Observational study: 27 years of severe malaria surveillance in Kilifi, Kenya
Abstract Background Many parts of Africa have witnessed reductions in Plasmodium falciparum transmission over the last 15 years. Since immunity to malaria is acquired more rapidly at higher transmission, the slower acquisition of immunity at lower transmission may partially offset the benefits of re...
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| Format: | Article |
| Language: | English |
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BMC
2019-07-01
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| Series: | BMC Medicine |
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| Online Access: | http://link.springer.com/article/10.1186/s12916-019-1359-9 |
| _version_ | 1818525661500801024 |
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| author | Patricia Njuguna Kathryn Maitland Amek Nyaguara Daniel Mwanga Polycarp Mogeni Neema Mturi Shebe Mohammed Gabriel Mwambingu Caroline Ngetsa Kenedy Awuondo Brett Lowe Ifedayo Adetifa J. Anthony G. Scott Thomas N. Williams Sarah Atkinson Faith Osier Robert W. Snow Kevin Marsh Benjamin Tsofa Norbert Peshu Mainga Hamaluba James A. Berkley Charles R. J. Newton John Fondo Anisa Omar Philip Bejon |
| author_facet | Patricia Njuguna Kathryn Maitland Amek Nyaguara Daniel Mwanga Polycarp Mogeni Neema Mturi Shebe Mohammed Gabriel Mwambingu Caroline Ngetsa Kenedy Awuondo Brett Lowe Ifedayo Adetifa J. Anthony G. Scott Thomas N. Williams Sarah Atkinson Faith Osier Robert W. Snow Kevin Marsh Benjamin Tsofa Norbert Peshu Mainga Hamaluba James A. Berkley Charles R. J. Newton John Fondo Anisa Omar Philip Bejon |
| author_sort | Patricia Njuguna |
| collection | DOAJ |
| description | Abstract Background Many parts of Africa have witnessed reductions in Plasmodium falciparum transmission over the last 15 years. Since immunity to malaria is acquired more rapidly at higher transmission, the slower acquisition of immunity at lower transmission may partially offset the benefits of reductions in transmission. We examined the clinical spectrum of disease and predictors of mortality after sustained changes in transmission intensity, using data collected from 1989 to 2016. Methods We conducted a temporal observational analysis of 18,000 children, aged 14 days to 14 years old, who were admitted to Kilifi County Hospital, Kenya, from 1989 to 2016 with malaria. We describe the trends over time of the clinical and laboratory criteria for severe malaria and associated risk of mortality. Results During the time periods 1989–2003, 2004–2008, and 2009–2016, Kilifi County Hospital admitted averages of 657, 310, and 174 cases of severe malaria per year including averages of 48, 14, and 12 malaria-associated deaths per year, respectively. The median ages in years of children admitted with cerebral malaria, severe anaemia, and malaria-associated mortality were 3.0 (95% confidence interval (CI) 2.2–3.9), 1.1 (95% CI 0.9–1.4), and 1.1 (95% CI 0.3–2.2) in the year 1989, rising to 4.9 (95% CI 3.9–5.9), 3.8 (95% CI 2.5–7.1), and 5 (95% CI 3.3–6.3) in the year 2016. The ratio of children with cerebral malaria to severe anaemia rose from 1:2 before 2004 to 3:2 after 2009. Hyperparasitaemia was a risk factor for death after 2009 but not in earlier time periods. Conclusion Despite the evidence of slower acquisition of immunity, continued reductions in the numbers of cases of severe malaria resulted in lower overall mortality. Our temporal data are limited to a single site, albeit potentially applicable to a secular trend present in many parts of Africa. |
| first_indexed | 2024-12-11T06:11:55Z |
| format | Article |
| id | doaj.art-c1befe849c3e438fbf36d5ac55551b4a |
| institution | Directory Open Access Journal |
| issn | 1741-7015 |
| language | English |
| last_indexed | 2024-12-11T06:11:55Z |
| publishDate | 2019-07-01 |
| publisher | BMC |
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| series | BMC Medicine |
| spelling | doaj.art-c1befe849c3e438fbf36d5ac55551b4a2022-12-22T01:18:06ZengBMCBMC Medicine1741-70152019-07-011711910.1186/s12916-019-1359-9Observational study: 27 years of severe malaria surveillance in Kilifi, KenyaPatricia Njuguna0Kathryn Maitland1Amek Nyaguara2Daniel Mwanga3Polycarp Mogeni4Neema Mturi5Shebe Mohammed6Gabriel Mwambingu7Caroline Ngetsa8Kenedy Awuondo9Brett Lowe10Ifedayo Adetifa11J. Anthony G. Scott12Thomas N. Williams13Sarah Atkinson14Faith Osier15Robert W. Snow16Kevin Marsh17Benjamin Tsofa18Norbert Peshu19Mainga Hamaluba20James A. Berkley21Charles R. J. Newton22John Fondo23Anisa Omar24Philip Bejon25KEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIKilifi County Department of HealthKilifi County Department of HealthKEMRI-Wellcome Trust Research Programme, CGMR-C, KEMRIAbstract Background Many parts of Africa have witnessed reductions in Plasmodium falciparum transmission over the last 15 years. Since immunity to malaria is acquired more rapidly at higher transmission, the slower acquisition of immunity at lower transmission may partially offset the benefits of reductions in transmission. We examined the clinical spectrum of disease and predictors of mortality after sustained changes in transmission intensity, using data collected from 1989 to 2016. Methods We conducted a temporal observational analysis of 18,000 children, aged 14 days to 14 years old, who were admitted to Kilifi County Hospital, Kenya, from 1989 to 2016 with malaria. We describe the trends over time of the clinical and laboratory criteria for severe malaria and associated risk of mortality. Results During the time periods 1989–2003, 2004–2008, and 2009–2016, Kilifi County Hospital admitted averages of 657, 310, and 174 cases of severe malaria per year including averages of 48, 14, and 12 malaria-associated deaths per year, respectively. The median ages in years of children admitted with cerebral malaria, severe anaemia, and malaria-associated mortality were 3.0 (95% confidence interval (CI) 2.2–3.9), 1.1 (95% CI 0.9–1.4), and 1.1 (95% CI 0.3–2.2) in the year 1989, rising to 4.9 (95% CI 3.9–5.9), 3.8 (95% CI 2.5–7.1), and 5 (95% CI 3.3–6.3) in the year 2016. The ratio of children with cerebral malaria to severe anaemia rose from 1:2 before 2004 to 3:2 after 2009. Hyperparasitaemia was a risk factor for death after 2009 but not in earlier time periods. Conclusion Despite the evidence of slower acquisition of immunity, continued reductions in the numbers of cases of severe malaria resulted in lower overall mortality. Our temporal data are limited to a single site, albeit potentially applicable to a secular trend present in many parts of Africa.http://link.springer.com/article/10.1186/s12916-019-1359-9Severe malariaSecular trendMortalityAfricaLongitudinal surveillance |
| spellingShingle | Patricia Njuguna Kathryn Maitland Amek Nyaguara Daniel Mwanga Polycarp Mogeni Neema Mturi Shebe Mohammed Gabriel Mwambingu Caroline Ngetsa Kenedy Awuondo Brett Lowe Ifedayo Adetifa J. Anthony G. Scott Thomas N. Williams Sarah Atkinson Faith Osier Robert W. Snow Kevin Marsh Benjamin Tsofa Norbert Peshu Mainga Hamaluba James A. Berkley Charles R. J. Newton John Fondo Anisa Omar Philip Bejon Observational study: 27 years of severe malaria surveillance in Kilifi, Kenya BMC Medicine Severe malaria Secular trend Mortality Africa Longitudinal surveillance |
| title | Observational study: 27 years of severe malaria surveillance in Kilifi, Kenya |
| title_full | Observational study: 27 years of severe malaria surveillance in Kilifi, Kenya |
| title_fullStr | Observational study: 27 years of severe malaria surveillance in Kilifi, Kenya |
| title_full_unstemmed | Observational study: 27 years of severe malaria surveillance in Kilifi, Kenya |
| title_short | Observational study: 27 years of severe malaria surveillance in Kilifi, Kenya |
| title_sort | observational study 27 years of severe malaria surveillance in kilifi kenya |
| topic | Severe malaria Secular trend Mortality Africa Longitudinal surveillance |
| url | http://link.springer.com/article/10.1186/s12916-019-1359-9 |
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