MTYHD.org - Validation Studies

The Monterey County Public Health Laboratory has developed several diagnostic tests that are not commercially available as FDA approved kits. These so-called "laboratory developed tests" are frequently molecular methods such as PCR. Laboratory developed tests must be verified and the performance parameters made available to the ordering physician in order to be used for diagnostic purposes. Performance parameters for the laboratory developed tests available from the Monterey County Public Health Laboratory are provided below. Tests which are pending verification are investigational use only.

PCR (Target)	Verified Specimens	Sensitivity, Specificity, PPV, NPV
TB (ITS 2)	Respiratory (Sputum & Bronch Wash)	Sensitivity 85.5% Specificity 99.3% PPV 82.1% NPV 96.8%
Pertussis (IS485)	Nasopharyngeal	Sensitivity 97.1% Specificity 100% PPV 100% NPV 99.5%
Coccidioides immitis/posadaii (ITS2)	Respiratory (Sputum & Bronch Wash)	Sensitivity 95.4% Specificity 98.6% PPV 89.1% NPV 99.4%
Salmonella (spaQ)	Bacterial isolates, stool enriched in Selenite, environmental samples (food or water) enriched in MRVP
Shiga toxin 1 &2 (stx 1 & 2)	Bacterial isolates and envionmental sample (food/water) enriched in MBWP with Vancomycin
Methichillin resistant Staph aureus (mecA)	Bacterial isolates	Investigational use; not verified for diagnostic purpose
Neisseria meningitidis (ctrA)	CSF, Blood	Investigational use; not verified for diagnostic purpose
RT PCR (Target)	Verified specimens	Sensitivity, Specificity, PPV, NPV
Influenza typing (A & B)	Upper respiratory (Nasopharyngeal swab, wash or aspirate, throat swab) Lower respiratory tract (tracheal aspirate, bronchoalveolar lavage)	Sensitivity 93.3% Specificity 92.3% PPV: Unavailable NPV: Unavailable
Influenza subtyping (H1, H3, H5)	See above	Sensitivity: 93.1% (H1) 100% (H3) Specificity: 99.5% (H1)90.5% (H3) PPV: Varies with seasonal prevalence NPV: Unavailable
Norovirus	Stool	Sensitivity: Unavailable Specificity: Unavailable PPV: Unavailable NPV: Unavailable
Measles