The relationship between facility-based malaria test positivity rate and community-based parasite prevalence.
<h4>Introduction</h4>Malaria surveillance is a key pillar in the control of malaria in Africa. The value of using routinely collected data from health facilities to define malaria risk at community levels remains poorly defined.<h4>Methods</h4>Four cross-sectional parasite pr...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2020-01-01
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| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0240058 |
| _version_ | 1818366268053389312 |
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| author | Alice Kamau Grace Mtanje Christine Mataza Lucas Malla Philip Bejon Robert W Snow |
| author_facet | Alice Kamau Grace Mtanje Christine Mataza Lucas Malla Philip Bejon Robert W Snow |
| author_sort | Alice Kamau |
| collection | DOAJ |
| description | <h4>Introduction</h4>Malaria surveillance is a key pillar in the control of malaria in Africa. The value of using routinely collected data from health facilities to define malaria risk at community levels remains poorly defined.<h4>Methods</h4>Four cross-sectional parasite prevalence surveys were undertaken among residents at 36 enumeration zones in Kilifi county on the Kenyan coast and temporally and spatially matched to fever surveillance at 6 health facilities serving the same communities over 12 months. The age-structured functional form of the relationship between test positivity rate (TPR) and community-based parasite prevalence (PR) was explored through the development of regression models fitted by alternating the linear, exponential and polynomial terms for PR. The predictive ranges of TPR were explored for PR endemicity risk groups of control programmatic value using cut-offs of low (PR <5%) and high (PR ≥ 30%) transmission intensity.<h4>Results</h4>Among 28,134 febrile patients encountered for malaria diagnostic testing in the health facilities, 12,143 (43.2%: 95% CI: 42.6%, 43.7%) were positive. The overall community PR was 9.9% (95% CI: 9.2%, 10.7%) among 6,479 participants tested for malaria. The polynomial model was the best fitting model for the data that described the algebraic relationship between TPR and PR. In this setting, a TPR of ≥ 49% in all age groups corresponded to an age-standardized PR of ≥ 30%, while a TPR of < 40% corresponded to an age-standardized PR of < 5%.<h4>Conclusion</h4>A non-linear relationship was observed between the relative change in TPR and changes in the PR, which is likely to have important implications for malaria surveillance programs, especially at the extremes of transmission. However, larger, more spatially diverse data series using routinely collected TPR data matched to community-based infection prevalence data are required to explore the more practical implications of using TPR as a replacement for community PR. |
| first_indexed | 2024-12-13T22:33:27Z |
| format | Article |
| id | doaj.art-b605086f336941c99a2e0cc1d6290414 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-13T22:33:27Z |
| publishDate | 2020-01-01 |
| publisher | Public Library of Science (PLoS) |
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| series | PLoS ONE |
| spelling | doaj.art-b605086f336941c99a2e0cc1d62904142022-12-21T23:29:02ZengPublic Library of Science (PLoS)PLoS ONE1932-62032020-01-011510e024005810.1371/journal.pone.0240058The relationship between facility-based malaria test positivity rate and community-based parasite prevalence.Alice KamauGrace MtanjeChristine MatazaLucas MallaPhilip BejonRobert W Snow<h4>Introduction</h4>Malaria surveillance is a key pillar in the control of malaria in Africa. The value of using routinely collected data from health facilities to define malaria risk at community levels remains poorly defined.<h4>Methods</h4>Four cross-sectional parasite prevalence surveys were undertaken among residents at 36 enumeration zones in Kilifi county on the Kenyan coast and temporally and spatially matched to fever surveillance at 6 health facilities serving the same communities over 12 months. The age-structured functional form of the relationship between test positivity rate (TPR) and community-based parasite prevalence (PR) was explored through the development of regression models fitted by alternating the linear, exponential and polynomial terms for PR. The predictive ranges of TPR were explored for PR endemicity risk groups of control programmatic value using cut-offs of low (PR <5%) and high (PR ≥ 30%) transmission intensity.<h4>Results</h4>Among 28,134 febrile patients encountered for malaria diagnostic testing in the health facilities, 12,143 (43.2%: 95% CI: 42.6%, 43.7%) were positive. The overall community PR was 9.9% (95% CI: 9.2%, 10.7%) among 6,479 participants tested for malaria. The polynomial model was the best fitting model for the data that described the algebraic relationship between TPR and PR. In this setting, a TPR of ≥ 49% in all age groups corresponded to an age-standardized PR of ≥ 30%, while a TPR of < 40% corresponded to an age-standardized PR of < 5%.<h4>Conclusion</h4>A non-linear relationship was observed between the relative change in TPR and changes in the PR, which is likely to have important implications for malaria surveillance programs, especially at the extremes of transmission. However, larger, more spatially diverse data series using routinely collected TPR data matched to community-based infection prevalence data are required to explore the more practical implications of using TPR as a replacement for community PR.https://doi.org/10.1371/journal.pone.0240058 |
| spellingShingle | Alice Kamau Grace Mtanje Christine Mataza Lucas Malla Philip Bejon Robert W Snow The relationship between facility-based malaria test positivity rate and community-based parasite prevalence. PLoS ONE |
| title | The relationship between facility-based malaria test positivity rate and community-based parasite prevalence. |
| title_full | The relationship between facility-based malaria test positivity rate and community-based parasite prevalence. |
| title_fullStr | The relationship between facility-based malaria test positivity rate and community-based parasite prevalence. |
| title_full_unstemmed | The relationship between facility-based malaria test positivity rate and community-based parasite prevalence. |
| title_short | The relationship between facility-based malaria test positivity rate and community-based parasite prevalence. |
| title_sort | relationship between facility based malaria test positivity rate and community based parasite prevalence |
| url | https://doi.org/10.1371/journal.pone.0240058 |
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