Surveillance of foodborne botulism in Poland: 1960-1998

High prevalence of Clostridium botulinum in vegetarian sausages

Clostridium botulinum is a significant food safety concern due to its ability to produce highly potent neurotoxin and resistant endospores. Vegetarian sausages have become a popular source of plant protein and alternative for meat products. While vegetarian sausages have not been linked to botulism, numerous outbreaks due to preserved vegetables suggest a frequent occurrence of C. botulinum spores in the raw material. The product formulation of vegetarian sausages involves limited NaCl and preservatives, and shelf-lives may be several months. The safety of vegetarian sausages thus relies mainly on heat treatment and chilled storage. The main food safety concern is C. botulinum Group II that can grow and produce toxin at refrigeration temperatures. Here we show a high overall prevalence (32%) of C. botulinum in 74 samples of vegetarian sausages from seven producers. Both Groups I and II strains and genes for neurotoxin types A, B, E and F were detected in the products. The highest cell counts (1200 spores/kg) were observed for C. botulinum Group II in products with remaining shelf-lives of 6 months at the time of purchase. We conclude that vacuum-packaged vegetarian sausage products frequently contain C. botulinum spores and may possess a high risk of C. botulinum growth and toxin production. Chilled storage below 3°C and thorough reheating before consumption are warranted.

Public Health Risk Associated with Botulism as Foodborne Zoonoses

Botulism is a rare but severe neurological disease in man and animals that is caused by botulinum neurotoxins (BoNTs) produced by Clostridium botulinum and atypical strains from other Clostridium and non-Clostridium species. BoNTs are divided into more than seven toxinotypes based on neutralization with specific corresponding antisera, and each toxinotype is subdivided into subtypes according to amino acid sequence variations. Animal species show variable sensitivity to the different BoNT toxinotypes. Thereby, naturally acquired animal botulism is mainly due to BoNT/C, D and the mosaic variants CD and DC, BoNT/CD being more prevalent in birds and BoNT/DC in cattle, whereas human botulism is more frequently in the types A, B and E, and to a lower extent, F. Botulism is not a contagious disease, since there is no direct transmission from diseased animals or man to a healthy subject. Botulism occurs via the environment, notably from food contaminated with C. botulinum spores and preserved in conditions favorable for C. botulinum growth and toxin production. The high prevalence of botulism types C, D and variants DC and CD in farmed and wild birds, and to a lower extent in cattle, raises the risk of transmission to human beings. However, human botulism is much rarer than animal botulism, and botulism types C and D are exceptional in humans. Only 15 cases or suspected cases of botulism type C and one outbreak of botulism type D have been reported in humans to date. In contrast, animal healthy carriers of C. botulinum group II, such as C. botulinum type E in fish of the northern hemisphere, and C. botulinum B4 in pigs, represent a more prevalent risk of botulism transmission to human subjects. Less common botulism types in animals but at risk of transmission to humans, can sporadically be observed, such as botulism type E in farmed chickens in France (1998-2002), botulism type B in cattle in The Netherlands (1977-1979), botulism types A and B in horses, or botulism type A in dairy cows (Egypt, 1976). In most cases, human and animal botulisms have distinct origins, and cross transmissions between animals and human beings are rather rare, accidental events. But, due to the severity of this disease, human and animal botulism requires a careful surveillance.

Epidemiology of foodborne botulism in Romania 1980-2009

In 2007, Romania, the largest southeastern European country, reported the highest notification rate of botulism cases in the European Union (0.18 per 100,000 inhabitants), which was 18 times higher than the reported rate in the United States (0.01 per 100,000 inhabitants). This report aims to analyze published and unpublished surveillance data on foodborne botulism in Romania from 1980 to 2009 in the context of political and economical changes that occurred in the former communist countries. The mean annual incidence rate of botulism cases was significantly lower during the late communist period, 1980-1989 (0.06±0.03 cases per 100,000 inhabitants), than during the years 1990-1999 (0.1±0.04 cases per 100,000 inhabitants, p=0.01) and 2000-2009 (0.12±0.04 cases per 100,000 inhabitants, p<0.01). The highest incidence rates were registered in 1998 and 2007 (0.18 cases per 100,000 inhabitants), whereas the lowest incidence rate was registered in 1983 (0.02 cases per 100,000 inhabitants). The disease was usually associated with the consumption of home prepared meat products (mainly raw sausages, smoked-dried meat). Most of the laboratory-confirmed cases tested positive for type B toxin (99%). During 2007-2009, the incidence was particularly high in northwestern and western Romania (0.5 and 0.3 cases per 100,000 inhabitants, respectively). The fatality rate was 60% before 1995 and decreased to 12.2±8.5% during 1999-2009. The general ascending trend of infection rates throughout the period studied demonstrates the need for the implementation of correct public health and educational measures to fully prevent this severe disease.

Food-borne botulism in the United Kingdom

Food-borne botulism is a rare but serious disease caused by ingestions of neurotoxin [botulinum neurotoxins (BoNTs)] produced as a result of the growth of the bacterium Clostridium botulinum in foods before consumption. The disease is rare in the United Kingdom, and only 62 cases have been recognized between 1922 and 2005. This report provides a brief review of C. botulinum and food-borne botulism as well as descriptions of the six episodes (33 cases with three deaths) of this disease that occurred in the United Kingdom between 1989 and 2005. The six incidents illustrate the importance of the risk factors of poor processing or storage of commercially prepared foods, improper home preservation of foods and travel to countries where botulism is much more common than in the United Kingdom. Even small outbreaks of food-borne botulism can precipitate a national emergency and inundate public health and acute care provision. This report provides a reminder to public health professions of the occurrence, diagnosis, treatment and control of this rare but serious food-borne disease.

Foodborne botulism in the Republic of Georgia

In the Republic of Georgia, high rates of foodborne botulism are largely caused by home-preserved vegetables.

Foodborne botulism is a potentially fatal, paralytic illness that can cause large outbreaks. A possible increase in botulism incidence during 2001 in the Republic of Georgia prompted this study. We reviewed surveillance data and abstracted records of patients with botulism who were hospitalized from 1980 to 2002. During this period, 879 botulism cases were detected. The median annual incidence increased from 0.3 per 100,000 during 1980 to 1990 to 0.9 per 100,000 during 1991 to 2002. For 706 botulism patients hospitalized from 1980 to 2002, 80% of their cases were attributed to home-preserved vegetables. Surveillance evaluation verified that botulism incidence varied greatly by region. Georgia has the highest nationally reported rate of foodborne botulism in the world. A strategy addressing individual behaviors in the home is needed to improve food safety; developing this strategy requires a deeper understanding of why botulism has increased and varies by region.