The Subcommittee on Prevention of Torture, (SPT), have given advice to States Parties and National Preventive Mechanisms on the 25th March 2020. You can read the full advice here. The advice states:

Within the space of a few short weeks, Coronavirus (COVID-19) has had a profound impact on daily life, with many facing imposing severe restrictions upon personal movement and personal freedoms to enable the authorities to better combat the pandemic through public health emergency measures.

Persons deprived of their liberty comprise a particularly vulnerable group owing to the nature of the restrictions which are already placed upon them and their limited capacity to take precautionary measures. Within prisons and other detention settings, many of which are severely overcrowded and insanitary, there are also increasingly acute problems. 

Please read the full advice for detail of the importance of continued monitoring and a list of recommendations from the SPT to States and NPMs.