Medical Hydrology and Balneology: Environmental Aspects

Legionella infection from spa waters and
peloids: a risk assessment study
Drasar V (1) , Polcar R (2) , Lück C (3)
(1) Public Health Institute Ostrava. National Legionella Reference Laboratory. Vyskov.
Czech Republic
(2) Factor.E. Brno. Czech Republic
(3) National Legionella Reference Laboratory. TU Dresden. Germany
vdrasar@infos.cz
Introduction and Objectives
Czech spas have a long and well-established tradition for hydrotherapy and
drinking. Five travel-associated legionella infections have been notified to the
European Legionnaires' Disease Surveillance Network to date with two fatalities.
The cases were linked to the two largest spas in West Bohemia. A study was conducted
to track sources, elucidate the role of thermal waters and carry out a risk
assessment in the two complexes. Peloids from five different localities were also
included.
Materials and Methods
Samples were taken, processed and Legionella identified by standardized and
accredited methods.
Results
1. Spa No.1.
Thirteen thermal springs for drinking were sampled at client outlets. Eleven
were negative, two contained low counts of Legionella pneumophila serogroup (sg)
6 (53°C, 30°C). The hottest spring produces water at72°C, which is stored and
distributed to spa hotels . Although Legionella were not detected in the spring
water, hotel storage vessels were highly positive. Cold and hot water from 25 hotels
were also examined. Fifteen fully complied with legislation , 5 represented a risk
due to presence of the virulent monoclonal antibody (Mab) subgroup Pontiac of
L.pneumphila sg1. Two hotels were implicated as a source of infection ( Mab
Benidorm). There was a high diversity in the Legionella species isolated from hot
and thermal waters indicating possible artificial enrichment of the latter with potable
water. Two new sequence types (STs) of L. pneumophila and one novel Legionella
species were identified.
2. Spa No.2.
Two cases of L.pneumophila sg 1, Mab Philadelphia, ST1, were investigated.
Two hotels were confirmed as sources of infection. Water isolates matched a clinical
strain. These hotels are fed with a mixture of two thermal springs whose tem-
Balnea
2012, núm. 6, 241-242
241
ISBN: 978-84-669-1887-0
978-84-669-3482-4