C

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CÁC B?NH TH?C PH?M

• GS , TS LÊ HOÀNG NINH

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B?nh t? th?c ph?m

• 1.Ð?i cuong
• 2.B?nh sinh và s? lây truy?n
• 3.Các b?nh sinh quan tr?ng / dôc t?/ hóa ch?t
• 4.Ch?n doán Lab và di?u tra
• 5.Ði?u tr? và phòng ng?a

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1.Ð?i cuong

• B?nh t? th?c ph?m (nhi?m d?c và nhi?m trùng) là
  b?nh thông qua an các th?c ph?m b? nhi?m trùng
  hay nhi?m d?c
• Bùng phát b?nh t? th?c ph?m
• Khi có 2 hay hon 2 tru?ng h?p m?c b?nh do an cùng
  m?t lo?i th?c ph?m
• hay
• khi s? ca b?nh vu?t hon s? d? ki?n x?y ra

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1.Ð?i cuong

• Gánh n?ng b?nh t? th?c ph?m trên toàn c?u là r?t
  cao ( s? m?c và ch?t)
• Tiêu ch?y nhi?m trùng có t? 3 to 5 t? lu?t m?c
  và có 1.8 tri?u tru?ng h?p t? vong hàng nam
• Theo CDC ( M?) có 76 tri?u ca m?c và 5000 ca
  ch?t / nam t?i M?
• T?i ?n Ð? s? v? bùng phát tang hon 2 l?n t? nam
  2008 - 2009 (120 v? 2009 and 50 v? nam 2008)

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Nhi?m trùng / nhi?m d?c t? th?c ph?m

• Nhi?m trùng
• Vi trùng/virus / ký sinh trùng
• Thâm nh?p và/ho?c nhân lên trong ru?t
• Th?i k? ? b?nh
• gi? -gt ngày
• Tri?u ch?ng lâm sàng
• tiêu ch?y , bu?n nôn, nôn m?a, dau b?ng qu?n,
  s?t
• Lây truy?n
• Các y?u t? ?nh hu?ngn?u không phù h?p, nhi?m
  chéo, v? sinh kém, ti?p xúc tay tr?n

• Nhi?m d?c
• Ð?c t? ( t? nhiên / t? vi trùng / hóa ch?t)
• Không thâm nh?p hay nhân lên
• Th?i k? ? b?nh
• phút -gt gi?
• Tri?u ch?ng lâm sàng
• bu?n nôn, nôn m?a, tiêu ch?y, nhu?c co, y?u co,
  các d?u hi?u th?n kinh khác
• Không lây truy?n
• Các y?u t? ?nh hu?ng n?u nu?ng không dúng, nhi?t
  d? x? l? không phù h?p

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M?t s? v? d?ch x?y ra ? ?n Ð?
Tác nhân Nam Khu v?c S? ngu?i nhi?m Th?c ph?m
Salmonella paratyphi A 1995 Yavatmal 33 Vegetarian food
Clostridium butyricum 1996 Gujarat- residential school 34 students Sevu (Gram flour crisp)
Salmonella Enteritidis 1998 Armed Forces 78 personnel Frozen fowl
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M?t s? v? bùng phát ? ?n Ð?
Agent Year Region People affected Implicated Food
Norwalk like Virus 2002 Delhi Hospital 130 nurses Salad Sandwiches
Staph. Aureus 2007 MP gt100 children n adults Bhalla ( fried potato balls)
Salmonella welteverden and Wein 2008-09 Mangalore 34 and 10 Chicken and Fish
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M?t vài b?nh sinh, d?c t?, hóa ch?t qua th?c ph?m

• 1. Bacteria - Bacillus cereus , Brucella ,
  Campylobacter, Clostridium sp , E.coli,
  Salmonella sp , Listeria , Staph aureus , Vibrio
  cholera and V.parahemolyticus
• 2. Viruses - Hepatitis A and E , Rotavirus ,
  Norvovirus
• 3. Protozoa Cryptosporidium , Cyclospora ,
  Entamoeba , Giardia , T. gondii
• 4. Trematodes , Cestodes and Nematodes

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B?nh sinh th?c ph?m d?c t? và hóa ch?t

• Ð?c t? - marine biotoxins , tetrodotoxin (puffer
  fish), pyrrolizidine alka (Endemic ascites) ,
  mushroom toxins , shellfish toxins ,
  mycotoxins-(Aflatoxins ,Ergot and Fusarium),
  plant intoxicants , BOAA (Lathyrism)
• Hóa ch?t pesticides (OPP,sb) , radionuclides ,
  nitrites (food preservatives) toxic metals - cd,
  cu, hg, pb, sn, fluoride

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Pathogenesis and Transmission

• Inoculum / size of Li?u nhi?m -Can be as small as
  10-100 bacterial cysts for Shigella , EHEC ,
  Giardia, E. histolytica
• Animals / humans harbouring infection ? shed in
  feces ? contaminate water , fruits , vegetables
  ?inadequate cooking / improper storage ?
  infection
• Warm temperature(10-50 degree cent.)-
• multiplication of pathogens

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M?t s? tác nhân do vi trùng bùng phát qua th?c
ph?m
Th?i k? ? b?nh tác nhân H?i ch?ng Th?c ph?m thu?ng g?ps
1-6 hours Staph aureus (enterotoxin) Nausea, vomitting, diarrhea Milk n milk products, ham, poultry, salads, custards
Bacillus cereus (enterotoxin) Nausea, vomitting, (emetic form) Fried rice
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Some common bacterial food poisons
Th?i k? ? b?nh tác nhân h?i ch?ng Th?c ph?m thu?ng g?p
8-16 hours Clostridium perfringes (spores) Abd.cramps, diarrhea Nausea and Vomitting -rare Meat, poultry, legumes. gravies
Bacillus cereus ( diarrheal form- preformed n stable toxins) Diarrhea, abd.pain, nausea, vomitting/fever-No

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Mo65t5 vài tác nhân vi trùng
Th?i k? ? b?nh tác nhân h?i ch?ng Th?c ph?m thu?ng g?p
gt16 hours Vibrio cholera Rice watery stools Water and ice creams, sea food
Salmonella spp Inflammatory diarrhea Meat , milk n milk products, poultry
Shigella sp dysentry Potato/raw eggs-salad
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Ch?n doán phát hi?n s?m và di?u tra

• 1.Ðánh giá, khai thác ban d?u ca b?nh
• b?nh s? chi ti?t g?m th?i di?m kh?i phá
  ngày gi?, phút, tri?u ch?ng kh?i phát, di?n bi?n
  lâm sàng, ti?n s? ti?p xúc, di du lich, dám ti?c,
  các b?a an, cách th?c n?u an, ca b?nh khác cùng
  có tri?u h?i ch?ng
• 2.Khám lâm sàng
• d?u hi?u sinh t?n, d?u hi?u và d? m?t nu?c,
  nh?ng d?u hi?u khác (n?u có )

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Phân tích Lab

• Main objectives-
• a) Ch?n doán xác d?nh d?a vào k?t quã phân l?p
  t?i Labo t? các m?u b?nh-v?t ph?m
• eg . stool , vomitus / gastric aspirate ,
  food specimens
• b) Ð?m b?o vi?c xác nh?n s? ca b?nh là dúng
• c) Xác d?nh tác nhân n?u chúng hi?n di?n trong
  th?c ph?m xác h?p v?i các d? li?u d?ch t? h?c

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Collection of food samples

• Dùng các k? thu?t l?y m?u, ch?a m?u, b?o qu?n m?u
  phù h?p ? samples be refrigerated during storage
  and transport ? must arrive lab within 3 days of
  collection
• Adequate sample - minimum 100 grams
• Containers - not to be filled gt75 of capacity
• Proper labelling is utmost important ? labelled
  specimen be placed in zip lock bag and sealed
• Vaccine carrier with ice packs for transport and
  cold chain maintenance ( avoid freezing )

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các bu?c trong di?u tra d?ch
Establishing existence
Co-ordination
Collection and transport
Lab testing
Control and preventive measures
Definition of cases, population
Description of epidemiology
Possible hypotheses
Epidemiological study
Analysis of data and interpretation
Reporting
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Treatment

• 1. Initial T/t - Assessment and reversal of
  dehydration ( ORT / IV Fluids )
• 2. Cause specific treatment if any- eg.
  chelating agents in case of pesticide poisoning
• 3. Use of antibiotics can be considered if
  bacterial cause is identified

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Steps of outbreak investigation

• Establishing existence of outbreak(detailed
  baseline epidemiological information)?Co-ordinatio
  n with key personnel?Collection and transport of
  clinical specimens and food samples for lab
  testing?Implementation of control and preventive
  measures?definition of cases,population at risk
  and finding cases?Description of
  epidemiology?Development of possible
  hypotheses?Epidemiological study to evaluate
  hypotheses?Analysis of data and
  interpretation?Reporting findings of outbreak
  investigation

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Phòng ng?a trong c?ng d?ng

• Proper handwashing and personal hygiene
• Proper storage (refrigeration)
• Food saftey education community and food
  handlers
• Environmental measures - Discourage sewage
  farming for growing fruits and vegetables

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Phòng ng?a

• Hazard Analysis and Critical Control Point
  (HACCP) -
• Systematic preventive approach to food safety
• Addresses physical , chemical and biological
  hazards as means of prevention rather than
  finished product inspection
• Food industry - Food safety hazards identified at
  all stages of food production and preparation
  processes ? key action taken at Critical Control
  Points (CCP s)

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Principles of Hazard Analysis and Critical
Control Point ( HACCP )

• Analyse hazards ? Identify critical control
  points ? Establish preventive measures with
  critical limits for each CCP ? Establish
  procedures to monitor CCPS ? Establish corrective
  actions when monitoring shows that critical limit
  has not met ? Establish procedures to verify that
  system is working properly ? Establish effective
  record keeping for documentation

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Lu?t an toàn th?c ph?m
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5 chìa khóa an toàn th?c ph?m

• 1. Keep Clean
• Wash hands before handling food and often
  during
• preparation
• Wash hands after going to toilet
• Wash n sanitise all surfaces n equipment for
  food preparation-protect kitchen from insects ,
  pets
• 2. Separate raw and cooked food-
• Separate raw meat , poultry n seafood from
  other foods
• Use separate utensils for handling raw foods
• Store food in containers to avoid contact
  between raw and cooked foods

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Five Keys to Safer Food

• 3. Cook Thoroughly
• esp. Meat , poultry , eggs and Seafood
• Bring soups n stews to boiling
  (ensuregt70degree temp)
• Reheat cooked food thoroughly
• 4. Keep food at safe temperature -
• Dont leave cooked food at room temp.gt2 hours
• Prompt refrigeration of cooked n perishable
  food
• Keep cooked food piping hot(gt60 de.) prior
  to serving
• Dont store food too long even in
  refrigerator
• Dont thaw frozen food at room temperature

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Five keys to safer food

• 5. Use safe water and raw materials-
• Use safe water or treat to make it safe
• Select fresh and wholesome fruits
• Choose foods processed for safety - pasteurised
  milk
• Wash fruits n vegetables if eaten raw
• Dont use food beyond expiry date

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References

• 1. CD Alert December 2009, vol.13No.4
  Food Borne
• Diseases, page no. 1-12
• 2.Parks Textbook of PSM , Twentieth Edition,
  Intestinal
• infections Food Poisoning , page no.
  210-212
• 3.Internet- www.nicd.nic.in