Cross-infection in the ambulant setting - complete

Question

Hello,
since I forgot some points, here they are again (sorry!)
I have a question that's been on my mind.
What happens if two CF patients meet outside of the CF clinic in a doctor's office, and one of them has a problematic strain of Burkholderia Cepacia?

Does the patient with the problematic strain also have to wear a mask in the doctor's office?

What is the risk in the following situation: the doctor's office had to be crossed twice. The first time, there was a greater distance, and the Cepacia patient wore a mask. The second time, it was in a hallway, with a distance of just under one meter. The Cepacia patient wasn't wearing a mask and said "Goodbye," but the patient without Cepacia wore an FFP2 mask and just quickly walked past, disinfecting his hands immediately after leaving the office.

There was no treatment or waiting in the same room, as the doctor's office only had to be crossed twice briefly.

Is there any significant risk in this situation?

What's it like when you're sitting together in the waiting room? Or being seen one after the other in the examination room?

The question might sound a bit odd, but since the CF clinic has even introduced special days to avoid such encounters, I'm wondering if it wouldn't be better to switch general practitioners, or if this is completely over the top.

Another question: If you do get infected, are you only contagious to other CF patients? Can you not infect your own children and other family members as long as they don't have CF?

And: If you have Kaftrio/Trikafta® and an excellent lung function (FeV1 94%, MEF25 98%: How long do germs survive on clothing after such contact?

Best regards

Answer

Dear inquirer,
this is a very complex question. Firstly, Burkholderia cepacia is a complex (BCK) of various species that can have quite different properties. Generally speaking, however, the BCK species are all quite resilient environmental bacteria (e.g., found in water, soil, and on plants), but they are relatively sensitive to desiccation. Survival on inanimate surfaces depends on many factors, such as the surface's composition, humidity, temperature, the initial amount of bacteria, and the environment (e.g., coughed up and then embedded in secretion droplets or indirectly transferred via hands). Transmission via inanimate surfaces is undoubtedly possible. The data on survival rates is rather poor, as only a few, generally older, studies exist on this topic. Therefore, it is difficult to provide concrete figures, especially for specific situations (car seats, fabric, clothing). Under unfavorable conditions, the number of germs usually decreases significantly in the first few hours (e.g., due to evaporation of moisture), but the pathogens can still be detected for longer, e.g., over 24 hours. This serves only as a guideline. Infectiousness, in turn, depends on the number of germs and the type of contact. If there is a concrete possibility of medically relevant contamination of surfaces, surface disinfection would always be carried out.

CF patients with problematic germs (e.g., BCK) should ideally avoid contact and, in my opinion, should definitely wear a face mask when visiting healthcare facilities where other CF patients are treated. Ultimately, it is the responsibility of the respective institution to establish hygiene measures designed to minimize the transmission risk of problematic germs (e.g., hospital-acquired infections). There are recommendations from the KRINKO (Commission for Hospital Hygiene and Infection Prevention at the Robert Koch Institute (RKI)) and, for CF events, a hygiene guideline from the German Cystic Fibrosis Association (Mukoviszidose e.V.). Anyone treating CF patients should be aware that special hygiene measures may be necessary. Ultimately, however, a risk can only be addressed if it is known, and each patient also bears a certain personal responsibility towards their fellow patients. If a CF patient (BCK-free) wearing an FFP2 mask passes a CF patient (BCK-positive, without a mask), I consider transmission extremely unlikely. Of course, distance and contact time are also relevant. A distance of at least two meters should be maintained, as the typical fluid droplets settle in this area. Again, in the specific situation you described, I consider the risk of transmission to be virtually nonexistent. In other situations (e.g., longer waiting times in the waiting room, shared treatment room, etc.), the potential risk formally increases to a level that cannot be precisely defined. Therefore, regardless of the individual risk associated with a particular contact situation, the simplest measure would be to avoid these hygiene-relevant contacts. For this reason, experienced CF clinics schedule patients separately based on the presence of problematic pathogens and usually still wear a face mask. These questions are entirely valid, but even the best hygiene measures cannot completely prevent transmission, as they are based on recommendations, must be practical, and ultimately serve to minimize risk in terms of a benefit-risk assessment.

The decision to change practices is yours to make and depends on several factors. It is worth considering first identifying the specific problem (concern about transmission) and then carefully weighing the pros and cons to determine appropriate measures.

BCK plays a very special role in cystic fibrosis, and possibly, though very rarely, in certain diseases of the immune system or other, primarily structural, lung diseases. However, it has no infectious relevance in the general population or in other forms of disease. Furthermore, the pathogens are ubiquitous in the environment. If the airways of a CF patient are colonized and there is close, regular contact (family members, partners, etc.) and thus exposure, it is theoretically possible that colonization of the non-CF contact person could occur, which would then most likely be only transient and not result in an infection. BCK are not adapted to the 'normal, healthy' airways. Humans are exposed to many (environmental) bacteria, and atypical, short-term colonization without clinical significance can always occur (incidental findings). The individual susceptibility of the person, even in CF, plays a role. There are many examples of siblings with cystic fibrosis (CF) who exhibit a completely different spectrum of pathogens, while in other cases, nearly identical pathogen spectra are found. Thus, susceptibility is undoubtedly determined by the severity of the CF lung disease. Under modulation therapy, pathogens are often no longer detectable, and it can also be assumed that the risk of colonization with typical CF pathogens is lower.

Sincerely,
Dr. M. Hogardt

20.02.2026