ALGERIA’S 75-year-old President Abdelmadjid Tebboune is self-isolating because some officials in "upper ranks of the government" are sick with COVID-19, he has said in a Tweet. Tebboune took office in December in an election that came amidst months of mass protests which forced his predecessor Abdelaziz Bouteflika from power after 20 years. "I assure you, my brothers and sisters, that I am well and healthy and that I continue my work," he said, saying his decision was taken on the advice of medical staff. The global pandemic struck Algeria's economy as it faced long-term challenges posed by the decline of…