Digestive Diseases

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 AureusFood 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

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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

Digestive Diseases