Abstract
The prevalence of free-living amoeba and associated Legionella spp. in hospital water systems may pose a risk of Legionnaires’
disease to immuno-compromised patients. This study investigated the occurrence of amoeba-associated Legionella pneumophila
in three South African hospital water systems. A total of 98 water and/or biofilm samples were collected from the sterilisation
unit, theatres, neonatal ward and intensive care units. Amoebae were isolated from 71 (72.4%) samples. Isolated amoebae were
analysed using qPCR and culture methods to test for the presence of Legionella. L. pneumophila did not grow on selective media
in any of the samples. A total of 7 out of the 71 (9.9%) amoeba-positive samples showed a positive reaction for L. pneumophila
using qPCR. Although relatively few samples were positive for Legionella in this preliminary study, the association with amoeba
still presents a potential public health risk to immuno-compromised patients when exposed to contaminated water.