In addition to the toxin-producing Vibrio cholerae strains O1 and O139, the cholera pathogens, 200 other non-toxin-producing serogroups(Vibrio cholerae non O1 and non O139) are known. They lack the ability to produce the cholera toxin. In order to clearly distinguish them from the cholera pathogens, they are therefore grouped together under the term non-cholera vibrios. Non-cholera vibrios can also cause diseases, but these are usually less severe than cholera.

worldwide

Non-Cholera vibrios are mainly found in bodies of water. Some species are considered salt-dependent, i.e. they are found particularly in seawater, lagoons, brackish water (mixture of salt and fresh water, e.g. in river estuaries) and in some cases also in inland lakes that have an increased salt content. They multiply more strongly at water temperatures above 20 °C.

Oral ingestion or direct contact (e.g. wounds) with contaminated water

Non-Cholera vibrios can cause diarrhoea, wound infections, otitis media, inflammation of the skin sub-tissues and subsequently blood poisoning. According to medical literature, typical risk groups include elderly and immunocompromised persons. People with pre-existing conditions such as liver disease, diabetes mellitus, cancer/chemotherapy and severe heart disease have an increased risk of contracting an infection and becoming seriously ill.

Therapy depends on the type of infection and consists of antibiotic treatment, but may also require surgical intervention and intensive medical care.

In Austria, two cases of illness caused by infections with non-Cholera vibrios became known in the summer of 2015. An 80-year-old person with pre-existing conditions died at the end of 2015.

The increased occurrence of non-cholera vibrios in Austrian lakes may be linked to the extreme heatwave and the exceptional lack of precipitation in the summer of 2015: During additional investigations by AGES in summer 2015, non-cholera vibrios were detected in a further seven freshwater bodies of water in Lower Austria and Burgenland. Migratory birds and waterfowl are considered a possible source of introduction. The classic indicator bacteria enterococci and E. coli, which are routinely used as indicators of increased risk as part of EU bathing water monitoring, were not elevated in the positive detections of non-cholera vibrio. The EU bathing waters analysed therefore also complied with the legal requirements.

The Federal Ministry of Labour, Social Affairs, Health, Care and Consumer Protection (BMASGPK) commissioned a scientific assessment from the European Centre for Disease Prevention and Control (ECDC) on this rather new topic for Austria.

Periods of heat and thus the warming of water bodies may occur more frequently in future as a result of global warming. This also increases the probability of the occurrence of non-cholera vibrios in bodies of water. Until now, only the East Sea was considered an area with an increased potential occurrence. The ECDC has set up a monitoring system for the Baltic region that uses the water temperatures of the Baltic Sea to calculate and predict the probable occurrence of non-cholera vibrios.