Ep 78 Bartonella: Keep Calm and Carrión

Transmission

The transmission of Bartonella bacteria involves various vectors, with lice playing a significant role. During World War I, soldiers faced relentless infestations of body lice, which were later identified as vectors for Bartonella quintana, the cause of trench fever 1. Despite efforts to control lice, such as using ointments and steam disinfectors, lice remained a persistent problem, with 95% of soldiers infested 2.

It wasn't carried in the serum, but in the blood itself. All it took was one louse who became infectious five days after feeding on an infected person and could remain infectious for at least four months.

--- Erin Welsh

This highlights the challenges in managing lice and the diseases they transmit, emphasizing the need for effective control measures 3.

   

Evolution

Bartonella species demonstrate fascinating evolutionary transitions, moving from environmental pathogens to vertebrate pathogens. Initially, Bartonella likely existed as an environmental pathogen, evolving into an insect gut symbiont before becoming a vertebrate pathogen 4. This transition is believed to have occurred around the Cretaceous-Paleogene boundary, coinciding with mammal diversification.

Researchers think that Bartonella probably started out as an environmental pathogenous, and Bartonella bacteria are closely related to some plant pathogens and symbionts, and then that environmental pathogen turned into an insect gut symbiont, which then turned into a vertebrate pathogen.

--- Erin Welsh

Bartonella's ability to infect various mammals highlights its adaptability and the complex dynamics of host-pathogen interactions, with bats and rodents playing key roles in its diversification and spread 5.