Limits...
The age patterns of severe malaria syndromes in sub-Saharan Africa across a range of transmission intensities and seasonality settings.

Roca-Feltrer A, Carneiro I, Smith L, Schellenberg JR, Greenwood B, Schellenberg D - Malar. J. (2010)

Bottom Line: A systematic literature review identified studies which reported the age of paediatric hospital admissions with cerebral malaria (CM), severe malarial anaemia (SMA), or respiratory distress (RD).Sites with 'no marked seasonality' showed more evidence of skewed age-patterns compared to areas of 'marked seasonality' for all three severe malaria syndromes.Although the peak age of CM will increase as transmission intensity decreases in Africa, more than 75% of all paediatric hospital admissions of severe malaria are likely to remain in under five year olds in most epidemiological settings.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Disease Control, Faculty of Infectious & Tropical Disease, London School of Hygiene & Tropical Medicine, Keppel Street, London, UK. arantxa.roca-feltrer@lshtm.ac.uk

ABSTRACT

Background: A greater understanding of the relationship between transmission intensity, seasonality and the age-pattern of malaria is needed to guide appropriate targeting of malaria interventions in different epidemiological settings.

Methods: A systematic literature review identified studies which reported the age of paediatric hospital admissions with cerebral malaria (CM), severe malarial anaemia (SMA), or respiratory distress (RD). Study sites were categorized into a 3 × 2 matrix of Plasmodium falciparum transmission intensity and seasonality. Probability distributions were fitted by maximum likelihood methods, and best fitting models were used to estimate median ages and to represent graphically the age-pattern of each outcome for each transmission category in the matrix.

Results: A shift in the burden of CM towards younger age groups was seen with increasing intensity of transmission, but this was not the case for SMA or RD. Sites with 'no marked seasonality' showed more evidence of skewed age-patterns compared to areas of 'marked seasonality' for all three severe malaria syndromes.

Conclusions: Although the peak age of CM will increase as transmission intensity decreases in Africa, more than 75% of all paediatric hospital admissions of severe malaria are likely to remain in under five year olds in most epidemiological settings.

Show MeSH

Related in: MedlinePlus

Age-patterns of respiratory distress in Sub-Saharan Africa. Percentage of respiratory distress admissions per month of age in children under 10 years of age, by transmission intensity (TI) and seasonality of malaria transmission.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2992028&req=5

Figure 3: Age-patterns of respiratory distress in Sub-Saharan Africa. Percentage of respiratory distress admissions per month of age in children under 10 years of age, by transmission intensity (TI) and seasonality of malaria transmission.

Mentions: Figures 1, 2 and 3 show the percentage distribution of each severe malaria syndrome by age for children under 10 years, such that the integral of the curve is equal to 100% of expected cases. As shown in these figures, the age-pattern of each specific syndrome varied by seasonality: for a given transmission intensity, a shift of the peak age to younger children was observed in 'no marked seasonality' settings compared to 'marked seasonality' settings.


The age patterns of severe malaria syndromes in sub-Saharan Africa across a range of transmission intensities and seasonality settings.

Roca-Feltrer A, Carneiro I, Smith L, Schellenberg JR, Greenwood B, Schellenberg D - Malar. J. (2010)

Age-patterns of respiratory distress in Sub-Saharan Africa. Percentage of respiratory distress admissions per month of age in children under 10 years of age, by transmission intensity (TI) and seasonality of malaria transmission.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2992028&req=5

Figure 3: Age-patterns of respiratory distress in Sub-Saharan Africa. Percentage of respiratory distress admissions per month of age in children under 10 years of age, by transmission intensity (TI) and seasonality of malaria transmission.
Mentions: Figures 1, 2 and 3 show the percentage distribution of each severe malaria syndrome by age for children under 10 years, such that the integral of the curve is equal to 100% of expected cases. As shown in these figures, the age-pattern of each specific syndrome varied by seasonality: for a given transmission intensity, a shift of the peak age to younger children was observed in 'no marked seasonality' settings compared to 'marked seasonality' settings.

Bottom Line: A systematic literature review identified studies which reported the age of paediatric hospital admissions with cerebral malaria (CM), severe malarial anaemia (SMA), or respiratory distress (RD).Sites with 'no marked seasonality' showed more evidence of skewed age-patterns compared to areas of 'marked seasonality' for all three severe malaria syndromes.Although the peak age of CM will increase as transmission intensity decreases in Africa, more than 75% of all paediatric hospital admissions of severe malaria are likely to remain in under five year olds in most epidemiological settings.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Disease Control, Faculty of Infectious & Tropical Disease, London School of Hygiene & Tropical Medicine, Keppel Street, London, UK. arantxa.roca-feltrer@lshtm.ac.uk

ABSTRACT

Background: A greater understanding of the relationship between transmission intensity, seasonality and the age-pattern of malaria is needed to guide appropriate targeting of malaria interventions in different epidemiological settings.

Methods: A systematic literature review identified studies which reported the age of paediatric hospital admissions with cerebral malaria (CM), severe malarial anaemia (SMA), or respiratory distress (RD). Study sites were categorized into a 3 × 2 matrix of Plasmodium falciparum transmission intensity and seasonality. Probability distributions were fitted by maximum likelihood methods, and best fitting models were used to estimate median ages and to represent graphically the age-pattern of each outcome for each transmission category in the matrix.

Results: A shift in the burden of CM towards younger age groups was seen with increasing intensity of transmission, but this was not the case for SMA or RD. Sites with 'no marked seasonality' showed more evidence of skewed age-patterns compared to areas of 'marked seasonality' for all three severe malaria syndromes.

Conclusions: Although the peak age of CM will increase as transmission intensity decreases in Africa, more than 75% of all paediatric hospital admissions of severe malaria are likely to remain in under five year olds in most epidemiological settings.

Show MeSH
Related in: MedlinePlus