Furunculosis of the nasal vestibule: causes, diagnosis, complications, treatment

This Topic is to discuss the types of viruses that cause inflammation of the Liver " Hepatitis " which are HAV , HBV , HCV , HDV and HEV .

We will illustrate each virus type separately concerning its route  of infection,people at Risk , Incubation period , methods of Prevention & Prophylaxis .

Hepatitis A Virus (HAV):       - Infections: fecal-oral.                  - People at risk are those living in Or traveling to areas with bad sanitation. - Mainly in children & young adults. - Incubation period: 2-8 weeks .

- Acute stage: usually mild. - No chronicity & not related to hepatocellular carcinoma. - Prophylaxis: vaccination or immunoglobulins . Hepatitis B Virus (HBV): - Infection: parenteral, sexual & from mother to baby.            - Cases are Sporadic                                            - People at risk are: o       Haemophiliacs & haemolytic anaemia patients. o       Parenteral drug abusers. o       Homosexuals & prostitutes. o       Doctors & nurses. o       Babies born to HBsAg positive mothers. o    People living in high prevalence areas. - Occurs at any age . - Incubation period: 1-6 months. - Acute stage: usually severe. - May cause chronic infection, especially when infection occurs in infnts - It is a carcinogenic virus that can cause HCC, even without cirrhosist - Prophylaxis : immunoGlobulins & vaccination . Hepatitis C Virus (HCV): Infection: post transfusion & parenteral.  - Sporadic. - Age: more common above 16 years.  - Incubation period: 1-6 months.                  Acute infection :  mild or unnoticed ii1 85% of cases. - Chronicity occurs in 85% of infected patients. - Chronic infection causes cirrhosis in 15% of cases in 5-25 years. - Hepatocellular carcinoma, occurs in cirrhotic patients   (5% every year). -  Prophylaxis and Prevention :  safe blood transfusion, safe medical procedures and avoiding the use of sharp abjects as razors by more than one person.  Hepatitis D Virus (Delta Virus, HDV): - This is an incomplete virus that needs HBsAg for its survival, so it only causes hepatitis in HBsAg positive patients. - It spreads by blood transfusion & parenterally. - Incubation period: 1-6 months. - There are 2 forms of infection: 1. Co-infection: where the host is infected with HDV & HBV together. This gives the picture of severe acute hepatitis. 2. Super- infection: where there is super-infection of a chronic B patient with HDV. This causes exacerbation of hepatitis. -It may lead to chronicity. -Prophylaxis: Vaccination against HBV . Hepatitis E Virus (HEV): - Infection: fecal - oral. - Sporadic or epidemic. - People at risk are those living in or traveling to areas with bad sanitation. - Usually in children & young adults . - Incubation period: 2-8 weeks. - Acute stage: Usually mild, except in pregnant women . - No chronicity & not related to hepatocellular carcinoma . - Prophylaxis : Improving Hygiene and Immunoglobulins .