Hussein was taken by Egyptian security officers on December 20 last year and accused of reporting "false news with the aim of creating chaos".
Al Jazeera Media Network denies all allegations against Hussein and has demanded his immediate and unconditional release.
Here is a timeline of the events since Hussein joined the Qatar-based news organisation.
2010: Started working for Al Jazeera in Cairo.
2013: Following Egypt's July 3 Coup, Al Jazeera's Cairo bureau is closed.
2015: Hussein moves to the headquarters in Doha.
December 19, 2016: Hussein travels to Cairo on holiday.
December 20, 2016: Hussein arrives in Cairo and is stopped, questioned and detained by authorities for 15 hours, according to his family.
December 23, 2016: According to his family, Hussein was brought home at 1:30am, in handcuffs, along with approximately 30 police officers - some were masked. They searched his entire house.
When they couldn't find anything, they arrested two of his brothers.
The family didn't know their whereabouts until local media announced their arrest a few days later.
His brothers were later released without charges.
December 25, 2016: Egypt confirms Hussein's arrest. He is allegedly accused of "disseminating false news and receiving monetary funds from foreign authorities in order to defame the state's reputation."
Smear campaign begins against Hussein, and three videos of him are circulated in local media, including one of him "confessing".
January 4, 2017: Hussein's detention extended for 15 days.
February 4, 2017: Hussein's detention extended by 45 days, marking the fourth time it's been extended.
March 21, 2017: Hussein released from solitary confinement after three months and placed into a cell with other prisoners.
June 13, 2017: Hussein sustains an injury to his left arm leading to its fracture. He did not receive medical attention for 72 hours due to the prison's medical unit being unequipped for such situations.
July 17, 2017: Hussein not allowed to undergo surgery or have his cast changed.
October 17, 2017: Hussein marks 300 days in prison.
November 4, 2017: Hussein's detention is extended by 45 days, for the ninth time.
December 12, 2017: Hussein turns 51 in prison.
December 14: Hussein's detention is extended by 45 days, for the tenth time.
December 20, 2017: One year in detention.
January 24, 2018: 400 days in prison.
Source: Al Jazeera News