Operation Sea-Spray: (Bacteria over San-Francisco)
On October 11, 1950, eleven residents checked into Stanford Hospital for very rare, serious urinary tract infections. Although ten residents recovered, one patient, Edward J. Nevin, died three weeks later. None of the other hospitals in the city reported similar spikes in cases, and all 11 victims had urinary-tract infections following medical procedures, suggesting that the source of their infections lay inside the hospital.[1] Cases of pneumonia in San Francisco also increased after Serratia marcescens was released, though a causal relation has not been conclusively established.[4][5] The bacterium was also combined with phenol and an anthrax simulant and sprayed across south Dorset by US and UK military scientists as part of the DICE trials which ran from 1971 to 1975.[1][6] (wiki)
UK Germ War tests between 1940-1979 at least…
https://www.theguardian.com/politics/2002/apr/21/uk.medicalscience
https://www.independent.co.uk/news/uk/politics/how-the-british-government-subjected-thousands-of-people-to-chemical-and-biological-warfare-trials-10376411.html