The leishmaniases: WHO TRS N°701

Overview

Although the leishmaniases give rise to important public health problems, current efforts to control these diseases are insufficient. The wide diversity of both the clinical forms of the diseases and the epidemiological situations means that each focus requires specific control principles and methods. Moreover, leishmaniases control is usually hampered by ignorance of the true prevalence of the diseases and underestimation of the human suffering and invalidity they cause.

The Committee expressed deep concern about the increasing spread and occurrence of leishmaniases in the world. Kala azar, if left untreated, has a high mortality rate. New World mucocutaneous forms are mutilating and difficult to treat, and the disfigurement caused by cutaneous forms has a lifelong psychological impact (Fig. 1). The danger that these diseases represent for the health of children should be specially emphasized since this age group is not only more vulnerable, but is also the group in which the risk of failure of diagnosis is the highest.

Movements of migrants, temporary labourers, and any large-scale population displacement may result in a high incidence of infection among such groups. Increasingly, tourists visiting endemic areas are reported to return infected. Among the population in endemic areas, the permanent risk of an epidemic creates constant and genuine fear.

Control of some of these diseases is possible, but the personnel of public health services often appear to be discouraged by the complicated nature and wide diversity of the epidemiology of these diseases, and in some instances, the available treatment and preventive measures are unsatisfactory. It is therefore impracticable to adopt a universal control strategy.

In the present report, an effort is made to review current methods of control and to define strategies for a variety of circumstances and at different levels of sophistication. The report covers all the forms of leishmaniasis, and consequently it cannot include detailed accounts of each of the many technical subjects related to this group of diseases. It is the hope of the Expert Committee that its report will stimulate investigations into the state of infection in leishmaniases foci throughout the world and that it will assist those who are responsible for organizing and implementing the control of and research into these diseases.