Archive · 29 Aug 2026
How Influenza Became Notifiable in Delhi After 7,044 Deaths
More than 100 years ago, influenza spread through Delhi very quickly.
One of the first recorded patients was a European who had come from Shimla.
At first, the illness seemed mild, but it became much more dangerous in October 1918.
Some people developed pneumonia and other serious problems.
Records say 7,044 people died in Delhi city, while 23,175 died across Delhi Province.
After the outbreak, officials discussed how to watch for influenza more carefully.
In September 1920, they officially made ordinary influenza a disease that had to be notified.
Today, certain infections such as H1N1 receive special reporting, but not every seasonal flu case must be reported individually.
An ailing European from Shimla was among Delhi’s first recorded 1918 influenza cases.
Influenza cases at Delhi’s Civil Hospital rose to more than 100 daily by October’s third week.
The 1918 outbreak killed 23,175 people in Delhi Province, including 7,044 in Delhi city.
Delhi officials reviewed notification rules in July 1920 and issued the final declaration in September.
Today, H1N1 is reportable in Delhi, while seasonal influenza is generally tracked through surveillance and laboratories.
- Who
- Delhi health officials, doctors, influenza patients and residents were involved; archival records identify an ailing European from Shimla among the first recorded cases.
- What
- Influenza spread widely in Delhi in 1918, causing thousands of deaths, and was formally declared a notifiable infectious disease in 1920.
- When
- The deadliest outbreak occurred in 1918, while officials reviewed notification in July 1920 and issued the final declaration in September 1920.
- Where
- Delhi city and the wider Delhi Province, under the Punjab Municipal Act at the time.
- Why
- Officials believed notification would help detect influenza and influenza pneumonia, protect the public and give the municipality powers to control the disease.
- Delhi city deaths
- 7,044 influenza deaths were recorded in 1918.
- Delhi Province deaths
- 23,175 deaths were recorded across the province in October and November 1918.
- First recorded case
- An ailing European who had recently arrived from Shimla.
- Hospital surge
- Delhi Civil Hospital recorded 181 influenza cases on October 14, 1918.
- 1920 review
- The Sanitation Sub-committee considered notification in July 1920.
- Final declaration
- Ordinary influenza was formally declared an infectious disease in Delhi in September 1920.
- Current reporting
- H1N1 is covered by Delhi infection-control guidelines, while seasonal flu is not individually reportable in every case.