5 Food and waterborne disease in Malaysia
Typhoid • Cholera • Food poisoning • Dysentery • Hepatitis A
Bacteria species food
Salmonella spp, Shigella spp, Vibrio cholera, Escherichia coli, Listeria monocytogenes, Clostridium sp
Fungi species food
Candida spp,
Sporothrix spp
Virus species food
Hepatitis A, Adenovirus, Norovirus, Rotavirus
Parasites species food
Entamoeba histolytica, Giardia
Water-borne diseases:
- Typhoid fever
- Cholera
- Hepatitis A
- Leptospirosis
Salmonella dose
Higher dose up to 10,000 -1,000,000 organisms per gram to cause infection
Causes of salmonella
inadequate cooking, thawing
cross contamination
vectors
Typhoid causative agent
salmonella typhi
Why Typhoid still ongoing?
- Healthy Carrier
- Cases have not been clean-up
- Personal Hygiene
- Vaccination for food handler
- Food Premises
- Sanitation/Water supply
Who are at
risk of typhoid (4)
Children
Travellers to endemic areas
Occupation related
Immunocompromised
types of typhoid outbreak (4)
Sporadic -
involving only one or two persons in a household
Family outbreaks -
several members of the family are affected
Large outbreaks
caused by a widely distributed infective food item
Institutional outbreaks -caused by a contaminated single food item
Typhoid incubation
2 weeks, but might vary between 3-28 days
typhoid symptoms/ complications
- Fever, headache, constipation, bradycardia
- complication: intestinal perforation, chronic carrier
The abdominal symptoms are severe
Fever and illness may
continue for 4-6 weeks
characteristics of a typhoid carrier
• Persistent positive stool culture for Salmonella
typhi for a year after the onset of acute typhoid
fever
• transmit infection to others
• Carrier state: 15% of patients, depending on age,
become chronic carriers harbouring S.typhi in the
gallbladder
Management of Typhoid
Notification: Malaysian Act 342
• Hygienic control of food and water supplies
• Detection and treatment of chronic carriers
• Vaccination.
cholera species that cause diarrhoea
Inaba
Ogawa
dosage for infection, cholera
small
method of action, cholera
multiplies in small intestine, makes toxins. isotonic fluid leaves into lumen of bowel
symptoms of cholera
Rice-watery stool-severe • Dehydration • With/without vomiting • Muscle cramps • Hypovolemic shock • Scanty urine
management of cholera
Rehydration
• Monitor vital signs-blood pressure/pulse rate/urine output
• Antibiotic-for severe cases
• Proper sewage disposal/ good personal hygiene
• Proper cooking and hygienic handling of food
• Vaccination
Dysentery causes
wht• Shigella spp
• Entamoeba histolytica
• Escherichia coli O157
what is dysentery
blood mucus-rich diarrhoea
Shigella spp- dose
low
Shigella spp- lifespan
long term, in tap water 6 months, sea water 2-5 month
Shigella shigellosis symptoms
Frequent passage of scanty amount of stools, mostly mixed with blood and mucus
• Moderate to high grade fever
• Severe abdominal cramps
• Tenesmus– pain around anus during defecation
Shigella spp-diagnosis
Clinical Microbiological investigations • specimen: stool/blood • test: Microscopic/macroscopic • identification of bacteria: biochemical test
Escherichia coli- food species
Enteropathogenic E. coli (EPEC),
Enterotoxigenic E. Coli (ETEC),
Enteroinvasive E. coli (EIEC)
Enterohemorrhagic E. coli (EHEC)
Enterohemorrhagic E. coli- symptoms and duration; complications
hemorrhagic colitis: diarrhoea, abdominal pain, vomiting.
lasts for 4 - 8 days, may extend to 13 days.
Complications: bloody diarrhoea, acute ulcerative or ischemic colitis and sub-mucosal edema with severe
colonic inflammation
What is special about E. coli O157:H7
heat sensitive but rsistant to freezing - cook your food
what is hemolytic uremic syndrome (HUS)
E coli 0157 leading to acute renal failure, microangiopathic hemolytic anemia and thrombocytopenia
Entamoeba histolytica cause, who does it affect, what’s different about it
cyst on hands
usually elderly chronic in nature
more mucus, less blood in stools; stools are very offensive and bulky
Laboratory diagnosis -Entamoeba
Stool Examination:
Saline – motile trophozoites with ingested RBCs
Iodine – body stains yellow, nucleus with a central karyosome, brown glycogen mass
Food poisoning symptoms
Acute onset of vomiting and / or diarrhoea and / or other symptoms
associated with ingestion of contaminated food.
neurological symptoms: motor weakness and cranial nerve palsies.
food poisoning species
Staphylococcus aureus, Bacillus cereus, Listeria
monocytogenes, Clostridium spp
Staphylococcus aureus bacteria type, growth range
non spore forming, gram negative
grows at a range temperature between 12-44C (optimum 37C)
pH range 4.0-9.83 (optimum 7.4-7.6)
Symptoms, incubation of staph aureus
1-6 hours
nausea, headache, vomiting, diarrhoea
Bacillus cereus mechanism, food and symptoms
Spore forming gram positive rods
consumption of enterotoxins
slow cooled rice, improper reheat
Fever, diarrhoea, vomiting
Bacillus presentation
Good hygiene
Proper cooking of foods to destroy spores
Keep food at low temperature
Fast cooling of food
Listeria monocytogenes features
Gram positive bacterium pathogenic to animals and human
Able to survive for many years in the cold in naturally infected sources
Faecal carriage 1-5% of healthy people
Trans-placental spread from mother to neonate
Listeria symptoms
Abortion in pregnant women
Meningitis in newborn infants and immunocompromised adults.
Risk: Pregnant women, infants and elderly people.
Deaths have been reported in fetuses, neonates and other individuals with compromised health status.
Clostridium perfringens features
spore-forming, anaerobic, gram positive bacillus
enterotoxin
Bacteria is found in the soil, dust, water, sewage marine sediments, decaying
cooling causes toxin growth, food cooked one day served the next
Botulism features
Enterotoxins produced by Clostridium botulinum.
C. botulinum is an obligate, spore-forming anaerobe, and Gram positive bacilli
Neurotoxins, that are highly toxic, heat labile (inactivated by heating at 80oc for 10 min)
Unstable at alkaline pH, resistant to pepsin and acidic environment.
Resist the action of the gastric and intestinal juices.
Fucking lethal
incubation period: 12-72 H
Neuro symptoms
1-10 days duration
fungal intoxication
from metabolites, mycotoxins, mproper drying before storage
complications of food poisoning
- Dehydration
- Electrolyte imbalances
- Tetany
- Convulsions
- Hypoglycemia
- Renal failure
Viral food borne infections features
acid resistant, attacks certain lining cells in GIT to replicate, High virus content in fecal matter
Hep A
30 day incubation
long lasting
rotavirus
green shit, gradual onset, kids 1-2, fever
general investigation of FBD
Stool microscopy &Stool cultures Blood cultures ELISA for rotavirus Immunoassays, bioassays or DNA probe tests to identify E. coli strains Detection of toxins
management of FBD
Symptomatic treatment • Rehydration • Antipyretic • Anti-emetic • Antibiotic for severe cases
vaccines
Vaccine is available for
• Typhoid
• Cholera
• Hepatitis A