Category : virus
I have yellow fever doctor, said a patient. How do you know you have yellow fever? The doctor asked. The patient reply "Doc, I have fever and my eyes are yellow."
Here in lies the sea of confusion between Yellow fever, Jaundice and Hepatitis. There seems to be a great deal of confusion about the trio of Yellow fever, Jaundice and Hepatitis. To many people, it would seem that fever along with yellow discoloration of the eyes and mucous membranes and skin (technically called Jaundice) must be yellow fever.
However in the science of medicine, there is a great gulf between these diseases. The yellow fever virus causes yellow fever. A wide range of viruses or toxins on the other hand may cause hepatitis. Both diseases cause inflammation of the liver. An inflamed liver is unable efficiently the breakdown of red blood cells. This results in the accumulation of bilirubin in the blood and connective tissues leading to what is called jaundice. The subject of yellow fever is beyond the scope of this article. Suffice it to say that it is a very deadly ailment with high mortality but totally preventable by an affordable yet very effective yellow fever vaccine which is taken once every ten years.
The specific viruses that cause viral hepatitis include Hepatitis A virus (HAV); Hepatitis B virus(HBV); Hepatitis D virus (HDV) delta agent; Hepatitis E virus (HEV) transmitted in epidemic form in Asia, North Africa and Mexico. There are other viruses that have been implicated in causing hepatitis such as Hepatitis G virus (HGV), SEN-V virus and TT virus (TTV).
The HAV causes the sporadic or epidemic causes of hepatitis. The virus is transmitted or spread through contaminated food and water sources which may therefore lead to outbreaks in large population groups. Its spread is therefore favored by overcrowding, poor sanitation and personal hygiene. The incubation period is usually a few days, 30 days on the average. The illness is usually self-limiting with complete recovery within two weeks. Long lasting infection does not occur. Infections may be severe in adults but may occur in children without any symptoms or indeed ill health. Death from hepatitis A is very rare.
Hepatitis B is usually spread through the inoculation of infected blood or blood products or by sexual intercourse. The virus (HBV) may be found in blood, saliva, semen and vagina fluids in infected persons. A mother who is infected is able to transmit the HBV to the child at the time of delivery. The risk of chronic infection in such cases is very high. HBV tends to occur very commonly in homosexual or gay men and intravenous drug users (IVDUs). Certain groups of people are at higher risk of contracting the infection; doctors, nurses, dentists, blood bank staff, patients and staff of haemodialysis centers etc. Sadly, it takes less blood to transmit HBV than HIV which causes AIDS.
From the time of infection, it takes 6 weeks to 6 months (average 12-14 weeks) for the infected person to become clinically ill. Hepatitis B may also present as very severe form of hepatitis called fulminant hepatitis in about 1% of infected persons. In this group, death may occur in as many as 60% of them. In yet another group, the illness may persist as chronic hepatitis B. In this group, the infection persist for years and then the patient go on to develop liver cirrhosis and liver cancer.
HEPATITIS D (DELTA AGENT)
Hepatitis D is a defective virus that is unable to cause hepatitis on its own except in association with HBV. HDV may therefore co-infect a person with HBV or super infected a person with chronic hepatitis. When it occurs concurrently with acute hepatitis or severe chronic hepatitis leading rapidly to cirrhosis.
May be transmitted by blood transfusion, intravenous drug use, sexual contact and from mother to child. Having multiple sexual partners would therefore increase the risk of infection by hepatitis C virus. Incubation period is around 6-7 weeks.
This is a waterborne hepatitis virus. Outbreaks occur in India, Burma, Afghanistan, Algeria and Mexico. The illness is self-limiting with no carrier state. But mortality is usually high in infected in infected pregnant women (up to 10-20%).
This virus has been detected in blood donors, intravenous drug users, haemodialysis patients, haemophiliacs and patients with chronic hepatitis B or C. Hepatitis G does not appear to cause any important liver disease.
CLINICAL PICTURE OF HEPATITIS
The onset of illness may be abrupt or insidious. There is usually a flu-like illness with generalized malaise, fever, muscle aches, joint pains, easy fatigability, sore throat, nasal discharge and loss of appetite, nausea and vomiting. Frequently there is diarrhea, constipation and aversion to smoking for those that smoke. Then as the fever begins to ebb, jaundice sets in 5-10 days. Chill or chillness may occur. The liver is enlarged and painful to touch. The spleen and lymph node may become enlarged also. The diagnosis as to which type of hepatitis is aided through various laboratory tests.
The treatment of hepatitis includes bed rest where applicable. Diet should consist of palatable meals as identified by the patient. Fluid replacement and multivitamin supplements are adjuncts to the treatment. The drug Alpha Interferon has been used in patients with acute hepatitis C and found to reduce the risk of progression to chronic hepatitis C.
In general, the careful handling of needles and the screening of blood before transfusion are useful ways to prevent hepatitis. Hepatitis A may be prevented by vaccination and the use of immunoglobin in people who are in close contact with patient of HAV infection. Hepatitis B has a very potent and effective vaccine, which gives a lifelong protection and requires only intermittent booster doses. Hepatitis B immunoglobulin may also protect or attenuate the severity of illness, if given within seven days of exposure to the HBV.