Lower Alimentary Tract Infections

These flashcards cover key concepts related to lower alimentary tract infections, including bacterial flora, types of infections, pathogen mechanisms, specific pathogens, and viruses related to gastrointestinal diseases.

What are the major types of lower alimentary tract infections?

Infections and intoxications.

What is the predominant genus of bacteria in the normal flora of the gastrointestinal tract?

Bacteroides species.

What is the difference between dysentery and gastroenteritis?

Dysentery involves severe diarrhea with blood, while gastroenteritis is inflammation of the stomach and intestinal mucosa, typically without pus.

What are the key clinical features of viral intestinal infections?

Symptoms include diarrhea, vomiting, and abdominal cramps, caused by viruses like norovirus and rotavirus.

What is the main mode of transmission for most GI infections?

Fecal-oral transmission.

What are the consequences of GI infections in infants?

Diarrhea is a major cause of infant mortality due to dehydration.

What are the major pathogenic mechanisms of lower alimentary tract pathogens?

Attachment, cell invasion, loss of microvilli, and exotoxin production.

Which bacterium is known for causing cholera?

Vibrio cholerae.

What are common sources of gastroenteritis caused by intoxication?

Foods like meats, custards, salads, and improperly preserved vegetables.

What is the incubation period for Salmonella gastroenteritis?

12-36 hours.

Which virus causes viral gastroenteritis in children?

Rotavirus.

What is the typical symptom of Staphylococcal food poisoning?

Vomiting within 2-4 hours after ingestion.

What is Enterohemorrhagic E. coli (EHEC) commonly associated with?

Hamburger disease, characterized by hemorrhagic colitis.

Which hepatitis virus is transmitted via fecal-oral route?

Hepatitis A virus (HAV).

What key distinguishing feature does Hepatitis D virus have?

It needs Hepatitis B virus to grow.

What are the general symptoms of Hepatitis A?

Nausea, fever, anorexia, vomiting, jaundice.

What treatment is available for Hepatitis B, according to current standards?

Antivirals like Harvoni and Sovaldi.

What is unique about the transmission of Hepatitis E?

It’s associated with poor sanitation and fecal-oral transmission.

What kind of bacteria is Clostridium perfringens, and what does it cause?

Gram positive bacilli causing gastrointestinal pain and diarrhea.

What is a characteristic symptom of cholera?

Profuse watery diarrhea often described as 'rice water stool'.

What is a significant complication associated with E. coli O157:H7 infections?

Hemolytic uremic syndrome (HUS).

What is the primary prevention method for viral gastroenteritis?

Hand hygiene and proper sanitation.

What distinguishes the mechanism of action of exotoxins in gastrointestinal pathogens?

They can either increase water and electrolyte secretion or inhibit protein synthesis, causing cell death.