What Is Candida Parapsilosis?

Medically Reviewed by Carol DerSarkissian, MD on February 14, 2024
Written by Susan Adcox
4 min read

Candida is a yeast, which is a type of fungus. Most people have Candida on their skin and in their mouths, throats, genital areas, and intestines. Usually, these small organisms are not harmful. An overgrowth of Candida can cause problems that range from mild to life-threatening.

There are over 150 species of Candida, but only six commonly appear in humans. The most common type is Candida albicans. In recent years, other types of Candida have become more common. Candida parapsilosis is one type that has grown rapidly. It causes serious infections in some people.

Candida can cause yeast infections in the vagina. It also causes a condition called thrush in the mouth. An overgrowth of Candida is called candidiasis. Although candidiasis can cause some uncomfortable symptoms, it's rarely serious.

If Candida gets into the organs or the bloodstream, it can be dangerous. This type of infection is called invasive candidiasis. It can affect the heart, brain, and bones. A condition called candidemia results if the fungus gets into the blood. Candidemia can cause serious illness, long hospital stays, and death.

In many locations, Candida parapsilosis (C. parapsilosis) is the second most common cause of yeast infections after Candida albicans. In some hospitals in South America, Asia, and Europe, C. parapsilosis infections outnumber infections with C. albicans. Certain qualities of C. parapsilosis make this a worrisome development.

Candida parapsilosis differs from other types of Candida because it's widely found in nature. It grows in soil and water. Insects and domestic animals can transmit it. Also, it's commonly found on human skin.

C. parapsilosis has four qualities that make it a special problem:

  • It thrives in a hospital environment.
  • It can be spread by the hands of medical staff.
  •  ‌It grows in parenteral nutrition, which is nutrition given through a vein. 
  • It grows on tubes, catheters, and other implanted devices.

Yeast infections pose little danger to healthy people. Invasive candidiasis is a big problem in hospital intensive care units. It's difficult to estimate how many deaths result from invasive candidiasis because many of the patients who get it are already very sick. One study estimated that Candida in the bloodstream resulted in death 19% to 24% of the time.

A Candida parapsilosis yeast infection is high risk for certain groups, including:

  • Newborns, especially those born prematurely or with low birth weight
  • Those with medical devices and implants, including tubes and catheters
  • Those fed through a tube
  • Patients with human immunodeficiency virus (HIV) that has progressed to AIDS
  • Surgical patients, especially if the surgery was abdominal

One reason Candida microorganisms are so dangerous is their ability to grow biofilms. A biofilm is a colony of bacteria or fungi that grows on a surface. The colony grows through a series of steps. It attaches firmly to the surface, grows a protective layer of slime, and becomes a mature colony. The final stage of growth is dispersal, in which microorganisms may spread to other parts of the body. 

The structure of a biofilm can help it resist treatments. The antifungal agents used to treat Candida may have trouble penetrating a biofilm. Also, the film can keep the body's immune system from recognizing the colony as a threat. 

Candida parapsilosis symptoms are like those caused by other species of Candida. Chills and fever are the main symptoms. Other symptoms can occur if the infection invades different parts of the body. Doctors also suspect Candida when an infection does not respond to an antibiotic.

Doctors diagnose candidiasis by taking a sample of blood or tissue and sending it to a lab. They can learn the particular species of Candida if a culture grows. Some newer methods of diagnosis do not require a culture. 

‌Antifungal drugs are used to treat candidiasis. Typically, doctors first use a drug from a class known as echinocandins, given in a vein. They may change drugs if they are able to identify the species of Candida. Fluconazole and amphotericin B are other commonly used drugs.  

Candida parapsilosis treatment can be difficult because the fungus can be resistant to some drugs. When an infection is resistant to treatment, results are poorer and the cost of treatment is higher. 

Another reason Candida microorganisms are so dangerous is their ability to grow biofilms. The antifungal agents used to treat Candida may have trouble penetrating a biofilm. Also, the film can keep the body's immune system from recognizing the colony as a threat. 

If Candida parapsilosis is growing on a tube, catheter, implant, or other medical device, the device may have to be removed. The removal of some devices, such as heart valves and artificial joints, is an extremely serious step. 

Because treating candidiasis can be difficult, doctors may try to prevent it instead. They may give high-risk patients antifungal drugs as a preventive measure.

Handwashing is important in preventing the spread of C. parapsilosis. During hospital outbreaks, researchers have found identical species of Candida on the hands of medical staff. In one study, 28% of the medical staff had C. parapsilosis on their hands.