Digestive Diseases

Shigellosis

Staphylococcus aureus food intoxication

Cholera

Shigellosis (Bacillary Dysentery) An acute intestinal disease caused by the

bacterium Shigella

Dysentery means diarrhea with abdominal cramping

The term bacillary dysentery is reserved for infection by the four species of Shigella: S. dysenteriae, S. flexneri, S. boydii, and S. sonnei

Shigellosis contiued Endemic in North America, Europe, and the

tropics

Infection is more common in children ages 1-4 years and in the elderly , debilitated and malnourished

The only reservoir for Shigella organism is the human intestinal tract, and infected feces are always the source of the infection

Incubation period is usually 1 to 3 days

Transmission Directly by fecal-oral route transmission or indirectly

through contact with contaminated objects. Widest distribution of the organism is through contaminated

water or food

Transmission occurs primarily through individual who fail to wash their hands or clean their fingernails after defecation

Food can also be contaminated by flies that carry enough of the organism for it to multiply to an infectious dose in food

When dogs ingest human feces, the infection can be passed by them to children or other susceptible persons

Symptoms Shigellae invade the intestinal mucosa and

cause inflammation

In children: usually produces diarrhea, high fever, nausea, vomiting, abdominal pain with distention, irritability, and drowsiness Pus, mucus, and blood may appear in stools as a

result of the intestinal ulceration (typical of this infection)

In adults: produces many of the same symptoms except that adults generally do not have fever

Treatment

Persons with mild infections usually recover quickly without antibiotic treatment

Many strains of Shigella are resistant to antibiotics If an effective one can be found, then the shigellae can be

eliminated quickly When many persons in a community are affected by shigellosis,

antibiotics are sometimes used to treat only the most severe cases

The antibiotics commonly used for treatment are ampicillin, trimethoprim/sulfamethoxazole (also known as Bactrim* or Septra*), ceftriaxone (Rocephin*), or, among adults, ciprofloxacin

Some antidiarrheal drugs can make the illness worse and should be avoided

Prevention No vaccine at present Control of the human reservoir and sanitary

control of environmental sources through: Adequate treatment of water and sewage, fly

control and protection of food, water, and milk from human or mechanical vectors

Staphylococcus aureus

Food Intoxication

Staphylococcus Aureus Food Intoxication One of the most common causes of foodborne illness

in the U.S. and the world

S. aureus is a natural inhabitant of the human body and is also responsible for boils and other infections

Occasionally, the reservoir may also be cow with infected udders

Most persons are susceptible to this kind of foodborne illness

Short lasting and rarely fatal

Transmission The illness is caused by ingesting food in

which staphylococci have been multiplying and producing toxin

Staphylococci grow in many foods, especially pre-cooked hams, milk, custards, cream fillings, and salad dressings

Source of food contamination is usually a person with an infected lesion on the hands, arms, and face

Foods implicated in staphylococcal outbreaks reported to CDC during a 5

year period

Meat (ham, pork, beef)

Multiple sources, unknown

Vegetables and fuits ShellfishDairy (milk, cheese, butter)

Poultry

Baked goods Salad (potato, egg, other)

38%

20%

2%

2%3%

10%

10%

15%

Symptoms The interval between eating the food and the onset

of symptoms may be as little as 30 minutes or as long as 7 hours Usually the incubation period is 2-4 hrs.

Abrupt and sometimes violent onset, which helps to disntinguish it from other types of foodborne illness

Nausea, vomiting, cramps, and diarrhea are the typical symptoms Loss of fluid and violent vomiting may lead to prostration,

low-grade fever, and lowered blood pressure

Treatment Not necessary unless the individual

becomes dehydrated If dehydration occurs: oral rehydration

in extreme cases: Intravenous (IV) therapy may be used to replace fluids

Prevention Time from preparation of food to serving

needs to be as short as possible

Proper heating or cooling procedures need to be followed

Any individual with boils, or other infected lesions on hands, face, or nose should be prohibited from food handling

Food handlers and others should be educated about food hygiene, sanitation and cleanliness

Cholera

Cholera

Acute gastrointestinal infections caused by Vibrio cholerae

Caused by an exotoxin produced by the organism

Most likely to be found and spread in places with inadequate water treatment, poor sanitation, and inadequate.

Humans are the only know reservoir, although there is a possibility of environmental reservoirs

Transmission Transmitted through feces or vomitus of

carriers or persons with active infections

Epidemic spread usually results from contaminated water supplies

Food is involved more often in sporadic cases in endemic areas

Hands, utensils, clothing, and flies may contaminate food or carry the infection directly to the mouth

Symptoms Infection is often mild or without symptoms, but can

sometimes be severe

Incubation period is generally 2-3 days Communicability lasts as long as the stools are positive , usually only

a few days after recovery

White flecks appear in the stools as they increase (“rice water stools”)

Due to massive loss of fluid, other symptoms occur: Thirst, weakness, sunken eyes, muscle cramps, and cardiovascular

problems

Collapse, shock, and death may follow if the patient is not continuously rehydrated until the infection subsides

Treatment Electrolyte solution must be given

immediately and continuously to replace lost fluids

Mild cases Oral fluid replacement is adequate

Tetracycline and other antibiotics are used if symptoms persist Effective in reducing duration and volume of

diarrhea Speeds the elimination of the bacteria from the

feces

Prevention Proper sanitation and vaccine are the best

methods of prevention Currently, there are two oral cholera vaccines

available

People traveling to epidemic areas in other countries may be required to have a vaccination

Control methods are the same as they are for other diseases acquired through the alimentary route