Missionary
Medical
Moment
A brief summary of a current topic of medical interest to missionaries.
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MISSIONARY MEDICAL MOMENT
Hepatitis - (Part 2)
(Hepatitis - Part 2
The prevention of viral hepatitis is related primarily to avoidance of
contact with sources of infection, along with immunization against
infection, now available for certain types of hepatitis virus. For
missionaries, lifestyle issues that might pose risks to acquiring
hepatitis B and hepatitis C, such as sexual promiscuity and intravenous
drug use, should not be present. Yet risk from unexpected exposure to
blood (emergency need for transfusion, needles used in obtaining
laboratory specimens, contact with wounds) may present risk for infection.
Hepatitis B is endemic in sub-Saharan Africa and Southeast Asia, and more
than 20% of the population may carry the virus. Hepatitis A is endemic in
all underdeveloped countries, and may also occur in outbreaks in residential
settings (jails, child-care centers, barracks) anywhere in the world. Food
and water borne outbreaks occur commonly. Avoiding contact with potentially
contaminated water, and washing of all fruits and vegetables prior to eating,
are basic preventative measures.
Immunization against certain types of hepatitis is now possible. For a number
of years, injections of immune globulin ("IG") were recommended for protection
primarily against hepatitis A. IG was obtained by pooling the antibodies from
many different donors who had been exposed to the virus previously; the recipient
was in essence "borrowing" antibodies, which would not last more than a number
of weeks or months. Such "passive immunization" would have to be repeated
every 3 months, and IG immunization against hepatitis B was available only
under specific circumstances.
Now, active vaccines against the viruses
that cause hepatitis A (HAV) and hepatitis B (HBV) are available. These
vaccines can confer permanent immunity against infection in most people that take them.
The vaccine against HAV is given in a single dose intramuscularly, which
is repeated in 6-12 months to confer lasting immunity in 99% of those who get both
injections. The first dose may take two to three weeks to stimulate a protective
antibody response, so if a person is traveling to an area of risk before that time,
temporary protection should be obtained through passive immunization (IG; see above).
Anyone who travels or lives in endemic regions (which is basically everywhere except
the US, Canada, Western Europe, Japan, Australia, and New Zealand) should receive
HAV immunization. Immunization of children is recommended as well as adults.
Vaccination against HBV is also available; about 5% of adults will fail to
develop protective antibodies even after completing the recommended course of
three injections (the second injection given six weeks after the first, the third
given six months after the first). Smoking, obesity, and being over 60 years of
age can decrease the body's ability to produce lasting antibodies after a full
course of vaccination. A blood test to measure the success of vaccination is available.
Vaccination of children is not only available, but is now recommended by pediatricians
for all children, with the first dose being given within a day after birth. All
individuals traveling to endemic areas, all health care workers, and anyone who
might come into contact with blood or blood products, should be immunized.
At this time, there is no vaccine against hepatitis C (HCV), nor is
passive immunization with IG effective.
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