Age-patterns of malaria vary with severity, transmission intensity and seasonality in sub-Saharan Africa: a systematic review and pooled analysis.
<h4>Background</h4>There is evidence that the age-pattern of Plasmodium falciparum malaria varies with transmission intensity. A better understanding of how this varies with the severity of outcome and across a range of transmission settings could enable locally appropriate targeting of...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2010-02-01
|
| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0008988 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850110204303114240 |
|---|---|
| author | Ilona Carneiro Arantxa Roca-Feltrer Jamie T Griffin Lucy Smith Marcel Tanner Joanna Armstrong Schellenberg Brian Greenwood David Schellenberg |
| author_facet | Ilona Carneiro Arantxa Roca-Feltrer Jamie T Griffin Lucy Smith Marcel Tanner Joanna Armstrong Schellenberg Brian Greenwood David Schellenberg |
| author_sort | Ilona Carneiro |
| collection | DOAJ |
| description | <h4>Background</h4>There is evidence that the age-pattern of Plasmodium falciparum malaria varies with transmission intensity. A better understanding of how this varies with the severity of outcome and across a range of transmission settings could enable locally appropriate targeting of interventions to those most at risk. We have, therefore, undertaken a pooled analysis of existing data from multiple sites to enable a comprehensive overview of the age-patterns of malaria outcomes under different epidemiological conditions in sub-Saharan Africa.<h4>Methodology/principal findings</h4>A systematic review using PubMed and CAB Abstracts (1980-2005), contacts with experts and searching bibliographies identified epidemiological studies with data on the age distribution of children with P. falciparum clinical malaria, hospital admissions with malaria and malaria-diagnosed mortality. Studies were allocated to a 3x2 matrix of intensity and seasonality of malaria transmission. Maximum likelihood methods were used to fit five continuous probability distributions to the percentage of each outcome by age for each of the six transmission scenarios. The best-fitting distributions are presented graphically, together with the estimated median age for each outcome. Clinical malaria incidence was relatively evenly distributed across the first 10 years of life for all transmission scenarios. Hospital admissions with malaria were more concentrated in younger children, with this effect being even more pronounced for malaria-diagnosed deaths. For all outcomes, the burden of malaria shifted towards younger ages with increasing transmission intensity, although marked seasonality moderated this effect.<h4>Conclusions</h4>The most severe consequences of P. falciparum malaria were concentrated in the youngest age groups across all settings. Despite recently observed declines in malaria transmission in several countries, which will shift the burden of malaria cases towards older children, it is still appropriate to target strategies for preventing malaria mortality and severe morbidity at very young children who will continue to bear the brunt of malaria deaths in sub-Saharan Africa. |
| format | Article |
| id | doaj-art-9760c3bd9e0f46a5977f71e52dc5fd70 |
| institution | OA Journals |
| issn | 1932-6203 |
| language | English |
| publishDate | 2010-02-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj-art-9760c3bd9e0f46a5977f71e52dc5fd702025-08-20T02:37:52ZengPublic Library of Science (PLoS)PLoS ONE1932-62032010-02-0152e898810.1371/journal.pone.0008988Age-patterns of malaria vary with severity, transmission intensity and seasonality in sub-Saharan Africa: a systematic review and pooled analysis.Ilona CarneiroArantxa Roca-FeltrerJamie T GriffinLucy SmithMarcel TannerJoanna Armstrong SchellenbergBrian GreenwoodDavid Schellenberg<h4>Background</h4>There is evidence that the age-pattern of Plasmodium falciparum malaria varies with transmission intensity. A better understanding of how this varies with the severity of outcome and across a range of transmission settings could enable locally appropriate targeting of interventions to those most at risk. We have, therefore, undertaken a pooled analysis of existing data from multiple sites to enable a comprehensive overview of the age-patterns of malaria outcomes under different epidemiological conditions in sub-Saharan Africa.<h4>Methodology/principal findings</h4>A systematic review using PubMed and CAB Abstracts (1980-2005), contacts with experts and searching bibliographies identified epidemiological studies with data on the age distribution of children with P. falciparum clinical malaria, hospital admissions with malaria and malaria-diagnosed mortality. Studies were allocated to a 3x2 matrix of intensity and seasonality of malaria transmission. Maximum likelihood methods were used to fit five continuous probability distributions to the percentage of each outcome by age for each of the six transmission scenarios. The best-fitting distributions are presented graphically, together with the estimated median age for each outcome. Clinical malaria incidence was relatively evenly distributed across the first 10 years of life for all transmission scenarios. Hospital admissions with malaria were more concentrated in younger children, with this effect being even more pronounced for malaria-diagnosed deaths. For all outcomes, the burden of malaria shifted towards younger ages with increasing transmission intensity, although marked seasonality moderated this effect.<h4>Conclusions</h4>The most severe consequences of P. falciparum malaria were concentrated in the youngest age groups across all settings. Despite recently observed declines in malaria transmission in several countries, which will shift the burden of malaria cases towards older children, it is still appropriate to target strategies for preventing malaria mortality and severe morbidity at very young children who will continue to bear the brunt of malaria deaths in sub-Saharan Africa.https://doi.org/10.1371/journal.pone.0008988 |
| spellingShingle | Ilona Carneiro Arantxa Roca-Feltrer Jamie T Griffin Lucy Smith Marcel Tanner Joanna Armstrong Schellenberg Brian Greenwood David Schellenberg Age-patterns of malaria vary with severity, transmission intensity and seasonality in sub-Saharan Africa: a systematic review and pooled analysis. PLoS ONE |
| title | Age-patterns of malaria vary with severity, transmission intensity and seasonality in sub-Saharan Africa: a systematic review and pooled analysis. |
| title_full | Age-patterns of malaria vary with severity, transmission intensity and seasonality in sub-Saharan Africa: a systematic review and pooled analysis. |
| title_fullStr | Age-patterns of malaria vary with severity, transmission intensity and seasonality in sub-Saharan Africa: a systematic review and pooled analysis. |
| title_full_unstemmed | Age-patterns of malaria vary with severity, transmission intensity and seasonality in sub-Saharan Africa: a systematic review and pooled analysis. |
| title_short | Age-patterns of malaria vary with severity, transmission intensity and seasonality in sub-Saharan Africa: a systematic review and pooled analysis. |
| title_sort | age patterns of malaria vary with severity transmission intensity and seasonality in sub saharan africa a systematic review and pooled analysis |
| url | https://doi.org/10.1371/journal.pone.0008988 |
| work_keys_str_mv | AT ilonacarneiro agepatternsofmalariavarywithseveritytransmissionintensityandseasonalityinsubsaharanafricaasystematicreviewandpooledanalysis AT arantxarocafeltrer agepatternsofmalariavarywithseveritytransmissionintensityandseasonalityinsubsaharanafricaasystematicreviewandpooledanalysis AT jamietgriffin agepatternsofmalariavarywithseveritytransmissionintensityandseasonalityinsubsaharanafricaasystematicreviewandpooledanalysis AT lucysmith agepatternsofmalariavarywithseveritytransmissionintensityandseasonalityinsubsaharanafricaasystematicreviewandpooledanalysis AT marceltanner agepatternsofmalariavarywithseveritytransmissionintensityandseasonalityinsubsaharanafricaasystematicreviewandpooledanalysis AT joannaarmstrongschellenberg agepatternsofmalariavarywithseveritytransmissionintensityandseasonalityinsubsaharanafricaasystematicreviewandpooledanalysis AT briangreenwood agepatternsofmalariavarywithseveritytransmissionintensityandseasonalityinsubsaharanafricaasystematicreviewandpooledanalysis AT davidschellenberg agepatternsofmalariavarywithseveritytransmissionintensityandseasonalityinsubsaharanafricaasystematicreviewandpooledanalysis |