1

Case 6: The Surprising Christmas Party Mr and Mrs Orrhoea share everything. However, when they both awoke one morning 7 days before Christmas with Diarrhoea & Vomitting, they thought it a bit much. The husband, Rhyn, had a headache and seemed to be experiencing a mild fever. His wife, Di, also felt feverish and had both abdominal pain and aching joints. They decided to make an appointment with their GP.

Upon examination, Dr Runns finds that both Rhyn and Di have a temperature (38° and 38.5° respectively) with pain and tenderness in the right lower abdominal quadrant. Dr Runns suspects food poisoning. He provides Rhyn and Di Orrhoea each with a sample pot to collect a stool sample and a specimen card requesting routine microbiology analysis. He asks whether their symptoms have lasted longer than a week and if the symptoms are becoming more severe. As the answer to both these questions was “no’ Dr Runns does not prescribe any treatment at this time, but they are advised to drink plenty of water and over-the-counter rehydration drinks are recommended. They are told that antibiotics may be administered later dependent upon the laboratory results or if their symptoms persist or deteriorate.

After 4 days they are called back in to see their GP and are told that the microbiology department has cultured Campylobacter organisms. Further, their specimen had been passed on to the Food, Water and Environmental (FWE) laboratory that had further identified Campylobacter jejuni. The couple were asked how they were feeling and both reported that their fever and aches and pains had disappeared, the vomiting had stopped and the diarrhoea was now mild (<twice per day) and improving. The Orrhoeas ask the doctor where they may have picked-up the infection, as they have concerns over a meal that they ate at a Christmas party a couple of weeks previously: others attending the meal had experienced similar symptoms.

Dr Runns informs them that C. jejuni infection can be associated with undercooked poultry and unpasteurised milk products. He explains that the infection is usually self-limiting and that their symptoms were typical of C. jejuni.

Dr Runns informs them that the FWE laboratory has notified the faculty of Public Health Medicine of a possible C. jejuni outbreak and that the couple should expect a letter or visit from an Environmental Health Officer (EHO).

Case 6 the surprising Christmas party.

Symptoms

Rhyn Di

headache feverish

seemed to be experiencing a mild fever abdominal pain

38°C aching joints

38.5 °C

Diarrhoea

Vomiting

pain and tenderness in the right lower abdominal quadrant

symptoms less than a week

symptoms are not becoming more severe

4 days later:

Campylobacter jejuni cultivated from stool sample

fever and aches and pains had disappeared,

the vomiting had stopped

the diarrhoea was now mild (<twice per day) and improving

2

Gastroenteritis is a common condition where the stomach and intestines become inflamed. It is usually

caused by a viral or bacterial infection.

(Source: http://www.nhs.uk/Conditions/Gastroenteritis/Pages/Introduction.aspx)

……………………………………………………………………………………………………………………………

Campylobacter jejuni- a food-borne pathogen generally associated with faecal contamination of food or

water is a common cause of bacterial enteritis.

Key points:

Spirally shaped, flagellate bacteria.

Small, Gram-negative rods.

Single flagellum at one or both poles.⇒ High mobility.

Oxidase and catalase tests –positive.

Carbohydrate test –negative.

80-85% human campylobacter infections.

Recovery: 3-7 days.

Do not multiply in food. ⇒explosive food-poisoning outbreaks are rare.

Colonize mucous membranes and penetrate mucous with particular facility.

The jejunum and ileum –colonized the first.⇒ Extend distally. ⇒The colon and rectum infected.

Symptoms usually evident within 7 days.

The generally self-limiting clinical presentation includes:

o Acute abdominal pain,

o Diarrhoea: Likely to result from:

The production of toxins – cytolethal distending toxin (blocks the cell cycle of host

cells).

Disruption of the intestinal mucosa due to cell invasion.⇒ inflammatory response.

o Vomiting.

Well-developed infection:

o Mesenteric lymph nodes are enlarged, fleshy and inflamed.

o Transient bacteraemia.

‘’Disruption of glycosylation pathways in C. jejuni affects host cell invasion and intestinal

colonization. Extensive glycosylation may reflect molecular mimicry of host epitopes as part of a

strategy to avoid host immune responses.’’

Immune response:

o Humoral antibodies appear after ≈10 days.

o Peak in 2-4 weeks. *seriously?? Different than in the case*

o Most antibodies –IgG.

o Healthy person exposed to repeated infection shows a progressive increase in IgA.⇒

Substantial immunity.

o ‘’Mild watery diarrhoea or even asymptomatic colonization, may result in increased level of

immunity and/or development of tolerance from repeated infections.’’

Examination of mucosa shows:

o Acute neutrophil response ⇒ Mesenteric lymph nodes are enlarged.

o Oedema.

o Sometimes superficial ulceration.

Antibiotic treatment required in severe cases.

Clinical features of campylobacter enteritis:

3

o Average incubation period - 3days. Range 1-7 days.

o Start with abdominal pain, diarrhoea, or an influenza-like prodrome of fever, aching and

sometimes with rigors and sweating.

o Abdominal pain and diarrhoea –the main symptoms. Caused by the bacterial infection of the

stomach and bowel.

o Watery diarrhoea. ⇒ Prostration.

o Leukocytes in the faeces.

o Frank blood in the faeces may appear.

o Cannot be distinguished clinically from salmonella or shigella infection.

o The immune response against the C. jejuni may result in an autoimmune reaction against

the host’s own tissues. After 1-2 weeks:

Aseptic arthritis:

Affects ankles, knees, wrists.

Self-limiting.

Affects 1-2% of patients.

Guillain-Barre syndrome:

Affects 1 out of 1000 patients per year.

May cause serious and fatal paralysis.

Antibodies cross-react with the myelin in nerve sheaths, causing

demyelination.

Nearly 30% cases related to C. jejuni.

Diagnosis:

o Incubation at 42-43oC ⇒ rapid growth of C. jejuni.

o Incubation for 48h.

o Isolation of campylobacters from faeces requires selective culture to inhibit competing faecal

flora.

o Charcoal-based blood-free agar containing bile acids is used as a selective culture.

o ‘’Isolation by a membrane inoculation (laid on non-selective media). ⇒ C. jejuni small

enough to swim through the membrane, which is removed before incubation.’’

Sources and transmission:

o Animal hosts -direct contact with farm and domestic animals.

o Raw or inadequately pasteurized milk.

o Untreated water.

o Raw or undercooked meat and poultry

o Possible transmission from flies.

(Source: Greenwood, D., Barer, M., Slack, R., Irving, W., (2012). Medical Microbiology. 7th ed.

London: Churchill Livingstone)

……………………………………………………………………………………………………………………

Diarrhoea -loose or watery stools at least three times a day. Blood/ mucus can appear in the stools

with some infections.

Signs of dehydration:

o thirst, o less frequent urination than normal, o dark-coloured urine, o dry skin, o fatigue, o light-headedness, o inability to sweat Headache, o muscular cramps,

4

o Sunken eyes.

Symptoms of severe dehydration in adults include: o Weakness. o Confusion. o Rapid heart rate. o Coma. o A greatly reduced amount of urine that you make.

(Source: http://www.webmd.com/digestive-disorders/diarrhea-10/prevent-dehydration

http://www.patient.co.uk/health/acute-diarrhoea-in-adults-leaflet)

……………………………………………………………………………………………………………………

………………………………………….

Investigation:

o Haematology

FBC –a folate- and B12- deficient megaloblastic anaemia.

o Biochemistry

Serum, calcium, phosphate may reveal biochemical osteomalacia.

Serum albumin may be low.

o Microbiology

Stool examination.

o Histopathology

Small bowel biopsies suggest the diagnosis by showing inflamed mucosa with partial

villous atrophy.

(Source: Axford, J., O’Callaghan, C.,(2004). Medicine. 2nd ed.Oxford: Blackwell Publishing)

…………………………………………………………………………………………………………

Fever present due to inflammation. See: immunity notes.

‘’A very restricted range of the upper physiological temperatures supports the activation of

resting lymphocytes for proliferation and effector formation in the two major limbs of the

immune system, cell-mediated immunity and humoral immunity.’’ (Source:

http://www.ncbi.nlm.nih.gov/pubmed/9100921).

Headaches. Why???

What other test is necessary be carried on?

Cannot be distinguished clinically from salmonella or shigella infection. Why????