Early treatment with medications to kill the Plas-
modiumparasites is essential, particularly when
the infective PARASITEis P. falciparum,which causes
life-threatening illness. Because antimalarial med-
ications 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 anti-
malarial medication, primaquine, can kill liver-
based Plasmodium. The specific medications and
length of treatment depend on the type of infec-
tion, region of the world where the person
acquired the infection, and the person’s age and
other health circumstances.
MEDICATIONS TO TREAT MALARIAatovaquone-proguanil chloroquine
doxycycline mefloquine
primaquine quinine
sulfadoxine-pyrimethamine
Aggressive mosquito-control measures are the
most successful preventive approach. These meas-
ures include public health efforts to eradicate mos-
quito populations, such as through insecticide
application and eliminating standing water that
serves as mosquito breeding grounds, and per-
sonal prevention efforts, such as wearing clothing
that protects against mosquito bites. People plan-
ning travel to regions where Plasmodiuminfection
is possible should take prophylactic medications.
See also ERYTHROCYTE; TOXOPLASMOSIS; TYPHOID
FEVER.
measles An illness resulting from INFECTIONwith
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 child-
hood 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 contamina-
tion via airborne transmission (sneezing and
coughing) as well as direct contact. The virus
invades the lining of the THROATand the LUNGS,
where it replicates. The virus then uses the lym-
phatic system to enter the BLOODcirculation, 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 symp-
toms and history of exposure.
The risk for complications from measles is high,
primarily because the measles virus’s use of the
IMMUNE SYSTEMto distribute itself compromises the
IMMUNE RESPONSE, lowering resistance to infection
from other pathogens. As a consequence secondary
bacterial infections, notably OTITISmedia (middle
EARinfection) and PNEUMONIA, are common. Such
bacterial infections require treatment withANTIBI-
OTIC MEDICATIONS, though antibiotics do not treat
measles. The measles virus may also cause viral
pneumonia and MENINGITIS. IMMUNOGLOBULINmay
prevent or moderate illness in people exposed to
measles. However, ANTIVIRAL MEDICATIONS are not
effective. Complications are more common in peo-
ple 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 BRAINand SPINAL
CORD. Meningitis may result from bacterial, viral,
or fungal INFECTION. Viruses are the most common
causes of meningitis and can be highly contagious.meningitis 343