Beneficial results from the use of selectively toxic agents

An annual record of what selectively toxic agents have accomplished, where they have lost groimd, or what they have yet to do, can be found in the Annual Report of the Director-General to the World Health Assembly and to the United Nations issued separately or boimd annually in The Work of WHOi and abstracted and supplemented in the monthly WHO Chronicle (all are published in Geneva, Switzerland). The following account owes much to this source (WHO, 1976,1977). 

Infectious diseases. Malaria is still the disease that causes the greatest amount of debility, illness, and death in the whole world. WHO has long given top priority to advising nations on the elimination of this disease by draining and spraying to eliminate the insect vector, and by medication, both prophylactic and curative. WHO also labours constantly to find improvements in all these approaches. Projects approved for a country by WHO can expect to be funded internationally. 

After malaria, trypanosomiasis, leishmaniasis (kala-azar), and ameobiasis (amoebic dysentery) are the most serious of the diseases caused hy protozoa. 

Visceral leishmaniasis is caused by a trypanosome-like protozoon transmitted by sandfly bites in China and India and the Eastern Mediterranean. With enlarged spleen and liver, the patient becomes increasingly listless and soon dies. A cutaneous form of the disease is caused by another species of Leishmania. Both forms, together affecting 12 million, respond to selectively toxic drugs. 

Amoebiasis, common in many tropical countries but not confined to them, responds well to drugs, particularly metronidazole (Section 6.3c). 

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Beneficial results from the use of selectively toxic agents. 7... 

I. I Beneficial results from the use of selectively toxic agents. 7 1.2 The physical basis of selectivity the three principles. 15... 

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