Anemia and neurologic disease drove longer hospitalization in severe malaria
Severe malaria in adults still fills hospital beds across malaria-endemic parts of sub-Saharan Africa, and this Brazzaville cohort shows how anemia can stretch that burden further. In adults hospitalized for severe malaria at four hospitals in the Republic of the Congo, anemia did more than mark illness severity; it tracked with longer stays, especially when paired with neurologic compromise or other major severity criteria.
The study reviewed medical records from January 2020 through December 2024 and focused on adults aged 18 years and older who met World Health Organization criteria for severe malaria. Among 523 hospitalized patients, 296 met the inclusion criteria for analysis. Median age was 25.5 years, the interquartile range was 20 to 40 years, 51.7% were female, and 82.1% had low socioeconomic status. Median hemoglobin was 10.55 g/dL, and the median length of stay was 4 days, with an interquartile range of 3 to 5 days.
A short admission was defined as fewer than 5 days. Anything longer was treated as prolonged hospitalization.
Hemoglobin deficits tracked with worse throughput and more complex disease
The central signal in this analysis was simple and clinically familiar: patients who arrived later and sicker stayed longer. Each additional day of delay to consultation increased the odds of prolonged hospitalization, with an adjusted odds ratio of 1.25 per day. In a setting where malaria can progress quickly from fever to multiorgan dysfunction, that delay likely reflects a larger inflammatory burden, greater parasitemia, and a higher chance that patients enter care with multiple organ systems already affected.
Anemia stood out as a major driver. Isolated anemia carried an adjusted odds ratio of 7.07 for prolonged length of stay compared with isolated hemoglobinuria, the reference severity category. Convulsions were associated with an adjusted odds ratio of 5.86, prostration with 4.42, and impaired consciousness with 4.29. These findings place anemia inside the broader pathobiology of severe malaria rather than treating it as a laboratory abnormality detached from bedside course.
Anemia did not behave like a background finding.
In severe malaria, red cell destruction, impaired erythropoiesis, and microvascular dysfunction converge. Reduced oxygen-carrying capacity can worsen tissue hypoxia, slow recovery, and complicate the management of neurologic symptoms, weakness, and hemodynamic instability. When anemia overlaps with cerebral manifestations, the threshold for transfusion, closer monitoring, and longer supportive care rises quickly, and that likely helps explain why hospital days lengthen.
Combined severity criteria produced the steepest rise in risk
The strongest associations emerged when anemia appeared alongside other severe malaria features. Anemia with prostration had an adjusted odds ratio of 8.58 for prolonged stay. Anemia combined with jaundice or hemoglobinuria carried an adjusted odds ratio of 16.21. The most striking estimate came from impaired consciousness with anemia, which reached an adjusted odds ratio of 33.31.
Those combinations matter because they reflect compound physiologic failure rather than a single isolated complication. Prostration can limit oral intake and delay recovery. Jaundice may signal hemolysis or hepatic dysfunction. Impaired consciousness raises concerns about cerebral malaria, aspiration risk, inability to maintain hydration, and the need for more intensive observation. Once anemia is layered onto these conditions, the patient becomes more fragile and less likely to stabilize quickly enough for early discharge.
The authors’ framing of anemia as potentially modifiable is especially relevant in this context. Screening hemoglobin early, triaging more aggressively when anemia coexists with neurologic compromise, and improving access to safe blood transfusion could shorten admission times if those steps are delivered promptly and consistently. In resource-constrained hospitals, a shorter stay also means fewer occupied beds and less pressure on staff who are already managing a high clinical load.
Why the delay to care may be as important as the hemoglobin value
Delay to consultation emerged as a separate independent predictor, and that result is easy to interpret at the bedside. In malaria, treatment delay allows parasite burden and systemic inflammation to deepen. By the time patients reach the hospital, they may have already crossed the threshold from uncomplicated febrile illness into severe disease with anemia, neurologic signs, or hemoglobinuria. Earlier presentation also gives clinicians a wider window to start antimalarial therapy, evaluate for transfusion needs, and prevent downstream complications that prolong hospitalization.
This study did not randomize treatment, and it cannot prove that correcting anemia alone will reduce length of stay. Even so, the pattern of associations is biologically coherent. Severe malaria damages red blood cells, disrupts microcirculation, and can impair cerebral function; each of those processes can delay recovery independently, and in combination they create a slower inpatient course. The data suggest that hemoglobin should be treated as a dynamic marker of severity, not a passive laboratory result.
What this cohort adds to severe malaria care in Central Africa
Data on adult severe malaria in Central Africa remain limited, which gives this cohort added practical value. The median age of 25.5 years shows that the burden falls heavily on younger adults, not only on children. The high proportion of patients with low socioeconomic status also points toward a health system reality in which delayed access to care may be shaping outcomes before admission even begins.
The analysis used multivariable logistic regression with backward stepwise selection to identify factors independently associated with prolonged stay. That approach isolates the strongest predictors available in the record-based dataset, but it also means the results depend on the quality and completeness of documentation. Still, the findings are internally consistent: more severe disease, later presentation, and lower hemoglobin all moved in the direction of longer hospitalization.
For frontline clinicians, the message is direct. Adults with severe malaria who present with anemia, especially when neurologic symptoms are present, deserve rapid escalation and close monitoring. The practical goal is not simply to treat malaria; it is to interrupt the cascade that keeps patients in hospital longer and increases strain on already limited beds and transfusion resources.
The preprint status also matters. These findings have not yet undergone peer review, so they should not be used alone to alter practice. Even so, the study identifies a clinically plausible pathway linking anemia, disease severity, and hospital throughput in Brazzaville, and it defines the next questions clearly: whether earlier transfusion, faster presentation, or more aggressive triage can shorten stays without introducing new safety concerns.