2nd Long Exam

• Food borne diseases are acute illnesses associated with the recent consumption of food
• Two classification of food borne disease

  1. Intoxication
  2. Infection
• Food borne diseases can either be fungal, bacterial, viral or parasitic
• bacterial food borne infections include Cholera, salmonellosis, typhoid fever, shigellosis, Yersiniosis,  Escherichia coli  infection Campylobacteriosis, Vibrio parahemolyticus and Listeriosis
• Mycotic food borne infections include Candida spp., Sporothrix spp., Wangiella spp. etc),
• Viral food borne infections include hepatitis A , Norwak virus and poliomyelitis virus
• The salmonellae constitute a group of organisms with over 2000 different serotypes
• Salmonella abortus ovis causing abortion in ewes
• Salmonella gallinarum the cause of fowl typhoid
• some salmonella serotypes are associated with human disease and are not known to affect animals e.g. S. typhi and Salmonella paratyphi
• A heavy dose up to 10,000 -1,000,000 organisms per gram of food is required to cause infection
• They can remain alive in moist earth for one year and in dry earth for 16 months
• They are not destroyed in carcasses or offal maintained at chilling or freezing temperatures, or in the usual pickling solutions
• Sporadic cases involving only one or two persons in a household
• Family outbreaks in which several members of the family are affected
• Large outbreaks caused by a widely distributed infective food item
• Institutional outbreaks which may be caused by a contaminated single food item
• Food poisoning is more likely to occur if the total number of microorganisms present is high
• The ordinary symptoms of Salmonellosis include abdominal pain, headache, diarrhea, fever, vomiting, prostration and malaise
• In severe cases of Salmonellosis there is septicaemia with leucopenia, endocarditis, pericarditis
• Mortality of Salmonellosis is up to 13%
• Enteric fevers include typhoid and paratyphoid fevers caused by Salmonella typhi and Salmonella paratyphi A, B and C respectively
• S. typhi possesses capsular (vi). antigen in addition to the usual O and H antigens found in other serotypes.
• Incubation period of typhoid fever is around 2 weeks
• Incubation period of paratyphoid fever is between 1 and 15 days
• The enteric fevers are generalized septicaemic infections with a frequent, if not constant bacteraemia during the first two weeks of the disease
• The bacteria can be transmitted by the contamination of water, milk or food by flies.
• Only a few organisms are needed to cause disease.
• Vaccination using TAB-vaccine is used for typhoid and paratyphoid.
• Campylobacter are a group of tiny strictly micro-aerophilic curved or spiral gram-negative rods
• Campylobacter jejuni occur in large numbers in cattle feces, and poultry as normal flora.
• Campylobacter coli are commonly associated with human diarrhoea, and enteritis in pigs mostly in association with Treponema hyodysenteriae
• Campylobacter jejuni and C. coli cause illness characterized by diarrhoea, abdominal pain, fever, nausea, vomiting, and abdominal complaints
• The jejunum, ileum and colon are primarily affected resulting in acute inflammation and occasionally, abscess formation
• Incubation period of Campylobacteriosis is around 2-11 days, with an average of 3-5 days
• Infection occurs by ingestion of campylobacter organisms in contaminated foodstuffs.
• Among the meats, poultry constitutes the greatest potential source of infection to humans in campylobacteriosis
• Microorganisms are present in poultry gut and feces up to 1,000,000 organisms/g of feces.
• Pork is a major source of Campylobacter coli.
• The serotypes of E. coli are characterized by using O-somatic and H-flagella antigens.