Malaria remains probably the most serious single threat to health throughout the tropics and subtropics. A newcomer to an area in which malaria is highly endemic may be misled by the apparently robust health of most of the local people. The adults, however, are simply the relatively resistant survivors of a disease that regularly kills a large percentage of infants. The previously unexposed immigrant to virtually all of Africa, most of Southeast Asia, and much of Latin America is at grave risk of contracting malaria, some forms of which have a mortality rate of 10 % in untreated cases. Military forces and construction crews throughout history have been inactivated by this disease. Experiences in Vietnam and on construction projects in Africa continue to demonstrate that antimalarial drugs do not offer complete protection. Malaria is almost always underestimated as to its very wide geographic distribution, the high risk of infection, and the severity of the disease in nonimmune subjects.
An important point that is stressed in the passage is that ___.
outsiders going to work in areas where malaria is endemic should avoid contact with the local people
malaria is only dangerous if it goes untreated
most forms of malaria are harmless
a great many people do not realize just how dangerous malaria is
the incidence of malaria even in Africa is rapidly decreasing
We understand from the passage that where malaria is endemic ___.
the whole population is in poor health
it causes the death of very many young children
people easily develop an immunity to the disease
strenuous physical effort should be avoided
medical care is ineffective
It is clear from the passage that people who have not been exposed to malaria and acquired an immunity to it ___.
are only at risk if they are in poor health
have nothing to fear so long as they take antimalarial drugs when in areas where it is endemic
can very easily contract the disease
should take certain precautions until they have acquired an immunity
are in the majority even in regions where malaria is endemic