Evidence of malarial chemoprophylaxis among travellers who died from malaria: a systematic review and meta-analysis

BACKGROUND: Chemoprophylaxis is a prevention method for malaria during travel in malaria-endemic countries. This study aimed to collate and synthesize the evidence of malarial chemoprophylaxis among malaria death cases. METHODS: Studies documenting malarial chemoprophylaxis related to malaria deaths were searched in PubMed, Scopus, MEDLINE, Embase, and CENTRAL until 3 July 2022. The pooled proportion of malarial chemoprophylaxis among death cases was synthesized using logit transformation and back transformation to a proportion performed using generalized linear mixed models. The pooled log odds ratio (log-OR) with a 95% confidence interval (CI) of malarial chemoprophylaxis in death cases compared to survivors were synthesized. RESULTS: Fifty-eight studies were included in the systematic review and the meta-analysis. Of 602 pooled malaria death cases, the number of patients who took chemoprophylaxis was 187 (30%) (95% CI 22–40, P < 0.01, 58 studies), and those who took adequate chemoprophylaxis were 24 (5%) (95% CI 2–13, P < 0.01, 42 studies). A comparable log-OR of underwent chemoprophylaxis was observed between malaria death cases and survivors (P = 0.94, pooled log-OR: − 0.02, 95% CI − 0.46–0.42, I(2): 0%, 17 studies). Similarly, a comparable log-OR of adequate chemoprophylaxis was identified between malaria death cases and survivors (P = 0.15, pooled log-OR: 0.83, 95% CI − 0.30–1.97, I(2): 47.08%, 11 studies). CONCLUSIONS: Among the studies where malarial chemoprophylaxis was reported, approximately 30% of malaria death cases had taken such prophylaxis. Notably, only 5% of these cases adhered fully or adequately to the recommended chemoprophylactic regimen. However, the analysis did not reveal a significant difference in the odds of malarial chemoprophylaxis between malaria death cases and survivors. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12936-023-04794-x.