Biology Reference
In-Depth Information
5.184 million DALYs in 2010, with ascariasis contributing 1.3148
million, trichuriasis 0.6382 million, and hookworm 3.2311 million. The
estimate for ascariasis is much lower than that for 1990, where ascari-
asis contributed 4.2173 billion DALYs
a decline that mirrors the
precipitous reduction in the prevalence of A. lumbricoides in China and
part of Asia.
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LIMITATIONS OF THE DALY APPROACH AND
A BROADER VIEW OF IMPACT
The use of DALYs as a measure of disease burden has its advantages
and disadvantages. The main advantage is that DALYs provide
a composite, internally consistent measure of population health which
can be used to evaluate the relative burden of different diseases and
injuries and compare population health by geographic region and over
time. Combined with information on the effectiveness and cost of
different interventions, such estimates can guide priority setting.
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The
main disadvantage of DALYs is that they focus solely on health and do
not capture the broader societal impact of diseases. This is especially
true for ascariasis and other intestinal nematodes which have subtle,
lasting impacts on child development and education. For example,
recent studies in Africa, as well as reanalysis of the extensive Rock-
efeller Foundation control programs in the southern United States at
the beginning of the 20th century, have shown remarkable long-run
effects on productivity and employment and wages of treating chil-
dren at school age.
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There is also an important equity issue that
goes beyond health: ascariasis and other neglected tropical diseases
(NTDs) affect the poorest communities and are, as Caroline Anstey of
the World Bank has said, diseases of neglected populations. Thus,
tackling ascariasis and other NTDs should be seen as part of broader
efforts to reduce global poverty. This argument provides perhaps the
most compelling case for de-worming, rather than some scientific
quantification of health impacts.
Acknowledgments
SJB is supported by a Wellcome Trust Senior Fellowship in Basic Biomedical Science (098045)
and RLP is supported by a grant from the Bill & Melinda Gates Foundation.
References
1. de Silva NR, Guyatt HL, Bundy DA. Worm burden in intestinal obstruction caused by
Ascaris lumbricoides. Trop Med Int Health 1997;2:189
90.
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