The clinical profile of severe paediatric malaria in an area targeted for routine RTS,S/AS01 malaria vaccination in Western Kenya.

BACKGROUND: Malaria prevalence has declined in western Kenya resulting in risk of neurological phenotypes in older children. This study investigates clinical the profile of paediatric malaria admissions ahead of the introduction of RTS,S/AS01 vaccine. METHODS: Malaria admissions, aged 1 month to 15 years, were identified from routine standardised inpatient clinical surveillance data collected between 2015 and 2018 from 4 hospitals in western Kenya. Malaria phenotypes were defined based on available data. RESULTS: 5,766 malaria admissions were documented; the median age was 36 (interquartile range, 18-60) months; 15% were aged between 1-11 months of age, 33% were aged 1-23 months of age, and 70% were aged 1 month to 5 years. At admission, 2,340 (40.6%) children had severe malaria; 421/2,208 (19.1%) with impaired consciousness, 665/2,240 (29.7%) with inability to drink or breastfeed, 317/2,340 (13.6%) with two or more convulsions, 1,057/2,340 (45.2%) with severe anaemia, and 441/2,239 (19.7%) with severe respiratory distress. Overall, 211 (3.7%) of malaria admissions died; 163/211 (77% deaths, case fatality 7.0%) and 48/211(23% deaths, case fatality 1.4% ) met criteria for severe malaria and non-severe malaria at admission respectively. Median age for fatal cases was 33 (interquartile range, 12-72) months and case fatality was highest in those unconscious (44.4%). CONCLUSION: Severe malaria in western Kenya is still predominantly among the younger paediatric age group and current interventions targeted for those <5 years are appropriate. However, there are increasing numbers of children older than 5 years and on-going hospital surveillance would identify when interventions should target older children.