CDC reports three unusual deadly bacterial infections with mystery source

The US Centers for Disease Control and Prevention has reported three cases of a severe and often fatal bacterial infection called melioidosis. The source of these infections is unknown at this time, with the CDC saying these cases are "unusual" because none of the three victims had traveled outside of the US before presenting symptoms.

Melioidosis infections are caused by a bacterial pathogen called Burkholderia pseudomallei, which is classified as a Tier 1 agent, the same category that's home to other serious pathogens like the Ebola virus and the neurotoxins that cause botulism.

Though these infections are common in subtropical and tropical parts of the world, they typically only appear in the US when someone had traveled to an area these the infections are widespread. That makes these three cases — the first of which was reported in March and was fatal — particularly unusual as they didn't involve travel outside of the US.

Following the initial fatal case, two other patients were reported in May, one who later recovered enough to be moved to a transitional care unit; the other remains hospitalized. Though identities haven't been revealed, the CDC did provide some basic details.

The three victims involved one male and two females, with one of them being a child. These patients were also from three very different parts of the US: Kansas, Texas, and Minnesota. The state health departments and services in these three states are working with the CDC to investigate what may be behind the cases.

Experts say genomic sequencing was used to link the three cases with what is likely the same source. The origin of these infections may be an animal or a product, but the CDC doesn't have any information to report on the matter at this time. Unfortunately, symptoms of the infection vary and may delay treatment of the disease.

The CDC says melioidosis symptoms may include things like fever, cough, headache, lung issues, joint pain, stomach pain, chest pain, weight loss, and more. Some pre-existing conditions increase one's odd of severe or fatal outcomes from the infection, which have a fatality rate from 10- to 50-percent.

The CDC has provided guidance for doctors who may encounter melioidosis infections, but doesn't have any information for the public in regards to prevention or source at this time.