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Improvements on restricted insecticide application protocol for control of Human and Animal African Trypanosomiasis in eastern Uganda.

Muhanguzi D, Picozzi K, Hatendorf J, Thrusfield M, Welburn SC, Kabasa JD, Waiswa C - PLoS Negl Trop Dis (2014)

Bottom Line: Incidence was estimated at 9.8/100 years in RAP regimens, significantly lower compared to 25.7/100 years in the non-RAP regimens (incidence rate ratio: 0.37; 95% CI: 0.22-0.65; P<0.001).Contrary to our expectation, level of protection did not increase with increasing proportion of animals treated.Reduction in RAP coverage did not significantly affect efficacy of treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomolecular and Biolaboratory Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda; Division of Pathway Medicine, Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom.

ABSTRACT

Background: African trypanosomes constrain livestock and human health in Sub-Saharan Africa, and aggravate poverty and hunger of these otherwise largely livestock-keeping communities. To solve this, there is need to develop and use effective and cheap tsetse control methods. To this end, we aimed at determining the smallest proportion of a cattle herd that needs to be sprayed on the legs, bellies and ears (RAP) for effective Human and Animal African Trypanosomiasis (HAT/AAT) control.

Methodology/principal finding: Cattle in 20 villages were ear-tagged and injected with two doses of diminazene diaceturate (DA) forty days apart, and randomly allocated to one of five treatment regimens namely; no treatment, 25%, 50%, 75% monthly RAP and every 3 month Albendazole drench. Cattle trypanosome re-infection rate was determined by molecular techniques. ArcMap V10.3 was used to map apparent tsetse density (FTD) from trap catches. The effect of graded RAP on incidence risk ratios and trypanosome prevalence was determined using Poisson and logistic random effect models in R and STATA V12.1 respectively. Incidence was estimated at 9.8/100 years in RAP regimens, significantly lower compared to 25.7/100 years in the non-RAP regimens (incidence rate ratio: 0.37; 95% CI: 0.22-0.65; P<0.001). Likewise, trypanosome prevalence after one year of follow up was significantly lower in RAP animals than in non-RAP animals (4% vs 15%, OR: 0.20, 95% CI: 0.08-0.44; P<0.001). Contrary to our expectation, level of protection did not increase with increasing proportion of animals treated.

Conclusions/significance: Reduction in RAP coverage did not significantly affect efficacy of treatment. This is envisaged to improve RAP adaptability to low income livestock keepers but needs further evaluation in different tsetse challenge, HAT/AAT transmission rates and management systems before adopting it for routine tsetse control programs.

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Related in: MedlinePlus

Relative Change in trypanosome prevalence by Regimen 1–5.Lines represent the relative changes from the baseline prevalences, presented are the means from the 4 village estimates. The dotted lines represent average prevalence in RAP (2–9; brown) and non- RAP (1&5; black) regimens respectively.
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pntd-0003284-g003: Relative Change in trypanosome prevalence by Regimen 1–5.Lines represent the relative changes from the baseline prevalences, presented are the means from the 4 village estimates. The dotted lines represent average prevalence in RAP (2–9; brown) and non- RAP (1&5; black) regimens respectively.

Mentions: Fourteen days post the second dose of diminazene diaceturate (denoted as time 0), trypanosome prevalences generally increased in all regimens up to month 6 when they started decreasing (Regimen 2, 3 and 4) over time. In regimens 1 and 5 trypanosome prevalences increased up to about 12 and 15 months respectively and started decreasing thereafter. The slope of curves representing trypanosome prevalences over time in different regimens is in increasing order of Regimen 2<3<4<1<5 (Figures 2& 3). T.vivax was the most predominant species detected in any regimen while T. brucei s.l. was the least predominant species detected over the study period (Table 2).


Improvements on restricted insecticide application protocol for control of Human and Animal African Trypanosomiasis in eastern Uganda.

Muhanguzi D, Picozzi K, Hatendorf J, Thrusfield M, Welburn SC, Kabasa JD, Waiswa C - PLoS Negl Trop Dis (2014)

Relative Change in trypanosome prevalence by Regimen 1–5.Lines represent the relative changes from the baseline prevalences, presented are the means from the 4 village estimates. The dotted lines represent average prevalence in RAP (2–9; brown) and non- RAP (1&5; black) regimens respectively.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4214683&req=5

pntd-0003284-g003: Relative Change in trypanosome prevalence by Regimen 1–5.Lines represent the relative changes from the baseline prevalences, presented are the means from the 4 village estimates. The dotted lines represent average prevalence in RAP (2–9; brown) and non- RAP (1&5; black) regimens respectively.
Mentions: Fourteen days post the second dose of diminazene diaceturate (denoted as time 0), trypanosome prevalences generally increased in all regimens up to month 6 when they started decreasing (Regimen 2, 3 and 4) over time. In regimens 1 and 5 trypanosome prevalences increased up to about 12 and 15 months respectively and started decreasing thereafter. The slope of curves representing trypanosome prevalences over time in different regimens is in increasing order of Regimen 2<3<4<1<5 (Figures 2& 3). T.vivax was the most predominant species detected in any regimen while T. brucei s.l. was the least predominant species detected over the study period (Table 2).

Bottom Line: Incidence was estimated at 9.8/100 years in RAP regimens, significantly lower compared to 25.7/100 years in the non-RAP regimens (incidence rate ratio: 0.37; 95% CI: 0.22-0.65; P<0.001).Contrary to our expectation, level of protection did not increase with increasing proportion of animals treated.Reduction in RAP coverage did not significantly affect efficacy of treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomolecular and Biolaboratory Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda; Division of Pathway Medicine, Centre for Infectious Diseases, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom.

ABSTRACT

Background: African trypanosomes constrain livestock and human health in Sub-Saharan Africa, and aggravate poverty and hunger of these otherwise largely livestock-keeping communities. To solve this, there is need to develop and use effective and cheap tsetse control methods. To this end, we aimed at determining the smallest proportion of a cattle herd that needs to be sprayed on the legs, bellies and ears (RAP) for effective Human and Animal African Trypanosomiasis (HAT/AAT) control.

Methodology/principal finding: Cattle in 20 villages were ear-tagged and injected with two doses of diminazene diaceturate (DA) forty days apart, and randomly allocated to one of five treatment regimens namely; no treatment, 25%, 50%, 75% monthly RAP and every 3 month Albendazole drench. Cattle trypanosome re-infection rate was determined by molecular techniques. ArcMap V10.3 was used to map apparent tsetse density (FTD) from trap catches. The effect of graded RAP on incidence risk ratios and trypanosome prevalence was determined using Poisson and logistic random effect models in R and STATA V12.1 respectively. Incidence was estimated at 9.8/100 years in RAP regimens, significantly lower compared to 25.7/100 years in the non-RAP regimens (incidence rate ratio: 0.37; 95% CI: 0.22-0.65; P<0.001). Likewise, trypanosome prevalence after one year of follow up was significantly lower in RAP animals than in non-RAP animals (4% vs 15%, OR: 0.20, 95% CI: 0.08-0.44; P<0.001). Contrary to our expectation, level of protection did not increase with increasing proportion of animals treated.

Conclusions/significance: Reduction in RAP coverage did not significantly affect efficacy of treatment. This is envisaged to improve RAP adaptability to low income livestock keepers but needs further evaluation in different tsetse challenge, HAT/AAT transmission rates and management systems before adopting it for routine tsetse control programs.

Show MeSH
Related in: MedlinePlus