Question

Case Study #1

During Sept 1995, a patient at a hemodialysis center in Montreal, Canada received treatment on a hemodialysis machine to help relieve the effects of kidney disease. The treatment was preformed without any incident. The next day, a 2nd patient received treatment on the same machine. His treatment also went normally, and he returned to his usual activities after the session was completed.

In the following days, both patients experienced bloodstream infections. The had high fever, muscular aches and pains, sore throat, and impaired blood circulation. Because the symptoms were severe, the patients were hospitalized. Both patients had infections of Enterobacter cloacae, gram negative rod. In the following months, an epidemiological investigation reviewed other hemodialysis patients at the center. In all, seven additional adult patients were identified who had used the same hemodialysis machine. All had similar bloodstream infections.

Inspection of the hemodialysis machine indicated the presence of biofilms containing Enterbacter cloacae, specifically where fluid flows. These cultures were identical to those found in the patients. The hospital personnel were disinfecting the machine correctly. The problem was that the valves in the drain line were malfunctioning, allowing backflow of the contaminated material. Health officials began a hospital education program to ensure that further outbreaks of infection were prevented.

Part A: Explain what a biofilm is and how it contributed to the infection of the users of the hemodialysis machine.

Part B: Suggest how the hemodialysis machine originally became contaminated.

Part C: Why weren't the other 5 cases of infections correlated with the hemodialysis machine until the epidemiological investigation was begun?​​​​​​​

Part D: How could future outbreaks of infection be prevented?​​​​​​​

Answer 1

Part A.

Bioflim refers to the growth of microorganisms in the following ways. A single organism or the bacteria may stick on to the surface. There it forms a small colony .Then the microorganism gets separated from it and travels along the ways .Here the bioflim developed in the drain line and then it multiplied and invaded to the humans during dialysis.

Part B.

The hemodialysis machine originally became contaminated due to the malfunctioning of the valves. Which led to the backflow of the contaminated material in to the drain line and spreading it.

Part C.

The other five infections where not correlated with the hemodialysis machine because there was no confirmation for the source of infection until the epidemiological investigation was begun.

Part D.

The future outbreak of infection can be prevented by

• Regular checking of the hemodialysis machine by the technician
• Education to the staff
• Safe handling of patients and creating awareness to the patients as well.