool.  • HAV is excreted in large quantities approximately 11 days prior to appearance of symptoms or anti-HAV IgM antibodies in the blood.

  6. Symptoms Hepatitis A signs and symptoms typically don't appear until you've had the virus for a month. Signs and symptoms of hepatitis A include: Fatigue Nausea and vomiting Abdominal pain or discomfort, especially in the area of your liver on your right side beneath your lower ribs Loss of appetite Low-grade fever Dark urine Muscle pain Itching Yellowing of the skin and eyes (jaundice) Signs and symptoms of hepatitis A usually last less than two months, but may last as long as six months. Not everyone with hepatitis A develops signs or symptoms.

  7. Incubation period • 30 days on average (range 15-50 days) • infectious latter half of incubation period while asymptomatic through 1 week after having jaundice.

  8. TRANSMISSION • Close personal contact(e.g., household contact, sex contact, child day-care centers) • Contaminated food, water(e.g., infected food handlers) • Blood exposure (rare)(e.g., injection drug use, rarely by transfusion)

  9. Geographic Distribution of HAV Infection Anti-HAV Prevalence High Intermediate Low Very Low

  10. Risk factors You're at increased risk of hepatitis A if you: Travel or work in regions with high rates of hepatitis A Are a man who has sexual contact with other men Use injected or noninjected illicit drugs Live with another person who has hepatitis A Receive clotting-factor concentrates for hemophilia or another medical condition

  11. CONCENTRATION OF HEPATITIS A VIRUS IN VARIOUS BODY FLUIDS Feces Serum Body Fluids Saliva Urine 102 104 100 106 108 1010 Infectious Doses per mL Source: Viral Hepatitis and Liver Disease 1984;9-22 J Infect Dis 1989;160:887-890

  12. Hepatitis A - United States, 1966-2007 Vaccine Licensed Year

  13. Tests and diagnosis Blood tests are used to detect the presence of hepatitis A in the body. A sample of blood is taken, usually from a vein in the arm, and sent to a laboratory for testing. signs and symptoms

  14. Laboratory Diagnosis • Acute infection is diagnosed by the detection of HAV-IgM in serum by EIA. • Past Infection i.e. immunity is determined by the detection of HAV-IgG by EIA.

  15. Treatment No specific treatment exists for hepatitis A. Your body will clear the hepatitis A virus on its own. In most cases of hepatitis A, the liver heals completely in a month or two with no lasting damage. Hepatitis A treatment usually focuses on coping with signs and symptoms of hepatitis A infection. For instance: Expect to have less energy. Many people with hepatitis A infection feel tired and have less energy for their daily tasks. Rest when you need to. You may need several days off work or school in order to recover.

  16. Find ways to cope with nausea. Nausea can make it difficult to eat. Find ways to make food more appealing. Eat small snacks throughout the day, rather than three large meals. Try soft, easily digested foods, such as soup or broth, yogurt and toast, as these may be the most appealing. • Give your liver a rest. Your liver may have difficulty processing medications and alcohol if you have hepatitis A. Review your medications, including over-the-counter drugs, with your doctor. Your doctor may recommend stopping or changing some of your medications. Stop drinking alcohol while you have signs or symptoms of hepatitis A infection.

  17. Prevention • Shot of immune globulin up to 2 weeks after exposure • Good hand washing • Cook food well • Good diaper hygiene • Only drink clean water • VACCINE!!!

  18. Hepatitis A • Who needs immune globulin? • Living with someone with Hep A • Eaten food handled by someone with Hep A • Sexual contact with person with Hep A • Traveling to an area where Hep A is common • Child or employee at a child care program where someone else has Hep A

  19. HEPATITIS A VACCINES • Highly immunogenic • 97%-100% of children, adolescents, and adults have protective levels of antibody within 1 month of receiving first dose; essentially 100% have protective levels after second dose • Highly efficacious • In published studies, 94%-100% of children protected against clinical hepatitis A after equivalent of one dose

  20. Hepatitis A Vaccines • Adult • 1 dose • booster dose 6-18 months after first dose • Children and Adolescents • 1 dose • booster dose 6-18 months after first dose

  21. Hepatitis E • Recently identified cause of enterically transmitted non-A, non-B (NANB) hepatitis • Calicivirusspherical, non enveloped, 27-34 nm particles containing a ssRNA genome.

  22. Hepatitis E Virus

  23. Clinical Features Incubation period 30-40 daysAcute, self limiting hepatitis, no chronic carrier stateAge: predominantly young adults, 15-40 years

  24. Hepatitis E - Clinical Features • Incubation period: Average 40 days • Range 15-60 days • Case-fatality rate: Overall, 1%-3%Pregnant women, 15%-25% • Illness severity: Increased with age • Chronic sequelae: None identified

  25. Hepatitis E - Epidemiologic Features • Most outbreaks associated with faecally contaminated drinking water. • Several other large epidemics have occurred since in the Indian subcontinent , China, Africa and Mexico. • In the United States and other nonendemic areas, where outbreaks of hepatitis E have not been documented to occur, a low prevalence of anti-HEV (<2%) has been found in healthy populations. The source of infection for these persons is unknown. • Minimal person-to-person transmission.

  26. Spherica Spherical

  27. Stability • HEV is extremely sensitive to high salt concentrations • HEV should be stored as cold as possible, • It is rapidly degraded when freeze-thawed. • The virus is sensitive to degradation by proteolytic enzymes

  28. Pathogenesis Similar to hepatitis A; virus replicates in the gut initially, before invading the liver, and virus is shed in the stool prior to the onset of symptoms.Viraemia is transient. A large inoculum of virus is needed to establish infection.

  29. symptoms • Prodromal-phase symptoms include the following: • Fever with mild temperature elevations (25-97%) • Anorexia (66-100%) • Nausea/vomiting (30-100%) • Weight loss (typically 2-4 kg) • Dehydration • Right upper quadrant pain that increases with physical activity • Icteric-phase symptoms include the following: • Jaundice - May be difficult to see with some patients' natural skin color; serum bilirubin level is greater than 3 mg/dL; scleralicterus is present • Dark urine • Light-colored stools (20-40%) • Pruritus (50%)

  30. Other features include the following: • Diarrhea • Rapidly increasing serum amino transferase (alanineaminotransferase [ALT], aspartateaminotransferase [AST]) levels that peak within 4-6 weeks of onset and gradually decrease to normal within 1-2 months • Viral excretion in stool persisting 14 days from onset • Symptoms of HEV are similar to other hepatitides and include the following: • Abdominal pain (35-80% of patients) • Jaundice • Anorexia • Hepatomegaly (10-85%) • Malaise (95-100%) • Vomiting

  31. Predisposing factors • International travelers to regions of the world where HEV is endemic • Refugees residing in overcrowded temporary camps following catastrophies, especially in Sudan, Somalia, Kenya and Ethiopia • Persons who have chronic liver disease • Possibly persons working with non-human primates, pigs, cows, sheep and goats

  32. Transmission • HEV is spread by the oral-faecal route • Consumption of faecally contaminated drinking water has given rise to epidemic cases, • Ingestion of raw or uncooked shellfish has been the source of sporadic cases in endemic areas • Most outbreaks associated with faecally contaminated drinking water

  33. Susceptibility and Resistance • People who never have contracted HEV are at risk of infection • Poor sanitation

  34. Host immune response • Virus excretion in stools continues for up to 14 days after onset of illness, • Antibodies to HEV (IgM and IgG) develop at the time symptoms occur,

  35. Diagnosis No routine laboratory tests are available as yet. Virus cannot be cultured in vitro. • 1) Calicivirus-like particles in the stool, by electron microscopy2) Specific IgM in serum3) PCR HEV-specific sequences in stool

  36. The most characterisitc markers of infection are the serum aminotransferases • ALT and AST • Increase proportionally during the prodromal phase and can reach 20 x normal. • Peak when the patients are jaundiced. • Bilirubin can reach 20 mg/dL

  37. Treatment • There are no specific medicines that can cure hepatitis E. Therefore, treatment of hepatitis E is focused on dealing with any symptoms or complications that may occur. This is known as supportive care. Even without specialized treatment for acute hepatitis E, most people recover completely within a few weeks. • However, there are some things you can do that might help you feel better. There are also certain things that you should avoid. • Specific Hepatitis E Treatment Suggestions • Get enough calories. Many people with hepatitis E get nauseated, especially late in the day. In order to get enough calories, try eating the majority of your calories early in the day. Eating several small meals throughout the day (instead of three large meals) may also be helpful. If you feel sick in the morning, try eating some crackers or dry toast before getting out of bed. It may also help to drink lemon water or have a lemon drop. 

  38. Get as much rest as you can while your body fights off the virus.  • Drink plenty of fluids. You should try to drink at least 10 to 16 glasses a day of water, clear juices, or other drinks that do not have caffeine in them.  • Avoid alcohol. Alcohol poisons your liver and can cause even more damage to the cells that are already fighting the hepatitis E virus. The exact amount of alcohol that will harm the liver isn't known. Therefore, it's generally recommended that people with hepatitis E avoid alcohol completely.  • Exercise regularly. Do light-to-moderate exercise, such as walking, for 30 minutes a day.  • Once a person has recovered from a hepatitis E infection, the virus is no longer present in the body.

  39. Vaccines •Subunit HEV vaccines The direct intramuscular injection of purified plasmid DNA containing the full-length ORF2 of HEV has induced a prolonged humoral immune response (>12 months) To the expressed structural protein ORF2 in 80% and 100% of two separate groups of challenged mice, respectively

  40. THANK YOU

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