At least one person has died as a result of the outbreak, which officials several weeks ago said had affected 300 people in Dushanbe.
The spread of the disease has been blamed on untreated drinking water piped to the half million inhabitants of Dushanbe from a nearby mountain river, the Varzob, which was washed with rain carrying noxious substances.
While city authorities say they have gotten the outbreak under control, many of Dushanbe's hospitals and clinics are full to overflowing, and the number of sick may well exceed the official figure.
The authorities set up a special task force to halt the spread of the outbreak, sending 1000 medical staff around the city to warn inhabitants not to drink tap water and closing off water supplies in schools and kindergartens.
In the last major typhoid epidemic, in 1997, more than 17,000 people fell ill
The last major epidemic of typhoid fever in Tajikistan broke out in 1997, when more than 17,000 people fell ill and dozens died.
Land-locked Tajikistan in Central Asia is the most impoverished of the 15 former Soviet republics.