Viral gastroenteritis (stomach flu) - Vejthani Hospital | JCI Accredited International Hospital in Bangkok, Thailand.

Viral gastroenteritis (stomach flu)

Overview 

Viral gastroenteritis, also known as the stomach flu, is an intestinal infection characterized by symptoms such as watery diarrhea, stomach cramps, nausea, vomiting, and occasionally fever. While viral gastroenteritis can result from various causes, including bacteria or parasites, the symptoms tend to be similar. 

The common route of contracting viral gastroenteritis is direct contact with an infected person or consuming contaminated food or water. Generally, individuals in good health tend to recover without complications. However, for vulnerable populations like infants, older adults, and individuals with weakened immune systems, viral gastroenteritis can have severe consequences, and it can even be lifethreatening. 

In the case of viral gastroenteritis, there is no specific medication that can effectively cure the condition. Therefore, the primary approach is preventive in nature. It is advisable to avoid consumption of food and beverages that could potentially be contaminated.  

Symptoms

Viral gastroenteritis symptoms typically manifest within 13 days of infection, and their intensity can vary from mild to severe. Although these symptoms usually resolve within a day or two, in some cases, they might persist for up to 14 days. The primary manifestations of viral gastroenteritis are as follows: 

  • Diarrhea 
  • Nausea and vomiting 
  • Decreased appetite 
  • Abdominal pain and cramps 

These symptoms start from inflammation in the stomach and intestines. Despite the term gastroenteritispredominantly referring to the stomach and small intestine, inflammation can extend to the large intestine as well. This inflammatory response is triggered by the immune system to combat the viral infection. 

When the infection is more severe or when the immune system reacts strongly, you might notice symptoms that affect your entire body. This happens because inflammation spreads beyond the digestive system, indicating a stronger immune response to the virus. Systemic symptoms may include: 

  • Fever 
  • Chills 
  • Fatigue 
  • Muscle aches 
  • Headaches 
  • Enlarged lymph nodes[Text Wrapping Break] 

Seek medical help if: 

    • For Adults: 
      • Unable to keep liquids down for 24 hours 
      • Vomiting or diarrhea for over two days 
      • Vomiting blood 
      • Dehydration signs: excessive thirst, dry mouth, dark yellow or no urine, severe weakness 
      • Blood in bowel movements 
      • Severe stomach pain 
      • Fever above 104°F (40°C) 
    • For Infants and Children: 
      • Fever of 102°F (38.9°C) or higher 
      • Extreme irritability or fatigue 
      • Severe discomfort or pain 
      • Bloody diarrhea 
      • Signs of dehydration: reduced drinking, urination, dry mouth, thirst, lack of tears 
      • Infant concerns: frequent vomiting, no wet diaper for six hours, bloody stools, sunken fontanel, dry mouth, excessive sleepiness 

Causes 

Various viruses can lead to gastroenteritis, an infection of the gastrointestinal system. The most common cause are: 

  • Norovirus: A major cause of foodborne illness globally, affecting both children and adults. It spreads through contaminated food, water, and close contact. It’s highly transmissible in confined spaces. 
  • Rotavirus: Most prevalent in children, causing severe gastroenteritis. Transmission occurs through touching contaminated objects and food. Adults can carry and spread the virus without symptoms. 
  • Astrovirus: Affecting children under 3, often spreading through daycare centers and elder care homes. 
  • Adenovirus: While adenoviruses typically lead to respiratory infections, they can also trigger gastrointestinal issues if accidentally ingested, affecting all age groups. 

Risk factors 

Viral gastroenteritis can affect individuals of any age group. The following groups might be at a higher risk for gastroenteritis:  

  • Young children. Children attending child care centers or elementary schools could be particularly susceptible due to the gradual development of their immune systems over time. 
  • Older adults. As individuals age, their immune systems tend to become less effective, particularly in later stages of life. Elderly residents of nursing homes face increased vulnerability due to the weakening of their immune systems. Additionally, their close proximity to fellow residents creates a higher risk of germ transmission. 
  • Schoolchildren or dormitory residents. Environments where individuals gather closely in groups can serve as settings where intestinal infections can easily spread.
  • Anyone with a weakened immune system. If your immune system is weakened, which could occur due to factors such as HIV/AIDS, undergoing chemotherapy, or having another medical condition, you could be particularly susceptible to risks.