Volume 1, Issue 4 
4th Quarter, 2006


Consciousness in Humans and Elsewhere

Barry Blumberg, Ph.D.

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There are several possible outcomes following infection. The most common response is the development of a protective antibody against the surface antigen (anti-HBs). Most people who develop the antibody will not become sick, but some develop acute Hepatitis B, from which they ordinarily recover in weeks or months. Some of these people may go on to develop chronic infection that can lead to chronic liver failure and/or primary cancer of the liver. Some infected individuals, particularly those infected from their mother before or at the time of birth or those infected when young, will become HBV carriers. They can remain acutely infected for decades and are at a high risk of developing liver failure and/or primary cancer of the liver. 

The nature of the response is determined by several factors. These include age of infection, gender, the presence of other environmental factors, and a series of susceptibility genes that affect whether the person develops anti-HBs and is immune to subsequent disease or becomes a carrier and is at risk for chronic liver disease and/or primary cancer of the liver.

HBV is one of the most common infectious agents worldwide. Figure 2 shows the global distribution of chronic HBV infection.

Blumberg
Figure 2: Global Distribution of Chronic HBV Infection

About two billion people – one third of the world’s population – have been or are infected. There are about 375 million people who are currently infected and most are asymptomatic HBV carriers. As noted, they are at increased risk of developing serious liver disease later in life. 

The overall strategy of HBV can be explained as a drive to maintain relatively high titers[1] of virus in the host’s blood stream for as long as possible to increase the probability that the virus will be transmitted from an infected host to another person. It is advantageous to the virus that the infected host survive for a long time to increase the likelihood of replication and transmission of HBV. People infected at birth or early childhood may remain asymptomatic for decades. It is only after transmission has had ample time to happen that the infected person becomes ill with what is often a very deadly disease. The infected person is spared from death for a very long time to increase the probability of transmission.

HBV is transmitted from person to person by close contact and specifically by the transmission of blood and other body fluids from an infected to an uninfected person. The mechanisms of transmission include transmission from an infected mother to her unborn or just born child, infection of children by their siblings, and venereal transmission. HBV has “selected” methods for transmission that are necessary for the survival of humans; the virus can expect to survive and flourish as long as their human hosts do so. 

The virus can also be transmitted by social practices that are common in many populations. These include tattooing, a ritual common in many non-Western as well as contemporary western populations; ritual circumcision; exchange of blood between “blood sisters” or “blood brothers”, and other exotic practices. Blood is also transferred by the use of “dirty needles” by drug injections, including recreational drugs, and by the use of transfused blood and renal dialysis machines as well as other medical devices. 

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Footnote
1. Titer – The concentration of a solution or the strength of such a solution by titration or perform the operation of titration (The process, operation or method of determining the concentration of a substance in a solution to which the addition of a reagent having a known concentration is made in carefully measured amounts until a reaction of definite and known proportion is completed). Stedman’s. Medical dic·tion·ar·y, second edition. Boston, New York: Houghton Mifflin Company, 2004: 827. (back to top)

 

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