What is Vibrio parahaemolyticus Infection ?
An infection caused by Vibrio parahaemolyticus, a type of bacteria, can result in different levels of sickness. These can range from gastroenteritis – an inflammation of the stomach and intestines that can cause symptoms like diarrhea and vomiting – to wound infections, and in severe cases, it can lead to sepsis, a life-threatening condition that occurs when the body has a severe reaction to these bacteria in the blood. While this type of infection is less common in the United States, it is a frequent cause of bacterial gastroenteritis in Asia, particularly in Japan. Although not very common, there have recently been an increasing number of outbreaks of V. parahaemolyticus infections in the United States.
What Causes Vibrio parahaemolyticus Infection ?
V. parahaemolyticus is a type of bacteria that first came to be known in Japan in the 1950s. This bacteria is found in marine environments like the sea and brackish water, which is a mix of fresh and sea water. It’s often linked with eating raw seafood, particularly shellfish like mussels.
V. parahaemolyticus tends to grow well in warm waters and areas where the water isn’t very salty.
Risk Factors and Frequency for Vibrio parahaemolyticus Infection
V. parahaemolyticus gastroenteritis is a major cause of stomach and intestinal inflammation—also known as gastroenteritis—in Japan. However, it’s less common in the United States. In 2016, there was a low number of cases reported by the Center for Disease Control, but it has been steadily increasing. This sickness usually occurs more often during the warmer months, from May through October and often happens during outbreaks.
Interestingly, even though this bacteria grows best in warmer waters, it has been found even in cold areas like Alaska. V. parahaemolyticus is usually found in saltwater and can be further concentrated in shellfish such as mussels because these seafood filter and retain the bacteria in their system.
- V. parahaemolyticus gastroenteritis is a major cause of gastroenteritis in Japan, but is less common in the US.
- Even though the incidence of this disease is currently increasing in the US, it is still relatively low.
- This disease typically occurs more often from May through October.
- Outbreaks of this disease have been reported even in cold regions like Alaska.
- The bacteria is often found in higher concentrations in shellfish, like mussels, as they filter the water and thus concentrate the bacteria within them.
Signs and Symptoms of Vibrio parahaemolyticus Infection
Vibrio parahaemolyticus infection is a condition that is diagnosed based on its symptoms and the patient’s recent history. The predominant symptoms resemble those of gastroenteritis and include abdominal cramps, nausea, vomiting, and fever. However, these symptoms are pretty common and don’t effectively separate this condition from the many others that share them. Therefore, it’s important to ask patients if they have recently traveled near the ocean or eaten seafood, especially raw oysters. This condition most frequently appears in coastal cities, but can also occur in people who have traveled to the coast and then returned home. On average, symptoms start appearing about 17 hours after consumption of contaminated food.
It’s also crucial to ask about any other health conditions a patient has, as these can influence the progression and severity of V. parahaemolyticus infection. Patients with liver disease, diabetes, or alcoholism are more likely to experience complications like septicemia.
Physical examination findings are also rather vague. Examiners may note signs of dehydration, general abdominal pain, and occasionally bloody stools. Around 7% of patients may have this symptom. Cellulitis, especially on areas of the body like the feet and lower legs that may have been exposed to contaminated water, should be looked for as well. Vital signs should be carefully checked to assess for sepsis. Because the physical signs are so generalized, this condition can be challenging to diagnose without a detailed patient history. Hence, having a comprehensive history is crucial to suspect and ultimately diagnose a V. parahaemolyticus infection.
Testing for Vibrio parahaemolyticus Infection
If your doctor suspects that you have an infection from a bacterium called V. parahaemolyticus, the most effective way to confirm it is through a stool sample. This sample is grown in a lab using a special kind of culture medium known as Thiosulfate Citrate Bile-salts Sucrose (TCBS). TCBS makes it easier for the V. parahaemolyticus bacteria to grow.
Additionally, the bacteria may show specific signs like breaking down hemoglobin in red blood cells (hemolysis) and producing an enzyme called urease. Your doctor will communicate their suspicions to the lab, which may then use specific methods to increase the chances of successfully growing the bacteria.
If your doctor thinks the infection may have spread to your blood (septicemia) or is present in a wound, they may also collect blood and wound samples for testing.
Treatment Options for Vibrio parahaemolyticus Infection
The main treatment for most cases of gastroenteritis, also known as stomach flu, involves hydration and fixing any electrolyte imbalances. This process, much like other types of gastroenteritis, involves getting fluids through an IV. Normally, stomach flu can clear up on its own and does not require further treatment. Medication to stop diarrhea is generally not recommended.
In more severe situations like wound infections and sepsis (a potentially life-threatening condition caused by the body’s response to an infection), the use of antibiotics may be needed. However, no large studies have specifically looked at the use of antibiotics for V. parahaemolyticus infection – a type of stomach infection. Recommendations are taken from guidelines that review treatments for other similar infections.
If a patient shows severe signs of gastroenteritis, an antibiotic called doxycycline may be used. In the case of simpler wound infections, minocycline or doxycycline could be used as treatment. If the wound looks severe or if the patient is at high risk for sepsis, a type of strong antibiotic known as a third-generation cephalosporin may be considered.
Certain risk factors can increase the likelihood of a person developing sepsis, including a history of liver disease, regular alcohol consumption, and diabetes. If sepsis is suspected, the patient may be admitted to the hospital to receive further intravenous fluid therapy and consultation on infectious diseases.
Mild cases, where the patient is stable, may be looked after and treated in the emergency department. If the patient remains stable and does not show any signs of sepsis, they may be discharged and allowed to go home.
In terms of preventing this kind of infection, the methods are similar to prevention measures for food-related diseases. It is recommended to store seafood correctly and cook it thoroughly before eating. The Center for Disease Control and Prevention urges people not to eat raw oysters or other shellfish, especially if they belong to a high-risk group. People with open wounds should also avoid contact with brackish or salty water to reduce their chance of infection.
What else can Vibrio parahaemolyticus Infection be?
There are several illnesses that show similar symptoms, including:
- Bacterial gastroenteritis (bacterial infection of the stomach and intestines)
- Cholera (an infectious disease affecting the intestines)
- Toxic shock syndrome (a severe illness caused by bacterial toxins)
- Necrotizing fasciitis (a serious bacterial skin infection also known as flesh-eating disease)
Possible Complications When Diagnosed with Vibrio parahaemolyticus Infection
Various serious conditions can occur due to different reasons. Those conditions include:
- Compartment Syndrome: A painful and severe condition caused by increased pressure in a muscle compartment. It can lead to muscle and nerve damage and problems with blood flow.
- Reactive Arthritis: A type of inflammatory condition that occurs in response to an infection in another part of the body.
- Shock: A life-threatening condition that requires immediate medical attention. It occurs when the body isn’t getting enough blood flow, leading to the failure of multiple organs.
- DIC (Disseminated Intravascular Coagulation): A condition that causes blood clots to form throughout the body’s small blood vessels. These clots can limit or block blood flow, which can damage the body’s organs.
- Multi-organ Failure: A severe, life-threatening condition where two or more of the vital organ systems stop functioning. It’s often a complication of sepsis and shock.