Most Likely Causes of Vomiting and Diarrhea in Nursing Home Residents
In nursing home residents presenting with vomiting and diarrhea, the most likely causes are norovirus (particularly in outbreak settings) and Clostridioides difficile infection (especially in individual cases with recent antibiotic exposure). 1, 2, 1
Primary Infectious Etiologies
Norovirus
- Norovirus is the predominant cause during outbreaks and accounts for the majority of fatal gastroenteritis cases in long-term care facilities 1
- Highly contagious with very small numbers of viral particles being infectious, transmitted by direct contact, fomites, or aerosolization during vomiting 1, 2, 1
- Residents who vomit are significantly more infectious, infecting 2.12 times the number of individuals compared to non-vomiters 3
- Typically presents with abrupt onset of nausea, vomiting, and diarrhea with minimal fever 2
Clostridioides difficile
- C. difficile is the most common readily identifiable cause of infectious diarrhea in individual nursing home residents 1
- Asymptomatic colonization rates approach 10-30% in long-term care facilities 1
- One-third of colonized residents will develop symptomatic disease within 2 weeks of receiving antibiotics 1
- Highest rates occur in subacute and rehabilitative units, especially after recent hospital admission 1, 2, 1
- Recent strains are associated with increased severity, hospitalization, intensive care needs, surgical intervention, and death in older adults 1
Clinical Approach Algorithm
When to Suspect C. difficile
- Test for C. difficile first if the patient exhibits colitis symptoms (severe fever, abdominal cramps, bloody diarrhea, or white blood cells in stool), particularly with antibiotic use within the previous 30 days 1
- Consider C. difficile in any older patient with severe leukocytosis (≥30,000 cells/mm³), even without diarrhea or recent antibiotic use 1
- Submit a single diarrheal stool specimen for C. difficile toxin assay; if negative and diarrhea persists, submit 1-2 additional specimens 1
When to Suspect Norovirus or Other Viral Pathogens
- Consider norovirus when 2 or more cases occur simultaneously in the same unit or when rates exceed baseline facility thresholds 1
- Prominent vomiting with rapid person-to-person spread strongly suggests norovirus 1, 3
- Index cases tend to be residents (versus staff) who vomit and generate considerably more secondary cases 3
Other Infectious Causes to Consider
- Foodborne enterotoxin-producing organisms (Bacillus cereus, Clostridium perfringens, Staphylococcus aureus) present with abrupt onset within 1-72 hours after suspect food ingestion in multiple patients, lacking fever and inflammatory signs, resolving in 24-48 hours 2
- Invasive bacterial pathogens (Campylobacter, Salmonella, Shigella, E. coli O157:H7) should be tested if colitis symptoms occur without recent antibiotic use and C. difficile testing is negative 1
- Parasites (Giardia, Cryptosporidium) are less common but should be examined if symptoms persist beyond 7 days in severely ill residents 1, 2
Critical Infection Control Measures
For C. difficile
- Alcohol hand preparations do NOT inactivate C. difficile spores—vigorous handwashing with soap, friction, and running water is mandatory 1
- Nosocomial person-to-person transmission is well-recognized in institutional settings 1
For Norovirus
- Alcohol hand preparations may not completely inactivate norovirus—vigorous handwashing with soap and water is preferred 1
- Stringent infection control procedures are mandatory due to transmission via direct contact, fomites, and aerosolization during vomiting 1
Key Risk Factors in Nursing Home Populations
- Age-related physiologic changes including increased achlorhydria and reduced intestinal motility allow organisms to survive in the stomach with slowed gastrointestinal transit 1
- Medications and underlying diseases affecting gastric acidity and gut motility increase susceptibility 1
- Environmental sources, direct contact with infected residents, contaminated hands of personnel, contaminated food/water, and visits by children and animals contribute to transmission 1
- Devices such as feeding tubes or thermometers can introduce pathogens directly into the gastrointestinal tract 1
Mortality Considerations
- One-third of all diarrheal deaths occur in long-term care facility residents, with more than half of all diarrheal deaths involving adults aged 74 years or older 1
- An estimated one-third of nursing home residents will experience a diarrheal episode annually 1
- Fatal norovirus cases occur predominantly among long-term care facility residents 1, 2, 1
When to Notify Public Health
Contact local public health authorities if: 1
- Gastroenteritis or colitis rates exceed baseline facility thresholds
- Two cases occur simultaneously in the same unit
- A reportable pathogen is isolated