Human Botulism in France, 1875-2016

Botulism in fish: a review

Published information about fish botulism is scant. We review here the current literature on fish botulism. Freshwater fish are susceptible to botulism. Only anecdotal evidence exists about possible botulism cases in saltwater fish. With only a few exceptions, the etiology of all cases of fish botulism reported is Clostridium botulinum type E, although fish are sensitive to, and may carry, various C. botulinum types. Clinical signs of botulism in fish include loss of equilibrium and motion, abducted opercula, open mouths, dark pigmentation, and head up/tail down orientation in which attempts to swim result in breaching the surface of the water. Dark pigmentation is thought to be associated with acetylcholine imbalance in botulinum neurotoxin (BoNT)-affected fish. Rarely, but similar to the situation in other animal species, fish can recover from botulism. Fish botulism can cause secondary outbreaks of the disease in birds, as botulism-affected fish stand out from normal fish, and are selectively preyed upon by fish-eating birds, which thus become intoxicated by the BoNT present in sick fish. The source of BoNT in fish has not been definitively confirmed. Fish may ingest C. botulinum spores that then germinate in their digestive tract, but the possibility that fish ingest preformed BoNT from the environment (e.g., dead fish, shellfish, insects) cannot be ruled out. The presumptive diagnosis of botulism in fish is established based on clinical signs, and as in other species, confirmation should be based on detection of BoNT in intestinal content, liver, and/or serum of affected fish.

Foodborne botulism outbreak involving different nationalities during the Rugby World Cup: critical role of credit card data and rapid international cooperation, France, September 2023

In September 2023, a severe outbreak of type B botulism with fifteen cases was linked to consumption of canned sardines at a restaurant in Bordeaux, France, during the Rugby World Cup. The cases were from seven countries. One death was recorded. Outbreak investigation using credit card data, rapid communication between health authorities of the affected countries and broad media communication allowed identification of cases and exposed persons and prevented further severe outcomes.

Foodborne Botulism, Canada, 2006-20211

During 2006-2021, Canada had 55 laboratory-confirmed outbreaks of foodborne botulism, involving 67 cases. The mean annual incidence was 0.01 case/100,000 population. Foodborne botulism in Indigenous communities accounted for 46% of all cases, which is down from 85% of all cases during 1990-2005. Among all cases, 52% were caused by botulinum neurotoxin type E, but types A (24%), B (16%), F (3%), and AB (1%) also occurred; 3% were caused by undetermined serotypes. Four outbreaks resulted from commercial products, including a 2006 international outbreak caused by carrot juice. Hospital data indicated that 78% of patients were transferred to special care units and 70% required mechanical ventilation; 7 deaths were reported. Botulinum neurotoxin type A was associated with much longer hospital stays and more time spent in special care than types B or E. Foodborne botulism often is misdiagnosed. Increased clinician awareness can improve diagnosis, which can aid epidemiologic investigations and patient treatment.

Dual-Toxin ("Bivalent") Infant Botulism in California, 1976-2020: Epidemiologic, Clinical, and Laboratory Aspects

OBJECTIVE

To assess the consequences of infant botulism that result from Clostridium botulinum strains that produce 2 botulinum toxin serotypes, termed "bivalent."

STUDY DESIGN

Epidemiologic investigations used a standard questionnaire. Clostridium botulinum strains were isolated by standard methods. Botulinum neurotoxin (BoNT) serotypes and the relative amounts of toxins produced were identified using the standard mouse bioassay. BoNT subtypes and genomic locations were identified by DNA nucleotide sequencing.

RESULTS

Thirty bivalent cases of infant botulism occurred in the 45 years (1976-2020), representing 2.0% of all California infant botulism cases, in the 3 geographic regions of southern California, the southern Central Valley, and mid-northern California. Toxin serotype combinations were Ba (n = 22), Bf (n = 7), and Ab (n = 1). More patients with illness caused by bivalent C botulinum Ba and Bf strains needed endotracheal intubation at hospital admission, 60.0% (18/30), than did patients with illness caused by monovalent BoNT/B strains, 34.3% (152/443). The Cbotulinum Ba and Bf strains produced BoNT/B5 and either BoNT/A4 or /F2. The Ab strain produced BoNT/A2 and /B1. All toxin gene clusters were on plasmids.

CONCLUSIONS

Infant botulism caused by bivalent Cbotulinum strains occurs sporadically and in diverse locations in California. Affected patients with bivalent Ba and Bf strains lacked distinguishing epidemiological features but appeared to be more severely paralyzed at hospital presentation than patients with illness caused by only BoNT/B. These bivalent strains produced BoNT subtypes A2, A4, B1, B5, and F2, and all toxin gene clusters were on plasmids.

Crystal structures of OrfX1, OrfX2 and the OrfX1-OrfX3 complex from the orfX gene cluster of botulinum neurotoxin E1

Botulinum neurotoxins (BoNTs) are among the most lethal toxins known to humans, comprising seven established serotypes termed BoNT/A-G encoded in two types of gene clusters (ha and orfX) in BoNT-producing clostridia. The ha cluster encodes four non-toxic neurotoxin-associated proteins (NAPs) that assemble with BoNTs to protect and enhance their oral toxicity. However, the structure and function of the orfX-type NAPs remain largely unknown. Here, we report the crystal structures for OrfX1, OrfX2, and an OrfX1-OrfX3 complex, which are encoded in the orfX cluster of a BoNT/E1-producing Clostridium botulinum strain associated with human foodborne botulism. These structures lay the foundation for future studies on the potential roles of OrfX proteins in oral intoxication and pathogenesis of BoNTs.

Clostridium botulinum type C, D, C/D, and D/C: An update

Clostridium botulinum is the main causative agent of botulism, a neurological disease encountered in humans as well as animals. Nine types of botulinum neurotoxins (BoNTs) have been described so far. Amongst these "toxinotypes," the A, the B and E are the most frequently encountered in humans while the C, D, C/D and D/C are mostly affecting domestic and wild birds as well as cattle. In France for instance, many cases and outbreaks are reported in these animal species every year. However, underestimation is very likely at least for avifauna species where the detection of dead animals can be challenging. Knowledge about BoNTs C, D, C/D, and D/C and the diseases they cause in animals and humans is still scarce and unclear. Specifically, the potential role of animal botulism outbreaks in cattle and poultry as a source of human illness needs to be further assessed. In this narrative review, we present the current knowledge about toxinotypes C, D, C/D, and D/C in cattle and poultry with, amongst various other aspects, their epidemiological cycles. We also discuss the zoonotic potential of these toxinotypes and some possible ways of risk mitigation. An adapted and effective management of botulism outbreaks in livestock also requires a better understanding of these less common and known toxinotypes.

Anaerobes and Toxins, a Tradition of the Institut Pasteur

Louis Pasteur, one of the eminent pioneers of microbiology, discovered life without oxygen and identified the first anaerobic pathogenic bacterium. Certain bacteria were found to be responsible for specific diseases. Pasteur was mainly interested in the prevention and treatment of infectious diseases with attenuated pathogens. The collaborators of Pasteur investigated the mechanisms of pathogenicity and showed that some bacterial soluble substances, called toxins, induce symptoms and lesions in experimental animals. Anaerobic bacteriology, which requires specific equipment, has emerged as a distinct part of microbiology. The first objectives were the identification and taxonomy of anaerobes. Several anaerobes producing potent toxins were associated with severe diseases. The investigation of toxins including sequencing, mode of action, and enzymatic activity led to a better understanding of toxin-mediated pathogenicity and allowed the development of safe and efficient prevention and treatment (vaccination with anatoxins, specific neutralizing antisera). Moreover, toxins turned out to be powerful tools in exploring cellular mechanisms supporting the concept of cellular microbiology. Pasteurians have made a wide contribution to anaerobic bacteriology and toxinology. The historical steps are summarized in this review.

Tracing Foodborne Botulism Events Caused by Clostridium botulinum in Xinjiang Province, China, Using a Core Genome Sequence Typing Scheme

Foodborne botulism is a rare but life-threatening illness resulting from the action of a potent toxin mainly produced by Clostridium botulinum. It grows in an oxygen-deficient environment and is extremely viable in meat and soy products, making it one of the most virulent bacteria. How to track foodborne botulism events quickly and accurately has become a key issue. Here, we investigated two foodborne botulism events that occurred in Xinjiang in 2019 based on whole-genome sequencing and also successfully traced the relationship between clinical and food C. botulinum isolates using whole-genome core gene markers. All 59 isolates were classified as group I strains. Of the strains isolated in this study, 44 were found to be botulinum toxin A(B), and 15 isolates contained only the toxin B locus. Both the toxin A and B gene segments were located on the chromosome and organized in an ha cluster. Antibiotic resistance and virulence factors were also investigated. A set of 329 universal core gene markers were established using C. botulinum strains from a public database. These core gene markers were applied to the published C. botulinum genomes, and three outbreaks were identified. This work demonstrates that universal core gene markers can be used to trace foodborne botulism events, and we hope that our work will facilitate this effort in future. IMPORTANCE In this study, we analyzed 59 foodborne botulism (FB)-related strains isolated in Xinjiang Province, China. Our findings not only reveal the group classification, neurotoxin locus organization, antibiotic resistance and virulence factors of these strains but also establish a set of core gene markers for tracing foodborne botulism events, which was verified using published genomes. These findings indicate that these gene markers might be used as a potential tracing tool for FB events caused by C. botulinum group I strains, which have relatively stable genomic components.

Botulism in Spain: Epidemiology and Outcomes of Antitoxin Treatment, 1997-2019

BACKGROUND

Botulism is a low incidence but potentially fatal infectious disease caused by neurotoxins produced mainly by Clostridium botulinum. There are different routes of acquisition, food-borne and infant/intestinal being the most frequent presentation, and antitoxin is the treatment of choice in all cases. In Spain, botulism is under surveillance, and case reporting is mandatory.

METHODS

This retrospective study attempts to provide a more complete picture of the epidemiology of botulism in Spain from 1997 to 2019 and an assessment of the treatment, including the relationship between a delay in antitoxin administration and the length of hospitalization using the Cox proportional hazards test and Kruskal-Wallis test, and an approach to the frequency of adverse events, issues for which no previous national data have been published.

RESULTS

Eight of the 44 outbreaks were associated with contaminated commercial foods involving ≤7 cases/outbreak; preserved vegetables were the main source of infection, followed by fish products; early antitoxin administration significantly reduces the hospital stay, and adverse reactions to the antitoxin affect around 3% of treated cases.

Human and animal botulism surveillance in France from 2008 to 2019

Botulism is a human and animal neurological disease caused by the action of bacterial neurotoxins (botulinum toxins) produced by bacteria from the genus Clostridium. This disease induces flaccid paralysis that can result in respiratory paralysis and heart failure. Due to its serious potential impact on public health, botulism is a closely monitored notifiable disease in France through a case-based passive surveillance system. In humans, this disease is rare, with an average of 10 outbreaks reported each year, mainly due to the consumption of contaminated foods. Type B and to a lesser extend type A are responsible for the majority of cases of foodborne botulism. Each year, an average of 30 outbreaks are recorded on poultry farms, about 20 cases in wild birds and about 10 outbreaks in cattle, involving a large number of animals. Mosaic forms C/D and D/C in birds and cattle, respectively, are the predominant types in animals in France. Types C and D have also been observed to a lesser extent in animals. With the exception of botulinum toxin E, which was exceptionally detected throughout the period in wild birds, the types of botulism found in animal outbreaks are different from those identified in human outbreaks over the last ten years in France and no human botulism outbreaks investigated have been linked to animal botulism. In line with the One Health concept, we present the first integrative approach to the routine surveillance of botulism in humans and animals in France.

Food borne-botulism during SARS-CoV-2 pandemic time. A case and a possible familial outbreak in Barcelona

INTRODUCTION

Botulism is a potentially fatal neuroparalytic syndrome caused by Clostridium botulinum neurotoxin. The 25% are food-borne botulism cases.

CASE REPORT

We describe a confirmed case of botulism attended in our hospital in September 2020, together with a second case in a patient's relative, suspected but not confirmed by laboratory tests. Clinical presentation consisted on general weakness, bilateral cranial palsy, mydriasis, and rapidly progressive tetraparesis in case 1, involving respiratory and swallowing function so she required hospitalization and support treatment. Non specific and transient symptoms occurred in case 2. SARS-CoV-2 infection was initially suspected in both cases due to pandemic situation in our country, ruled out by negative PCR. When B neurotoxin was detected in stool sample of patient 1 we confirmed the diagnosis of food-borne botulism probably linked to home-made conserved beans.

CONCLUSION

Early clinical suspicion, together with laboratory and electromyography findings, and support treatment provided at hospital were crucial for favourable outcome. Being aware of this rare syndrom might contribute to its better management.

Pauci-symptomatic foodborne botulism due to Clostridium botulinum type B with predominant ophthalmologic presentation possibly after consumption of honey

Foodborne botulism, a toxin-mediated illness caused by Clostridium botulinum, is a public health emergency, and rarely reported in France. We report herein the case of two family members (a father and his son) from Franche-Comté, France, presented with ophthalmological symptoms which occurred after non-specific gastro-intestinal symptoms after a trip to Serbia with a recent consumption of artisanal honey, and suggestive of botulism. The suspected intoxication appeared to be caused by a type B strain of C. botulinum, as demonstrated by toxin-neutralization in the lethal mouse bioassay. Regarding the mild-to-moderate form, the patients were treated symptomatically with monitoring, against antitoxins, with no evidence of relapse afterwards. We want to highlight the importance of recognizing clinical ophthalmologic botulism symptoms as unreactive bilateral mydriasis with lack of accommodation to contribute to earlier diagnosis in case of pauci-symptomatic botulism.

Epidemiology of botulism in the north-western Romania-a 7-year survey

Botulism is a rare, acute, life-threatening neuro-paralysis. The digestive onset may raise diagnostic issues. The objective of our study was to analyze the clinical and epidemiological data of patients diagnosed with botulism and hospitalized in "Gavril Curteanu" Municipal Clinical Hospital (Oradea, Romania). Detection of the Clostridium botulinum neurotoxin (type B) in the laboratories of the National Institute of Medical-Military Research Development "Cantacuzino", Bucharest, Romania (using the mouse bioassays method) confirmed the diagnostics. The statistical analysis was performed using the IBM SPSS software. Forty-eight patients with the diagnosis of foodborne botulism were hospitalized between 2012 and 2018 (36.92% of the total number of cases of botulism reported in Romania). The winter-spring period was the period when most cases were registered (36 patients, p=0.020). Women from rural areas were predominant (but not statistically significant), and the patients' mean age was 39.93±12.59 years. The most common source/cause of botulism was the consumption of homemade ham. The incubation period was 26.68±22.94 h, and 2.25±1.68 days passed from the clinical onset to diagnosis. The results prove that botulism is still a public health issue, especially in areas where homemade products are prepared using inappropriate/unsafe recipes/procedures.

Botulinum Neurotoxin-C Detection Using Nanostructured Porous Silicon Interferometer

Botulinum neurotoxins (BoNT) are the most potent toxins, which are produced by Clostridium bacteria and cause the life-threatening disease of botulism in all vertebrates. Specifically, animal botulism represents a serious environmental and economic concern in animal production due to the high mortality rates observed during outbreaks. Despite the availability of vaccines against BoNT, there are still many outbreaks of botulism worldwide. Alternative assays capable of replacing the conventional in vivo assay in terms of rapid and sensitive quantification, and the applicability for on-site analysis, have long been perused. Herein, we present a simple, highly sensitive and label-free optical biosensor for real-time detection of BoNT serotype C using a porous silicon Fabry–Pérot interferometer. A competitive immunoassay coupled to a biochemical cascade reaction was adapted for optical signal amplification. The resulting insoluble precipitates accumulated within the nanostructure changed the reflectivity spectra by alternating the averaged refractive index. The augmented optical performance allowed for a linear response within the range of 10 to 10,000 pg mL−1 while presenting a detection limit of 4.8 pg mL−1. The practical aspect of the developed assay was verified using field BoNT holotoxins to exemplify the potential use of the developed optical approach for rapid bio-diagnosis of BoNT. The specificity and selectivity of the assay were successfully validated using an adjacent holotoxin relevant for farm animals (BoNT serotype D). Overall, this work sets the foundation for implementing a miniaturized interferometer for routine on-site botulism diagnosis, thus significantly reducing the need for animal experimentation and shortening analysis turnaround for early evidence-based therapy.

Asymptomatic Carriage of C. botulinum Type D/C in Broiler Flocks as the Source of Contamination of a Massive Botulism Outbreak on a Dairy Cattle Farm

In winter 2018, a massive type D/C cattle botulism outbreak occurred on a mixed dairy and broiler farm in France. An investigation was conducted based on the hypothesis of asymptomatic carriage in poultry. We set out to identify the source of contamination of the dairy cattle and to monitor the contamination of broilers over time, including the hatchery delivering chicks to the farm. Environmental samples were collected on the farm during the cattle outbreak (n = 40), after the outbreak for three successive broiler flocks (n = 128), and once in the hatchery delivering the chicks (n = 58). These samples were analyzed using real-time PCR after an enrichment step to detect Clostridium botulinum type D/C. The results showed contamination in the manure from the broilers raised just before the onset of the cattle outbreak (5 + /5), as well as in some of the components of the cattle ration (3 + /17). This latter contamination is likely due to the use of the same tractor bucket to remove litter from the poultry house and to prepare the cattle ration on the same day. Contamination monitoring over several months revealed continuous asymptomatic carriage in the broilers (4 + /20 and 17 + /20 cloacal swabs in 2 successive flocks), a persistence of C. botulinum type D/C in the ventilation system of the poultry house (8 + /14), and contamination of the equipment coming from the hatchery used for delivering the chicks (3 + /18). Further investigations conducted in the hatchery demonstrated contamination in the hatchery by C. botulinum type D/C (6 + /58). Comparison of samples using a multilocus variable number tandem repeat analysis showed the same profile for samples collected on broilers, cattle and in the hatchery. This study highlighted the crucial role of the implementation of biosecurity measures in mixed farms to avoid cross-contamination between production units given the potential asymptomatic carriage of poultry. This study also revealed the contamination of the poultry hatchery. Further investigations are required to better understand the role of hatcheries in the epidemiology of animal botulism.

Suspected botulism outbreak after the consumption of vegetarian pâté in the south of Viet Nam

Botulism and other botulinum neurotoxins-producing clostridia  are potentially life-threatening diseases caused by toxins produced by Clostridium botulinum. Here we reported a case series of six patients who presented with botulism following ingestion of commercially made pâté. The key features of presentation were acute onset of bilateral cranial nerve palsies and symmetrical descending weakness in the absence of fever resulting in the need for mechanical ventilation in all six patients. The clinical diagnosis of botulism was confirmed through the identification of C. botulinum from the suspected food source.  Given that botulinum antitoxin was not available in Vietnam at the time, and their severe status, all patients received a trial of plasma exchange therapy, but no clear benefit was seen. Due to its rarity, diagnosing botulism is a challenge, demanding high clinical suspicion. Successful outcomes depend upon early recognition and rapid initiation of specific treatment with botulinum antitoxin. There is a need to improve global access to antitoxin.  These cases, the first in Viet Nam, serve as a reminder of the need to maintain the highest possible food hygiene and preservation practices.

Infant botulism: an underestimated threat

Infant botulism (IB) is defined as a potentially life-threatening neuroparalytic disorder affecting children younger than 12 months. It is caused by ingestion of food or dust contaminated by Clostridium botulinum spores, which germinate in the infant's large bowel and produce botulinum neurotoxin. Although the real impact of IB is likely underestimated worldwide, the USA has the highest number of cases. The limited reporting of IB in many countries is probably due to diagnostic difficulties and nonspecific presentation. The onset is usually heralded by constipation, followed by bulbar palsy, and then by a descending bilateral symmetric paralysis; ultimately, palsy can involve respiratory and diaphragmatic muscles, leading to respiratory failure. The treatment is based on supportive care and specific therapy with Human Botulism Immune Globulin Intravenous (BIG-IV), and should be started as early as possible. The search for new human-like antibody preparations that are both highly effective and well tolerated has led to the creation of a mixture of oligoclonal antibodies that are highly protective and can be produced in large quantities without the use of animals. Ongoing research for future treatment of IB involves the search for new molecular targets to produce a new generation of laboratory-produced antitoxins, and the development of new vaccines with safety and efficacy profiles that can be scaled up for clinical use. This narrative literature review aims to provide a readable synthesis of the best current literature on microbiological, epidemiological and clinical features of IB, and a practical guide for its treatment.

Toxin-associated infectious diseases: tetanus, botulism and diphtheria

PURPOSE OF REVIEW

The incidence rates of the toxin-related infectious diseases, tetanus, diphtheria and botulism declined dramatically over the past decades mainly because of the implementation of immunization programs also in low-and-middle-income countries (LAMICs) and by improving hygiene conditions. But still, single cases occur, and they need fastest possible recognition and management.

RECENT FINDINGS

Over the past 20 years, the incidence of neonatal tetanus has declined by more than 90%. This success was achieved by immunizing women in reproductive age in areas of high risk as sub-Saharan Africa and parts of Asia. Larger regional outbreaks of diphtheria have been reported from the former Soviet Union in the 1990s and from India in 2017. Botulism is still rare, mainly seen in infants and, in recent years, in intravenous drug abusers.

SUMMARY

Tetanus, diphtheria and botulism are rarities in high-income countries (HICs) with unlimited access to immunization programs and standard hygiene procedures. The diagnosis of all three diseases is still, even in the 21st century, based upon patient's history and clinical signs and symptoms. Neither biochemical bedside tests nor neuroradiological investigations help to confirm the diagnosis in an emergency situation.

Botulism outbreak after the consumption of vegetarian pâté in the south of Viet Nam

Botulism is a potentially life-threatening disease caused by toxins produced by Clostridium botulinum. Here we reported a case series of six patients who presented with botulism following ingestion of commercially made pâté. The key features of presentation were acute onset of bilateral cranial nerve palsies and symmetrical descending weakness in the absence of fever resulting in the need for mechanical ventilation in all six patients. The clinical diagnosis of botulism was confirmed through the identification of C. botulinum from the suspected food source.  Given that botulinum antitoxin was not available in Vietnam at the time, and their severe status, all patients received a trial of plasma exchange therapy, but no clear benefit was seen. Due to its rarity, diagnosing botulism is a challenge, demanding high clinical suspicion. Successful outcomes depend upon early recognition and rapid initiation of specific treatment with botulinum antitoxin. There is a need to improve global access to antitoxin.  These cases, the first in Viet Nam, serve as a reminder of the need to maintain the highest possible food hygiene and preservation practices.

Autoinducer-2 Could Affect Biofilm Formation by Food-Derived Bacillus cereus

Bacillus cereus is a foodborne pathogen and cause a frequent problem due to the biofilms forming in equipment of food production plants. Autoinducer-2 (AI-2) involved in interspecies communication, plays a role in the biofilm formation of B. cereus. In this study, biofilm formation by thirty-nine B. cereus strains isolated from foods produced in Korea was determined. To investigate the effect of AI-2 on biofilm formation by B. cereus SBC27, which had the highest biofilm-forming ability, biofilm densities formed after addition of the AI-2 from Staphylococcus aureus and Escherichia coli were analysed. As a result, it was found that the quorum sensing molecule AI-2 could induce biofilm formation by B. cereus within 24 h, but it may also inhibit biofilm formation when more AI-2 is added after 24 h. Thus, these results improve our understanding of biofilm formation by food-derived B. cereus and provide clues that could help to reduce the impact of biofilms, the biggest problem in food processing environments, which has an impact on public health as well as the economy.

Botulism outbreak after the consumption of vegetarian pâté in the south of Viet Nam

Botulism is a potentially life-threatening disease caused by toxins produced by Clostridium botulinum. Here we reported a case series of six patients who presented with botulism following ingestion of commercially made pâté. The key features of presentation were acute onset of bilateral cranial nerve palsies and symmetrical descending weakness in the absence of fever resulting in the need for mechanical ventilation in all six patients. The clinical diagnosis of botulism was confirmed through the identification of C. botulinum from the suspected food source.  Given that botulinum antitoxin was not available in Vietnam at the time, and their severe status, all patients received a trial of plasma exchange therapy, but no clear benefit was seen. Due to its rarity, diagnosing botulism is a challenge, demanding high clinical suspicion. Successful outcomes depend upon early recognition and rapid initiation of specific treatment with botulinum antitoxin. There is a need to improve global access to antitoxin.  These cases, the first in Viet Nam, serve as a reminder of the need to maintain the highest possible food hygiene and preservation practices.

Botulism outbreak after the consumption of vegetarian pâté in the south of Viet Nam

Botulism is a potentially life-threatening disease caused by toxins produced by Clostridium botulinum. Here we reported a case series of six patients who presented with botulism following ingestion of commercially made pâté. The key features of presentation were acute onset of bilateral cranial nerve palsies and symmetrical descending weakness in the absence of fever resulting in the need for mechanical ventilation in all six patients. The clinical diagnosis of botulism was confirmed through the identification of C. botulinum from the suspected food source.  Given that botulinum antitoxin was not available in Vietnam at the time, and their severe status, all patients received a trial of plasma exchange therapy, but no clear benefit was seen. Due to its rarity, diagnosing botulism is a challenge, demanding high clinical suspicion. Successful outcomes depend upon early recognition and rapid initiation of specific treatment with botulinum antitoxin. There is a need to improve global access to antitoxin.  These cases, the first in Viet Nam, serve as a reminder of the need to maintain the highest possible food hygiene and preservation practices.