Evidence of and deaths from malaria and severe pneumonia co-infections in malaria-endemic areas: a systematic review and meta-analysis

Malaria and pneumonia are the leading causes of childhood mortality in children under 5 years of age. Nevertheless, the proportions and deaths of malaria co-infection among patients with severe pneumonia, particularly in children under 5 years of age, and characteristics of co-infection remain poorly explored. Hence, the present study aimed to collate the evidence of malaria among patients with severe pneumonia, severe pneumonia among patients with malaria, and the proportion of deaths among patients with co-infections. Potentially relevant studies were searched in six databases including PubMed, Scopus, Web of Science, Embase, Ovid, and MEDLINE to identify studies on malaria and severe pneumonia co-infections that were published until 21 July 2022 with a restriction for the non-English language but no restriction for the publication year. The quality of the included studies was determined using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE). The pooled estimates, including the pooled proportion of malaria among patients with severe pneumonia, and the proportion of deaths among patients with co-infections, were estimated by the random-effects model. Of the 4094 studies examined, 11 studies that met the eligibility criteria were included in the review. Meta-analysis results showed that the proportion of malaria (2162 cases) among patients with severe pneumonia (9738 cases) was 19% (95% CI 12–26%, I²: 98.79%, 11 studies). The proportion of severe pneumonia (546 cases) among patients with malaria (10,325 cases) was 20% (95% CI 0–40%, I²: 99.48%, 4 studies). The proportion of deaths among patients with co-infection was 13% (95% CI 2–23%, I²: 85.1%, 3 studies). In conclusion, nearly one-fifth of patients with severe pneumonia have malaria, one-fifth of patients with malaria have severe pneumonia, and about 13% of co-infections lead to deaths. This information raised the clinical importance of diagnosis and management of concurrent infections. Patients with severe pneumonia should be investigated for malaria, and vice versa. Detection of co-infections might provide the information to inform the physician to manage and cure co-infected patients who live in areas where both diseases were endemic.