Infectious Disease Project:

HEPATITIS

 

 

 

 

Pictures: (Nick)

 

 

 

Type of agent that spreads the disease: (Nick)

• A virus spreads Hepatitis. 

Hepatitis A

 

• Hepatitis A virus (HAV), classified as hepatovirus, is a small, unenveloped symmetrical RNA virus which shares many of the characteristics of the picornavirus family, and is the cause of infectious or epidemic hepatitis transmitted by the fecal-oral route.

Hepatitis B

 

• Hepatitis B virus (HBV), a member of the hepadnavirus group, double-stranded DNA viruses which replicate, unusually, by reverse transcription. Hepatitis B virus is endemic in the human population and hyperendemic in many parts of the world. A number of variants of this virus have been described. Natural hepadna virus infections also occur in other mammals including woodchucks, beechy ground squirrels and ducks.
   

Hepatitis C

 

• Hepatitis C virus (HCV), is an enveloped single-stranded RNA virus which appears to be distantly related (possibly in its evolution) to flaviviruses, although hepatitis C is not transmitted by arthropod vectors. Several genotypes have been identified. Infection with this more recently identified virus is common in many countries. Hepatitis C virus is associated with chronic liver disease and also with primary liver cancer in some countries.  

Hepatitis D

 

• Hepatitis D virus (HDV) is an unusual, single-stranded, circular RNA virus with a number of similarities to certain plant viral satellites and viroids. This virus requires hepadna virus helper functions for propagation in hepatocytes, and is an important cause of acute and severe chronic liver damage in many regions of the world.

Hepatitis E

 

• Hepatitis E virus (HEV), the cause of enterically-transmitted non-A, non-B hepatitis, is another non-enveloped, single-stranded RNA virus, which shares many biophysical and biochemical features with caliciviruses. The most similar genome to HEV is found in a plant virus, beet necrotic yellow vein virus, and there are similarities in the functional domains to rubella virus. Final taxonomic classification is yet to be agreed upon. 

 

• Hepatitis E virus is an important cause of large epidemics of acute hepatitis in the subcontinent of India, Central and Southeast Asia, the Middle East, parts of Africa and elsewhere. This virus is responsible for high mortality (15-20%), during pregnancy particularly during the third trimester.

 

 

 

Type of infection and/or transmission: (Kevin)

 

• Hepatitis A:

   

- This virus is usually spread from person to person as a result of poor hygiene habits

 

(Especially when handling food.) It can also be contracted from drinking

 

Contaminated water or eating food that has been processed with sewage

 

Contaminated water.

 

- Hepatitis A is usually less severe than other types of hepatitis.

 

- People with this virus may show no symptoms.

 

 

 

• Hepatitis B:

   

- This virus is transmitted through contact with blood of a person with Hepatitis B, by

 

Intravenous drug use with a contaminated needle, and by sexual contact with a

 

person infected with hepatitis B.

 

- Women with Hepatitis B may pass it on the their newborn during the birth process, so

 

standard protocol is the do screening during pregnancy.

 

 

 

• Hepatitis C:

   

- This virus can be transmitted by exposure to infected blood. People in the medical

 

field who are routinely exposed to blood or people who have received blood

 

transmission are susceptible to this type. To prevent this, careful screening is done

 

of any blood donated prior to transfusions and medical staff must follow strict safety

 

protocols to protect themselves and their patients.

 

- The virus is also transmitted via sharing of needles contaminated by infected drug

 

users.

 

- Though uncommon, it also can be passed on through sexual contact with an infected

 

person.

 

- Sporadically, cases of Hepatitis C have turned up in people with no exposure history

 

what so ever.

 

 

Symptoms: (Nick)

 

• Hepatitis produces an initial “acute phase,” often with few if any symptoms. If there are symptoms, they tend to mimic "flu-like" symptoms such as:

   

• mild fever

   

• muscle or joint aches

   

• nausea

   

• vomiting

   

• loss of appetite  

   

• slight abdominal pain

   

• diarrhea

   

• fatigue

   

The acute phase and its symptoms is rarely serious or fatal, although occasionally a so-called fulminant or rapidly progressing form leads to death.

 

As the condition worsens, the person also may experience these additional symptoms:

 

• jaundice (yellowed skin, mucous membranes and eye-whites)

   

• dark urine

   

• light colored stools that may contain pus

   

• itching

   

• enlarged spleen (symptom of alcoholic hepatitis only)

   

• hives

   

• headache (symptom of toxic/drug-induced hepatitis only)

   

• dizziness (symptom of toxic/drug-induced hepatitis only)

   

• drowsiness (symptom of toxic/drug-induced hepatitis only)

   

• circulation problems (symptom of toxic/drug-induced hepatitis only)

   

The course of the hepatitis and the different outcomes after the acute phase that distinguish the various types.

 

 

Treatment: (Nick)

 

• There is no specific treatment for hepatitis A. The doctor will recommend the abstinence of alcohol and drugs during recovery. Most cases of hepatitis A resolve themselves spontaneously.

   

• The only treatment for hepatitis B is rest, combined with a high protein/high carbohydrate diet to repair damaged liver cells and protect the liver. If hepatitis B persists, the doctor may recommend an antiviral agent called interferon.

   

• The only approved treatment for hepatitis C virus, and the only one with demonstrated efficacy, is interferon alfa-2b (Intron A).

   

• Currently, there is not effective treatment for hepatitis D and E.

   

• For treatment of nonviral hepatitis, the doctor will first remove the harmful substance by flushing out the stomach via inducing vomiting or hyperventilation. If necessary, the patient with drug-induced hepatitis will be treated with corticosteroids.

   

Control/Prevention: (Kevin)

 

 To prevent hepatitis A, remember to:

• Wash hands well after using any washroom.

   

• Eat only freshly cooked foods.

   

• Drink only commercially bottled water or boiled water in places where sanitation and the water supply are questionable and do not eat non-peelable raw fruits or vegetables unless cleaned thoroughly.

   

• Get a hepatitis A vaccination before traveling to areas such as Mexico, eastern Europe and developing countries. 
   

To prevent hepatitis B, remember to:

• Tell your sex-partners if you are a carrier.

   

• Practice safe sex.

   

• Don't share needles, razors, toothbrushes, manicure tools or other items that could bear contaminated blood.

   

• Get the hepatitis B vaccination series if you are at risk.

   

• Don't allow yourself to be pierced with non-sterile equipment.

   

To prevent hepatitis C, remember to:

• (if carrier) Cover open wounds, don't share razors or manicure tools.

   

• Practice safe sex.

   

• Don't share needles, razors, toothbrushes, manicure tools or other items that could bear contaminated blood.

   

• Don't allow yourself to be pierced with non-sterile equipment.

   

• Limit alcohol intake.

   

• Never share IV drug needles or other drug equipment.

   

To prevent hepatitis D:

 

Since the hepatitis D virus cannot infect on its own without hepatitis B, use the preventive measures outlined in hepatitis B.

 

To prevent hepatitis E, remember to:

 

• Wash hands well after using any washroom.

   

• Eat only well and freshly cooked foods.

   

• Drink only commercially bottled water or boiled water in places where sanitation and the water supply are questionable, and don't eat non-peelable raw fruits or vegetables unless cleaned thoroughly.

   

To prevent alcoholic hepatitis, remember to:

 

• Limit the amount of alcohol consumption.

   

To prevent toxic/drug-induced hepatitis, remember to:

 

• Be aware of the lethal contents of all chemicals.

   

• Face the spray away from the body.

   

Wear protective equipment if applicable

 

Number of people infected each year: (Kevin)

 

•   Approximately 2 billion people are infected with the hepatitis B virus (HBV), making it the most common infectious disease in the world today. Over 350 million of those infected never rid themselves of the infection.

• Hepatitis A is a highly contagious liver disease caused by the hepatitis A virus. Spread primarily by the fecal-oral route or by ingestion of contaminated water or food, the number of annual infections worldwide is estimated at 1.4 million.

• 4 million more are infected every year with hepatitis C
   

Where it occurs: (Nick)

 

•  The lowest seroprevalence is found in the Nordic countries (about 15%). In Australia, other parts of Europe, Japan and in the United States, 40%–70% of the adult population has demonstrable antibodies to HAV (Hepatitis A). Practically all adults living in developing areas of the world have serological evidence of past infection. 

 

• In much of the developing world, (sub-Saharan Africa, most of Asia, and the Pacific), most people become infected with HBV during childhood, and 8% to 10% of people in the general population become chronically infected. In these regions liver cancer caused by HBV figures among the first three causes death by cancer in men.

  High rates of chronic HBV infection are also found in the Amazon and the southern parts of Eastern and Central Europe. In the Middle East and Indian sub-continent, about 5% are chronically infected. Infection is less common in Western Europe and North America, where less than 1% are chronically infected.

  Young children who become infected with HBV are the most likely to develop chronic infection. About 90% of infants infected during the first year of life and 30% to 50% of children infected between 1 to 4 years of age develop chronic infection. The risk of death from HBV-related liver cancer or cirrhosis is approximately 25% for persons who become chronically infected during childhood.

 

 

Group members

 

• Nick R
• Kevin C
• Nate L

 

 

Sources

 

1. www.vmedcenter.org/HBW/pdf/hepatit.pdf

2. http://www.factmonster.com/ipka/A0903696.html

3. http://www.healthscout.com/ency/68/39/main.html#TreatmentofHepatitis

4. http://www.who.int/vaccines/en/hepatitisa.shtml