Infectious Diarrhea Flashcards
Diarrhea Definition
3 or more loose or watery stools within a 24-hour period
Timeframe(s):
- Acute Diarrhea
- Persistent Diarrhea
- Chronic Diarrhea
- Acute Diarrhea - < 14 days
- Persistent Diarrhea - more than 14-30 days
- Chronic Diarrhea - > 30 days
Two classification of infectious diarrhea
- Inflammatory Diarrhea
- Non-inflammatory Diarrhea
- Presents with blood in loose-watery stools and fever
- Secondary to tissue damage to lining of the colon from certain bacteria, and/or toxins
Inflammatory Diarrhea
Watery stools with NO blood & absence of fever
Non-inflammatory Diarrhea
Community outbreaks of diarrhea are highly suggestive of what cause
common food source, or viral etiology.
Prevalence/Demographics:
- Apart from age, no known demographic difference in DoD personnel predispose or protect one person over another.
- does tend to be more common in young adult travelers than in older travelers
Diarrhea
Contributing Factors:
- Warmer climates where many people lack access to plumbing/latrines, leading higher rate of stool contamination in the environment that is more accessible to flies (vector).
- Inadequate electrical capacity leading to frequent blackouts and subsequent lack of refrigeration, resulting in unsafe food storage.
- Lack of safe water, leading to foods & drinks prepared with contaminated water & ice.
Inadequate water supply leading to shortcuts in cleaning hands, surfaces, utensils, and foods such as fruits & vegetables.
- Handwashing may not be a social norm and could be an extra expense; thus there may be no handwashing stations in food preparation areas.
Diarrhea
Viral causes of Diarrhea
- Norovirus
- Rotavirus (primarily children)
Bacterial causes of Diarrhea
- EnterotoxigenicEscherichia coli (ETEC)
- Campylobacter jejuni
- Shigellaspp.
- Salmonellaspp.
- Bacterial toxin-releasing
Protozoal causes of Diarrhea
- Giardia
- Entamoeba histolytica
- Organism Type: Virus
- Scientific name: Nonenveloped, single-stranded RNA viruses genus Norovirus
- Subtypes: No subtypes exist
- Common Name: ‘stomach flu/bug’, ‘Norwalk virus’ based on the first strained identified in 1970. Known by some as the “cruise ship virus”.
- Prevalence: Common throughout the world & occurs year-round; in temperate climates, & peak activity during the winter. Estimated to cause 18% of acute gastroenteritis & 19–21M illnesses a year; ~58% of all foodborne disease outbreaks.
- Leading cause of vomiting & diarrhea from acute gastroenteritis in the US of all ages.
Viral Infectious Diarrhea
- Predisposing Factors: “Ready-to-eat” cold foods (sandwiches and salads), raw shellfish, especially oysters, contaminated ice. Close quarters living with high population density
- Transmitted Via: Primarily fecal–oral route, either direct person-to-person contact or indirectly via contaminated food & water. Also spreads through aerosols of vomitus and contaminated environmental surfaces/objects.
- Incubation Period: 12-48 hours (fast)
- Vaccine Preventable: No
- Reportable: Yes
- Lethal: Healthy adults (No), children (yes); responsible for ~200,000 deaths annually worldwide.
Viral Infectious Diarrhea
- Acute onset of abdominal cramps, nausea, vomiting, and non-bloody diarrhea.
- Other symptoms include body aches, headaches, and sometimes a low-grade fever.
- Illness is generally self-limited, and full recovery can be expected in 1–3 days for most patients.
- In some cases, dehydration, especially in patients who are very young or elderly, may require medical attention.
Norovirus
- Gram-negative bacteria that inhabit the gastrointestinal tract.Normal part of GI flora but can be pathogenic under certain circumstances. Most strains do not cause illness.
- Transmitted via the fecal–oral route (contaminated food or water), person-to-person contact, contact with animals/environment, swimming in untreated water.
- the most common bacterial infectious diarrhea worldwide, & among travelers returning from most regions.
Escherichia coli (E. Coli)
