Photos by @junmichaelpark @seoulphotographer for @lemondefr / In late November, I spent an afternoon following two public officers from the Seocho District Office in southern Seoul. These officers work as epidemiological investigators at the frontline of South Korea’s battle against Covid-19.

The country has contained the coronavirus through aggressive testing and contact tracing, a process to precisely establish a confirmed Covid-19 case’s past whereabouts and identify any person that may have come in contact with them. The officers’ work involves location tracking through GPS data, footages from CCTV cameras and credit card usage.

Many outside of Korea are put off and alarmed by what seems like an Orwellian measure. As I followed the investigators, however, I realized contact tracing still requires a considerable amount of human labor and judgment. Using discretion and following strict safeguards mandated by the law, the officers painstakingly went to every single place a case had visited several days prior to testing positive for Covid-19.

I’m grateful to these public officers and other unsung heroes who are tirelessly working to keep us safe. I hope they get compensated properly and fairly.

The story was featured on A1 in yesterday’s Le Monde, with the online version featuring 14 photographs of mine. Many thanks to photo editor Karine Granier Deferre and reporter Harold Thibault for this wonderful collaboration.

(Text editing by M.)