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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as the causative agent of the ongoing pandemic, has spread into more than 200 countries to date. The disease which is caused by the virus is termed COVID-19. In most cases, it presents at first like common flu with cough and other respiratory symptoms. Nevertheless, other symptoms have been reported, such as a feeling of extreme fatigue, gastrointestinal symptoms, or acute onset of olfactory and gustatory dysfunction. Here we report a series of 10 cases (1 male, 9 females) observed between February and April 2020, with an undulating appearance and disappearance of symptoms. Weeks passed before the diagnosis was established. Symptoms resolved rapidly after treatment with hydroxychloroquine. It seems that the course of COVID-19 can be mild or moderate but with a long persistence of symptoms, and may therefore remain obscure. This may cause a public health issue because of the long infectivity of these patients.