Introduction

Dengue fever has long posed a significant threat to public health globally, attributed primarily to its transmission by Aedes mosquitoes and infection by the dengue virus (DENV). While the disease became increasingly notorious in the last century, its roots date back earlier, with an intriguing narrative surrounding its occurrence in China.

Historical Spread of Dengue

Historically, DENV spread extensively across tropical regions during the 18th and 19th centuries, but its upward trajectory accelerated in the 20th and 21st centuries due to several factors. Among these are rapid urbanization, heightened human migration, advancements in transportation, global trade, climate change, and ineffective mosquito control measures. Notably, the rise of civil aviation in the 1970s significantly expanded the reach of dengue outbreaks globally, hinting at an intricate relationship between human activities and virus spread. Currently, the World Health Organization estimates that around 390 million dengue cases occur annually, with 2.5 to 4 billion individuals at risk.

Dengue in China Post-1978

China's dengue narrative took a sharp turn in May 1978 when a dengue outbreak, associated with the DENV-4 serotype, was reported in Foshan, Guangdong Province. The subsequent years witnessed repeated outbreaks in various provinces, particularly Guangdong and Hainan, that continue to echo in the region's public health records. Striking increases in dengue cases were observed in 1995, 2002, and 2006, with cases surpassing a thousand. The peak of these outbreaks during 2013-2014 saw the co-circulation of multiple DENV serotypes, marking a troubling evolution in the disease's epidemiology.

Exploring Historical Accounts

Interestingly, the historical accounts of dengue in China prior to 1978 remain sparse. With key records beginning in 1978, researchers now seek to uncover potential earlier dengue events through ancient Chinese literature. Preliminary examinations reveal references to symptoms resembling dengue fever under terms such as ‘yellow disease’ and ‘red exanthem.’ However, these descriptions often lack clarity, making precise identification challenging.

Verification of Ancient Texts

One widely cited source, the "Handbook of Prescriptions for Emergencies," dates back to the Jin Dynasty (AD 317–420) and purportedly documents possible dengue-like symptoms, although further scrutiny suggests these may not be clinically consistent with modern definitions of dengue. Other texts mention, ‘water poison’—a term associated with schistosome cercarial dermatitis, which produce symptoms diverging from those seen in dengue.

Challenges in Identification

Analysis of historical records indicates that while there were descriptors for fever and skin disorders in ancient texts, these often could relate to other conditions, making definitive identification of dengue prior to 1978 problematic. It is suggested that significant socio-political upheavals in China, coupled with limited trade activities before reforms in 1978, contributed to the relatively low incidence of dengue.

Emergence of Dengue

Between 1840 and 1949, however, the emergence of dengue increasingly correlated with urban trade centers, particularly along China’s southeast coast. Notably, in 1942, Taiwan faced a catastrophic dengue epidemic with recorded cases reaching 114,722, estimated to involve about five million individuals.

Post-1978 Dynamics

Following China's policy reforms post-1978, advancements in trade and travel have heightened the dengue infection rate, reflecting a notable correlation between increasing openness to foreign interaction and disease prevalence. Recent studies indicate a complex evolution of dengue's introduction and spread in urban areas like Guangzhou, shifting from a straightforward importation pattern to a multifaceted epidemic landscape.

Conclusion

In summary, while ancient Chinese literature hints at possible early signals of dengue, the lack of conclusive records renders it difficult to assert historical dengue prevalence within the country. Ongoing research and analysis are vital for understanding the complex tapestry of disease dynamics in China, particularly as the nation grapples with rising dengue threats in today's interconnected world. What mysteries still lie hidden in the shadows of history about this deadly disease? Only time and further exploration can reveal the full story!