Prevalence of Malaria and Chikungunya Co-Infection in Febrile Patients: A Systematic Review and Meta-Analysis.

Co-infection with malaria and chikungunya (CHIKV) could exert a significant public health impact with infection misdiagnosis. Therefore, this study aimed to collect qualitative and quantitative evidence of malaria and CHIKV co-infection among febrile patients. Potentially relevant studies were identified using PubMed, Web of Science, and Scopus. The bias risk of the included studies was assessed using the checklist for analytical cross-sectional studies developed by the Joanna Briggs Institute. The pooled prevalence of malaria and CHIKV co-infection among febrile patients and the pooled prevalence of CHIKV infection among malaria patients were estimated with the random effect model. The odds of malaria and CHIKV co-infection among febrile patients were also estimated using a random effect model that presumed the heterogeneity of the outcomes of the included studies. The heterogeneity among the included studies was assessed using the Cochran Q test and I statistics. Publication bias was assessed using the funnel plot and Egger's test. Of the 1924 studies that were identified from the three databases, 10 fulfilled the eligibility criteria and were included in our study. The pooled prevalence of malaria and CHIKV co-infection (182 cases) among febrile patients (16,787 cases), stratified by diagnostic tests for CHIKV, was 10% (95% confidence interval (CI): 8-11%, I: 99.5%) using RDT (IgM), 7% (95% CI: 4-10%) using the plaque reduction neutralization test (PRNT), 1% (95% CI: 0-2%, I: 41.5%) using IgM and IgG ELISA, and 4% (95% CI: 2-6%) using real-time RT-PCR. When the prevalence was stratified by country, the prevalence of co-infection was 7% (95% CI: 5-10%, I: 99.5%) in Nigeria, 1% (95% CI: 0-2%, I: 99.5%) in Tanzania, 10% (95% CI: 8-11%) in Sierra Leone, 1% (95% CI: 0-4%) in Mozambique, and 4% (95% CI: 2-6%) in Kenya. The pooled prevalence of CHIKV infection (182 cases) among malaria patients (8317 cases), stratified by diagnostic tests for CHIKV, was 39% (95% CI: 34-44%, I: 99.7%) using RDT (IgM), 43% (95% CI: 30-57%) using PRNT, 5% (95% CI: 3-7%, I: 5.18%) using IgM and IgG ELISA, and 9% (95% CI: 6-15%) using real-time RT-PCR. The meta-analysis showed that malaria and CHIKV co-infection occurred by chance (: 0.59, OR: 0.32, 95% CI: 0.6-1.07, I: 78.5%). The prevalence of malaria and CHIKV co-infection varied from 0% to 10% as per the diagnostic test for CHIKV infection or the country where the co-infection was reported. Hence, the clinicians who diagnose patients with malaria infections in areas where two diseases are endemic should further investigate for CHIKV co-infection to prevent misdiagnosis or delayed treatment of concurrent infection.