Severe anaemia in Kenyan children is shifting to older ages, 26-year study finds

Severe anaemia remains one of the commonest and deadliest reasons children are admitted to hospital in sub-Saharan Africa, and a 26-year record from a single Kenyan hospital shows both how heavy it still is and how its shape has changed. Of 84,348 admissions of children aged 1 month to 14 years to Kilifi County Hospital between August 1998 and July 2024, 16,715 — 19.8% — had severe anaemia, which was linked to roughly double the odds of dying in hospital and nearly triple the odds of a bloodstream infection [s1].

The most consequential finding is a shift in who is affected. As malaria transmission fell across the 2000s, the burden of severe anaemia moved from the youngest children towards older ones: the share of cases in children aged 5–14 years rose from 16.4% in the high-transmission era of 1998–2003 to 44.7% in the low-transmission era of 2010–2024 [s1]. A problem long framed as an affliction of under-fives is, in a lower-malaria setting, increasingly a problem of school-age children too.

What the surveillance captured

The study is a retrospective analysis of admission records systematically collected over 26 years at one hospital on the Kenyan coast, covering 64,499 unique children — 28,232 (43.8%) girls and 36,265 (56.2%) boys [s1]. Anaemia severity was classified using WHO age-specific haemoglobin thresholds, and children with missing haemoglobin data were excluded [s1]. That length of continuous, consistently coded surveillance is unusual, and it is what lets the authors see a trend rather than a snapshot.

Severe anaemia in these children was not one disease. It clustered with multiple co-occurring drivers — sickle cell disease, malaria, HIV and malnutrition — a reminder that "anaemia" is a common endpoint of several distinct problems rather than a single deficiency to be corrected with iron [s1]. That is also why the age shift matters: as malaria's contribution shrank, the other causes made up a larger share of a still-substantial total.

The link to bloodstream infection

The study's clinical point is about what severe anaemia signals. Compared with children who had mild or no anaemia, those with severe anaemia had higher adjusted odds of in-hospital death (adjusted odds ratio 2.1, 95% CI 1.9–2.3) and of bacteraemia (2.7, 2.5–3.0) [s1]. The association with specific pathogens was stronger still: the adjusted odds of non-typhoidal Salmonella bacteraemia were 6.1 (4.6–8.1) times higher, of Escherichia coli 5.7 (4.2–7.7), of Haemophilus influenzae 4.3 (3.0–6.4), of Streptococcus pneumoniae 3.5 (2.9–4.2) and of Klebsiella pneumoniae 2.4 (1.4–4.0) [s1]. Even moderate anaemia carried increased odds of both bacteraemia and death [s1].

Those numbers turn a haemoglobin reading into a triage signal. A severely anaemic child is not only short of red cells but, on these data, markedly more likely to be carrying an invasive bacterial infection — which argues for prompt evaluation for bacteraemia and closer monitoring rather than treatment of the anaemia alone [s1]. The authors frame their conclusion in exactly those clinical terms.

What it means for policy

An accompanying commentary draws out the programmatic implication: severe anaemia in African children should no longer be treated as a problem confined to the under-fives [s2]. Immunisation schedules, malaria control and anaemia screening are largely built around young children, yet the data show a rising share of the burden in an older group that current programmes are not designed to reach [s2].

The study is a single-site, hospital-based record, so it captures children sick enough to be admitted rather than anaemia in the community, and the coastal Kenyan setting will not map exactly onto high-malaria regions where the under-five pattern still dominates. But as a long, consistent series it does something short studies cannot: it shows a burden changing its age profile as its main driver recedes. It complements the long-run infant mortality record from the same Kilifi platform and sits alongside the wider picture of child undernutrition that is not converting into better outcomes. The practical message is that as malaria falls, the systems built to catch severe anaemia in toddlers will need to look higher up the age range as well.

Sources

• Severe anaemia and invasive bacterial infections in Kenyan children: a 26-year hospital surveillance observational study — The Lancet Global Health, 30 June 2026
• Severe anaemia in African children: look beyond under-fives — The Lancet Global Health, 30 June 2026