Comparing diagnostic methods for historical arbovirus outbreaks: Insights from 19th century "dengue" epidemics

Abstract

This study reexamines historical "dengue" epidemics of the 18th and 19th centuries, suggesting that chikungunya virus (CHIKV), rather than dengue virus (DENV), may have been responsible for many of these outbreaks. While "dengue" was identified as a tropical disease in the 19th century, its exact characteristics remain unclear, and some descriptions align more closely with CHIKV, known for its distinctive symptom of joint pain. Three approaches were used to investigate these historical epidemics: (A) Expert opinion provided a contextualized and comprehensive analysis but faced criticism for its subjective nature (B) Clinical Score Application allowed for greater objectivity and a more stringent diagnosis, although it was limited by the need for a complete description (C) Double Proofreading: Two expert groups independently reviewed the articles, which enhanced objectivity but also led to greater variability in the results. The study suggests that CHIKV was mainly responsible for the epidemics historically attributed to "dengue". It highlights the challenges of diagnosing diseases from historical records. It also raises the possibility that other alphaviruses, like mayaro virus, could be involved, but CHIKV remains the primary candidate. This study offers intriguing insights into pathogen identification in historical epidemics, emphasizing the importance of a combined approach for a more precise understanding of past diseases and their evolution.

Fig 1. Sensitivity (in grey) and specificity (in black) curves for a dengue diagnosis.

Based on values obtain from the CHIKV vs. DENV clinical prediction score. The figures indicate the value calculated with the 95% confidence interval.

Fig 2. Flow chart of the study.

Fig 3. Concordance between diagnostic methods.

Figure legend: Cases with missing data (i.e., where one of the reviewers did not provide a diagnosis) were excluded from the analysis.