L12: Cholera & Acute Food Poisoning Flashcards
Def of Cholera
- Cholera is an acute diarrhoeal infection caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae.
Cholera remains a global threat to public health & an indicator of inequity and lack of social development.
- Estimated that each year there are ……. cases of cholera & …….. deaths worldwide due to cholera .
- Most of those infected will have no or mild symptoms and can be successfully treated with oral rehydration solution .
- 1.3 to 4.0 million
- 21,000 to 143,000
A global strategy on cholera control, Ending Cholera
(2017): a global roadmap to 2030 ,targeted to reduce cholera deaths by 90%.
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Cholera can occur in …….
epidemics or pandemics
Global Epidemeology of Cholera
National Epidemeology of Cholera
Last epidemic in Egypt: 1947. and eliminated in 1948
No cases for 20 years.
Epidemic Threshold of Cholera
at least 1 confirmed case of cholera with evidence of local transmission in an area where there is not usually choler
Suspected Case of Cholera
- Any person 2 yrs old or more suffering from acute watery diarrhea (3 times or more within 24 hs) with severe dehydration. Or death due to acute watery diarrhea .
Probable Case of Cholera
None
Confirmed Case of Cholera
Suspected case confirmed by V.Cholerae O1 or O139 confirmed by stool culture or PCR
Causative Agent of Cholera
Compare between Classical vibrio & ElTor Vibrio in terms of
- Virulence
- Severity
- Infectivity
- Resistance
Reservoir of Cholera
- Man is the only source of infection either cases or carriers
- Cases Ranging from inapparent, subclinical, or clinical infection
- Carrier
❶ Incubatory
❷ Contact (the most serious)
❸ Convalescent (temporary)
The carriers are usually temporary but in El Tor biotype tend to be more chronic.
These characters of El-Tor biotype illustrate why the 7th pandemic occurred in about 100 countries and remain endemic in most of these countries.
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MOT of Cholera
❶ Ingestion of contaminated food or water
❷ Hand-to-mouth infection: (freshly contaminated hands with human excreta due to contact with cases or carriers)
❸ Indirect infection through contaminated eating& drinking tools
IP of Cholera
From few hours to 5 days,
internationally: 5 days
Infectivity Period of Cholera
7-10 days
- Carrier state may persists for several months
- Effective antibiotics shorten period of infectivity
Susceptibility of Cholera
General Prevention of Cholera
Refer to general preventive measures of food borne diseases
Specific prevention of Cholera
Active Vx of Cholera
Compare between oral Vxs for Cholera
Indications of chemoprophylaxis in Cholera
Drugs used in chemoprophylaxis in Cholera
Case Control Measures in Cholera
Contact Control Measures in Cholera
Epidemic Measures of Cholera
❶ Notify WHO
❷ Trace the source and channel of infection
❸ A single case of cholera in a person with a history of no overseas travel is considered an outbreak
❹ Adopt emergency measures to assure a safe water supply
❺ Ensure careful supervision of food and drink preparation.
International Measures in Cholera
International Measures for travellers in Cholera
Def of Acute Food Poisoning
- The presence of 2 or more cases with gastrointestinal symptoms with a history of ingestion of a common food or sharing the same place of food ingestion (time or place link).
- However, one case of botulism or chemical substance intake can be considered food poisoning.
Global Epi of Acute Food Poisoning
common, worldwide distribution .
National Epi of Acute Food Poisoning
Common in Egypt
Suspected Case of Acute Food Poisoning
- Any person suffers from two or more of the principal symptoms (colic – vomiting – nausea – fatigue – fever – diarrhea)
- Usually more than one person with time or place link.
Epidemic Threshold of Acute Food Poisoning
2 or more cases with epidemiological link
Probable Case of Acute Food Poisoning
not present
Confirmed Case of Acute Food Poisoning
Suspected case confirmed by lab
Compare between Cholera & AFP in terms of:
- 2ry CAses
- IP
- Vomiting
- Abdominal Tenderness
- Tenesmus
- Dehydration
- Muscle Cramps
- temperature
- Urine
Causative organsims of Acute Food Poisoning
Causative Organism of Salmonella Food Poisoning
Reservoir of Salmonella Food Poisoning
- Human: Cases (clinical –subclinical), Carrier (convalescent)
- Animals (mainly):
❶ Rodents: excreta of infected rats & mice (diseased or carriers).
❷ Cattle: excreta (contaminated milk) & tissues .
❸ Swine.
❹ Poultry especially turkey & ducks: eggs & tissues of infected birds.
Infectivity Period of Salmonella Food Poisoning
- Throughout course of infection
- continues for months in carrier state
MOT of Salmonella Food Poisoning
IP of Salmonella Food Poisoning
12 – 36 hours
Susepctibility of Salmonella Food Poisoning
General Prevention of Salmonella Food Poisoning
refer to prevention of food borne disease
Specific Prevention of Salmonella Food Poisoning
No specific prevention measures against salmonella
Ten Golden Rules for Safe food preparartion
Case Control Measures in Salmonella Food Poisoning
Contact Control Measures in Salmonella Food Poisoning
❶ Enlistment of contacts.
❷ Surveillance of persons who shared food and drink
❸ Stool examination, to detect mild cases and carriers .
Epidemic Measures in Salmonella Food Poisoning
Epidemiologic investigation to trace source & channels of infection .
Suspected Case of Staph Food Poisoning
Confirmed Case oof Staph Food Poisoning
Depends on epidemiological data & Isolation of S. aureus or detection of enterotoxin from suspected food items or vomitus and stool
Probable Case of Staph Food Poisoning
None
Causative Organism of Staph Food Poisoning
(Toxic agent) Enterotoxin of Staphylococcus aureus
Reservoir of Staph Food Poisoning
❶ Human: Nasal & throat carriers or persons with purulent discharge of infected finger or eye, abscess & acneiform facial eruption
❷ Animals: Cows with infected udders
MOT of Staph Food Poisoning
General Prevention of Staph Food Poisoning
refer to prevention of food borne disease .
Infectivity period of Staph Food Poisoning
As long as enterotoxins are stable & active or organisms are viable.
IP of Staph Food Poisoning
From ½ hour to 8 hours (average 2-4 hrs)
Specific Prevention of Staph Food Poisoning
No specific prevention measures against Staphylococcal food poisoning
Outbreak Measures in Staph Food Poisoning
Complete investigation to determine:
❶ Time and place of exposure
❷ Incremented food: origin, preparation, storage and serving.
❸ Population at risk.
Food Borne Botulism
Infant Botulism
Wound Botulism
Threpeutic Botulism
Inhalation Botulism
Def of Food-Borne Botulism
- Food borne botulism is an infectious food poisoning characterized by nervous manifestations rather than gastro-intestinal manifestations.
- It is a severe intoxication resulting from ingestion of pre-formed toxins present n contaminated food
- Less common forms (inhalation, wound, therapeutic and infant botulism may occur)
Global Epi of Food-Borne Botulism
- Worldwide distribution: sporadic cases, family & general outbreaks may occur.
National epi of Food-Borne Botulism
- Cases were reported in Egypt after consumption packed salted fish (Fesekh).
- Last epidemic occurred during 1991: 91 cases after ingestion of salted fish (Fesekh).
Epidemic threshold of Food-Borne Botulism
One confirmed case
Suspected Case of Food-Borne Botulism
Probable Case of Food-Borne Botulism
None
Confirmed Case of Food-Borne Botulism
suspected case confirmed by laboratory test
Causative Organism of Food-Borne Botulism
- Exotoxins produced by clostridium botulinum, a spore forming obligatory anaerobic bacillus .
- These exotoxins have a great affinity to the nerves resulting in muscle paralysis.
Reservoir of Food-Borne Botulism
Infectivity Period of Food-Borne Botulism
- As long as the microbe is excreted in stool of cases with no secondary cases
No person to person transmission
MOT of Food-Borne Botulism
IP of Food-Borne Botulism
- 12 –36 hours
- sometimes several days after eating contaminated food
Susceptibility of Food-Borne Botulism
General, but higher among patients with intestinal health problems and infants below 6 years due to Decreased immunity.
General Prevention of Food-Borne Botulism
Refer to prevention of food borne disease
Specific Prevention of Food-Borne Botulism
Case Control Measures of Food-Borne Botulism
Contact Control Measures of Food-Borne Botulism
❶ Person sharing same food: gastric lavage & high enema, kept under close observation
❷ Polyvalent antitoxin may be given .
Epidemic Measures of Food-Borne Botulism
Trace source of intoxication & eradicate it.
International Measures in Food-Borne Botulism
Proper checking of suspected food according to international health regulation
DDx between salmonella FP, Staph FP & Botulism FP
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