Russian Flu in Iran from 1889 to 1894.

The 'Russian flu,' also referred to as the 'Asiatic flu,' spread globally between 1889 and 1894. According to estimates from international organizations, this epidemic resulted in the deaths of approximately one million individuals. However, there is no information available on the exact number of deaths in Iran. The earliest outbreak of the epidemic was reported in May 1889 in Bukhara, Central Asia, which was part of the Russian Empire. The Russian Railway facilitated the spread of the epidemic from Siberia to the easternmost regions of Russia, westward to Moscow, and subsequently to countries such as China, Sweden, Finland, and Western Europe, eventually reaching the United States and Argentina. It subsequently spread from southern Russia to the South Caucasus and Baku, then moved into Iran from the north, northeast, and northwest, suddenly appearing in cities such as Bandar Anzali, Sari, Rasht, Mashhad, Tabriz, Tehran, Isfahan, Shiraz, and Kerman. The epidemic caused unexpected casualties in the country and startled both modern and traditional physicians. Notably, this epidemic, which appeared in Iran in two waves during 1890 and 1892, was somewhat mitigated due to the country's insufficient transportation infrastructure. As Tehran and Tabriz were either overpopulated or closer to Russia, doctors in these cities witnessed more cases of the Russian flu, prompting them to write several medical dissertations on this epidemic. This study examines the Russian flu in Iran as documented in historical, journalistic, and medical records.