Medical Diagnostic Lab Tests For Fungus, Yeast, Candida, And Parasites
Page 1 -- General Information About Available Tests (This Page)
Sections on this page:
TYPES OF TESTS
FUNGAL ANTIBODY TESTS
FOR BLOOD SERUM
TABLE OF ANTIBODY AND PCR TESTS
URINE TESTS FOR CANDIDIASIS
This page is about medical diagnostic lab tests that will discover “clinical” evidence of a fungus, yeast, Candida, or intestinal parasite infection. The following material is a survey of medical labs having specialty tests or a reputation for executing standard tests to actually find these organisms. Candida and other fungus and yeast infections are notoriously difficult to identify. Yeast infections, and in particular, intestinal Candida yeast infections (and systemic Candidiasis), can lurk for years with few overt symptoms that allow a diagnosis. Consequently, medical diagnostic lab tests that irrefutably identify a yeast infection are vital in order for your doctor to be convinced, and for you to receive proper treatment.
This is a considerably complex subject. Medical diagnostics is a large industry with many players, a significant percentage of whom pride themselves and promote themselves by producing unique advancements. There are test producers who manufacture and sell test kits and supplies to diagnostic labs which conduct the tests on patient samples. Different diagnostic labs buy test kits and supplies from different manufacturers, and some diagnostic labs supplement vendor provided tests with their own, uniquely derived tests or testing procedures. As you read through the information on this page, you will realize that there is no right or wrong, best or worst…. For suggestions on how to make sense of it all, go to the page MAKING SENSE OF TESTS.
Although this web site is oriented to fungus and yeast infections, this section includes information on diagnostic testing for intestinal parasites since they occur commonly in conjunction with intestinal yeast infections.
Available diagnostic tests include tests of blood, stool, urine, saliva , and tissue or bodily fluid samples (for example, cerebrospinal fluid from a spinal tap, fluid irrigated from the lungs, etc.).
Blood tests include antibody tests that look for IgG, IgA, and IgM antibodies to a specific fungus or yeast, and PCR (Polymerase Chain Reaction) tests which discover the presence of DNA of the fungus or yeast. (PCR is a method of multiplying an infinitesimally small amount of DNA into a measurable quantity.) Whereas antibodies may be present even after the infection is cured, the existence of DNA is positive indication of a current infection -- the bug is actually there, floating around in your blood stream. PCR may also be used to identify a specific strain of bacteria, fungus, or yeast.
In addition, blood may be cultured to discover the presence of bacteria, fungus and yeast infections, although blood cultures are hard to grow, and most turn out negative. "Finding Candida by blood culture is considered the definitive test for systemic yeast infection. However, in one of the most intensive studies done (18), there was a very high incidence of false negatives using blood cultures for Candida. In children who really did have yeast invasion of their organs including brain, liver, or heart that was confirmed by autopsy, only 17% of the children's blood samples tested positive for yeast even though they had been tested repeatedly (an average of ten times) for Candida." (Quote from Dr. Shaw at Great Plains Lab.)
Stool tests include microscopic visual examination for parasites and yeast, and culturing for specific pathogenic bacteria and yeasts. Since stool may contain a great many varieties of bacteria, mainstream labs normally only conduct cultures to discover a particular and suspected bacterial pathogen, as requested by the doctor. Similarly, they do not culture for fungus and yeast. However, there are several specialized labs that perform comprehensive analyses of stool, including culturing for bacteria and yeasts.
There are widespread opinions expressed on the web that the mainstream commercial and hospital labs are not attuned to the problems of intestinal yeasts and parasites, and consequently these infections may go undetected despite the submission of numerous specimens. Therefore, there appears to be a consensus among alternative medical thinking expressed on the web that patients and doctors attempting to diagnose and identify the cause of suspected intestinalyeast and parasite infections should steer stool analyses to labs that focus on these problems. Several of these labs are identified on this page.
Culturing for fungi and yeast is problematic – many are very slow growing (fastidious) – so fungal and yeast cultures usually require 4 weeks before the lab will call it negative. However, only a culture can show the sensitivity of a discovered pathogen to drugs, so unless a culture is performed the selection of the drug is an empirical choice. You can find selection criteria at the excellent DOCTORFUNGUS site.
A fungal antibody test is a blood test that shows either Positive or Negative, but only for the specific fungi or yeast in the test. Basically, they put a drop of your blood serum, a drop of an antibody for the fungus or yeast being tested, and a drop of a “control” blood serum each into a separate spot in a Petri dish filled with a thin gel. (The antigen is the bad thing; the antibody is the good thing in the immune system that tries to kill the bad thing.) The control blood serum has a known quantity of the antigen (the fungus or yeast) being tested for and is used to ensure that the test was performed correctly – it should always show a positive reaction. The blood components and the antibody slowly diffuse through the gel (hence, it’s an “immunodiffusion test”), and will meet in about 30 minutes. If the antigen and antibody are an exact match the antibody latches onto the antigen and precipitates out, forming a visible line. If a line shows up, the test is positive, if not, it is negative. A positive may be reported as an “identity”, since it demonstrates that the antigen in your blood serum is identical to the antigen in the control blood serum.
The two major diagnostic labs in the U.S. are Quest Diagnostics and Labcorp and both offer a version of the fungal antibody test. The Quest test (single immunodiffusion) is qualitative only – it detects the presence of the fungal antibody but does not indicate the degree of infection; by contrast, the Labcorp test (double immunodiffusion) also indicates the amount of antibody present.
You can read more from IMMY (Immuno-Mycologics, Inc.), the manufacturer of the Quest test, at this description of their antibody test. There is a somewhat better description provided for the Candida test. “Immunodiffusion tests are used for the detection of precipitating antibodies (primarily of the IgG and IgA classes) against antigens of C. albicans. The presence of precipitating antibodies indicates active or recent infection.”
The Quest test number is 4077N, and the Labcorp test number is 091454. Each test suite only covers the most common pathogenic fungi as listed in the table. The Quest test includes Candida; the Labcorp test does not. A doctor does not need to specify the test number since he may not know which lab will be used – the doctor can simply order “fungal antibody test”. However, if Candida is suspected, the doctor’s order obviously must specify Candida to steer the request to an appropriate lab (e.g. “fungal antibody test with Candida”). Most labs, presumably including Labcorp, will send out to another lab to fulfill a request if they don’t provide it themselves.
AAL Reference Laboratories provides a Candida-specific antibody test #2323 Candida Antibodies (IgG, IgM & IgA) with Candida Immune Complexes. Immune complexes are other proteins floating in the blood in accompaniment with the antibodies. "The only laboratory test that has been proven by independent clinical studies to be effective for the detection and monitoring of Active Candida Overgrowth is the Candida Immune Complex Assay." Their reported rationale for measuring the Candida immune complexes in addition to the Candida antibodies is as follows:
- Elevated IgM levels suggest active or recent infection.
- Elevated IgG levels suggest a past infection.
- Elevated IgA levels are seen in patients who have had localized mucosal Candida infections (i.e., vaginal or mouth).
- IgM antibodies are transient and therefore, present for only a short period of time.
- IgG antibodies persist for many years after the infection has been cured.
- Antibodies tests lack the specificity for a conclusive diagnosis of clinical candidiasis (active Candida overgrowth).
- Elevated Candida Specific Immune Complexes establish the presence of Candida overgrowth
- Immune Complexes levels drop quickly when the Candida load is reduced
- Candida Specific Immune Complexes are useful in monitoring the effectiveness of treatment. (Candida Immune Complexes will be reduced if the patient has responded to treatment).
- Elevated Candida Immune Complexes correlates with clinical symptoms of Candidiasis or Candida Overgrowth
- Candida Immune Complexes levels decrease with patient improvement
Standard Candida antibody analyses are both sensitive and specific with the following benefits:
Although these tests have applications to the physician for the above reasons, they have the following limitations:
Why Test for Candida Specific Immune Complexes?
For may years, Antibody Assay Laboratories has provided Candida specific immune complex measurements to physicians. They have found it extremely useful in the diagnosis and treatment of patients with active Candida overgrowth (Candidiasis) for these important reasons:
Note: For maximum effectiveness, Antibody Assay Laboratories suggests to repeat the Candida Immune Complexes assay after three months of treatment or when symptoms subside.
Saliva Antibody Test: A laboratory in London, the Institute for Individual Wellbeing, has modified the standard blood serum antibody test to work from a saliva sample. Performing the test is still complex (see Candida Saliva ELISA Test on this link), and requires a professional lab environment, but collecting the sample should be easier than a blood draw with the presumed intent for the patient to collect their own sample and mail to the lab.
Saliva Antibody Test: Also see BioHealth Diagnostics Mucosal Barrier Function #304 discussed below. This is a comprehensive test that evaluates a number of conditions. It detects antibodies to yeasts, and aerobic and anaerobic bacteria, among others. The test kit can be sent directly to the patient.
The above table is not intended to be comprehensive and omits tests and testing organizations that cover only Candida.
Multiple laboratories perform an "organic acid" test on urine to detect metabolic byproducts of Candida and other pathogens that pass into the blood stream from the intestines and are discarded in the urine. Versions of this test are available from several sources, including Great Plains Labs, Metametrix Lab, the Biamonte Center, and JackTips (all discussed below). (We should point out that the Biamonte Center and JackTips are treatment organizations, not labs, and probably either use purchased lab kits or send the samples out to a qualified lab.) "Organic acid tests can analyze a much broader spectrum of health conditions by examining a large number of different types of metabolites. Intestinal dysbiosis can be a significant factor in many health problems. The Metametrix Dysbiosis Metabolic Marker Profile measures the byproducts of bacterial and yeast metabolism that are excreted in urine. The Dysbiosis Profile is particularly useful in detecting the presence of pathogenic microbial overgrowth and monitoring therapy." See the Metametrix publication and the Great Plains lab test description.
Urine Test: A urine test for systemic candidiasis, called the Bio-Screen 'Yeast Cult' test, is available from Advanced Nutrition, Broadway House, Tunbridge Wells, Kent, UK. TN1 1QU (Tel: 01892-542012). The reference for this is from Carol Mason in the UK. This is likely to be an organic acid test as just previously described.
In addition to the more common tests that have been described, there are a number of other tests to mention. Here is a listing provided by Cerodex Labs, a wholly owned subsidiary of IMMY:
- Histoplasma mycelial antigen
- Histoplasma yeast antigen
- Blastomyces A antigen
- Coccidioides antigen
- Aspergillus fumigatus antigen
- Antibody detection:
- Histoplasma antibody
- Coccidioides ('IDTP') antibody
- Sporothrix schenckii antibody
- Antigen detection:
- Cryptococcus neoformans capsular polysaccharide antigen
- Cryptococcus neoformans antibody
Complement Fixation tests for antibody to:
Latex Agglutination tests
Due to the esoteric nature of these tests, one would presume (or hope) that the lab would make the determination of when the use of each is appropriate, rather than expecting the requesting physician to know exactly what to ask for.
The Candisphere test, once produced by IMMY and available through Cerodex, has been discontinued, presumably replaced by more effective tests (the immunodiffusion antibody tests discussed above). Candisphere was an Enzyme Immunoassay test (EIA) detecting antibody to Candida cytoplasmic antigens. The term Candisphere appears with some frequency on Candida associated web sites.
CHROMagar is a diagnostic test developed by French biologist Dr. Alain Rambach which causes specific pathogens to appear in unique colors as they grow in a Petri dish coated with the proprietary agar growth medium. The growth medium product CHROMagar Candida will not only allow the growth and detection of yeasts - like traditional media - but in addition, just by the color of the colony, will instantly differentiate various Candida species. For detection and differentiation of major Candida species by colony color:
- Candida albicans- green
- Candida tropicalis - steel blue
- Candida krusei - rose, fuzzy
The growth medium product CHROMagar Orientation, although primarily intended for the detection of urinary tract pathogens, also serves as a general nutrient agar for isolation of various microorganisms. For rapid detection and differentiation of pathogens, including gram negative and gram positive bacteria - pathogens which are identified by unique colors include:
- E. Coli - red
- Klebsiella - steel blue
- Enterococcus - turquoise blue
- Proteus - brown halo
- Pseudomonas - yellow
- Staphylococcus - white
Distributors in the U.S. and elsewhere sell the liquid growth medium as well as prepared Petri dishes to diagnostic labs. Some of the labs listed in this report are likely to use CHROMagar as part of their testing suite.
AAL Reference Laboratories, Inc. provides a blood serum antibody test to detect intestinal permeability (Intestinal Permeability Evaluation #2330) (also see the above discussion of AAL's Candida blood serum Antibody test):
"There appears to be a relationship between intestinal Candida overgrowth and increased intestinal permeability. This occurs particularly in patients that have chronic unresponsive Candida overgrowth with persistently elevated Candida immune complexes, despite prolonged antifungal therapy. These patients may have casein (from milk) and/or gliadin (from wheat) antibodies. Therefore, we recommend that patients with Candida overgrowth should also be evaluated for intestinal permeability by measuring IgA & IgG to casein or gliadin, as well as Candida immune complexes. Conversely, patients with suspected intestinal permeability should have Candida immune complexes measured as well as antibodies to casein and gliadin.
"A recent study 11 has also shown that patients with chronic unresponsive Candida overgrowth and increased intestinal permeability, also have a reduction in leucocyte phagocytosis. It is suggested in this study that this reduction is secondary to free radical damage to the neutrophils. It is important to identify these patients with poor leucocyte phagocytosis, because they may benefit from increased antioxidant therapy.
"The treatment of these patients should be focused on resolving their bowel dysfunction and should include: antifungal measures, mineral supplements, and antioxidants. Initially, they should have casein and gliadin removed from their diet and then after six months of this regime casein and gliadin can be reintroduced. Retesting for casein and gliadin IgA and IgG antibodies should be performed in the next month to assess the current intestinal permeability status."
Other labs performing Intestinal Permeability tests include Great Smokies Lab, and the Do It Yourself Tests from JackTips.