Biology Reference
In-Depth Information
PREVENTIVE CHEMOTHERAPY AS THE WHO
STRATEGY FOR STH CONTROL
Preventive chemotherapy (PC) is “the use of anthelmintic drugs, either
alone or in combination, as a public health tool against helminth infec-
tions”
9
and is the key public health strategy recommended by the WHO to
reduce morbidity and transmission of STH.
Operationally, PC is characterized by population-level diagnosis,
population-level
treatment
and by
implementation at
regular
intervals.
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Population-based diagnosis. Population-based diagnosis consists of
assessing the significance of STH in a population through surveys
applied to a sample of its individuals. Appropriate diagnostic tests,
or standard questionnaires screening for pathognomonic symptoms
or signs or for behaviors associated with risk of infection, can be
used alternatively. Population-based diagnosis can also be carried
out retrospectively by analyzing existing epidemiological data.
Based on its results, an appropriate intervention is selected.
Population-based diagnosis distinguishes PC from the clinical
approach in which diagnosis is performed at the individual level
prior to treatment.
Population-based treatment. In PC, administration of anthelmintic
drugs is not the outcome of a personalized, case management
treatment approach performed by medical personnel on individuals
reporting to health facilities. It rather entails actively targeting
population groups at risk (pre-school and school-aged children and
women of child-bearing age) with delivery of single-administration
medicines by non-medical personnel (teachers, volunteers or
community drug distributors).
Implementation at regular intervals. PC is implemented at regular
intervals of time; the retreatment interval is based on the
epidemiological characteristics of the disease as measured by the
population-based diagnosis; the intervention is repeated without the
need for further diagnostic interventions,
8
although implementation of
a monitoring system is recommended.
COLLATERAL BENEFITS OF PREVENTIVE
CHEMOTHERAPY
Preventive chemotherapy for the control of neglected tropical diseases
(NTDs) has the advantage of being effective against other parasitic
infections that are not directly targeted by the intervention, for example
