During haemodialysis, a patient develops fever and chills. What is the most likely cause of this infection?

In the context of a patient undergoing haemodialysis who develops fever and chills, the most likely cause of infection is Staphylococcus epidermidis. This organism is part of the normal skin flora and is a common culprit in catheter-related infections, particularly in patients who are undergoing long-term dialysis.

Patients on haemodialysis often require the use of vascular access devices, such as central venous catheters, which can serve as a gateway for infections. Staphylococcus epidermidis is known for its ability to form biofilms on these devices, making it challenging to eliminate and leading to persistent infections. The organism is opportunistic and typically affects individuals with compromised immune systems or those with foreign bodies, which aligns with the situation of haemodialysis patients.

The other organisms listed, while also potential causes of infections, are less likely in this specific scenario. For example, Escherichia coli is more commonly associated with urinary tract infections. Pseudomonas aeruginosa is known for causing infections in immunocompromised patients or in cases of wound infections but is not the most frequent pathogen encountered in dialysis-related infections. Streptococcus pneumoniae primarily causes respiratory infections and is not typically linked to catheter-related infections in this patient group.