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Bacterial food born diseases

communicable diseases

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Bacterial food born diseases

  1. 1. Dr. Dalia El-Shafei Lecturer, Community medicine department, Zagazig university
  2. 2. Food born infections
  3. 3. Salmonellae have more than 2000 serotypes, of which pathogens of Human disease is: *Typhoidal salmonellae: S. typhi, & S. paratyphi A, B, C. *Nontyphoidal salmonellae, of salmonella food poisoning and salmonellosis.
  4. 4. Causative Organism:
  5. 5. Reservoirs Carriers cholecystiti s & urinary lesions Incubatory Last days of IP (faeces) Convalesc ent Temporary 10% Chronic 2- 5% Contact 2 wks Healthy Sub-clinical infection 2 wks Cases
  6. 6. Foci and exit of infection:  Small intestine (Peyers patches) & gall- bladder: faeces (faecal carrier).  Kidney: urine (urinary carrier).  Faecal carriers:more common than urinary  Urinary: more frequent in endemic Schistosomiasis Haematobium.
  7. 7. Susceptibility
  8. 8. classical untreated typhoid (4 weeks) Prodroma • FHMA (stepladder, evening, low pulse) • Rash (macular rosy spots , abdomen,7th day , 25%) Advance • High fever, worse physical & mental condition, • Abdominal distension & tenderness Decline • Gradual improvement • Drop of temperature Convalescence • Relapse(s) after one to two weeks: 10- 20%, usually mild.
  9. 9. Atypical presentation: infection by antimicrobial resistance strains & in children (respiratory symptoms & diarrhea) Case fatality: 15-30% in untreated cases & decreases with treatment to 1-2%.
  10. 10. Bl. culture 1st wk • Bacteremia Widal test 2nd wk • Agglutination test (rising titer) • High titer O & low titer H → Recent infections • High titer H & low titer O → Past Infections Stool & Urine culture 2nd & 3rd wk • 3 times, • Practically valuable to detect carriers, rather than diagnosis
  11. 11. TAB (TABC) vaccine • Parenteral heat-killed • Adults: 2 doses of 0.5 & 1.0ml SC, 4 weeks apart. Children over 2 years can be given smaller dosage. • Booster Doses: adult dose of 1.0 ml (smaller for children) is given every 3 years. • Protective Value: moderate (50-75%)/and may not be protective on exposure to heavy infection Typhoid Oral Vaccine • Protective value is around 65% • 4 oral doses on alternate days Polysaccharide vaccine • Parental vaccine containing Vi Ag in single dose
  12. 12. Vaccination in endemic areas is given to (indications): *Occupational groups at-risk: Food handlers, Lab workers, HCW, waste disposal. *Camps & other closed communities. *Slum areas. *At-risk communities during epidemics & outbreaks.
  13. 13. CONTROL CASES Release:  3 -ve cultures of stools & urine, 24 or more hours apart.  1st sample: 2 weeks after drop of temperature to normal (to exclude possibility of relapse).
  14. 14. Control of Carriers • Diagnosis especially among food handlers & during pre-employment examination: by Widal test for Vi antigen, if +ve: stool & urine culture can be done (repeated cultures are indicated). • Health education. - Not to be licensed to work in food handling.
  15. 15.  For chronic gall-bladder carrier: Ampicillin for 1-3 months until 3-ve successive samples. cholecystectomy is indicated.  For chronic urinary carrier: Foci surgical removal.
  16. 16. Endemic in Egypt even with increasing incidence because of animals' importation from different countries.
  17. 17. No man-to-man infection
  18. 18. Incubation Period: varies, usually 6-60 days. Case fatality of untreated cases is 2% or less & usually results from endocarditis
  19. 19.  Brucellin test: ID hypersensitivity test (survey studies), to show prevalence of infection in man.
  20. 20. Prevention Man Milk & Meat sanitation Occupational control Airborne infection Animals Veterinary care Sanitary wastes disposal Vaccination
  21. 21. Vaccination (live attenuated) of young calves by strain 19 or RB51 of B.abortus and of young sheep & goats by Rev-1 strain of B.melitensis in endemic areas. Agglutination survey: +ves are infected animals, to be slaughtered if of small percent, otherwise to be segregated.
  22. 22. DIARRHEAL DISEASE
  23. 23. DIARRHEAL DISEASE - Increased bowel motions than the usual own pattern of individual. OR the passage of 3 or more abnormal loose stools that may be associated with fever, vomiting & change in color & presence of
  24. 24. Etiology: infective & no infective. Infective include: 1- Cholera 2-Infectious food poisoning 3-Infective diarrheal disease of children (GE) 4-Dysenteries.
  25. 25. 2315 case (2007)
  26. 26. Bio-type Sero-group Sero-type Vibrio cholera O1 Classical 3 El-Tor 3 O139
  27. 27. Causative agent:  The organisms liberate potent exotoxins (enterotoxins). That remain in intestine causing destruction of mucosa.  Current 7th pandemic: O1 sero-groups El-Tor biotype.
  28. 28. Resistance:  V. cholera O1 & O139 can persist in water for long periods & multiply in moist leftover food.  Killed within 30 minutes by heating at 56 C & within few seconds by boiling.  El-Tor biotype is more resistant  The classical vibrio cause more virulent & cause more severe clinical cases while El-Tor biotype is less virulent causing mild cases, subclinical cases with high carrier rate &Infectivity
  29. 29. Reservoir: Man is the only source of infection either case or carriers. 1-Cases: inapparent, subclinical or clinical. 2-Carriers: incubatory, contact & convalescent. Usually temporary but in El-Tor biotype tend to be more chronic.  Exit: Stool and vomitus of cases. Stool of carriers.
  30. 30. Mode of transmission: 1. Ingestion of contaminated water or food. 2. Beverages prepared with contaminated water, ice and even commercial bottled water have been incriminated
  31. 31. Susceptibility
  32. 32. Clinical picture: • In most cases it may be asymptomatic or causes mild diarrhea, especially with El-Tor biotype. • Profuse painless watery stool (rice water stool). * Nausea & profuse vomiting early in the course of illness.
  33. 33. Complications
  34. 34. Fatality: - Case-Fatality is high (exceeding 50%) among severe dehydrated cases, - But greatly declined (less than 1%) due to: better diagnostic facilities, better management through dehydration and effective chemotherapy.
  35. 35. Koll's vaccine • Heat killed phenol preserved • 2 Doses (0.5&1 ml) 4 wks apart-booster every 6 ms. • Partial protection (50% efficacy) • Short duration (3-6 months) • Only antibacterial & not antitoxic immunity • Not prevent asymptomatic infection & carrier state. • Associated with adverse effect . • Not recommended by WHO Oral vaccines • Live vaccine (strain CVD 103-HgR) & a killed vaccine(inactivated vibrios + B-subunit of the cholera toxin) • 2 dose regimen • O1 strain • Significant protection • Several months • Safe • Travelers from industrialized countries
  36. 36. Chemoprophylaxis Tetracycline • 500 mg/6 hours for 3 days • Single dose of 1gm • ½ dose for children • Contacts • Travelers • Pilgrims Doxycycline • Single daily dose of 300 mg for 3 days
  37. 37. International measures: 1- Notification to WHO. 2-Chemoprophylaxis: Tetracycline or Doxycycline for travelers coming from endemic or infected areas. Vaccination certificate is not required internationally since the vaccine is not potent
  38. 38. Cases:  Early case finding and confirm diagnosis.  Report to LHO & WHO.  Isolation in fever hospital, quarantine or cordon.  Disinfection: Concurrent disinfection of all soiled articles & fomites, stool and vomitus using heat & carbolic acid. Terminal cleaning is sufficient.  Treatment: Adequate dehydration therapy using OR in mild cases, IV rehydration in severe cases. Treatment of hypoglycemia.
  39. 39. Food poisoning
  40. 40. Bacterial Food poisoning Presence of bacteria or other microbes which infect the body after consumption . Ingestion of toxins contained within the food, including bacterially produced exotoxins Food infection Food intoxication
  41. 41.  Food intoxication: staphylococcal, botulism & others (Clostridium Perfringes & Bacillus- cereus).  Food infection: salmonella & others.
  42. 42. Bacillus Cereus Found in soil, vegetation, cereals & spices Staphylococcus Aureus Found in human nose & throat (also skin) Clostridium Perfingens Found in animals & birds Salmonella Found in animals, raw poultry & birds Clostridium Botulinum Found in the soil & associated with vegetables & meats
  43. 43. SalmonellaBotulismSTAPH - Outbreaks - Egypt - Rare - sporadic cases - Commonest - Outbreaks Patter n Non typhoidal Salmonella (S.typhimuriu m & S.enteritidis) Exotoxin of Cl . Botulineum neurotoxin Botulus= Latin for sausage Performed thremostable Enterotoxin (Exotoxin) Causative agent - Animals: Rodents &cattle - Man: Cases &carriers - Soil: grown vegetables, fruits contaminated with spores - Animals: excreta of cattle, pigs& others 1. Man :Case or carrier(skin or resp. infec) > 5% of population having foci of skin or nose infection 2. Cattle: (staph.mastitis contaminate milk) Reservoirof infection
  44. 44. SalmonellaBotulismSTAPH 1. Ingestion of food from infected cattle or swine. 2. Ingestion of food contaminated with excreta of animals or rodents 3. Water polluted with excreta of man or animal 4-Hand to mouth Infection “auto- infection” Ingestion of food contaminated with Performed exotoxin of Cl.Botulieum (preserved vegetables without proper sterilization packed or canned meats or sausages or fish) *packing of salted raw fish (fessikh) Ingestion of enterotoxin contaminated food or milk by resp. discharge of food handlers Favored by: much handling& sufficient time between contamination & consumption without Refrigeration “koshary, belela” Modeoftransmission IP
  45. 45. SalmonellaBotulismSTAPH 1. Outbreaks: GE 2. Sporadic: salmonellosis 3. Enteric like Picture: self- limited disease Paralysis of occulo- motor & other cranial ns causing visual disturbances as diplopia, loss of accommodation, dysphagia, dysphonia & resp. paralysis case- fatality is high (70%) in few days due to resp. failure abrupt onset of GE (for hours then recovery slight or no fever Case- fatality is almost nil C/p - Mainly Clinically - Culture: Stool, Vomitus& Food remains (-ve results not exclude staph. as organism may be destroyed while the enterotoxin is not). Diagnosis
  46. 46. SalmonellaBotulismSTAPH General preventive measures of food borne diseases Preventio n In case of botulism: 1.Proper processing, packing, canning of food after sterilization 2. Food preservation at home 3. Suspected canned food to be spoiled (bulged from gas formation) rejected 4. Specific prevention: Trivalent Botulism antitoxin As food borne infection & investigation of outbreak 1. Sero-therapy by Trivalent Botulism antitoxin :limited value (irreversible effect of exotoxin on CNS) 2.Seroprophylaxis for person sharing food with diagnosed cases but no manifestations 3. Food remnants: destroyed after sampling for bacteriological testing Control
  47. 47. Botulism  Death may occur due to respiratory paralysis within 7 days.
  48. 48. Clostridium Welchii (Cl.Perfrinqens type A) Bacillus cereus Anerobic spore forming powerful enterotoxin Aerobic spore forming 2 enterotoxins “heat labile (diarrhea) & heat stable (vomiting)”. Agent : Animals (cattle, poultry &fish) Man (cases &carriers). Spores found in the soil “rice”. Reservo ir Ingestion of spore- contaminated meat Ingestion of spore- contaminated rice. Mode of Infectio n 6-24 hours.1-6 hours in emetic 6-24 hours in diarrheal cases. IP
  49. 49. Bacillus cereus Incubation period < 6 hours Severe vomiting Lasts 1-6 hours Incubation period > 6 hours Diarrhea Lasts 6-24 hours EMETIC FORM DIARRHEAL FORM
  50. 50. Investigation of outbreak of food poisoning Reservoir s Food Cases Outbrea k
  51. 51. Features & Circumstances of Outbreak Many cases. Share common food. Very short IP (hours). Similar manifestations.
  52. 52. 1. Enlistment & distribution of cases by TPP. 2. Proper history taking & examination. 3. Culture of faeces & vomitus of cases. 4. Look for other cases. Measures for cases:
  53. 53. 1. Listening of food & remnants. 2. Origin, preparation & storage. 3- Culture of suspected food remnants 4-Compare the attack rate Attack rate for food items eaten = no. of cases among those ate certain food x100 all who ate the same food Food items: Greatest difference in attack rates between those ate this food and did not eat Measures for food items:
  54. 54. Measures for reservoirs: 1. Food handlers: examination e.g. for staphylococcal infection: nose & throat swabbing for carriers, and examining skin & nails for lesions 2. Other possible sources of contamination e.g. rodents & their excreta
  55. 55. Diarrheal Disease Of Children
  56. 56. Gastro-enteritis is diarrheal disease of children below 5 years (infants & young children).
  57. 57. Bacterial Escherich ia Enterotoxigenic (ETEC) Travelers’ diarrhea Enterohaemorrh agic(EHEC) Hemorrhagic colitis Enteropathogenic (EPEC) Neonatal diarrhea Enteroinvasive (EIEC) Dysentery Staphylococcus aureus Non-typhoidal salmonellae Shigellae Campylobacter jejuni Viral RotavirusHospitalized Enteroviruses Cocksackie viruses,ECHO viruses, polioviruses,HAV Enteric Adenovirus epidemicviralGE Measles Protozo al GiardialambliaGE Entamoeba histolytica BalantidiumcoliDysentery
  58. 58. Reservoirs of Infection: 1- Man (cases or carrier) 2- Animals “non-typhoidal Salmonellae, Campylobacter jejuni, E.Histolitica, B. coli”.
  59. 59. Underlying Factors: 1.Community Underdevelopment: a) Insanitary environment. b) Illiteracy. c) Lack of effective health services 2. Host factors: Malnutrition, especially protein- energy malnutrition (PEM). Persisting systemic infection “chronic otitis media & bronchitis”. 3. Season: sporadic cases may occur all the year round. Monthly distribution of cases in developing countries shows 2 peaks: • A peak of higher morbidity & mortality in summer &
  60. 60. GEforms Epidemic diarrhea of the newborn “E-coli” Summer diarrhea Flies. Rapid multiplication of organisms in milk & food Diminished acid secretion of stomach Weaning diarrhea. Staphylococcal enteritis- Secondary enteritis Persistent systemic infection, specially the respiratory & urinary Recurrent diarrhea
  61. 61. Incubation Period: Vary according to the causative agents usually hours to 2-4 days. Clinical Picture: *Mild cases: mild diarrhea (less than 5 times throughout the day), no or mild fever, no vomiting, no or insignificant dehydration, and no or mild systemic manifestations (self-limited and clears up within days) *Moderate & severe cases: abrupt onset, with fever (usually high), frequent liquid or rice-water stools (up to 20 or more in a day), vomiting and
  62. 62. Basic Lines of Treatment: 1. Rehydration therapy: 1st line to replace loss of fluid & electrolytes, and restores fluid-electrolyte balance by oral rehydration, or parenteral route. a) Oral Rehydration Therapy (ORT): each of 5.5gm of sodium chloride, sodium bicarbonate (to correct acidosis), potassium chloride (to correct hypokalaemia) and glucose. it is dissolved in 200 ml water. b) Nasogastric Rehydration: repeated uncontrolled vomiting.
  63. 63. 2-Chemotherapy:for bacterial diarrhea cases. 3. Diet Therapy: a) Cases having no dehydration: keep on usual feeding, and give sufficient fluid. Supplementary vitamin B & C. b) Cases with dehydration: Mild cases: given ORS and milk, alternating, until cured. Moderate cases: initially given rehydration, with fasting (water can be given if necessary) for some hours until dehydration improves, then milk, then other foods can be given.
  64. 64. Dysentery
  65. 65. Dysentery Inflammation of the colon (large intestine).
  66. 66. Agent s Bacterial “Shigellae” Protozoa “Entamiba histolytica” Helminthis “Scistosoma”
  67. 67. Shigellosis
  68. 68. Shigellosis (Shigella) Bacillary Dysentery  Acute infectious inflammatory bacterial disease of the colon. It is a worldwide disease. It is usually sporadic cases. Outbreaks occasionally occur, in confined groups.  Incidence is higher with seasonal breeding of flies (spring, early summer and the fall) important vector role.
  69. 69. Causative Organism 4 groups of Shigella with no cross immunity.  Group A: S.dysenteriae (Shigella shiga), most virulent.  Group B: S. flexneri  Group C: S. bouydii  Group D: S. sonnei causing mild disease. Relatively resistant outside the body, but readily destroyed by heat & disinfectants. Locally: the exotoxin is enterotoxic, causing dysentery. * Toxaemia: the exotoxin is a neurotoxin, may be fatal
  70. 70.  Reservoir of Infection: man, cases and carriers.  Carriers: number is several times the cases, and forms the main reservoir of infection. They are contact, healthy and convalescent carriers.  Exit: in faeces  Infectivity: usually for few weeks, sometimes longer, and rarely for one or more years.
  71. 71. Incubation Period 1 -7 days (usually less than 4). Clinical Picture: More than one attack may occur, due to different groups and serotypes. Infection is usually followed by type-specific immunity. Mild disease that may pass unnoticed. 1-Acute cases : sudden onset, with fever, may be vomiting, and dysentery (tenesmus, squeezing pain of lower abdomen, and frequent loose scanty stools, mainly made of fresh blood, pus and mucus). Disease is usually self-limited, with recovery in few days. 2-Severe fulminate disease: with dysentery, the case shows systemic manifestations, and may be dehydration and complications (uncommon), due to exotoxin and toxaemia, and some cases may be fatal (especially in the young, elderly and
  72. 72. Case study 40 years old working female complained from headache, anorexia, vomiting, and constipation turned to diarrhea and upgrading fever few days ago. The fever is not responding to antipyretics. a) What are the other signs you have to look for in this case? b) What are the investigations you should do? c) What is the probable diagnosis? d) How will you manage this case? e) When can she return to work? f) What are the control measures you should do for contacts?
  73. 73. Other signs 1) Fever increase at night (stepladder) 2) Bradycardia( Pulse is relatively slower to temperature. 3) Rosy spots on the abdomen
  74. 74. Investigations  Blood culture: (the first week): positive culture conclusive, but the negative not exclusive  Widal test: (the 2nd week) agglutination test ,rising titer which is diagnostic  Stool and urine culture: in 2nd & third week valuable to detect carriers, rather than diagnosis.
  75. 75. Management of case  Case-finding  Notification to the local health office.  Isolation: allowed at home when sanitary requirements are fulfilled, otherwise must be at hospital.  Disinfection  Treatment
  76. 76. Release  after 3 -ve cultures of stools & urine, 24 or more hours apart.  1st sample is taken 2 weeks after drop of temperature to normal (to exclude possibility of relapse).
  77. 77. measures for contacts a) Family and Household contacts:  Enlistment& Active immunization.  Surveillance for two weeks, from date of last exposure to the case, for case-finding.  Food handlers: excluded from work, and bacteriologic ally examined until prove not to be carriers. b) Nursing personnel:  Active immunization  personal cleanliness  precautions on nursing the case  not to handle or serve food to the others.
  78. 78. Case study Three persons from a family in rural area drinking underground water and have latrines for sewage disposal are complaining from acute attack of watery diarrhea with no fever. a) What is the suspected diagnosis? Justify? b) How will you manage this case? c) How will you manage contacts?
  79. 79. suspected diagnosis  Cholera as Epidemics and pandemics of it strongly linked to unsanitary water supply, poor sanitary conditions  Cholera spreads easily in lower socioeconomic group  bad sanitary environment which act as favorite media for endemically.
  80. 80. management of case  Case finding.  Notification LHO and WHO.  Isolation in fever hospital, quarantine or cordon.  Disinfection  Treatment: Adequate dehydration therapy using OR in mild cases, IV rehydration in severe cases. Treatment of hypoglycemia  Release after 3 -ve successive stool sample.
  81. 81. Management of contacts  Enlistment: H.E  Isolation for 5 days calculated from the day of exposure.  Release after 3 negative successive stool sample.  Chemoprophylaxis.  repeated stool culture to prevent carrier state.

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