21 Feb 2003
Margareth Paul M.D.
Outbreak of Trichinella in Poland. The outbreak is from wild boars. There were many wild boars shot, but probably not all were examined by veterinary services. Such numbers are probably known only to] hunters and their families, and it is indeed very difficult to estimate how many animals were killed. Some animals shot were under the 20 kg minimum in force during the hunting season, so the hunters don't want to report them.
The number of number of people who so far have had contact with infected meat is at least 124, and we have hospitalised the 11th patient. The previous outbreak in West Poland was in July/August 2002, but the number of patients was not more than 70.
The current outbreak involves an equal mixture of domestic and wild pigs; both butchers involved had veterinary certificates for meat examination. Probably a small wild animal of about 30 kg was added during meat preparation. Such weight indicates an error in calculations of the total weight of meat used, so this may indicate, for example, the addition of a nutria or other animal that had no certificate of veterinary analysis for Trichinella.
Domestic pigs and horses are quite safe in Poland. Trichinella infection is not a problem in horses in Poland at present.
ProMed: Wild boar is a well-known source of Trichinella. Apparently the legislation introduced to ensure that meat is inspected is not respected; furthermore, such meat finds it way into food that is declared to be pure pork. - Mod.EP
Trichinellosis - Poland, background information The principal vehicle for human infection is pork, with boar meat accounting for some cases. The per 100,000 population has ranged between 0.68 (1999) and 0.09 (2000) over the past 5 years.
32 outbreaks (768 cases) were reported during 1993 to 1998, accounting for 1.3 percent of all food-related outbreaks. 18 fatal cases were reported in 1985; 6 in 1990; 0 in 2000.
An outbreak of 92 cases (none fatal) in Italy during 1998 was ascribed to horse meat imported from Poland. Rates per 100,000 among domestic pigs: 0.43 in 1997; 0.36 in 1998; 0.71 in 1999; 0.47 in 2000; 0.25 in 2001. Rates per 100,000 among wild boars: 310 in 1997; 160 in 1998; 240 in 1999; 180 in 2000.
ProMed: Horses often get infected from being fed offal from slaughterhouses and home-slaughtered domestic and wild animals. - Mod.EP