Impregnated Nets Cannot Fully Substitute for DDT : Field Effectiveness of Malaria Prevention in Solomon Islands
The incidence of malaria in Solomon Islands has been declining since 1992, but there is a large geographical variation between areas in the incidence level and the rate of decline. The authors used a mix of control interventions, including DDT resi...
| Main Authors: | , , , , |
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| Format: | Policy Research Working Paper |
| Language: | English en_US |
| Published: |
World Bank, Washington, DC
2014
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| Subjects: | |
| Online Access: | http://documents.worldbank.org/curated/en/2003/05/2360826/impregnated-nets-cannot-fully-substitute-ddt-field-effectiveness-malaria-prevention-solomon-islands http://hdl.handle.net/10986/18205 |
| Summary: | The incidence of malaria in Solomon
Islands has been declining since 1992, but there is a large
geographical variation between areas in the incidence level
and the rate of decline. The authors used a mix of control
interventions, including DDT residual house spraying and
insecticide-treated mosquito nets. Data on monthly incidence
and control activities performed from January 1993 to August
1999 were gathered for 41 out of the 110 malaria zones in
the country. Monthly reports on the number of fevers seen at
outpatient health clinics in the same zones over the same
period were also extracted from the clinical health
information system. The authors used multivariate random
effects regression, including calendar month as an
instrumental variable, to investigate the relationship
between the number of malaria or fever cases and the control
measures applied by month and zone, while adjusting for
rainfall and proximity to water. The results showed that DDT
house spraying, insecticide treatment of nets, and education
about malaria were all independently associated with
reduction in incident cases of malaria or fever, while
larviciding with temephos was not. This was true for
confirmed malaria cases even when a variable representing
the passage of time was included in the models. The results
show how much each method used was contributing to malaria
control in Solomon Islands and how it can be used to design
the most cost-effective package of interventions. The
evidence suggests that impregnated bednets cannot easily
replace DDT spraying without substantial increase in
incidence, but impregnated nets do permit a substantial
reduction in the amount of DDT spraying. |
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