A friend of mine told me something around a month ago. He joked that these flu pandemics seem to appear every 100 years. There was a similar pandemic in 1720, 1820 and in 1920.
Now, I remember my mother telling me a bit about this and I did my own research. The 1920 pandemic also affected Lagos. There was a quarantine, but some people were negligent in their duty and some people aboard one of the infected ships were able to come ashore. This enabled the Spanish Flu to spread in Lagos and people were taken to the Infectious Diseases Hospital in Ikoyi (I can’t remember for sure, but I think she said that the IDH was at the location that Creek Hospital [Military Hospital now occupies on Awolowo Road in Ikoyi).
The Bubonic Plague also affected Lagos later in the 1920s.
The Quarantine Act gives the president the power to declare any place within Nigeria or outside Nigeria as an infected place and it gives him the power to take all measures necessary to ensure that dangerous infectious diseases do not spread from that place to any other place in Nigeria.
These diseases led to the enactment of the Quarantine Act in 1926 (it has been amended a few times).
Here’s a link to the Quarantine Act. http://lawsofnigeria.placng.org/laws/Q2.pdf