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