We still dońt know who bleeds in Dengue. A systematic review of the literature

Abstract

Abstract Background Already, Dengue affects 400 million individuals every year. Its main drivers, urbanization, globalization, and climate change, however, will spread the disease even further and potentially threaten billions. In Dengue, bleeding occurs frequently. Severe bleeding strongly increases mortality and immediate medical response is crucial for survival. Predicting the occurrence and course of bleeding in advance would improve clinical outcome, reduce unnecessary hospitalization, and improve economic efficiency. Methods Following the PRISMA-guidelines, we conducted a systematic review of the literature to identify predictors of bleeding in acute confirmed Dengue. We searched Pubmed, Web of Science, IRIS, LILACS, and the Cochrane Archives and included all prospective longitudinal studies restricting neither language nor study sample characteristics. Results We included 19 studies but found that most data suffered from high risk of bias because of poor reporting and not accounting for confounding. Only five studies were more reliable, and they unanimously reported that age-, and platelet count predicted bleeding severity. The body of evidence was too weak to draw conclusions for the other 23 markers investigated. Crucially, the researchers had defined central concepts in fundamentally different ways and thus prevented the comparison of their findings. Conclusions Our systematic review of the literature showed that more research is needed to create a reliable prediction model for bleeding in Dengue. We have moderate certainty that platelet count- and age predict bleeding severity. Our study exposed the urgent need to improve the quality of research in Dengue epidemiology. Most importantly, our findings illustrate the necessity to harmonize central concepts within the Dengue research community. To tackle the challenge that Dengue is bound to become, we need dialogue across research groups and collaboration that overcomes the limited impact of individual studies. Key messages We know too little about predictors of bleeding in Dengue. Reliable data is needed to identify new markers and to confirm existing markers that are carried by a weak body of evidence. We urge investigators to collaborate. To overcome the limitations of individual studies, we need better comparability and a scientific dialogue based on common definitions of core concepts in Dengue.