Pseudomonas Is The Cause Of Hot Tub Infection
Question: We are from Ontario and visited Prince Edward Island recently. Just before we left for the trip, we used the hot tub in our new home. The previous owner installed this tub. Within two days, our older daughter developed a rash on her body. Shortly afterwards all of us had a similar rash, but it showed up only under the swimming trunks of my husband. The rash was a little painful, and as it progressed, there was pus underneath. The doctor in emergency room referred our daughters to a local paediatrician. He told us that it was due to an infection from the hot tub, and gave us an antibiotic called Cipro. We have completely recovered since, but I still wonder whether we got the infection from the tub. Our pharmacist told us that Cipro is recommended for adults only. Our two daughters had no side effect, but I am somewhat concerned.
Answer:
Your family had contracted a little known infection that is sometimes called “hot-tub dermatitis.” This condition occurs mostly in the summer, although it can happen any time of the year under the right circumstances.
Pseudomonas aeruginosa is the most common germ that causes this kind of infection. It grows best in warm or heated water in swimming pools and hot tubs. If swimming pools are properly maintained with chlorine and filtration, Pseudomonas cannot grow in large numbers to cause infection. However, if there is a breakdown in maintenance, Pseudomonas can grow very quickly into large numbers and endanger the health of any person getting into the pool.
The situation in hot tubs and whirlpools are different. They are often heated to around 37.8oC (or 100oF) without filtration. This temperature does not kill Pseudomonas, but enhances its growth instead. It is not hard to imagine that bacteria can grow to a dangerous level in that environment. Furthermore, it is not possible for those who venture into the tubs or whirlpools to know whether they are harbouring these germs. The water feels just as welcoming, whether there are germs in it or not.
This infection can also happen in other public facilities with water-slides and pools whenever there is a problem with maintenance. That is the reason why government regulates these public places. However, maintenance of hot tubs and whirlpools at home is completely up to the homeowner’s discretion. The owner’s manual likely will contain good maintenance information which can prevent this type of skin infection.
In all of these situations, the skin infection usually occurs within hours to several days after exposure to the contaminated water. The time from exposure to onset of infection depends on many factors, including how long the person was in the water, whether the person took a thorough shower afterwards, or continue to wear the wet swimming suit or trunk.
The rash usually begins under the swim suit or trunks as red spots. These spots gradually increase in size and number, and can develop pus in some of them. If these “pustules” are opened and cultured, Pseudomonas can be recovered quite easily. This rash is usually not very itchy, but can be rather painful.
Contaminated water can also cause other infections. These include urinary tract (or bladder) infection especially in females, and swimmers’ ears (also called otitis externa).
Pseudomonas is a germ that is not very easy to treat. Superficial skin infection like yours can be treated with oral antibiotics. One of the most effective antibiotics is Ciprofloxacin (also called Cipro). When this medicine was tested in animals, some rats and dogs developed damage to the cartilage of weight-bearing joints. As a result, this medicine is only recommended for adults, but not for children.
Because of the emergence of bacteria that are resistant to many antibiotics, Ciprofloxacin has to be used in some children with certain serious infections. The accumulated experience (although this is still limited experience) shows that Cipro did not cause damage to the joints in any of these children. We still cannot recommend Ciprofloxacin for children under 18 years of age, unless the infection cannot be treated effectively with other antibiotics.
In your family’s situation, I agree with the doctor that Ciprofloxacin was the right choice because Pseudomonas is resistant to most oral antibiotics. Other intravenous antibiotics can be used, but this would involve IV and staying in a hospital. The intravenous antibiotics also carry significant potential side effects.
I hope you can understand your family’s illness better and will start to make remedies to your hot tub to prevent any future infection.
[Note to Readers: The information in this column is still mostly current, after twenty years. Ciprofloxacin is used more often in children; they are advised not to be overly active while taking the medicine. More bacteria are becoming resistant to ciprofloxacin because of overuse by physicians in the last few decades.]