Limits...
Indoor residual spraying of insecticide and malaria morbidity in a high transmission intensity area of Uganda.

Kigozi R, Baxi SM, Gasasira A, Sserwanga A, Kakeeto S, Nasr S, Rubahika D, Dissanayake G, Kamya MR, Filler S, Dorsey G - PLoS ONE (2012)

Bottom Line: Routine data were collected on more than 90,000 patient visits at a single health facility over a 56 month period covering five rounds of IRS using three different insecticides.Overall, the impact of IRS was less pronounced among patients 5 years or older.IRS was associated with a reduction in malaria morbidity in an area of high transmission intensity in Uganda and the benefits appeared to be greatest after switching to a carbamate class of insecticide.

View Article: PubMed Central - PubMed

Affiliation: Uganda Malaria Surveillance Project, Kampala, Uganda.

ABSTRACT

Background: Recently the use of indoor residual spraying of insecticide (IRS) has greatly increased in Africa; however, limited data exist on the quantitative impacts of IRS on health outcomes in highly malaria endemic areas.

Methodology/principal findings: Routine data were collected on more than 90,000 patient visits at a single health facility over a 56 month period covering five rounds of IRS using three different insecticides. Temporal associations between the timing of IRS and the probability of a patient referred for microscopy having laboratory confirmed malaria were estimated controlling for seasonality and age. Considering patients less than five years of age there was a modest decrease in the odds of malaria following the 1(st) round of IRS using DDT (OR = 0.76, p<0.001) and the 2(nd) round using alpha-cypermethrin (OR = 0.83, p = 0.002). Following rounds 3-5 using bendiocarb there was a much greater decrease in the odds of malaria (ORs 0.34, 0.16, 0.17 respectively, p<0.001 for all comparisons). Overall, the impact of IRS was less pronounced among patients 5 years or older.

Conclusions/significance: IRS was associated with a reduction in malaria morbidity in an area of high transmission intensity in Uganda and the benefits appeared to be greatest after switching to a carbamate class of insecticide.

Show MeSH

Related in: MedlinePlus

Monthly trends in malaria slide positivity stratified by age groups among patients with suspected malaria referred for laboratory testing at the Aduku Health Center in Apac, Uganda.Vertical bars represent the duration of each round of IRS.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3412792&req=5

pone-0042857-g001: Monthly trends in malaria slide positivity stratified by age groups among patients with suspected malaria referred for laboratory testing at the Aduku Health Center in Apac, Uganda.Vertical bars represent the duration of each round of IRS.

Mentions: Temporal trends in the monthly SPR stratified by age groups are presented in Figure 1. Considering the reference time period, the SPR was 71% for patients under 5 years of age and 36% for patient 5 years of age or older. During the 6 months following the 1st round of IRS with DDT there was a significant decrease in the odds of having malaria among patients less than 5 years of age (OR = 0.76, 95% CI 0.67–0.86, p<0.001) and those 5 years of age or older (OR = 0.70, 95% CI 0.61–0.79, p<0.001). During the 4 months following the 2nd round of IRS with alpha-cypermethrin there was a significant decrease in the odds of having malaria among patients less than 5 years of age (OR = 0.83, 95% CI 0.73–0.93. p = 0.002), but not among those 5 years of age or older (OR = 1.09, 95% CI 0.99–1.22. p = 0.10) (Table 3). During the 4 months following the 3rd round of IRS with bendiocarb there was a significant decrease in the odds of having malaria that was more pronounced among patients less than 5 years of age (OR = 0.34, 95% CI 0.30–0.40, p<0.001) compared to those 5 years of age or older (OR = 0.76, 95% CI 0.68–0.84, p<0.001)(p<0.001 for interaction when comparing effects between two age groups). The greatest decrease in the odds of having malaria occurred during the 4 months following the 4th and 5th rounds of IRS using bendiocarb and was more pronounced among patients less than 5 years of age (ORs 0.16, 95% CI 0.14–0.19, p<0.001; and 0.17, 95% CI 0.15–0.20, p<0.001) compared to those 5 years of age or older (ORs 0.44, 95% CI 0.38–0.50, p<0.001, and 0.58, 95% CI 0.52–0.65, p<0.001)(p<0.001 for interaction when comparing effects between two age groups). There was a sharp decline in the SPR following the 3rd round of IRS (1st round with bendiocarb), sustained initially after the 4th round of IRS, then increasing prior to the 5th round followed by another sharp decline (Figure 1). Results were similar when restricting the analyses to only patients who reported residing in the Aduku sub-county (Table 3).


Indoor residual spraying of insecticide and malaria morbidity in a high transmission intensity area of Uganda.

Kigozi R, Baxi SM, Gasasira A, Sserwanga A, Kakeeto S, Nasr S, Rubahika D, Dissanayake G, Kamya MR, Filler S, Dorsey G - PLoS ONE (2012)

Monthly trends in malaria slide positivity stratified by age groups among patients with suspected malaria referred for laboratory testing at the Aduku Health Center in Apac, Uganda.Vertical bars represent the duration of each round of IRS.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3412792&req=5

pone-0042857-g001: Monthly trends in malaria slide positivity stratified by age groups among patients with suspected malaria referred for laboratory testing at the Aduku Health Center in Apac, Uganda.Vertical bars represent the duration of each round of IRS.
Mentions: Temporal trends in the monthly SPR stratified by age groups are presented in Figure 1. Considering the reference time period, the SPR was 71% for patients under 5 years of age and 36% for patient 5 years of age or older. During the 6 months following the 1st round of IRS with DDT there was a significant decrease in the odds of having malaria among patients less than 5 years of age (OR = 0.76, 95% CI 0.67–0.86, p<0.001) and those 5 years of age or older (OR = 0.70, 95% CI 0.61–0.79, p<0.001). During the 4 months following the 2nd round of IRS with alpha-cypermethrin there was a significant decrease in the odds of having malaria among patients less than 5 years of age (OR = 0.83, 95% CI 0.73–0.93. p = 0.002), but not among those 5 years of age or older (OR = 1.09, 95% CI 0.99–1.22. p = 0.10) (Table 3). During the 4 months following the 3rd round of IRS with bendiocarb there was a significant decrease in the odds of having malaria that was more pronounced among patients less than 5 years of age (OR = 0.34, 95% CI 0.30–0.40, p<0.001) compared to those 5 years of age or older (OR = 0.76, 95% CI 0.68–0.84, p<0.001)(p<0.001 for interaction when comparing effects between two age groups). The greatest decrease in the odds of having malaria occurred during the 4 months following the 4th and 5th rounds of IRS using bendiocarb and was more pronounced among patients less than 5 years of age (ORs 0.16, 95% CI 0.14–0.19, p<0.001; and 0.17, 95% CI 0.15–0.20, p<0.001) compared to those 5 years of age or older (ORs 0.44, 95% CI 0.38–0.50, p<0.001, and 0.58, 95% CI 0.52–0.65, p<0.001)(p<0.001 for interaction when comparing effects between two age groups). There was a sharp decline in the SPR following the 3rd round of IRS (1st round with bendiocarb), sustained initially after the 4th round of IRS, then increasing prior to the 5th round followed by another sharp decline (Figure 1). Results were similar when restricting the analyses to only patients who reported residing in the Aduku sub-county (Table 3).

Bottom Line: Routine data were collected on more than 90,000 patient visits at a single health facility over a 56 month period covering five rounds of IRS using three different insecticides.Overall, the impact of IRS was less pronounced among patients 5 years or older.IRS was associated with a reduction in malaria morbidity in an area of high transmission intensity in Uganda and the benefits appeared to be greatest after switching to a carbamate class of insecticide.

View Article: PubMed Central - PubMed

Affiliation: Uganda Malaria Surveillance Project, Kampala, Uganda.

ABSTRACT

Background: Recently the use of indoor residual spraying of insecticide (IRS) has greatly increased in Africa; however, limited data exist on the quantitative impacts of IRS on health outcomes in highly malaria endemic areas.

Methodology/principal findings: Routine data were collected on more than 90,000 patient visits at a single health facility over a 56 month period covering five rounds of IRS using three different insecticides. Temporal associations between the timing of IRS and the probability of a patient referred for microscopy having laboratory confirmed malaria were estimated controlling for seasonality and age. Considering patients less than five years of age there was a modest decrease in the odds of malaria following the 1(st) round of IRS using DDT (OR = 0.76, p<0.001) and the 2(nd) round using alpha-cypermethrin (OR = 0.83, p = 0.002). Following rounds 3-5 using bendiocarb there was a much greater decrease in the odds of malaria (ORs 0.34, 0.16, 0.17 respectively, p<0.001 for all comparisons). Overall, the impact of IRS was less pronounced among patients 5 years or older.

Conclusions/significance: IRS was associated with a reduction in malaria morbidity in an area of high transmission intensity in Uganda and the benefits appeared to be greatest after switching to a carbamate class of insecticide.

Show MeSH
Related in: MedlinePlus