- A -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Adenovirus |
Complement Fixation (CF) |
A 4 fold or greater rise in titer between acute and convalescent sera is evidence of infection with adenovirus. |
Weekly |
| Amebiasis |
Enzyme Immunoassay (EIA) |
|
Not Available at TDSHS |
| Aspergillus |
Immunodiffusion (ID) |
1 or 2 bands are present in any clinical phase; three or more bands indicate invasive disease. |
Weekly |
- B -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Blastomycosis |
Complement Fixation (CF) Immunodiffusion (ID)
|
CF titer parallels severity. Titers of 1:8 or greater is considered presumptive evidence for Blastomycosis. Negative CF reaction does not exclude the existence of B. dermatitidis infection. Cross-reactions occur frequently with Coccidioidomycosis and Histoplasmosis. A precipitin band in the Immunodiffusion test denotes recent or current infection. |
Weekly |
| Brucellosis |
Agglutination |
A single titer >= 1:160 is evidence of a prior infection, but does not confirm that it was recent. The most convincing evidence of recent infection is a 4 fold rise in titer between an acute and convalescent serum. |
Weekly |
- C -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Coccidiomycosis |
Complement Fixation (CF) Immunodiffusion (ID)
|
CF titer parallels severity. A titer of 1:32 indicates disseminating disease. A negative CF reaction does not exclude a diagnosis of coccidioidomycosis. A positive CF titer and the presence of a precipitin band denotes recent or current infection. |
Weekly |
| Cryptococcus |
Agglutination |
|
Not Available at TDSHS |
| Cytomegalovirus (CMV) |
Enzyme Immunoassay (EIA) |
A significant rise in titer between paired sera may indicate a recent primary infection or reactivation of a latent infection. However, virus isolation should be attempted. If the initial serum is negative, and the 2nd serum is positive, a diagnosis of primary infection can be made. Persistently high titers in infants with typical symptoms may indicate congenital infection. |
Weekly |
- D -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Dengue Fever |
Enzyme Immunoassay (EIA) |
A 4 fold change in antibody titer or the presence of Dengue-specific IgM in CSF confirms a recent infection. Reactive IgM result in a single serum sample is considered only presumptive evidence of recent infection, because the IgM can be detected for months and up to a year after Dengue infection. Serological cross-reactions with other flaviviruses (SLE and WN) preclude definitive diagnosis without confirmation by serum neutralization from the CDC. |
Weekly |
- E -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Eastern Equine Encephalitis (EEE) |
Enzyme Immunoassay (EIA) |
A 4 fold titer increase on paired sera is required for best evidence of current infection. Cross-reactions occur with Western Equine Encephalitis. |
Weekly |
| Ehrlichia |
Immunofluoresence (IFA) |
A 4 fold or greater rise in titer between acute and convalescent sera, collected 4 weeks apart, is evidence for infection with Ehrlichia. |
Twice Weekly |
- H -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Hantavirus |
Enzyme Immunoassay (EIA) |
A 4 fold rise in IgG antibody titer or the presence of IgM in acute-phase sera is diagnostic for hantaviral disease. |
Weekly |
| Hepatitis A Antibody |
Enzyme Immunoassay (EIA) |
Measures the total antibodies to HAV (IgG, IgM and IgA) and is positive in acute hepatitis A and remains positive indefinitely. The total antibody test to HAV is used to determine previous exposure to HAV and assess immune status. |
As Needed |
| Hepatitis A IgM |
Enzyme Immunoassay (EIA) |
A positive test is indicative of recent infection with HAV. |
As Needed |
| Hepatitis B core Antibody |
Enzyme Immunoassay (EIA) |
In the absence of HBsAg and antibody to HBsAg, a positive anti-HBc is a serological marker of recent infection. In the presence of antibody to HbsAg, a positive anti-HBc is a serological marker of past exposure. |
Twice Weekly |
| Hepatitis B e Antibody |
Enzyme Immunoassay (EIA) |
A positive anti-HBe sera indicates a reduced level of infectious virus and seroconversion in Hepatitis B carriers. Anti-HBe positivity in the Hepatitis B carriers is often associated with chronic asymptomatic infection. |
Not Available at TDSHS |
- H -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Hepatitis B e Antigen |
Enzyme Immunoassay (EIA) |
HbeAg is found in the early phase of the hepatitis B infection and is associated with increased risk of transmitting the virus to their contacts. Persistence of HbeAg in the hepatitis B carrier is often associated with chronic active hepatitis. |
Not Available at TDSHS |
| Hepatitis B surface Antibody |
Enzyme Immunoassay (EIA) |
Antibody to HBsAg with or without anti-HBc, specifies immunity against reinfection. Antibody to HBsAg without anti-HBc develops in persons who receive hepatitis B vaccine. |
Twice Weekly |
| Hepatitis B surface Antigen |
Enzyme Immunoassay (EIA) |
Repeatedly high reactive sera are not confirmed by a confirmatory test at TDSHS Laboratory. Low reactive results are further tested for the presence of HepBcore antibodies. |
Daily |
| Hepatitis C Antibody |
Enzyme Immunoassay (EIA) |
Sera positive for HCV by EIA method should be confirmed by additional supplementary test. |
Twice Monthly |
| Histoplasmosis |
Complement Fixation (CF) Immunodiffusion (ID)
|
CF titers parallel severity. Yeast-phase and mycelial-phase antigens are used. Cross-reactions are frequent with Blastomycosis and Coccidioidomycosis. Skin test affects antibody levels significantly. Demonstration of both an H and an M band is presumptive evidence for active disease. The M band may appear alone in either acute or chronic disease. The H band is found in active disease but is most affected by the skin test. |
Weekly |
- H -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Human Immunodeficiency Virus (HIV) |
Enzyme Immunoassay (EIA) |
Measures total antibody to HIV-1, the test will be positive in individuals with prior infection with HIV-1. The EIA is extremely sensitive, and as a result, nonspecific reactions may be seen in samples from some people. Because of this, specimens that are found to be repeatedly reactive on the EIA must be confirmed using a more specific test, the Western Blot. |
Daily |
| Western Blot (WB) |
The Western Blot also detects antibodies to HIV-1 present in human serum or plasma. If antibodies to any of the major HIV antigens are present in the specimen in sufficient concentration, bands corresponding to the position of one or more of the following HIV proteins (p) or glycoproteins (gp) will be seen on the nitrocellulose strip: p17, p24, p31, gp41, p51, p55, p66, gp120, gp160 (the number refers to apparent molecular weight in kilodaltons). Interpretation is based on the presence or absence of these bands. A sample that is repeatedly reactive in the EIA and reactive in the Western Blot is presumed to be reactive for antibodies to HIV-1. Individuals with reactive tests should be referred for medical evaluation. A diagnosis of AIDS can only be made if an individual meets the case definition established by the CDC. |
Daily |
- L -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Legionnaire's Disease |
Immunofluoresence (IFA) |
A 4 fold or greater rise in titer to 128 from acute-phase to convalescent-phase of illness is considered positive in a patient with pneumonia. |
Twice Weekly |
| Lyme Disease |
Enzyme Immunoassay (EIA) |
Lyme Disease results should serve as an aid to diagnosis and should be interpreted in relation to patient’s clinical picture and other epidemiological data. Sera from patients with other spirochetal diseases (including syphilis) and other conditions may have antibodies which cross-react with B. burgdorferi antigens. Some serum samples, especially those from early Lyme disease and those receiving antibiotic therapy early after EM, may not contain detectable levels of antibodies. |
Twice Weekly |
- M -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
Measles
PDF (487k)
viewing information |
Enzyme Immunoassay (EIA) |
Measles specific IgM in a single sera or a 4 fold or greater rise in titer between acute and convalescent phase sera taken at 7-14 day interval is the basis of diagnosis of acute infection. The presence of measles specific IgG antibody in a single serum indicates past infection or vaccination. |
Twice Weekly |
Mumps
PDF (271k)
viewing information |
Enzyme Immunoassay (EIA) Immunofluoresence (IFA)
|
Mumps specific IgM in a single sera by IFA or a 4 fold or greater rise between acute and convalescent phase sera by EIA is presumptive evidence for infection with mumps virus. Cross-reactivity between mumps and parainfluenza virus exists, therefore, simultaneous testing for parainfluenza virus is recommended in atypical mumps cases. |
Weekly |
- P -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Plague |
Hemagglutination |
A titer of >1:10, in the absence of known recent plague-vaccine history or exposure is a presumptive diagnosis for plague. A single serum titer of >1:128 in the absence of vaccination, or a 4 fold rise in titer between paired sera, collected more than 2 weeks apart, is considered positive for a recent infection and must be reported to health authorities. |
Weekly |
- Q -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Q Fever |
Immunofluoresence (IFA) |
A 4 fold or greater rise in titer between acute and convalescent phase sera is evidence for recent infection. In acute Q-fever infections, antibodies to the phase II antigen is usually higher than the antibody titer to phase I. In chronic Q fever infection, however, phase I titers eventually equal or exceed phase II titers. A single Q fever IFA titer >= 1:256 is evidence of a prior infection, but, it does not confirm that the infection was recent. |
Weekly |
- R -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Rocky Mountain Spotted Fever |
Immunofluoresence (FI) |
A 4 fold or greater rise in titer between acute and convalescent phase sera is convincing serological evidence of recent rickettsial infection. |
Twice Weekly |
Rubella IgG
PDF (423k)
viewing information |
Enzyme Immunoassay (EIA) |
A 4 fold or greater rise in antibody titer between paired acute and convalescent phase sera is confirmation of clinical rubella infection. The presence of rubella specific IgG antibody in a single serum specimen indicates prior infection and possibly immunity if the rubella specific IgG antibody titer is >=10 mIU/ml of serum. |
Daily |
Rubella IgM
PDF (423k)
viewing information |
Enzyme Immunoassay (EIA) |
Presence of rubella-specific IgM antibodies is confirmation of clinical rubella infection. |
Twice Weekly |
- S-^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| St Louis Encephalitis (SLE) |
Enzyme Immunoassay (EIA) |
A four fold change in antibody titer or the presence of SLE-specific IgM in CSF confirms a recent infection. Reactive IgM result in a single serum sample is considered only presumptive evidence of recent infection, because the IgM can be detected for months and up to a year after SLE infection. Serological cross-reactions with other flaviviruses (WN and Dengue Fever) preclude definitive diagnosis without confirmation by serum neutralization from the CDC. |
Weekly |
| Syphilis (Screen) |
Rapid Plasma Reagin (RPR) Card |
A reactive test may indicate past or present infection with a pathogenic treponeme. A 4 fold rise in titer on a repeat specimen may indicate an infection, a reinfection or a treatment failure. A 4 fold decrease in titer in early syphilis usually indicates adequate syphilis therapy. False positive reactions can result from serum antibodies unrelated to syphilis infection, therefore a reactive result should be confirmed by confirmatory treponemal tests. A nonreactive RPR card test and no clinical evidence of syphilis may indicate no current infection or an effectively treated infection, however false negative results can be observed during primary syphilis; in secondary syphilis as a result of prozone reaction; and in some cases of late syphilis. |
Daily |
| Syphilis (Confirmation) |
Treponema pallidum Particle Agglutinaiton (TP-PA) |
This is a confirmatory test for syphilis. A reactive TP-PA test on a specimen that is also positive with a cardiolipin test suggests current or past infection with a pathogenic treponeme. However, false positive results can be seen. A nonreactive TP-PA test on specimen that is reactive with a cardiolipin test is referred to as a biological false positive nontreponemal test and does not indicate syphilis. False-positive nontreponemal test results are seen in certain acute and chronic infections, following immunizations, in autoimmune disease and in intravenous drug users. A nonreactive TP-PA test on specimen that is also nonreactive with a cardiolipin test usually indicates the absence of syphilis infection, except in incubating syphilis and in early primary syphilis, in which the TP-PA can be falsely nonreactive. A more sensitive confirmatory test, FTA-ABS is available for early primary infections and for specimens that have an Inconclusive or Equivocal interpretation with the TP-PA test. All treponemal tests tend to remain reactive, probably for the life of the patient, therefore, they should not be used to evaluate response to therapy. |
Three Times Weekly |
| Syphilis (Neurosyphilils) |
Venereal Disease Resarch Laboratory (VDRL) |
A reactive test on cerebral spinal fluid (CSF), free of blood or other contaminants indicates past or present syphilis infection of central nervous system. A nonreactive test on CSF may indicate that the patient does not have neurosyphilis. However, a negative result can occur in some neurosyphilis patients. |
Twice Weekly |
| Syphilis Fluorescent Treponeal Antibody Absorption test (FTA-ABS)
|
Immunoflouresence (IFA) |
This is a confirmatory test for syphilis and similar to the TP-PA test should not be used to evaluate response to therapy. The FTA-ABS is more sensitive than the TP-PA test in untreated primary syphilis but compares similar to TP-PA on all other stages of syphilis. |
Twice Weekly |
- T -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Toxoplasma IgG |
Immunoflouresence (IFA) |
Toxoplasma-specific IgG titers may persist for life and are therefore diagnostic only if a rising or particularly high titer (>=1:1024), is demonstrated. In such cases, the clinician should be advised to consider toxoplasmosis and attempt to identify the disesase further. |
Twice Weekly |
| Toxoplasma IgM |
Enzyme Immunoassay (EIA) |
Toxoplasma-specific IgM antibodies generally persist for less than a year, therefore, demonstration of specific IgM antibodies is an indication, but not confirmation, of current or recent infection. |
Weekly |
| Typhus |
Immunofluoresence (IFA) |
A 4 fold or greater rise in titer between acute and convalescent phase sera is convincing serological evidence of recent rickettsial infection. |
Twice Weekly |
| Tularemia |
Agglutination |
A single agglutination titer >1:128 or a 4 fold rise in titer between acute and convalescent phase sera, collected at least 2 weeks apart, and in the absence of previous vaccination history is diagnostic as positive for F. tularensis exposure. |
Weekly |
- V -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Varicella (VZV) IgG |
Enzyme Immunoassay (EIA) |
A 4 fold or greater rise in antibody titer to VZV in the absence of a similar rise to Herpes Simplex Virus is diagnostic of a current VZV infection. |
Weekly |
- W -^ Top
|
Test
|
Type of Assay
|
Expected/Significant Results
|
Frequency of Testing
|
| Western Equine Encephalitis (WEE) |
Enzyme Immunoassay (EIA) |
A 4 fold or greater rise in titer between paired sera collected 10-14 days apart is the best evidence of recent infection. Serological cross-reactions occur with Venezuelan and Eastern Equine Encephalitis. |
Weekly |
| West Nile Virus |
Enzyme Immunoassay (EIA) |
A four fold change in antibody titer or the presence of WN-specific IgM in CSF confirms a recent infection. Reactive IgM results in a single serum sample is considered only presumptive evidence of recent infection, because the IgM can be detected for months after WN infection. Furthermore, serological cross-reactions with other flaviviruses (SLE and Dengue Fever) preclude definitive diagnosis without confirmation by serum neutralization from the CDC. |
Weekly - By request only
|