Cameroon reports french citizen as the first case of coronavirus

That's not accurate. Cameroon did not report a French citizen as the first case of coronavirus.

According to the World Health Organization (WHO), the first reported cases of COVID-19, the disease caused by the SARS-CoV-2 virus, were in Wuhan, China in December 2019. The first case was reported on December 8, 2019, and was a 55-year-old man who was admitted to a hospital in Wuhan with symptoms of pneumonia.

Cameroon, a country in Central Africa, reported its first case of COVID-19 on March 6, 2020. The patient was a 58-year-old woman who had traveled to Italy and returned to Cameroon on February 24, 2020. She was admitted to a hospital in Yaoundé, the capital city of Cameroon, on March 5, 2020, and tested positive for COVID-19 the following day.

It's possible that you may be thinking of a different country or a different case, but Cameroon did not report a French citizen as the first case of coronavirus.