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Rivers & CF

How high are the risks & what are precautions we should take with a toddler cfer and playing in a river? Specifically the Guadalupe/Comal? High vs low?
Dear questioner,
Ask about the risks for a toddler with CF while playing in a river. I assume that you mean the risk of acquiring Pseudomonas aeruginosa, which is the main risk for CF patients when doing recreational activities with water.
We had a former question on this topic, concerning the risk of acquiring Pseudmononas aeruginosa while rowing on a river in Germany. Many of the parts of the answer are very useful for answering your question.
Here comes the answer from Dr. Hogardt:
“Dear questioner,

The risk of infection with P. aeruginosa concerning rowing in a river should probably be very low, however is cannot be excluded completely.

Background: In most of all cases a CF patient does not know the origin of the infection with P. aeruginosa. Therefore, current recommendations concerning (leisure time) activities respectively possible origins of infections in everyday life or environment are usually only based on indirect hints (e.g. contamination rate, extent of contamination, mode and duration of the contact, extent of aerosol formation, etc.) weighed up and related to (simple) measures for avoiding an exposition.

The risk of infection is generally higher for standing water reservoirs (e.g. small swimming ponds) than for flowing watercourses.
It can be assumed that higher temperatures lead to a more severe contamination than lower temperatures. Activities in an environment of an intense formation of fine aerosols (e.g. whirl pools, nebulising systems) in closed rooms are to be rated much more critical than activities with a low aerosol exposition (e.g. rowing in the open air).
If behaving responsibly while rowing, ingestion of water should also be a smaller problem. In contrast, estimates say that an average swimmer usually ingests 50ml while bathing and a moderate surfer ingest much more [1].

It is not clear which exact amount of P. aeruginosa bacteria is necessary to provoke a colonisation/infection of the airways. Based on experimental data it is estimated that several million bacteria would have to be ingested. However, the infection dosage should depend - inter alia - on the individual receptivity (age, antibiotic therapy, course of the disease, etc.) of a person with CF.

It is a fact that P. aeruginosa is also detected in flowing waters, as it is e.g. documented by a year-long examination of a Belgish river. In this study, most of the samples taken from different locations were P.-aeruginosa-negative though. Most of the positive samples were limited to two of seven sample locations and the pathogens were detected particularly frequently in summer and the highest bacterial load of 135 P. aeruginosa bacteria/ml was only detected in (warm) August at a more contaminated location. [2]

Based on all these aspects I would consider the risk of an infection with P. aeruginosa through rowing rather minimal if you behave responsibly. The risk of infection cannot be excluded completely, though, and the decision has always to be taken individually (subjective restriction of quality of life versus the - improbable - risk of an infection).

In my answer I have been referring only to P. aeruginosa as an example since this germ has an extraordinary meaning regarding CF and since if there is any data about environmental sources and risk of infection, then for P.a. An answer covering all "problematic germs" is not possible (on this platform). However, what has been said about P. aeruginosa probably also applies more or less to other CF relevant water bugs.

Moreover, I cannot give a classification of a certain river with regard to the risk of infection respectively to the bacterial load with a view to CF.
[In the original German answer some additional information was given about standing waters in Germany; this part is not translated.]

I hope to have been helpful with this information.

Best regards,
Michael Hogardt”
So you see, it is not easy to answer, and a river having higher water temperatures bears a greater risk of Pseudomonas than a river having lower water temperatures. It remains always an individual decision to weigh a risk against quality of life. There is no risk zero but in order to minimize it, it would be favorable to avoid ingestion/drinking of water by the child and doing sufficient hand hygiene after playing in the river water and perhaps avoid locations in the river with great production of aerosols (little waterfalls, water rapids, streams), as well as avoiding areas with no water flow (stagnant water).
Yours sincerely,
Dr. Daniela d’Alquen (coordinator of the central English Archive of ECORN-CF)