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Understanding Heterogeneity in the Impact of National Neglected Tropical Disease Control Programmes: Evidence from School-Based Deworming in Kenya.

Nikolay B, Mwandawiro CS, Kihara JH, Okoyo C, Cano J, Mwanje MT, Sultani H, Alusala D, Turner HC, Teti C, Garn J, Freeman MC, Allen E, Anderson RM, Pullan RL, Njenga SM, Brooker SJ - PLoS Negl Trop Dis (2015)

Bottom Line: The reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school.Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community.Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom.

ABSTRACT

Background: The implementation of soil-transmitted helminth (STH) treatment programmes occurs in varied environmental, social and economic contexts. Programme impact will be influenced by factors that affect the reduction in the prevalence and intensity of infections following treatment, as well as the subsequent rate of reinfection. To better understand the heterogeneity of programme impact and its underlying reasons, we investigated the influence of contextual factors on reduction in STH infection as part of the national school based deworming (SBD) programme in Kenya.

Materials and methods: Data on the prevalence and intensity of infection were collected within the monitoring and evaluation component of the SBD programme at baseline and after delivery of two annual treatment rounds in 153 schools in western Kenya. Using a framework that considers STH epidemiology and transmission dynamics, capacity to deliver treatment, operational feasibility and financial capacity, data were assembled at both school and district (county) levels. Geographic heterogeneity of programme impact was assessed by descriptive and spatial analyses. Factors associated with absolute reductions of Ascaris lumbricoides and hookworm infection prevalence and intensity were identified using mixed effects linear regression modelling adjusting for baseline infection levels.

Principal findings: The reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school. Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community. Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores.

Conclusions: The study identifies factors associated with the impact of school-based deworming and in particular highlights how access to water, sanitation and hygiene and environmental conditions influence the impact of deworming programmes.

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Related in: MedlinePlus

School heterogeneity in relative infection reductions within counties.Counties were ranked lowest to highest according to the relative reduction in prevalence and average intensity of infection. For hookworm, 13 schools with zero infections in both the baseline and follow-up surveys were excluded from the box-plot; schools with increase in infection are plotted as zero relative reduction.
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pntd.0004108.g004: School heterogeneity in relative infection reductions within counties.Counties were ranked lowest to highest according to the relative reduction in prevalence and average intensity of infection. For hookworm, 13 schools with zero infections in both the baseline and follow-up surveys were excluded from the box-plot; schools with increase in infection are plotted as zero relative reduction.

Mentions: The geographic heterogeneity in relative reductions between baseline and follow-up surveys of A. lumbricoides and hookworm infections is shown in Fig 3. Prevalence and intensity reductions varied significantly by county for A. lumbricoides and hookworm (county random effects, all p<0.001). The relative reduction of infections also varied within counties by school (Fig 4). This heterogeneity was overall more apparent for A. lumbricoides prevalence and intensity reductions than for hookworm. However, for hookworm, the heterogeneity was more pronounced in counties with lower overall reductions. An increase in infection (prevalence or intensity) between baseline and follow-up was observed in 54 and 15 schools for A. lumbricoides and hookworm, respectively. Thirteen schools had zero hookworm infections at baseline and follow-up. These schools were mainly located in Bomet County and in areas with low land surface temperature. Maps showing baseline and follow-up infections by school and county are provided in Fig B and Fig C in S1 Text.


Understanding Heterogeneity in the Impact of National Neglected Tropical Disease Control Programmes: Evidence from School-Based Deworming in Kenya.

Nikolay B, Mwandawiro CS, Kihara JH, Okoyo C, Cano J, Mwanje MT, Sultani H, Alusala D, Turner HC, Teti C, Garn J, Freeman MC, Allen E, Anderson RM, Pullan RL, Njenga SM, Brooker SJ - PLoS Negl Trop Dis (2015)

School heterogeneity in relative infection reductions within counties.Counties were ranked lowest to highest according to the relative reduction in prevalence and average intensity of infection. For hookworm, 13 schools with zero infections in both the baseline and follow-up surveys were excluded from the box-plot; schools with increase in infection are plotted as zero relative reduction.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4589351&req=5

pntd.0004108.g004: School heterogeneity in relative infection reductions within counties.Counties were ranked lowest to highest according to the relative reduction in prevalence and average intensity of infection. For hookworm, 13 schools with zero infections in both the baseline and follow-up surveys were excluded from the box-plot; schools with increase in infection are plotted as zero relative reduction.
Mentions: The geographic heterogeneity in relative reductions between baseline and follow-up surveys of A. lumbricoides and hookworm infections is shown in Fig 3. Prevalence and intensity reductions varied significantly by county for A. lumbricoides and hookworm (county random effects, all p<0.001). The relative reduction of infections also varied within counties by school (Fig 4). This heterogeneity was overall more apparent for A. lumbricoides prevalence and intensity reductions than for hookworm. However, for hookworm, the heterogeneity was more pronounced in counties with lower overall reductions. An increase in infection (prevalence or intensity) between baseline and follow-up was observed in 54 and 15 schools for A. lumbricoides and hookworm, respectively. Thirteen schools had zero hookworm infections at baseline and follow-up. These schools were mainly located in Bomet County and in areas with low land surface temperature. Maps showing baseline and follow-up infections by school and county are provided in Fig B and Fig C in S1 Text.

Bottom Line: The reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school.Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community.Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom.

ABSTRACT

Background: The implementation of soil-transmitted helminth (STH) treatment programmes occurs in varied environmental, social and economic contexts. Programme impact will be influenced by factors that affect the reduction in the prevalence and intensity of infections following treatment, as well as the subsequent rate of reinfection. To better understand the heterogeneity of programme impact and its underlying reasons, we investigated the influence of contextual factors on reduction in STH infection as part of the national school based deworming (SBD) programme in Kenya.

Materials and methods: Data on the prevalence and intensity of infection were collected within the monitoring and evaluation component of the SBD programme at baseline and after delivery of two annual treatment rounds in 153 schools in western Kenya. Using a framework that considers STH epidemiology and transmission dynamics, capacity to deliver treatment, operational feasibility and financial capacity, data were assembled at both school and district (county) levels. Geographic heterogeneity of programme impact was assessed by descriptive and spatial analyses. Factors associated with absolute reductions of Ascaris lumbricoides and hookworm infection prevalence and intensity were identified using mixed effects linear regression modelling adjusting for baseline infection levels.

Principal findings: The reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school. Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community. Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores.

Conclusions: The study identifies factors associated with the impact of school-based deworming and in particular highlights how access to water, sanitation and hygiene and environmental conditions influence the impact of deworming programmes.

Show MeSH
Related in: MedlinePlus