Encyclopedia of Health and Medicine

meningitis 343
Early treatment with medications to kill the Plasmodium
parasites is essential, particularly when
the infective PARASITE is P. falciparum, which causes
life-threatening illness. Because antimalarial medications
are effective against the parasites in the
blood, it is essential to continue treatment
through several life cycles of the parasites to kill
those emerging from the liver. Only one antimalarial
medication, primaquine, can kill liverbased
Plasmodium. The specific medications and
length of treatment depend on the type of infection,
region of the world where the person
acquired the infection, and the person’s age and
other health circumstances.
MEDICATIONS TO TREAT MALARIA
atovaquone-proguanil
chloroquine
doxycycline
mefloquine
primaquine
quinine
sulfadoxine-pyrimethamine
Aggressive mosquito-control measures are the
most successful preventive approach. These measures
include public health efforts to eradicate mosquito
populations, such as through insecticide
application and eliminating standing water that
serves as mosquito breeding grounds, and personal
prevention efforts, such as wearing clothing
that protects against mosquito bites. People planning
travel to regions where Plasmodium infection
is possible should take prophylactic medications.
See also ERYTHROCYTE; TOXOPLASMOSIS; TYPHOID
FEVER.
measles An illness resulting from INFECTION with
the measles VIRUS. Once among the most common
childhood diseases worldwide, measles (also called
rubeola) now primarily exists in developing
nations where it remains a leading cause of childhood
blindness and death. Routine measles IMMU-
NIZATION, the standard of care since becoming
available in the early 1960s, has eradicated
measles from much of the industrialized world. In
the United States children generally receive
measles VACCINE through the combination MMR
(measles-mumps-rubella) vaccine.
Measles is one of the most highly contagious
infections and spreads through droplet contamination
via airborne transmission (sneezing and
coughing) as well as direct contact. The virus
invades the lining of the THROAT and the LUNGS,
where it replicates. The virus then uses the lymphatic
system to enter the BLOOD circulation, after
which prodrome symptoms emerge that include
• FEVER
• sensitivity to light (PHOTOPHOBIA)
• congestion of the nasal passages and profuse
nasal discharge
• nonproductive COUGH
Within two days the characteristic measles RASH
emerges. This red, itchy rash starts at the hairline
on the scalp and spreads to cover the entire body,
including the palms of the hands and soles of the
feet. The course of illness runs about 10 days after
the rash begins. The infection is most contagious
during the prodrome stage, though contagiousness
continues through the rash stage. Diagnosis is
clinical based on the characteristic nature of symptoms
and history of exposure.
The risk for complications from measles is high,
primarily because the measles virus’s use of the
IMMUNE SYSTEM to distribute itself compromises the
IMMUNE RESPONSE, lowering resistance to infection
from other pathogens. As a consequence secondary
bacterial infections, notably OTITIS media (middle
EAR infection) and PNEUMONIA, are common. Such
bacterial infections require treatment with ANTIBI-
OTIC MEDICATIONS, though antibiotics do not treat
measles. The measles virus may also cause viral
pneumonia and MENINGITIS. IMMUNOGLOBULIN may
prevent or moderate illness in people exposed to
measles. However, ANTIVIRAL MEDICATIONS are not
effective. Complications are more common in people
who have vitamin A deficiency, though doctors
do not know whether vitamin A supplementation
during illness with measles decreases this risk.
See also BACTERIA; CHICKENPOX; MUMPS; PATHOGEN;
PREVENTIVE HEALTH CARE AND IMMUNIZATION;
SNEEZE/COUGH ETIQUETTE; VITAMINS AND HEALTH.
meningitis INFLAMMATION of the MENINGES, the
membranes that surround the BRAIN and SPINAL
CORD. Meningitis may result from bacterial, viral,
or fungal INFECTION. Viruses are the most common
causes of meningitis and can be highly contagious.