recent years, the spread of malaria seems renewed,
especially in parts of sub-Saharan Africa. The
global health community was once confident at
their control of this disease, with many successes
in ridding large areas of malaria over the previous
decades; but now increasingly large numbers of
people are dying from the mosquito-borne ailment.
Forty percent of the world's population live
in the malaria-infected areas, and it also brings
around 260 million new cases.
The resurgence of malaria is occurring in several
parts of the world. However, it is most acute
in Africa, south of the Sahara Desert, where according
to a 1993 World Health Organization (WHO) report,
between 1.4 and 2.8 million people, half of their
children, now die each year from the disease.
This is triple the annual number of people in
the same region who die of AIDS. Actual numbers
of malaria deaths may be even larger because the
symptoms, such as chronic fever, are often mistaken
for other, unrelated illness, such as influenza
In the 1950s, subtropical regions in the United
States, Southern Europe and elsewhere were sprayed
with DDT, which eliminated the malaria parasite
where used appropriately but resulted in resistant
mosquitoes where sprayed too often. No only could
mosquitoes have resistance to the drugs applied
on them but people also are able to build up their
immune system. Take people who live in the countryside
of Africa for example, 5 percent of children
die of malaria, and the many who survive it go
on to become adults with a high degree of natural
Health workers, discouraged by the diminishing
effectiveness of malarial drugs, are seeking to
promote physical barriers to infection rather
than chemical ones. The concept of mosquito nets
hung over beds to keep mosquitoes away is certainly
not new, but recent efforts to improve them have
led to some success in protecting people from
malaria. In experiments in Gambia, the number
of children dying from malaria has dropped 50
percent since using nets soaked in insecticide.
To remain effective, the nets need to be re-soaked
only twice a year, and no drugs need to be taken
for prevention. The nets provide additional benefits
to the families who use them in that they prevent
other types of irritating insects from getting
Whether or not mosquito nets would be effective
on a large scale remains to be seen, as conditions
vary from place to place. Some users complaint
it is too hot under the nets to be able to sleep.
Furthermore, their cost limits the number of people
who can take advantage of them.
Thus, the search for a vaccine for malaria continues.
Manuel Patarroyo, a medical researcher from Colombia,
stated in 1993 that he had been successful in
trying a new vaccine on some 20,000 people in
South America. Similar testing of the vaccine
is being done in Africa, but health officials
are not convinced it will be effective because
the rate at which new cases of malaria develop
is many times higher than that in South America.
Complete the sentences below with words taken
from the above passage. Please don't fill in
more than one word for each blank space.