Measles Virus
Family: Paramyxoviridae Genus: Morbillivirus
Measles is an entirely preventable disease causing many needless deaths each year.
Power:
Measles is one of
the most contagious of all human viruses, with about forty million infections
world wide each year, and one to two million deaths. Measles outbreaks
are common in underdeveloped countries where there is lower socioecoomic
status, crowding, and low access to health care.
Offences:
All primary measles virus
infections give rise to the disease, however the result is lifelong immunity.
Measles causes rash, cough, and fever, and can lead to ear infection, pneumonia,
conjunctivitis, diarrhea, seizures, brain damage, and death. A rash appears
approximately three days after the initial symptoms of abrupt cough, runny
nose, and inflamed conjunctivae. Koplik spots (small bluish yellow spots)
occur in the mouth on buccal mucosa. The maculopapular rash appears first
on the head, and then progressively spreads over the chest, trunk, and
then limbs, eventually covering the entire body. Infection of the
measles virus occurs through the respiratory tract. The receptor
for the measles virus is the human complement regulatory cofactor protein
CD46. The disease usually runs its course in about two weeks, assuming
there are no complications. The measles virus kills cell by fusing
together the cell membranes of neighboring cells. The virus can replicate
in a variety of tissues, including the immune system and nervous system.
The virus enters the local lymphatics and is transported to the lymph nodes
where the virus multiplies and spreads to other lymph nodes, the spleen,
and then to the rest of the body.
Defences:
The Schwarz vaccine is used
to today and this live attenuated vaccine and should be given to every
child at about fifteen months which results in about 95-98% seroconversion,
with a booster recommended to ensure lifelong immunity. Measles
is a preventable disease and has the possibility of eradication with the
proper immunization program. Proper nutrition provides a good
defense to measles; the malnourished children of developing countries are
much more susceptible to complications and death.
Game action: WHO thanks you for getting your measles vaccination!!
You win extra points!
Reference:
Principles of Virology Flint, Enquist, Krug, Racaniello, and Skalka
(2000) p 538
Medical Virology by White and Fenner (1994) p 461-465