Ascaris worm found in a swimming pool in Tartu

In April 2013 Delfi brought an article on the finding of a worm in a public swimming pools in Tartu city, Estonia (link to article below).

The worm was identified as the nematode Ascaris sp. (roundworm) at the Department of Zoology, University of Tartu.

As a response to the finding the owners of the public pool closed the facility temporarily and increased the chlorine content in the water with the attempt of removing the possible contamination of Ascaris sp. eggs in the pool waters. However, chlorination alone has not been shown to be able to successfully inactivate Ascaris eggs (see article below).

Previous knowledge considered the intestinal nematode Ascaris lumbricoides as a species specific for human infections, while pigs were considered to be infected with Ascaris suum. Studies have shown what was previously considered two species had zoonotic potential (Ascaris suum infecting humans, and possibly the other way around). Recent advances in molecular biology show that this is very likely the case as Asarcis lumbricoides and Ascaris suum do not vary significantly genetically nor in morphology and should probably be considered a single species (see article below).

The Estonian University of Life Sciences is currently investigating how commonly Estonians and specific risk groups are exposed to Ascaris infections as part of the project "Epidemiology and risk factors of emerging zoonosis in Estonia. Investigation of needs for surveillance and development of surveillance systems" funded by the program "Tervishoiutehnoloogia teadus- ja arendustegevuse toetamine".  

Image: www.visualphotos.com


Full article on Ascaris in a public pool (in Estonian):
Aura keskuse külastaja leidis veest solkmetaolise ussi

Further reading on the effect of chlorine on Ascaris eggs:
Bandala ER, González L, Sanchez-Salas JL, Castillo JH. 2012. Inactivation of Ascaris eggs in water using sequential solar driven photo-Fenton and free chlorine. J Water Health, 10(1):20-30.

Further reading on why Ascaris is a zoonosis:
Leles D, Gardner SL, Reinhard K, Iñiguez A, Araujo A. 2012. Are Ascaris lumbricoides and Ascaris suum a single species? Parasit Vectors, 5:42.

Further reading on Ascaris distribution in the world
de Silva NR, Brooker S, Hotez PJ, Montresor A, Engels D, Savioli L. 2003. Soil-transmitted helminth infections: updating the global picture. Trends Parasitol.,19(12):547-51.