https://github.com/dessalines/essays/blob/main/us_atrocities.md

The one crime I bring up is the biological warfare that the US wages opportunistically. The most prominently documented was the biological crimes during the war of subjugation of Korea [PDF], where the US dropped bombs with infected insects (plague, cholera, anthrax) on Chinese and Korean civilians and armymen. The report, issued by a multinational team of scientists, strongly supports this claim. The former members of Japanese Unit 731 are thought to be culpable in these warcrimes, although it's corroborated more completely in a separate report from 1981. The pages 61, conclusion, would be of interest, as well as some photos on 709. This report was released by IADL, which the US subsequently labeled as communist, and tried to sentence a journalist who widely publicized the facts presented with sedition, and dropped charges against him after 5 years.

You can also see another instance of biological warfare in the github link which talks about a manufactured Dengue Fever outbreak in Cuba in 1981.