What Temperature Should Food Be Cooked To for Botulism Prevention?

Patient Presentation
The mother of an 11-month-old infant telephoned as she was cooking dinner and realized that she had put honey into the family’s stew. The food was being cooked in a home slow-cooker and would be cooked for several hours. She wanted to know if the infant could still eat the food since it would otherwise be appropriate for her. The nurse was not sure and asked the pediatrician who checked several reliable sources on the Internet. The pediatrician felt that although it was unlikely that a small amount of honey in the food would cause problems, the C. botulinum spores would not be killed at this temperature and advised not to feed the stew to the infant. He recommended other age-appropriate foods be offered instead.

Discussion
Clostridium botulinum is a gram-positive, motile, anaerobic rod. C. botulinum produces spores which themselves produce a toxin that causes paralytic disease which may be fatal. About 145 cases per year are reported in the US.

  • Foodborne botulism is caused by eating food contaminated with the spores or toxin. 15% of US cases yearly.
  • Wound botulism is caused by a wound that is infected with the spores which produces toxin causing botulism. 20% of cases yearly.
  • Infantile botulism is considered separate from foodborne botulism and is caused by consuming the spores and the toxin is produced in the infant’s gut causing the disease. Adults can have the same problem but it is extremely rare. 65% of US cases yearly.
  • Iatrogenic – caused by an overdose of botulinum toxin.
  • Inhalation botulism is very rare.

Classic symptoms includes visual changes (e.g. blurred or double vision, ptosis), speech and swallowing difficulties, dry mouth and muscle weakness. Infants have a weak cry, poor tone and weakness, poor feeding and lethargy. If untreated symptoms can progress to paralysis of the extremities, trunk and respiratory muscles. With foodborne disease, symptoms can occur at 6 hours – 10 days after eating the contaminated food but generally within 18-26 hours.

The differential diagnosis for infantile botulism commonly includes meningitis/sepsis, electrolyte abnormalities, congenital myopathy and Werdnig-Hoffman disease.

Learning Point
There is no vaccine for C. botulinum, and anti-toxin is not useful for prevention. Heating to high temperatures will kill the spores. Temperature greater than boiling (212°F) is needed to kill spores so pressure cookers are recommended for home canning (reaching at least 250-250°F). The toxin is heat-labile though and can be destroyed at > 185°F after five minutes or longer, or at > 176°F for 10 minutes or longer. Boiling homecanned foods for 10 minutes or longer is recommended.

Home canned foods should follow strict hygienic practices to reduce contamination, especially low acidic foods such as asparagus, green beans, beets and corn. But any food has the potential to be contaminated. Boiling home-canned foods for 10 minutes is recommended to ensure safety.

Potatoes baked in aluminum foil do not kill spores and may actually help spores germinate and produce toxin if held at room temperature. Potatoes in foil must be kept hot before consumption or refrigerated. Oils that are infused with herbs or garlic should be refrigerated.

Honey can contain spores of C. botulinum and has been a source of infection for infants. Children less than 12 months old should not be fed honey. For persons older than 1 year it is safe.

All leftover food should be refrigerated within 2 hours after cooking and within 1 hour if the ambient temperature is > 90°F.

If ever in doubt about potential safety the food should not be consumed.

Questions for Further Discussion
1. What food sources are potentially contaminated with C. botulinum?
2. How is botulism treated?
3. What other cultural practices can put an infant at risk for C. botulinum?
4. Why is Botox® safe?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Botulism

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Schneider KR, Silverberg R, Chang A, Goodrich Schneider RM. Preventing Foodborne Illness: Clostridium botulinum. University of Florida IFAS Extension. Available from the Internet at http://edis.ifas.ufl.edu/fs104 (cited 2/17/15).

UCSB Science Line. What Kills Botulism?. University of California Santa Barbara. Available from the Internet at
http://scienceline.ucsb.edu/getkey.php?key=1307
(cited 2/17/15).

Centers for Disease Control. Botulism Facts for HealthCare Providers. Available from the Internet at http://emergency.cdc.gov/agent/botulism/hcpfacts.asp (rev. 4/19/2006, cited 2/17/15).

Centers for Disease Control. Botulism Overview for Clinicians: Prevention. Available from the Internet at http://emergency.cdc.gov/agent/Botulism/clinicians/prevention.asp (rev. 10/06/2006, cited 2/17/15).

World Health Organization. Botulism. Available from the Internet at http://www.who.int/mediacentre/factsheets/fs270/en/ (rev. 8/13, cited 2/17/15).

Centers for Disease Control. Botulism. Available from the Internet at http://www.cdc.gov/nczved/divisions/dfbmd/diseases/botulism/ (rev. 4/25/14, cited 2/17/15).

Author

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital

Does a Primary Language Impairment Affect Both Languages in a Bilingual Child?

Patient Presentation
A 4-year-old Spanish-English speaking male came to clinic because his preschool teacher was concerned about his language development. His mother said that the teacher said he didn’t talk as much as the other children and seemed more shy. Using a Spanish interpreter, the mother reiterated that they had come to the United States 2 years ago because of work. Her English language skills were quite good, but she wanted a translator to make sure her concerns were understood. The child had been in the preschool for about 4 months and before this the child was taken care of at home where both parents and extended family spoke mainly Spanish. The mother said that she and the teacher had no concerns about his development otherwise. In Spanish he was able to speak 5 or more word sentences and easily tell a story, understand 2-3 step commands, follow directions and could be understood by others. Family members agreed with this assessment. The child would not use English with his family so his mother was not sure how good his English skills were. A Spanish-English teacher aide at the preschool had told the mother that she felt his Spanish was comparable to other children, but that he seemed quieter overall and hadn’t made as many friends yet at school.

The past medical history revealed a previously full-term infant with no prenatal or postnatal complications. He had no significant illnesses and had been fully vaccinated. The family history was negative for any developmental problems. The review of systems was negative.

The pertinent physical exam showed a healthy appearing male with normal vital signs and growth parameters were in the 75-90%. He had a normal neurological and general examination. He initially seemed quiet but then easily engaged with the pediatrician and was able to follow a simple game. His gross motor and fine motor skills were appropriate. He easily counted to 4 in English and named 2 colors in English and 3 in Spanish without hesitancy.

The diagnosis of a healthy child who was learning a second language was made. The pediatrician said that maybe he should be taught a way of asking for help with language in the classroom when he was working with English-speaking teachers and peers. Also having the Spanish-language teacher aide available in the classroom might also help him to be more comfortable and assist with his language acquisition. A designated consistent peer to be his “special friend” for language activities may also help. Additionally, the pediatrician recommended a hearing test which at followup during his well child check 4 months later was normal. The mother said that the teacher was now not concerned as he seemed to be learning and using more English. The mother said he seemed more comfortable at the preschool too.

Discussion
Internationally, bilingualism is the rule. Even in the US which many have considered the holdout for monolingualism, bilingualism is increasing with more than 18% of people (>5 years) speaking 2 languages and it is expected that by 2030 more than 40% of children will learn English as their second language (L2).

Children learn two or more languages in different contexts. A child may learn two language with parents speaking two different languages at home since birth, may have one language spoken at home and another in the community (such as a daycare setting) since birth, or may learn one at home since birth and a second at a later age when they have wider experiences (going to Kindergarten) with their community or immigrate to another country. There are places where bilingualism is less of an immigrant phenomenon and is an integral part of the community. Examples of stable bilingualism are French-English speaking parts of Canada, or Welsh-English speaking parts of Wales.

Children can successfully use both languages. Just because a child is young does not mean they will be more proficient in the second language (L2). There is data from children who immigrated in the year before school begins and the year afterwards. The older children who immigrated and moved directly into a school setting became more proficient. This is probably because they were older and more proficient in their primary language (L1).

Children use their languages differently depending on the audience (parents, partners, siblings, teacher, community member), and venue (home, school, Internet, work), purpose (asking for directions, explaining school work, telling stories at a family celebration) and their developmental abilities. The dominant language spoken may change across age and learning opportunities but both can be functional.

Children who learn two languages from birth have language acquisition that is comparable or greater than children who acquire only 1 language. But the growth is split between the two languages. A child may seem behind in one or both languages when looking at vocabulary and grammar development, but most children are within range of normal. There is some data that supports children’s skills ‘catching-up” to monolinguistic children by age 9-10 years.

“When both parents are minority language speakers, the children are more likely to sustain bilingual development than when only one is. Some studies also find that parents are more likely to use the minority language with daughters than with sons and that girls are more likely to develop as bilinguals than boys.”

“Language exposure in the context of book reading is particularly supportive of development in [both] language[s], and language exposure via television is not particularly supportive [of language development].”

Adolescent who speak both their home and their community language are more likely to graduate from high school, than peers who speak English only. Minority language use can be supported by continued close family and cultural connections.

Data from children who immigrate to another country have found that school age and adolescents need about 2-3 years to become conversationally fluent in their second language (L2) but it takes about 4-5 years to achieve proficiency conducive to academic achievement. Therefore adolescents who immigrate may not have enough time in the school environment to show their true academic achievement.

Learning Point
Primary language impairments in bilingual children can be difficult to discern. The main issues are to determine if the child has a global developmental issue, a primary language impairment (PLI) or learning disability, or does the child have difficulties learning the L2.

L1 proficiency and cognitive development are the key variables to L2 acquisition. A child who has a PLI, has problems in both languages. A child who has a PLI in their L1 will have problems learning a L2. This does not mean that they cannot be successful but they are less efficient in their learning than their unaffected bilingual peers.

“Poor performance on language tasks, in the face of otherwise typical development, is considered the critical marker of PLI.” There may be other cognitive weaknesses that are not as apparent such as working memory, attention, and information processing speed.

A review of indications for referral to speech therapy can be seen here.

Questions for Further Discussion
1. What services are available in your local community for bilingual education?
2. How are interpretative services best utilized?
3. How do socioeconomic factors affect second language acquisition?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Speech and Language Problems in Children

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Kohnert K. Bilingual children with primary language impairment: issues, evidence and implications for clinical actions. J Commun Disord. 2010 Nov-Dec;43(6):456-73.

Hoff E, Core C. Input and language development in bilingually developing children. Semin Speech Lang. 2013 Nov;34(4):215-26.

Clifford V, Rhodes A, Paxton G.Learning difficulties or learning English difficulties? Additional language acquisition: an update for paediatricians. J Paediatr Child Health. 2014 Mar;50(3):175-81.

Cote LR, Bornstein MH. Productive Vocabulary among Three Groups of Bilingual American Children: Comparison and Prediction. First Lang. 2014 Dec;34(6):467-485.

Author

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital

What Causes Vesicular Exanthams?

Patient Presentation
A 3-year-old male came to clinic with a history of fever and developing rash for 24 hours. The fever had been 38.2°C maximum and was responsive to antipyretics. The rash had been noticed during the night and was described as small spots on his arms and trunk. Since then they had developed a central vesicle. All the lesions looked the same, and the mother didn’t think that more were appearing. The family denied any travel. There were sick children at daycare but the family didn’t know what specific problems were occurring. There was no cough, emesis, diarrhea, pain or pruritus. He had rhinorrhea and had been drinking well but was refusing most solids. He was not particularly fatigued, lethargic or irritable. The past medical history showed a healthy child who was fully immunized. The review of systems was otherwise negative.

The pertinent physical exam showed a well-appearing child with a temperature of 38.3°C. Heart rate was 106 beats/minute and respiratory rate was 24/minute. HEENT showed no mucosal involvement, no oral lesions and his tympanic membranes were normal. He had mild clear rhinorrhea. Heart, lungs and abdominal examinations were negative. His skin had ~ 20 lesions that were distinct lesions, scattered on the upper torso and upper arms. They were 4-10 mm in size with a red, blanching base. Most had a central vesicle that was 2-3 mm in size with water-like fluid. All the lesions looked the same. There were no excoriations seen. There were no lesions on the palms or soles.

The diagnosis of a vesicular exanthem was made that was most likely due to a viral etiology such as coxsackie disease. He had a relative who had frequent contact with him and who was immunocompromised. Therefore a lesion was unroofed and a swab was sent for varicella polymerase chain reaction. The patient was started on acyclovir for possible varicella but when the test returned negative the acyclovir was stopped. When the physician contacted the mother the next day, she reported that the lesions had not progressed, his fever was lower and he was drinking well.

Discussion
Vesicles are circumscribed, elevated, fluid-filled lesions < 1 cm on the skin. They contain serious exudates or a mixture of blood and serum. They last for a short time and either break spontaneously or evolve into bullae. They can be discrete (e.g. varicella or rickettsial disease), grouped (e.g. herpes), linear (e.g. rhus dermatitis) or irregular (e.g. coxsackie) in distribution.

Associated symptoms such as pruritus, fever, myalgias, coryza and cough, along with a history of potential contact can be helpful. Vesicular rashes that are associated with systemic findings such as fever are usually due to infectious diseases (especially viruses and bacteria), while those that do not have systemic findings often are due to contact or infectious diseases that are non-respiratory contacts such as scabies or tinea.

Most patients do not need specific testing as the clinical history and physical examination will often be enough. In certain cases, scraping of the lesion to look for parasites (i.e. scabies) or multinucleated giant cells (i.e. herpes) or fungus may be indicated.

Most treatment is supportive. Topical agents such as calamine lotion or oatmeal baths may provide some relief. Medication for pain and pruritus can be helpful. Treatment for specific diseases such as acyclovir for herpes, antibiotics for bacterial disease and antifungal mediation for fungal diseases should be recommended as appropriate.

Bullae are also fluid-filled epidermal lesions that are filled with serous or seropurulent fluid. They are > 1 cm and often easily rupture due to their thin walls. The differential diagnosis is different for bullae than for vesicular lesions and is often more ominous including such diseases as Steven-Johnson, staphylococcal scalded skin and meningococcemia.

Vesicular or bullous exanthems should be investigated more extensively if there is skin sloughing, petechiae or purpura, fever and irritability, inflammation of the mucosa, urticaria, has respiratory distress, and diarrhea or abdominal pain.

Learning Point
The differential diagnosis for vesicular exanthems includes:

  • Viral
    • Coxsackie
    • Echo
    • Herpes
    • Smallpox
    • Varicella
  • Bacteria
    • Haemophilus
    • Staphylococcus
    • Streptococcus
    • Mycoplasma
  • Fungal
    • Trichophyton mentagrophytes
    • Tricophyton rubrum
  • Parasitic
    • Rickettsial diseases
    • Scabies
    • Tularemia
  • Other
    • Contact and Rhus dermatitis
    • Dishidrotic eczema
    • Kawasaki disease
    • Photosensitivity

Questions for Further Discussion
1. What is the differential diagnosis of bullous exanthems?
2. What is the difference between a pustular lesion and those that are vesicular or bullous?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Rash.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Sifuentes M. Vesicular Exanthems, in Pediatrics A Primary Care Approach. Berkowitz CD ed. W.B. Saudners and Co. Philadelphia, PA. 1996;400-403.

Feder HM Jr, Bennett N, Modlin JF. Atypical hand, foot, and mouth disease: a vesiculobullous eruption caused by Coxsackie virus A6. Lancet Infect Dis. 2014 Jan;14(1):83-6.

Barr KL. Evaluation of vesicular-bullous rash. ePocrates.
Available from the Internet at https://online.epocrates.com/u/2911775/Evaluation+of+vesicular-bullous+rash/Differential/Overview (rev. 10/3/14, cited 1/27/15).

Author

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital