Infant Botulism, Israel, 2007-2021

Infant botulism (IB) is an intestinal toxemia that manifests as descending paralysis, constipation, and, in some cases, respiratory failure. Laboratory-confirmed IB cases are rare, and recent data in Israel are lacking. We conducted a national multicenter retrospective study of laboratory-confirmed IB cases reported in Israel during 2007-2021. A total of 8 cases were reported during the study period. During 2019-2021, incidence may have increased because of a cluster of 5 cases. Infant median age for diagnosis was 6.5 months, older than previously reported (3 months). Most cases occurred during March-July. Honey consumption was reported in 1 case, and possible environmental risk factors (living nearby rural or construction areas, dust exposure, and having a father who works as a farmer) were reported in 6 cases. Although IB is rare, its incidence in Israel may have increased over recent years, and its epidemiology and risk factors differ from cases reported previously in Israel.

Genomic and Phenotypic Characterization of Clostridium botulinum Isolates from an Infant Botulism Case Suggests Adaptation Signatures to the Gut

In early life, the immature human gut microbiota is prone to colonization by pathogens that are usually outcompeted by mature microbiota in the adult gut. Colonization and neurotoxin production by a vegetative Clostridium botulinum culture in the gut of an infant can lead to flaccid paralysis, resulting in a clinical outcome known as infant botulism, a potentially life-threatening condition. Beside host factors, little is known of the ecology, colonization, and adaptation of C. botulinum to the gut environment. In our previous report, an infant with intestinal botulism was shown to be colonized by neurotoxigenic C. botulinum culture for 7 months. In an effort to gain ecological and evolutionary insights into this unusually long gut colonization by C. botulinum, we analyzed and compared the genomes of C. botulinum isolates recovered from the infant feces during the course of intoxication and isolates from the infant household dust. A number of observed mutations and genomic alterations pinpointed at phenotypic traits that may have promoted colonization and adaptation to the gut environment and to the host. These traits include motility, quorum-sensing, sporulation, and carbohydrate metabolism. We provide novel perspectives and suggest a tentative model of the pathogenesis of C. botulinum in infant botulism.

Toxemia in Human Naturally Acquired Botulism

Human botulism is a severe disease characterized by flaccid paralysis and inhibition of certain gland secretions, notably salivary secretions, caused by inhibition of neurotransmitter release. Naturally acquired botulism occurs in three main forms: food-borne botulism by ingestion of preformed botulinum neurotoxin (BoNT) in food, botulism by intestinal colonization (infant botulism and intestinal toxemia botulism in infants above one year and adults), and wound botulism. A rapid laboratory confirmation of botulism is required for the appropriate management of patients. Detection of BoNT in the patient's sera is the most direct way to address the diagnosis of botulism. Based on previous published reports, botulinum toxemia was identified in about 70% of food-borne and wound botulism cases, and only in about 28% of infant botulism cases, in which the diagnosis is mainly confirmed from stool sample investigation. The presence of BoNT in serum depends on the BoNT amount ingested with contaminated food or produced locally in the intestine or wound, and the timeframe between serum sampling and disease onset. BoNT levels in patient's sera are most frequently low, requiring a highly sensitive method of detection. Mouse bioassay is still the most used method of botulism identification from serum samples. However, in vitro methods based on BoNT endopeptidase activity with detection by mass spectrometry or immunoassay have been developed and depending on BoNT type, are more sensitive than the mouse bioassay. These new assays show high specificity for individual BoNT types and allow more accurate differentiation between positive toxin sera from botulism and autoimmune neuropathy patients.

Diversity of the Genomes and Neurotoxins of Strains of Clostridium botulinum Group I and Clostridium sporogenes Associated with Foodborne, Infant and Wound Botulism

Clostridium botulinum Group I and Clostridium sporogenes are closely related bacteria responsible for foodborne, infant and wound botulism. A comparative genomic study with 556 highly diverse strains of C. botulinum Group I and C. sporogenes (including 417 newly sequenced strains) has been carried out to characterise the genetic diversity and spread of these bacteria and their neurotoxin genes. Core genome single-nucleotide polymorphism (SNP) analysis revealed two major lineages; C. botulinum Group I (most strains possessed botulinum neurotoxin gene(s) of types A, B and/or F) and C. sporogenes (some strains possessed a type B botulinum neurotoxin gene). Both lineages contained strains responsible for foodborne, infant and wound botulism. A new C. sporogenes cluster was identified that included five strains with a gene encoding botulinum neurotoxin sub-type B1. There was significant evidence of horizontal transfer of botulinum neurotoxin genes between distantly related bacteria. Population structure/diversity have been characterised, and novel associations discovered between whole genome lineage, botulinum neurotoxin sub-type variant, epidemiological links to foodborne, infant and wound botulism, and geographic origin. The impact of genomic and physiological variability on the botulism risk has been assessed. The genome sequences are a valuable resource for future research (e.g., pathogen biology, evolution of C. botulinum and its neurotoxin genes, improved pathogen detection and discrimination), and support enhanced risk assessments and the prevention of botulism.

Development of immunodetection system for botulinum neurotoxin serotype E

Background & objectives

Botulism, a potentially fatal paralytic illness, is caused by the botulinum neurotoxins (BoNTs) secreted by Clostridium botulinum. It is an obligate anaerobic, Gram-positive, spore-forming bacterium. BoNTs are classified into seven serotypes based on the serological properties. Among these seven serotypes, A, B, E and, rarely, F are responsible for human botulism. The present study was undertaken to develop an enzyme-linked immunosorbent assay (ELISA)-based detection system for the detection of BoNT/E.

Methods

The synthetic gene coding the light chain of BoNT serotype E (BoNT/E LC) was constructed using the polymerase chain reaction primer overlapping method, cloned into pQE30UA vector and then transformed into Escherichia coli M15 host cells. Recombinant protein expression was optimized using different concentrations of isopropyl-β-D-1-thiogalactopyranoside (IPTG), different temperature and the rBoNT/E LC protein was purified in native conditions using affinity column chromatography. The purified recombinant protein was checked by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and further confirmed by western blot and matrix-assisted laser desorption ionization-tandem time-of-flight (MALDI-TOF). Polyclonal antibodies were generated against rBoNT/E LC using Freund's adjuvant in BALB/c mice and rabbit. Sandwich ELISA was optimized for the detection of rBoNT/E LC and native crude BoNT/E, and food matrix interference was tested. The developed antibodies were further evaluated for their specificity/cross-reactivity with BoNT serotypes and other bacterial toxins.

Results

BoNT/E LC was successfully cloned, and the maximum expression was achieved in 16 h of post-induction using 0.5 mM IPTG concentration at 25°C. Polyclonal antibodies were generated in BALB/c mice and rabbit and the antibody titre was raised up to 128,000 after the 2^nd booster dose. The developed polyclonal antibodies were highly specific and sensitive with a detection limit about 50 ng/ml for rBoNT/E LC and 2.5×10^[3] MLD₅₀ of native crude BoNT/E at a dilution of 1:3000 of mouse (capturing) and rabbit (revealing) antibodies. Further, different liquid, semisolid and solid food matrices were tested, and rBoNT/E LC was detected in almost all food samples, but different levels of interference were detected in different food matrices.

Interpretation & conclusions

There is no immune detection system available commercially in India to detect botulism. The developed system might be useful for the detection of botulinum toxin in food and clinical samples. Further work is in progress.

Efficacy of Human Botulism Immune Globulin for the Treatment of Infant Botulism: The First 12 Years Post Licensure

OBJECTIVES

To report the efficacy of Human Botulism Immune Globulin Intravenous (BIG-IV) in the first 12 years following its licensure in 2003 and to characterize its use nationwide in treating patients with infant botulism.

STUDY DESIGN

Medical records and billing information were collected for US patients treated with BIG-IV from 2003 to 2015. Length of hospital stay (LOS) and hospital charge information for treated patients were compared with the BIG-IV Pivotal Clinical Trial Placebo Group to quantify decreases in LOS and hospital charges.

RESULTS

The use of BIG-IV reduced mean LOS from 5.7 to 2.2 weeks. This shortened hospital stay resulted in a mean decrease in hospital charges of $88 900 per patient. For all US patients 2003-2015, total decreases in LOS and hospital charges were 66.9 years and $86.2 million, respectively. The decrease in mean LOS was time dependent: BIG-IV treatment on hospital days 0-3 reduced mean LOS by 3.7 weeks (P <.001 vs the BIG-IV Pivotal Clinical Trial Placebo Group), on hospital days 4-7 by 2.6 weeks (P <.001 vs the BIG-IV Pivotal Clinical Trial Placebo Group) and on hospital days 8-10 by just 1 week (P = NS). Since licensure, 1192 patients in 48 states and Washington, DC, have been treated with BIG-IV.

CONCLUSIONS

The use of BIG-IV since its licensure in 2003 treated approximately 93% of US patients with laboratory-confirmed infant botulism, and prevented >65 years in hospital stay and >$85 million in hospital charges from occurring. The greatest LOS reduction was achieved when BIG-IV was administered soon after hospital admission. Effective and appropriate use of BIG-IV in the US has continued in the postlicensure period.

Infant botulism due toC. butyricumtype E toxin: a novel environmental association with pet terrapins

We describe two cases of infant botulism due toClostridium butyricumproducing botulinum type E neurotoxin (BoNT/E) and a previously unreported environmental source. The infants presented at age 11 days with poor feeding and lethargy, hypotonia, dilated pupils and absent reflexes. Faecal samples were positive forC. butyricumBoNT/E. The infants recovered after treatment including botulism immune globulin intravenous (BIG-IV).C. butyricumBoNT/E was isolated from water from tanks housing pet ‘yellow-bellied’ terrapins (Trachemys scripta scripta): in case A the terrapins were in the infant's home; in case B a relative fed the terrapin prior to holding and feeding the infant when both visited another relative.C. butyricumisolates from the infants and the respective terrapin tank waters were indistinguishable by molecular typing. Review of a case ofC. butyricumBoNT/E botulism in the UK found that there was a pet terrapin where the infant was living. It is concluded that theC. butyricum-producing BoNT type E in these cases of infant botulism most likely originated from pet terrapins. These findings reinforce public health advice that reptiles, including terrapins, are not suitable pets for children aged <5 years, and highlight the importance of hand washing after handling these pets.

Infant botulism in Andalusia (Southern Spain)

BACKGROUND

Infant botulism (IB) is caused by the intestinal colonization by Clostridium botulinum in the first year of life and its subsequent production of neurotoxins. Traditionally, IB has been associated to honey consumption. IB cases tend to cluster in geographic regions. In Europe, IB is a rare disorder. From 1976 through 2006, 65 cases were identified in 13 European countries. In Spain, in the last 15 years, most of the cases have been reported in one region, Andalusia (Southern Spain). A specific treatment for IB type A and type B (BabyBIG) is available outside of the United States since 2005.

METHODS

and aims: We performed a retrospective review of IB cases detected in Andalusia since 1997 and compare them with the cases of IB reported in Europe.

RESULTS

We identified 11 confirmed cases of IB in Andalusia since 1997, and 14 cases in Spain. Nine out of 11 cases were detected since 2007; none of these infants had been exposed to honey consumption. One case in 1997 and another in 2000 were associated to honey. Two cases were treated with BabyBIG in 2007. In the period 2006-2012 the cases of IB reported in Europe were 54.

CONCLUSIONS

We identified a considerable increase in the incidence of IB since 2006. A tendency to a reduction in the number of cases of IB linked to honey consumption has also been identified. An increase in the exposure to these bacteria from the environment could be presumed. Clinicians should maintain a high index of suspicion for this treatable disorder.

Infant botulism and indications for administration of botulism immune globulin

Infant botulism is caused by the ingestion of Clostridium botulinum spores and leads to a life-threatening descending motor weakness and flaccid paralysis in infant children. This disease presents with symptoms such as constipation, weakness, and hypotonia and can lead to respiratory failure. Botulism immune globulin (BIG) was created to treat this deadly disease and functions by neutralizing all systemically circulating botulism toxins. It is indicated in children with clinically diagnosed infant botulism, before diagnostic confirmation, and has been shown to lead to a significant reduction in intensive care unit and hospital stay for these patients. This review article discusses the epidemiology, clinical presentation, history of BIG, and indications for administration of BIG.

Infant botulism with prolonged faecal excretion of botulinum neurotoxin and Clostridium botulinum for 7 months

In Finland in April 2010, a 3-month old baby was diagnosed with type A infant botulism. He excreted botulinum neurotoxin and/or Clostridium botulinum in his faeces until November 2010. Five months of excretion was after clinical recovery and discharge from hospital. C. botulinum isolates recovered from the household dust in the patient's home were genetically identical to those found in the infant's stool samples. Long-term faecal excretion of C. botulinum may pose a possible health risk for the parents and others in close contact with the infant.

Infant botulism following honey ingestion

An apparently well baby girl born at term was presented with signs and symptoms suggestive of acute onset of generalised floppiness at the age of 3 months. Clinically, the baby had lower motor neuron type of muscle weakness; detailed investigation lead to the diagnosis of neuromuscular junction disorder secondary to botulism toxicity. Further tests confirmed the botulism toxicity secondary to honey ingestion. The baby was treated with specific anticlostridium antibodies; she recovered remarkably, now growing and developing normally.

Two cases of type A infant botulism in Grenoble, France: no honey for infants

We report two severe cases of infant botulism diagnosed at Grenoble University Hospital, France, respectively in 2006 and 2009. Both cases were characterized by a delay in diagnosis, severe neurological manifestations and extended period of hospitalization in intensive care unit, but a complete recovery. Infant botulism is a rare but life-threatening disease. It primarily affects infants, and the main risk factor is honey ingestion. Diagnosis should be systematically evoked by pediatricians in infants suffering from constipation, fatigue, muscle weakness, difficult feeding and altered cry, but before the onset of generalized flaccid paralysis, so as to administer specific treatment (BabyBIG®, a human derived botulinum antitoxin) at an early stage of the disease when it is most effective. In conclusion, parents should be aware of the role of honey as a source of spores of Clostridium botulinum and therefore infant botulism in the first year of life.