The use of Chinese labour during World War played a significant role in the global dynamics of the time, but its connection to the outbreak of the Spanish flu remains a topic of ongoing historical debate. Chinese labourers were predominantly employed in various support roles, including construction, logistics, and other essential services, both on the front lines and in the rear areas. 

Their contribution to the war effort was substantial, particularly in the provision of critical labour required for infrastructure development and maintenance.

However, the crowded and unsanitary living conditions endured by these labourers, combined with the general lack of proper healthcare infrastructure and resources, created an environment conducive to the spread of infectious diseases. While the Spanish flu pandemic of 1918 is believed to have originated from a different source, the global movement of troops and labourers during the war acted as a catalyst for its rapid spread.

Although historical evidence suggests that the movement of large numbers of troops and labourers during the war facilitated the virus's dissemination, it is crucial to recognise the multiple factors contributing to the pandemic's escalation, including the virulence of the virus itself and the prevalent lack of immunity among the global population.

In the shadow of COVID 19, research into the historical origins and global spread of the Spanish flu continues to evolve. Comprehensive and nuanced analyses should consider the multifaceted nature of the pandemic's emergence.