The death of hundreds of elephants in Botswana and Zimbabwe has perplexed scientists and led to global speculation. After tests were finally conducted on the elephants in Zimbabwe, it was discovered that a little-known bacterium called Pasteurella Bisgaard taxon 45 was responsible for septicaemia, or blood poisoning, which caused their deaths. This bacterium has not previously been linked to elephant deaths. The decline in African savanna elephants, primarily due to poaching, is a major concern, and the paper suggests that infectious diseases should be recognized as another threat to their conservation. The investigation into these deaths was challenging due to difficulties in accessing the carcasses and the unknown nature of the disease.
https://www.theguardian.com/environment/2023/oct/25/scientists-discover-why-dozens-of-endangered-elephants-dropped-dead