25 July 2007

Outbreak of trichinellosis in Poland

An outbreak of trichinellosis has been reported in West Pomerania in north-west Poland [1]. The outbreak was first reported to the local public health department on 9 June 2007, and as of 18 July 2007, a total of 214 cases have been confirmed [2]. Eighty-one patients have been hospitalised.

Investigation of the outbreak has shown a link with the consumption of raw pork meat that was produced in a single meat processing plant. The plant was closed on 15 June and all meat products produced there have been recalled.

Several cases of trichinellosis associated with the outbreak in Poland have been reported in Ireland and Germany [2-4].

• A Polish national and his fiancée who are resident in Ireland. The couple visited relatives in north-west Poland in April 2007, and consumed lightly smoked sausage during their stay.
• Three members of a German family who visited Poland in June 2007. Whilst there they consumed various pork products including sausages purchased in West Pomerania. 
• A woman from Hamburg, Germany who visited relatives in West Pomerania in mid-May 2007 where she consumed raw pork sausage.
• A German man who visited relatives in West Pomerania in mid May 2007 is suspected of having contracted trichinellosis. During his stay, he consumed raw pork sausage.

Trichinellosis

Trichinellosis is a parasitic disease caused by an intestinal roundworm of the genus Trichinella. It is transmitted to humans following the consumption of undercooked or raw meat products containing Trichinella larvae. The larvae invade the intestinal mucosa, mature to adult worms, mate and produce more larvae that migrate via the bloodstream to invade the muscles and other organs. T. spiralis is responsible for most human infections and has worldwide distribution in many species of carnivorous and omnivorous animals. Domestically raised pigs are the most frequently implicated animal host, although wild game such as bear and boar, have recently been associated with case clusters [5].

The illness ranges from a sub-clinical infection to fulminating, fatal disease depending upon the number of larvae ingested. The incubation period is from one to three weeks. Intestinal invasion by larvae with maturation to adult worms can be accompanied by diarrhoea, abdominal pain and vomiting. Once larvae are produced and begin to migrate into muscle, symptoms can include the sudden onset of muscle soreness and pain together with fever. Periorbital and facial swelling, conjunctivitis, myalgia, rash and Eosinophilia can also be seen. In severe cases with central nervous system invasion, altered consciousness and coma can ensue.

Treatment is effective and should be commenced early; it is therefore usually initiated on the basis of a clinical diagnosis. Treatment consists of an anthelmintic, usually mebendazole or albendazole, in conjunction with corticosteroids.   

Advice for travellers

Trichinellosis can be prevented by ensuring that all meat products have been thoroughly cooked, particularly meats that are from wild animals or domestically raised pigs. All undercooked or raw meat products should be avoided.

Physicians who evaluate returned travellers from this area of Poland with suspected trichinellosis should be alert to the possible diagnosis and seek appropriate guidance on management from the local infectious disease or tropical medicine unit.

References

1. Golab E, Szulc M, Sadkowska-Todys M. Outbreak of trichinellosis in north-west Poland, June 2007. Euro Surveill 2007;12:E070712.1. [Accessed 25 July 2007] Available at: http://www.eurosurveillance.org/ew/2007/070712.asp#1

2. Golab E, Szulc M, Wnukowska N et al. Outbreak of trichinellosis in north-western Poland – update and exported cases, June-July 2007. Euro Surveill 2007;12:E070719.2. [Accessed 25July 2007] Available at: http://www.eurosurveillance.org/ew/2007/070719.asp#2

3. McHugh G, Kiely D, Low J et al. Importation of Polish trichinellosis cases to Ireland, June 2007. Euro Surveill 2007;12:E070719.3. [Accessed 25 July 2007] Available at http://www.eurosurveillance.org/ew/2007/070719.asp#3

4. Schmiedel S, Kramme S. Cluster of trichinellosis cases in Germany, imported from Poland, June 2007. Euro Surveill 2007;12:E070719.4. [Accessed 25 July 2007] Available at: http://www.eurosurveillance.org/ew/2007/070719.asp#4

5. McIntyre L, Pollock SL, Fyfe M et al. Trichinellosis from consumption of wild game meat. CMAJ 2007;176:449-51. [Accessed 25 July 2007] Available at http://www.cmaj.ca/cgi/reprint/176/4/449

Link to further information

Centers for Disease Control and Prevention (CDC) http://www.cdc.gov/ncidod/dpd/parasites/trichinosis/default.htm