Burkholderia Pseudomallei

Doesn't that sound lovely?

I have been learning a lot about infectious disease these days. (Who says orthopedics is only about the bones?) One would think that in a little hospital like this, you do not come across many types of bugs. Mainly just the Staph Aureus, at times some C.Diffs, and occasionally some gram negs (proteus mirabilis). 

How wrong were we. 

For on this faithful week, we were visited by not one, but two rare infections amongst our inpatients. I am not going into much details as it will be a boring read (I don't have many viewers to start with and this would definitely send the last of them fleeing - microbiology seems to be everyone's least favourite subject).

Hence, quick succinct case summaries as below, with plans as per ID consultant from Hobart:

Case 1

65yo F, presented with septic L knee. 

Joint fluid culture grew Burkholderia Pseudomallei.

B/G - Recent visit to Darwin during wet season. Had pneumonia 4 weeks prior to this admission - now resolved. No past medical history. 

Dx - Clinical picture consistent with melioidosis.

Mx - Extensive investigations warranted as occult sources of melioid might be present and can be asymptomatic (ECHO, CT, bloods etc). IV meropenem cover for at least 4 weeks, and then at least 6 months of oral antibiotics as prolonged eradication therapy.  Weekly bloods + inflammatory markers. Repeat investigations down the line as well.    

Sounds like a big deal? IT IS A BIG DEAL. Not a bug you ever want to get, as it has a high recurrence rate, as well as being associated with high mortality and morbidity. Technically, it behaves kinda like TB. Both being tropical diseases, endemic in Northern Territory of Australia, and South East Asia. Usually spread via contact with contaminated soil or water, at times even via inhaling dust particles. Increased susceptibility among the immuno-compromised, diabetes or cystic fibrosis patients. 

Main cause for melioidosis. Melioidosis is an infection caused by Burkholderia. Signs and symptoms may include pain in chest, bones, or joints; cough; skin infections, lung nodules and pneumonia. Might even cause liver abscess - typically with a "honeycomb" characteristic. Lung nodules and liver abscesses might at times be asymptomatic, hence the need to perform extensive investigations. The strange thing is, melioidosis is said to be able to affect any organs except for the heart valves (endocarditis). (*We are not sure how far this is true, so we did an ECHO just in case.)

Case 2

48yo F, presented with infected R index finger.  

Wound washout m/c/s grew Roseomonas Gilardii. 

B/G - Previous similar infection in thumb. Both infections requiring repeated surgical washouts and debridement. Both infections arise from simple cuts from household work. Works at a milk processing factory in the packaging department. 

Dx - Infected R index finger

Mx - x2 surgical washouts and debridement. For IV Tazocin + oral Ciprofloxacin until wound-healing is satisfactory. Then stepdown therapy with oral Ciprofloxacin + oral Augmentin DF for another 2 weeks then cease. For investigations of why she suffered recurrent similar infections (likely linked to her workplace). Occupational health physician to review with regards to workplace safety and prevention/precautions to be taken.

As compared to Case 1, this is a less menancing bug. However, it is very rarely known to cause human infections, and we were unsure how did the patient actually pick it up. Transmission is via contact with contaminated soil or reservoir water. The most likely explanation was that the source of infection was from her workplace, possibly from the pumped creek water they use for general cleaning purposes. 

Roseomonas infections tend to occur in the immunocompromised or debilitated host. Most patients recover completely from their infections. Bacteremia is the most common clinical presentation reported in the literature. The patients generally present with fever. Other rare presentations reported in the literature have been peritonitis, septic arthritis, ventriculitis, left ventricular assist device (LVAD) infection, vertebral osteomyelitis and keratitis.

Once again, kudos if you survived my boring blog post up to this point. You may call me a nerd, but I actually found these cases pretty interesting, so I thought imma share with you this time. Even the ID consultant was like:" these are not infections that you will normally see. You might not even get to see another case of Burkolderia infection ever again, especially if you are working in this part of the country (the very much non-tropical Tasmania)!" 

Once again, behold the beauty of a Burholderia colony on blood agar. And culturing these is apparently a biohazard to the lab and special isolation is needed! (sounds cool! Made me think of  my fav zombie movies i.e. Resident Evil) 

*all patients are fully de-identified and no patient details contained in these case summaries*