When I happen to read an article in the form of report with a title, " Report on the Cholera Epidemic of 1885 in Nepal; with short description of the topography and ihabitats of the valley", it was like time travel back to Rana regime.The author of the article is G H Gimlette, M.D., Residency - Surgeon and published on May 22, 1886. I think, this is the first scientific study and report of any disease outbreak investigation in Nepal. The description of the outbreak is vivid and the demography, geography and the sanitation and hygiene practice of those times are also decribed so clearly.
This article states that the first recorded epidemic of cholera in Nepal took place in 1823 and then next in 1831. Thereafter, there were series of epidemics in Kathmandu valley in 1843, 1856, 1862 and 1887.